Everyman’s Science Vol. XLVIII No. 4, Oct ’13 — EVERYMAN’S ... · Everyman’s Science Vol....

Everyman’s Science Vol. XLVIII No. 4, Oct ’13 — Nov ’13

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EVERYMAN’SSCIENCE

Vol. XLVIII No. 4 (Oct ’13 – Nov ’13)

EDITORIAL ADVISORY BOARD

Prof. Swapan Kumar Datta (New Delhi)

Prof. Premendu Prakash Mathur(Bhubaneswar)

Dr. R. L. Bharadwaj (Agra)

Prof. Rajneesh Dutt Kaushik(Haridwar)

Prof. Amarendra Kumar Sinha (Jaipur)

Dr. Mohan Khedkar (Amravati)

Dr. Pitamber Prasad Dhyani (Almora)

Dr. Subhash Chandra Yadav (Varanasi)

Prof. Lalit Mohan Manocha(Vallabh Vidyanagar)

Prof. D. S. Hooda (Guna)

Dr. Surya Kant Tripathi (Lucknow)

Prof. Parimal C. Sen (Kolkata)

Dr. Sanjeev Ramachandra Inamdar(Dharwad)

Prof. Surinder Pal Khullar (Chandigarh)

COVER PHOTOGRAPHS

Past General Presidents of ISCA

1. Prof. A. K. Saha (1980)

2. Prof. A. K. Sharma (1981)

3. Prof. M. G. K. Menon (1982)

4. Prof. B. Ramachandra Rao (1983)

5. Prof. R. P. Bambah (1984)

6. Prof. A. S. Paintal (1985)

For permission to reprint orreproduce any portion of thejournal, please write to theEditor-in-Chief.

EDITORIAL BOARD

Editor-in-Chief

Dr. Ashok Kumar Saxena

Area Editors

Dr. (Mrs.) Vijay Laxmi Saxena(Biological Sciences)

Dr. Pramod Kumar Verma(Earth Sciences, Engineering & Material Sciences)

Dr. Manoj Kumar Chakrabarti(Medical Sciences including Physiology)

Dr. Arvind Kumar Saxena(Physical Sciences)

Dr. (Mrs.) Vipin Sobti(Social Sciences)

General Secretary (Membership Affairs)Er. Nilangshu Bhushan Basu

General Secretary (Scientific Activities)Prof. Arun Kumar

Editorial SecretaryDr. Amit Krishna De

Printed and published by Dr. Ashok Kumar Saxenaon behalf of Indian Science Congress Associationand printed at Seva Mudran, 43, Kailash BoseStreet, Kolkata-700 006 and published at IndianScience Congress Association, 14, Dr. Biresh GuhaStreet, Kolkata-700 017, with Dr. Ashok KumarSaxena as Editor.

Annual Subscription : (6 issues)

Institutional 200/- ; Individual 50/-

Price : 10/- per issue


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EDITORIAL : 239

Arvind Kumar Saxena

ARTICLES :

Presidential Address : Man and Ocean : Resources and Development

B. Ramachandra Rao 241

Biological Rain – A New Window for Harvesting Atmospheric Moisture

A. K. Srivastava and Yogranjan 288

Diabetes and Medicinal Plants

R. U. Abhishek, D. C. Mohana, S. Thippeswamy and K. Manjunath 292

Formation and Importance of Biofilm

Aryadeep Roy Choudhury, Mayukh Chakraborty and Samadrita Bhattacharya 298

Surface Structure of Planetary Bodies—The Moon

Subhasis Sen 305

KNOW THY INSTITUTIONS 309

CONFERENCES / MEETINGS / SYMPOSIA / SEMINARS 313

S & T ACROSS THE WORLD 314

CONTENTS


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EDITORIAL

Most of the Indian population still resides in

rural and suburban areas where the literacy rate is

very low. Therefore, the recent science and

technology development impacts are supposed to

be very meager. But in fact our old culture of life

pattern is so robustly developed by Rishis and

Saints who acted as thinkers and were guiding

factor of the society that most of the religious

activities cater the need of food, shelter and

medicines sustainably without depleting the natural

resources for future generation. Some examples are

the protection of high medicinal value plants like

Tulsi, Pepal, Neem and Awala etc., which were

given a flavor of religious worship to enhance their

plantation and protection thus maintaining

environment and improving health. In the area of

material science the advancements were also very

high, e.g., the noncorrosive iron pillar in Meharauli

area at Delhi is an excellent example of forging

technology and knowledge of corrosion preservation,

the sweet wells on the sea shore of Rameswaram

temples at Rameswaram, Tamilnadu, which are an

excellent example of porous ceramic membrane

technology with reverse osmosis and self-cleaning

process having ion selectivity thus controlling the

continuous availability of controlled mineral

containing water having different natural color

impacts and matching the color of water of that

river on whose name the wells are named, floating

stones on water in the same area as an state of art

example of closed cell ceramic foams having high

strength and prepared using naturally occurring

materials etc.

But during recent past we have fallen in such an

economic race that due to which our developmental

process become unsystematic and unplanned which

invited number of natural disasters and causing

draught and flood in many parts of the country. The

most disastrous accident due to unruly development

occurred in Uttarakhand (Badrinath and Kedarnath)

where thousands lives were lost.

It is a matter of simple realization that nature is

like our mother and father and it creates, save and

punish if done something wrong. Infact, the nature

has provided us each and every thing as per our

requirement e.g., most essential things are given to

us in plenty without any effort like energy (Sun),

air (Purified by Plants) and water (Rains and ground

water). Those requirements which are not highly

required are given in restricted way by posing some

unusual properties e.g., radioactive substances are

having a half-life and critical mass for their auto

balance and use, nanomaterials have coagulation

property so that they cannot exist in nature as such

otherwise these may have number of ill effects on

health when in contact with living beings. So

nature as parent has tried to do its best to help us

but it is on us how we are using these boons. Our

own deeds cause the scarcity and depletion of these

natural resources.

So, in brief every science and technology is

available around us and infact we are trying to

copy nature as far as our scientific developmental

concepts are concerned. The nature is highly smart,

sustainable and progressive.


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So our effort is always to familiarize you withrecent trends of biomimetic science and technologyefforts going on all around world and providing an

imagination to achieve excellence in sustainableecofriendly growth with the regeneration of naturalresources for betterment of all living beings.

Dr. Arvind Kumar SaxenaDMSRDE, Kanpur

“Whether you can observe a thing or not depends on thetheory which you use. It is the theory which decides what canbe observed.”

— Albert Einstein


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D distinguished Prime Minister, ReveredChancellor, Respected Chief Minister,

Distinguished Scientists from abroad, Members ofthe Indian Science Congress Association, Ladiesand Gentlemen.

It gives me great pleasure to take this opportunityof expressing my heartiest gratitudes to the scientificcommunity for electing me as the President ofIndian Science Congress Association and thusenabling me to preside over the seventieth sessionof the Indian Science Congress at Tirupathi.Addressing such an august audience committed tothe pursuit of truth at an urge to explore thefrontiers of knowledge one perceives and evenencounters and adventure in ideas and insights,leading to the unfoldment of new layers ofconsciousness and voyage to a new discovery.Hopefully, this meeting of minds will generateincisive ideas and new vistas for harnessing thelatent untapped potentials of the rich and variedresources of oceans for the benefits of mankind.

It may appear to be little digression but I wouldlike to focus your attention on the origin of thefocal theme. On my election to the President of theIndian Science Congress Association, during thelast year, I was deeply concerned about the selectionof the topic of the focal theme of the seventiethScience Congress several weeks, in a mood ofintrospection and reflection, an idea occurred to methat I should take up the theme of Man and theOcean due to personal and scientific reasons. Let

PRESIDENTIAL ADDRESS

MAN AND OCEAN : RESOURCES AND DEVELOPMENT

PROF. B. RAMACHANDRA RAO. D.Sc. (HONORIS CAUSA) F.N.A. F.ASc. F.N.A. Sc.

us not forget that oceans are known to be our lastfrontiers.

I have personal affiliation with the theme in asense that my association with the sea extends toover half a century. I had a unique and rareopportunity of being brought up in close associationwith the sea right from my childhood days. As Igrew up, I began to take a perceptive interest in thebehavior of the sea in its various manifestationsand closely observed the diverse rich flora andfauna of the coastlines in the spirit of anenvironmentalist. The waves, the currents tides andstrems appeared to me like a rhythmic dance. Icould not understand why the oceans which providesuch remarkable resources of food, minerals, energyand petroleum also cause climatic fluctuations andspell catastrophe of worst magnitudes. What struckme most at that time was how the fishing communityand even explorers and navigators had a insightinto the art of living in harmony with the laws ofsea and never arrogated to themselves the power ofdislocating their equilibrium.

When I recalled those learning experiences whichI had the benefit of obtaining from fishermen,maritime traders and explorers. I am transportedinto a state of joy and delight and this leads to theprocess of self-examination. Since those days, myonly wish had been to understand the knowledge ofthe ocean, in-depth-knowledge being itself as anocean—and this led me to read the memories ofexplorers, navigators and naturalists. What impressedme most was the magnificent observational datawhich Charles Darwin collected during his historic

* General President, 70th Indian Science Congress held duringJanuary, 1983 at Tirupati.


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voyage in a Beagle ship. Perhaps today I consideras a part fulfilment of my childhood wish of doingsome theoretical exposition on the ocean.

In a science and technological-based world, it isan irony of the human race that over three-fourthsof the world’s population in this biosphere is stillliving in a primitive condition and in animpoverished socio-economic environment. Thesepeople suffer from various kinds of constraints,malnutrition, deprivation of basic physical and socialamenities, without any access to the moderneducational, health, transportation andcommunication systems; because the benefits ofthe development have been taken away by thedevelped societies of the world and only a smallfraction of the population of the developing societiescould avail of the advantages of Science andtechnology. This imbalanced development anddistribution of resources is inhibiting the goal ofinternational world order to which the UnitedNations system is firmly committed.

In any analysis of the scientific and technologicaladvancement, we should not overlook thefundamental fact that developed societies in theirquest for the mastery over laws of nature went onexploiting the precious and scarce natural resourcesof the biosphere in a ruthless and in anindiscriminate fashion. This process has resulted inthe shortages of non-renewable and even somerenewable resources needed for the developmentaltasks and brought about a staggering problem ofenvironmental pollution and an ecological crisis. Itnever occurred to the scientists, technologists andplanners that biosphere exists and survives by meansof a delicate self-regulating and self-maintainingbalance of natural forces. The constituents of thebiosphere are inter dependent and man is just asdependent in his relation with the biosphere as anyof the biosphere’s other present constituents. Thisdislocation has become a source of great disturbance,and a cause of serious concern and currently theplanners and policy-makers are looking before andafter as how to evolve new strategies of development

which are ecologically-oriented to prevent furtherdanger to our biosphere.

In looking towards forward the furtherdevelopmental scenario of the developing societies,one perceives gigantic problems of developmentinvolving an accelerated growth of food productionfor feeding millions of people who are ill-fed,providing them with the necessary medical, healthand educational facilities and other basic amenities.This is an extremely difficult task at a time whenthe population of developing societies is expandingat an explosive rate and consequently the naturalresources are depleting rapidly; and also theirexploitation by Science and technology is not beingaccomplished in a balanced fashion. What are thealternatives and options before us ? It is fascinatingto note that while Science and technology hasaccomplished a magnificent task in our generationby landing man on the moon, this feat has taught ussome lessons of practical importance of estimatingour prospects and choosing our policy on the earth.Even if moon is endowed with lot of preciousnatural resources, how far it would be an economicaland viable proposition to exploit its rich resourcesfor developmental purpose? A permanentcolonialisation of the moon by the people of theearth would be an extraordinarily difficult task. Insuch a situation, can we look forward to theexploration of our ocean resources which areenormously rich and are waiting for exploitation tomeet the requirement of food, chemicals, mineralsfuel and energy? The ocean provides a uniquechallenge and an exciting promise for development.

It is conceivable that most of the ocean resourcescould not be exploited because of theirinaccessibility, lack of technological capability andcomparatively high cost of development. The oceancomprising nearly three-forth of earth’s surfacepossesses vast latent, untapped potentials whichcould be appropriately exploited for thedevelopmental purposes with the help of effectiveuse of sophisticated instruments of Science andtechnology and highly trained manpower capability.


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The developmental aspect of the ocean can beconsidered for the terrestrial environment from thefollowing broad perspectives. To elaborate a littlefurther, they can be used for transportation, sourceof food and other organic and inorganic materials,fresh water and energy, habitation industry andbusiness activities, transmission of energy andfunctions of waste disposal, health, welfare andrecreation, education and training, gaining ofknowledge and understanding of national securityand international relations. While undertaking aprogram me of the development of the ocean, itwould be appropriate to proceed through an orderlysequence of analysis. In this process there are fourmajor steps :

1. identification of the contemplated resource;2. evaluation of the technological, legal

economic, sociological and political factors;3. estimation of the benefits anticipated, costs,

involved, goals, needs and time schedules;and

4. implementation through arrangements forfunds, authorization and assignment ofresponsibilities for management andregulation.

ISSUES

Perhaps, the time has come when the scientists,planners and policy makers and leaders in diversifiedareas of life must address themselves to thefollowing crucial issues involved in the process ofdevelopment of the ocean resources, both latentand identified, for the benefit of mankind. If thenatural resources of the land—both renewable andnon-renewable—are getting exhausted and accountof the ruthless and indiscriminate exploitation bythe developed societies, while the need for anoptimum use of scarce resources has assumed agrater urgency in the developing societies in a viewof their expanding population, can we look forwardto the potential resources of the ocean to meet theemerging and foreseeable threats of food problem,protein deficiencies, and the shortage of mineral,fuel, energy, oil and others? How far the ocean

research, especially in the developmental sector,can facilitate and accelerate the pace of developmentto improve the condition of the impoverished sectionof population, which constitutes two-third of thetotal world population, who despite variousbreakthroughs in Science and technology are livingill-fed, shelterless and without any access to moderncommunication system, modern transport and otherbasic amenities of life which are essentials in anycivilized society. If the agriculture system of mostof the developing societies especially in India, isstill dependent on the vagaries of monsoon, howfar multi-disciplinary research, specially in the areasof oceanography and climatology could regulate abalance so that the fluctuation in the rainfall couldbe minimised? How far the rich and varied floraand fauna of ocean reflecting the environmentaldiversity, which is being destroyed by indiscriminateand ruthless exploitation of these resources in theprocess of industrial development, could beprevented? How to accomplish the developmentaltask without dislocating the rich and varied faunaand flora of the coastlines?

In any analysis of the developmental strategy,we should not overlook the fundamental fact thatecological balance is the result of natural evolutionwhich dates back to several millions of years sincethe evolution of life on this planet. But this balancegot dislocated due to a combination of factors andhow to restore this equilibrium is a problem ofproblems.

If oceans are one of the major means of nationaland international trade and commerce, why did wenot pay adequate attention to optimise their use fortransportation and navigational purpose? If theoperational cost works out cheaper through oceanstransportation in comparison to land, why are thedeveloping societies not adequately exploiting thisbenefit?

If ocean’s voyages could contribute eitherexplicitly or implicitly to the enrichment of humancivilization through the monumental discovery oftheory of “Origin of Species” by Charles Darwin


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based on the observational data collected during hisvoyage on a ship called Beagle, why did ourscientists, planners and policy makers pay littleattention to the scientific expeditions on the highseas for discovering the hidden secrets of nature inthe sea and use them for various developmentalpurposes ?

If the task of harnessing the potentials of oceanresources for developmental purposes are of crucialimportance, did we not pay adequate attention tothe development of necessary infrastructure andcapabilities which are urgently needed to accomplishthe said task, when our land resources are in shortsupply?

Some of the other challenging issues are :

Can we augment our sea food resources bymodern methods of marine aquaculture ?

Can we augment our fresh drinking waterresources by modern methods of desalination ?

Is it possible to unfold the origin of monsoonand avoid recurrent droughts?

Are we not inadvertantly changing the globalclimate and local weather by polluting the ocean?

Can mankind draw perennially the power fromthe sea by new and cheaper methods?

Can we exploit economically the rich potentialof off-shore oil at a time when we are caught upin the midst of a major energy crisis?

Can’t we learn to mine the vast, yet untouchedmineral deposits of the ocean economically?

Are the oceans a safe dumping grounds for theradioactive waste?

It is not a fact that living in a inter-connectedworld with global systems and sub-systems, ourproblems of development have assumed globaldimensions and are of global scale and naturallyglobal developmental strategies and prioritiesare needed for the maintenance of ecosystemand a healthy life on the planet ? Is it notessential in the process that we have to cutacross artificial barriers which divide us intonationalities and races and work out a coherentplan of action on a global scale for harnessing

the rich potential for our oceans for development?If the developed societies are earnest and sincerein their approach towards developing thecoastlines of the third and fourth worlds, is thisnot a unique challenge and an opportunity beforethem ?

RETROSPECT

Looking retrospectively, oceans have been apotential source of food, energy and transportationfrom the dawn of human civilization. This becomesevident from the fact that our earlier settlements ofpopulation took place primarily on the coastline orby the side of sea. There are enough evidencesbased on religious literature, mythological legends,Vedas, Upanishads and Puranas giving greatsignificance to rivers and sea. Indeed, the people ofancients days looked at the rivers and sea withrespect and awe and had a clear perception andinsight as man has to live in harmony with thenatural phenomena.

Although ancient Indians could not developscientific techniques for observation, they had akeen sense of observation of phenomena like oceancurrents, winds, tides and the diurnal and seasonalvariations. As an evidence of their understanding ofthe ocean and also their engineering skill, it maynot be out of place to refer to the recentarcheological excavation at Lothal in the state ofGujrat, which revealed the remains of a well-designed dockyard built by the Harappan civilizationfive thousand years ago. There is thus ampleevidence to show that the engineers, at the time,knew how to build sturdy sea craft and dockyards.Obviously, they understood well the tidalphenomenon and cleverly used high tide period tobring in the sea craft into the dockyard for repairand maintenance. From archeological evidence, wecould infer that the Lothal civilization was successfulin harnessing the potential resources of rich coastlinefor food, energy, trade and other developmentalactivities.

India with its long coastline of 5800 miles hasalways been a seafaring nation. From times


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immemorial, Indian merchants carried on tradewith several countries all over the world by usingindigenously built sea craft. Many foreign nationalsfrom England, Portugal, France and Spain visitedIndia several centuries ago and established traderelations with different kingdoms is our country.There is ample evidence to show that our ancientIndians had sound knowledge of ocean and seacraftand that they had a flourishing trade with manycountries for several thousand of years. Yet, modernliterature on the subject traces the origin of the sea-going craft from 2000 B.C. The Greeks and Romanswere the first to exploit the sea for navigationalpurposes. The first economy based on sea-breezetrade was that of Minoan Crate between 1700 and1400 B.C.

Myceneans, Phonicians, Greeks and

Romans subsequently increased the scale of marinetrading (and warfare) throughout the Mediterraneanand beyond.

The first institutional attempt to promote theexploration of ocean for adventuring and tradepurposes was undertaken under the patronage ofPrince Henry, the Navigator in the fifteenth century.During the sixteenth to eighteenth century, wewitnessed for the first time remarkable developmentin the sea-faring activities and the emergence ofnew techniques by the dedicated efforts of a fewsea explorers and adventurers like Columbus,Magellan and Cook. These adventures wereprimarily the result of the initiative and efforts of afew dedicated individuals who made a historiccontribution towards the world-wide Europeancolonisation. The Portuguese, Britishers and Frenchwere the major European powers who were able toacquire the necessary capability in the sea-faringactivities. Indeed, the extent to which they wereable to wield power was determined by theirnavigational capability. Let us not forget that theBritish colonisation of the greater part of the globecould be attributed to their pre-eminent position intheir mastery of knowledge of the ocean and theirnavigational capability. Since the understanding ofthe ocean was at an embryonic stage, even thosecountries which were able to acquire some

knowledge of the ocean did not do much beyondthe preparation of the coastal charts ocean and thelore of the seaman and fisherman. Very little effortwas made by these explorers to investigate variousinputs of the ocean and how they could besuccessfully harrnessed for the developmental tasks.Over the years, most of the governments remainedsatisfied with the use of oceans for only trade andcommercial purposes and did not take the initiativefor promoting the research work in the area due toa combination of factors. It was only with thedevelopment of maritime activities, navigators andsailors took some degree of interest in the oceancurrents. Benjamin Franklin was able to produce achart of the Gulf Stream which he eventuallypublished in the Transaction of the AmericanPhilosophical Society in 1786. Capt. James Cook,the British explorer also collected scatteredoceanographic informations during his threecelebrated voyages. There were some of the sporadicattempts but no organized attempt was made tostudy the ocean as one of the major scientificdisciplines.

It was during the 19th century that a few seriousattempts were made by explorers and navigators tostudy this area in some depth due to a combinationof factors. Partly this interest was the result of therapid increase of interest in Science, in general, andpartly because of the emergence of disciplines likePhysics, Chemistry, Biology and Zoology, whichprovided the necessary support for the growth ofOceanography. The person who could be given thecredit for laying the foundation for science wasMathew Fountaina Maury (1806-73), a naval officerof remarkable vision and foresight. His first book,New Theoretical and Practical Treatise onNavigation published in 1836 was received withconsiderable interest and curiosity. With enormousobservational data collected during his voyage, hewas able to work out charts of major currents,prevailing winds and storms tracks which becamepart of every navigator’s equipment.

The potential value of charts showing thedirection and strength of winds and currents was

F–2


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soon realised by the navigators and sailors whoused to sail earlier without an accurate knowledgeof winds and storms and had to face many hazardsof sea life. The oceans are vast and the data atMaury’s personal disposal was limited. He overcamethese difficulties by enlisting the aid of navigatorsof the world. He got the support from variousnavigators and Maury’s charts were able to cut thesailing times drastically.

The average voyage between London and SanFrancisco, for example, was shortened by 180 days.In 1855, he published the first textbook ofOceanographic Physics–Physical Geography of theSea. He is also credited with inspiring theestablishment of the official meterological office inboth Great Britain and Germany.

Another naturalist who contributed immensely tothe enrichment of our ocean knowledge was EdwardForbes (1815-54). He was truly in the tradition ofAristotle and took up his mission of carrying onextensive research in the area. In analysing biologicialcollections, he made full use of geological knowledgeof the day, relating the succession of fossils in rockstrata to living marine plants and animals and tracingthe effect of the past history of land and sea on thepresent distribution of these organisms. He pointedout that the shape of the sea fotton of an importantenvironmental factor. He noted that the Chemistryand Physics of the sea—the concentrations andinteractions of nutrients and minerals held in thewater and the play of currents—were importantinfluences in the lives of marine animals. He wastruly a lively genius, with a free and independentspirit that roamed over a wide range in quest ofknowledge and occupation. He was the most brilliantand inspiring naturalist of his day. He made originalcontributions to knowledge in several branches ofnature. He will be remembered for his celebrated anderroneous theory of the Azoic Zone. This theory isthe result of his research in the Mediterranean.

Another famous natural scientist was CharlesWylle Thomas (1830-82), who led the mostcelebrated oceanographic expedition in history, the

voyage of the Challenger. The ChallengerExpedition of 1872-76, mounted by the BritishGovernment, to collect oceanographic informationwas a landmark in the history of ocean. Thisexpedition has been unsurpassed in the scope andintensity of the oceanographic exploration andresearch. On December 7, 1872, H.M.S Challenger,a full-rigged spar-decked corvette of 2,306 tonswith auxiliary steam power and a penchant forrolling like a barrel (46° one way and 52° theother), sailed out of the month of the Thomas.From then on, until May 24, 1876, she sailedaround the globe, logging 68,890 nautical miles inthe major oceans and gathering data and biologicalspecimens from waters of all depths and at almostall latitudes. The end product was a vast collectionof marine organisms such as the world had neverseen and fifty large quarto volumes of multi-disciplinary data, some of which is still useful asreference works today. More directly, practicalaspects of Oceanography was also developed.During this period it was because of this expeditionthat many new varieties of animals were located.Naturalists were able to identify 4717 new speciesand 750 new generas from the specimens broughtback in this expedition. All of them were unrelatedto the known contemporary forms. The Challengerdata marked out a major current system and watertemperature pattern.

The three-and-a-half year voyage of theChallenger still holds the records as the longestcontinuous scientific expedition. It also has beenunsurpassed in the scope and intensity of itsoceanographic probing. The success of theChallenger gave great impetus to many nationaloceanographic explorations from a number of othercountries during the remaining part of 19th century.By the turn of the century, Oceanography wasfirmly established as a regorous Science, but thegrowth of it has been relatively slow after its 19thcentury beginning.

Modern study of Oceanography in India startednearly a century ago beginning with the firstexploration of the fauna and flora of the Andamans


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carried out by Dr. J. Wood Mason, an Officer of theIndian Museum. Soon after the great success of theChallenger expedition, British Government createdthe post of Surgeon-Naturalist to carry out a workin Indian waters similar to that of Challenger. Thefirst Surgeon General, Dr. J. Armstrong startedoceanographic studies by using the survey vesselR.I.M.S Investigator I. Subsequently a larger vesselInvestigator II, with better scientific equipment,started making observations of salinity andtemperature of seawater and of some atmosphericparameters like temperature, pressure, humidity,velocity and direction of winds. This data waspublished by the Royal Asiatic Society of Bengal.Subsequently, a wealth of useful oceanographicdata was collected by Indian Research Vesselsduring Dana Expedition (1928-30). John MurrayExpedition (1933) and Galathea Expedition (1950-52). These expeditions brought out a wealth ofuseful information regarding the physical andsociological wealth of the Indian Ocean.

After the country attained independence, effortswere directed towards enhancing the fisheryresources from the sea. Keeping this in mind, theCentral Marine Fisheries Research Institute wasestablished in 1947 to carry out researches relatedto fisheries development. In the same year, theIndian Navy established the Naval PhysicalOceanography Laboratory at Cochin for physicalstudies of the ocean and also problems cocnerningdefence research. Andhra University at Weltair isone of the university which pioneered and carriedout commendable work on physical oceanographyand meteorology from 1952. In 1960, Governmentof India constituted the Indian National Committeeof Ocean Research to plan and coordinate oceanresearch in the country.

Undoubtedly, Indian ocean is the least exploredby ocean scientists and as such, UNESCO supporteda multi-national project entitled “InternationalIndian Ocean Expedition”. This was the first majorcollaborative experiment carried out during 1960-65 using 40 ships and scientists praticipating from20 countries. India, which contributed 4 ships for

this expedition took an active part by assigning acompetent group of scientists, well-trained toundertake this task. This work was mostly carriedout under the leadership of late Dr. N. D Panikkar,who later became the Director of the NationalInstitute of Oceanography which was established atGoa on 1 January, 1966 as a C.S.I.R Laboratorybased on the recommendation of the Indian NationalCommittee for Ocean Research. During the lastone and half decades, this laboratory has expandedin all directions and has taken upon itself a varietyof activities in the fields of physical, chemical,biological, geological, oceanography. One of thelandmarks in Indian Oceanography research wasthe acquisition of the first oceanographic researchvessel, R. V. Gaveshani on 31st December, in thecountry. Since then, Gaveshani has completed morethan 100 cruises and collected data and informationon all aspects of oceanography in Arabian Sea andBay of Bengal. Another research vessel recentlyacquired by Central Marine Fisheries ResearchInstitute at Cochin, will hopefully increase theopportunities and activities in the field ofoceanographic research.

THE UNDERWATER LANDSCAPE

While viewing the major components of theearth’s surface, one is struck by the fact that,beneath the ocean surface, there is a world ofgeography lying unexplored of which man is totallyignorant. He knows much less about the 70% of theearth’s surface lying submerged under the oceanthan the landscape on the near side of the moon.Soon after world war I an echo sounding device asSONAR was invented and used for measuring theocean depth by finding the time of travel of thesound pulse from the surface to the ocean bed andback. When this remarkable invention is fitted tooceangoing vessels, every research expeditionbecame a new voyage of discovery unfolding themysteries of the ocean bed. Soon oceanographersdiscovered towering mountain ranges, deep canyons,active volcanoes and steep cliffs in the oceans ofthe world. Man could discover the wonders of the


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hidden continents beneath the ocean having deeptrenches, longest mountain chains, broadest deltasand mountains nearly as tall as Mt. Everest.

There major components of the earth’s surfaceare the lithosphere (i.e. the thin outercrust of theland mass), the hydrosphere and the atmosphere.The ocean covers an area of 71 percent of theearth’s surface with an average depth of 3.7 km andfalls within the domain of hydrosphere.Comparatively, the average height of the land massabove the sea level which is 0.75 km is considerablyless. If all the land mass on the earth is smoothenedout both on land oceans, all land will be submergedto a depth of 2.5 km. Ocean is predominant in thesouthern hemisphere which is also known as marinehemisphere.

The five major oceans of the world are thePacific, the Atlantic, the Indian, the Arctic and theAntarctic. The coldest, deepest and the largest isthe Pacific ocean occupying more than half of thevolume of the ocean basin. The ocean whichreceived the largest amount of sediment from theAmazon, the Congo and the Mississippi is theAtlantic. The Indian Ocean is basically an ocean ofthe Southern hemisphere and is the smallest of thethree major oceans.

Although scientists debate about the origin ofthe solar system which is still a mystery, the originof the ocean is now fairly well-understood in termsof modern theories of sea-floor spreading, globalplate tectonics and continental drift. The origin ofseawater was explained in terms of followinghypotheses :

1. Condensation2. Weathering of volcanic rocks3. Degassing of the Mantle

The last of these hypotheses, as propounded byW.W. Rubey, is now considered to be acceptable asit explains the total volume of water and also whythe oceans are not saltier than they are. Thishypotheses corraborates the evidence that oceanscame into existence relatively late in the geologicaltime.

Looking at the physical features of the ocean,the floor could be broadly divided into four majorparts:

1. continental shelf2. continental slope3. continental rise and4. Abyssal planes.

The continental shelf which is the area beneaththe sea bordering the continent’s skirts most of theearth’s coasts gently sloping to a depth of 150-200meters. Atlantic ocean has more shoreline and widercontinental shelves than Pacific or the Indian ocean.

The land mass at the edge of the continentalshelf abruptly plunges down into the sea forming acontinental slope, which is a relatively steep slopeending at the bottom of the sea. These are thetallest and longest boundary walls between the landand the sea. In some parts of the coast such as thatalong Chile and Peru, the drop from the peak in themountains to the bottom of the trenches is indeedspectacular reaching a figure of more than ninemiles. Along many coasts, the continental slope isfurrowed by deep gorges and canyons caused byearthquakes, undersea currents and thick cascade ofsilt rushing down the slope, Mariana’s trench whichis one of the famous deep trenches discovered in1960 is 11 km deep.

At the edge of the continental slope, a continentalrise begins gently ending in the Abyssal planes.Abyssal planes are areas of deep ocean floorgenerally found at depths of 300 to 6000 meters.Nearly half of the earth’s surface is occupied by theAbyssal planes which are present in all the oceanand seas of the world. It was in this infinitely largeAbyssal planes that scientists made the most startlingdiscoveries about the earth’s hidden surface. Oneof the spectacular observations is that many of themountains, hills, cliffs projecting out of the Abyssalplanes remained fresh and unaltered over severalmillions of years.

More than a century ago, the celebrated scientistSir Charles Darwin explained that coral reefs are


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formed on top of sinking volcanoes and still manageto be in the top 150 feet of the sea, which is thefavourite level for the coral polyps, by growing atthe same rate as the rate of subsidence of thesinking volcano. This brilliant hypotheses was onlyrecently confirmed by US Navy Engineers, whodug out samples from coral topped sunken volcanicislands to reach the volcanic rock on an ancientcoral Eniwetok Atoll after cutting 4000 feet ofcoral reef.

Geologists and Geophysicists all over the worldhave been trying to understand in a systematicfashion the structure, composition and origin of theearth’s crust. The study of oceans revealed that thecrustal layer of the earth is sufficiently thinparticularly beneath the ocean bottom. Scientistshave taken up a mammoth drilling operation forpenetrating into the Mohorovicic discontinuity or‘Moho’ which is the boundary between the crust ofthe earth and the enormous 1800 mile thick mantlelayer underneath. During the early years of 1960’sUS Scientists undertook “Project Mohole” in orderto obtain core samples from the mantle beneath thesea. Project Mohole had to be abandoned aftercutting through 600 feet of sediment and rockwithout reaching the Mohorovicic discontinuity.Project Mohole successfully demonstrated thefeasibility of deep sea drilling and generated severalnew and useful ideas for improving and advancingthe deep-sea technology.

Putting this experience to good use in 1968, theDeep-Sea Drilling Project (DSDP) was undertakenby the Scrips Institution of Oceanography. For thisproject a 400 feet research ship Glomar Challengerwas specially designed and commissioned. TheProject was undertaken at a dept. of 20,000 feetbelow the sea-level to drill and obtain core samplesbeneath the ocean floor. With this highlysophisticated ship and modern facilities includingsatellite navigational system, digital computers, etc.,it was possible to penetrate the earth’s crust up to2,500 ft. thickness. Though this project also couldnot succeed to penetrated the Mohorovicicdiscontinuity, it has added a wealth of knowledge

in the field of Paleontology, magnetic properties ofrocks, Geotectonics and confirmed the theory ofcontinental drift which has an important bearing onthe evolution of the ocean basin.

The greatest single geographical triumph ofmodern times is the recent discovery of Mid-Oceanrange which is the single longest mountain rangehaving the width of a hundred kilometers andextending over several thousand kilometers.Although the first clue of Mid-Atlantic Ridge camefrom Challenger expedition, use of sonars afterworld war II led to the charting out of many of theridge under the oceans. While this study was goingon, seismologists noticed that the epicentres ofdeep sea earthquakes exactly coincided with thelocation of the newly discovered ridges. Based onthese observations, Ewing and Bruce C. Heezenmade two hold predictions. First was that mid-ocean ridges were present where deep-seaearthquakes occurred. The second, which was abold surmise, was that these deep-sea ridges wouldbe one long interconnected mountain range.Subsequent surveys and seismic results confirmedboth these predictions and showed that these ridges,which are also volcanically active, run right aroundthe world. The Atlantic, the Pacific and the mid-Indian Ocean ridges are the major ridges in theseoceans. The total length of Ocean ridge system(75,000 km) is long enough to girdle the earthtwice over.

This is not the place for me to discuss thetheory of continental drift propounded in 1855 byEdward Suess, a Swiss geologist who proposedthat the contents of South Africa, Africa, Antarctica,Australia and India were once joined into a singlelarge land mass called Gondwanaland. In his classicwork “On the Origin of Continents and OceanBasins”, Alfred Wegener showed that all continentswere once a part of a single super continent calledPangaea which was supposedly fragmented intotwo giant continents separated by the ancient seacalled Tithys sea. The second part of this fragmentcalled Laurasia encompassed North America andEurasia whereas the southern part was the


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Gondwanaland. Over millions of years, furtherfragmentation occurred thus forming the moderncontinents. It was estimated that Pangaea began tobreak up two hundred millions years ago, and thatthe second breakup began 135 million years agointo smaller plates. The entire theory is based onthe similarity of the coast lines which fit into eachother and also the similarity of the deposits of coal,of glacial deposits and of fossil plants and animalsin the countries of the Gondwanaland. The theoryof continental drifts is now well-established and itis generally accepted by all that the ocean basinsare opening and closing ever since they were createdduring the 4-5 billion years of Earth’s history.Very recently interest in this theory was revivedby the discovery of sea floor spreading thePaleomagnetism. One of the interesting andconvincing evidences in support of the theory,came from computerised continental driftreconstructions. They showed perfect fit betweenAfrica and North and South America.

Paleomagnetic studies of rocks of different ridgesin the ocean showed that the magnetic poles of theearth have been wandering in the geological pastleading to the concept of Polar wandering. This isdue to the continents and seas moving continuouslyrather than the pole itself changing its position. Thecrust of the earth has a high degree of mobilityover the mantle resulting in a slow shifting of thesolid lithosphere on the plastic asthenospherebeneath it leading to a change in the position of thepoles. The modern theory of global plate tectonicsassumes that the earth’s crust is broken into severallarge and small irregular segments called “plates”.These plates in the lithosphere ride on the relativelyfluid-like asthenosphere causing the plates to movehorizontally. There are six major plates identified.Each plate may contain a continent or an ocean orboth. The boundaries where the two plates meet aresubjected to enormous forces and are seats ofintense activity as this is the region whereconsiderable pressure is exerted by the two plateson each other. When plates diverge from eachother, new material from the earth’s mantle comes

up and new crust is created continuously, as hadhappened along the major ocean ridges. On theother hand, when two plates collide, one is pushedbeneath the other creating deep sea trenches andvolcanoes releasing fantastic amounts of energyoccasionally in the form of devastating earthquakes.One example of this is the collision of India withAsia bringing about a major continental upheavalresulting in lifting both continental and ocean floorrocks to form the majestic Himalayas which is theyoungest mountain range still growing taller.Although to a lesser extent, earthquake energy isalso released when two plates meet and moveparallel to each other but in opposite direction. Bya study of Plate Tectonics theory and its applications,scientists have come to the conclusion that modernocean basins are relatively young (less than twomillions years old). Ocean basins have been keptyounger over ages. The Ocean basins are in aperpetual state of motion although at animperceptible rate of the order of 1 to 16 cms peryear. These rates are least in the mid-Atlanticridges and highest in the East Pacific ridges.According to Sir Edward Buller the famousgeologist the entire floor of the Pacific ocean andthe Atlantic ocean were formed about 100 to 150million years ago which is quite young comparedto the 4.5 billion years of the age of the earth. TheIndian Ocean was also formed in recent geologicalpast when the Indian plate drifted away from theGondwanaland and collided with the Eurasian platein the North. At the present rate of motion of theplates, Atlantic and Indian oceans are expandingand Pacific ocean is shrinking, perhaps, to disappearin the future as many oceans have disappeared inthe geological past, such as the Eurasian oceanwhich existed between Siberia and Western Russiain the geological past. The Eural mountains areformed as a result of the collision between Russianand Siberian plates. The plate theory of continentaldrifts is one of the most outstanding discoveries inmodern times which not only explained the originof the continents, mountains and ocean basins butwill some day enable us to recreate the past historyof the earth over several hundred million years ago.


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Astrophysicists and geophysicists are deeplyinterested in the origin and evolution of the earth.In this task, they have very limited experimentalevidence for recreating the history of the past. Onesuch evidence has recently come to light whenscientists tried to estimate the length of the day inthe remote past. There is sufficient justification, ontheoretical grounds, to say that the length of theday increased slowly in geological time as earth’srotation has been slowed down by tidal friction andalso friction inside the mantle and core of earth. Asa result of the increase in the length of the day, thenumber of days in the year decreased. Theoreticalcalculations indicated that at the beginning ofCambian period some 570 million years ago, therewere 428 days in a year. Looking for a ‘clock’ innature which had recorded the number of days inancient geological period, scientists discovered thepossibility of using the bands on ancient corals,representing daily growth, to precisely arrive at thenumber of days in a year in the geological past.Examining the hard shell of the corals of the past,distinct bands indicating annual and daily growthcan be recorded to find out the number of days ina year and estimate the age of period by radioactivedating or stratigraphic evidence. It is indeed atriumph of the theory that the theoretical values ofnumber of days in a year in the early ages ofevolution of the earth agreed well with thoseestimate from coral “clocks”.

Having reviewed the work on undersea landscapeI cannot refrain from referring to continents of thevast Antarctica and its 14 million km area buriedunder a vast sea of ice. The average thickness of icein Antarctica is 2.16 km and the volume is 30.11cb. kilometers. If all the ice in the Antarctica meltsthe levels of the whole world will rise by 55meters, submerging many of the coastal towns. Itwas captain Cook’s adventures spirit which led himto cirumnavigate the Antarctica as early as1773-74. However, systematic scientific study wasstarted only during IGV (1957-58) when manynations undertook a well coordinated series ofobservations on this vast continent almost totally

buried under ice with hardly one per cent of theland exposed for geologists to collect samples fortheir investigations.

Currently about a dozen countries have set uptheir research stations and pursuing a systematicprogramme of research for peaceful purposeconfirming to the 30-years Antarctic Treatry ratifiedin 1961. Antarctica is a fascinating continent whichcontains 99% of the ice in the world and 90% ofglobal fresh water reserves. It is therefore notsurprising Antarctica plays a vital role on theclimate, the ocean, the solid earth and the life ofthis planet. A new and powerful technique calledthe radio echo-sounding, which replaced the slowand cumbersome echo-sounding technique, is nowextensively used not only to obtain the contourmaps of Antarctica ice sheet but also the profile ofthe bed rock. Strangely, a number of lakes werediscovered under the ice sheets of Antarctica, someof them more than 5 km wide. No one knowswhether any life exists in these lakes as they arepermanently burried under the sea. At best, theymight be having minerals and gases.

The success of the Indian team under theleadership of S. Z. Dr. Qasim to land on Antarcticon 9th January, 1982 is a major landmark in IndianOceanography. The team of meteorologists andgeologists, geophysicists, communication andnavigation experts has done a remarkable job intheir 77 days expedition. This was the first exposureof the Indian scientists to the frozen continent andto carry out studies on rock magnetism, glaciology,meteorology and radio propagation. It also affordedan opportunity for geologists and geophysicists tomake preliminary studies. The Indian teamestablished an unmanned station appropriatelynamed as “Dakshin Gangotry” for recordingcontinuously the weather data. Right now, thesecond Indian Ocean expedition is already on itsway and is likely to carry out in-depth studies forlonger periods.

The last three decades is an epoch makingperiod in the annals of the history of Earth Sciences,


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as it witnessed revolutionary discoveries which ledto a clear understanding of the origin and evolutionof continents. A new field of study has just beenopened up. This is the best opportunity for Indiangeologists and geophysicists, to follow up theapplication of this theory to understand the Geologyof our vast subcontinent particularly the technicallyunstable region along the junction of the Indian andAsian plate which was the seat of an ocean millionsof years ago. They may endeavour to gain deeperinsights to understand the driving mechanism ofthe plates, to refine the model and to investigatesome of the side effects which will lead them tounderstand the process of erosion, rate of depositionand even the effect of climate in the past history ofearth. May be such refined models of continentaldrift, paleoceanography and paleoclimatogy mayprovide important information guiding us indiscovering rich deposits of hydrocarbons and majormineral deposits. An extrapolation of knownresources available along continental margins couldaid in search of mineral deposits along othercontinental margins which are yet to be explored.

UNDERWATER VEHICLES ANDINSTRUMENTATION

To explore and exploit the rich resources of theocean, it is not enough if we drop sophisticatedscientific instruments, tools or cameras from thesurface of vessels to acquire a wealth of data.However remarkable, these floating laboratoriesare like our Research vessel “Gaveshini”, there aremany tasks which cannot be achieved unless mancan go down into the ocean, however deep it maybe and remain there at these great depthscomfortably and travel long distances along the seafloor or collect mineral and biological samples forfuture studies in the laboratory and to carry out insitu studies of behavior of sea life in their naturalhabitat.

Japanese pearl divers are experts in deep seadiving and could remain for a long time underwaterto collect oyster pearls. For well over a century,man have been able to work to a limited extent by

having a divine suit and helmet connected by an airhose to the mothership. It is only after thedevelopment of Scuba (Self-contained underwaterbreathing apparatus), the aqualung that man couldachieve complete independence from the mothershipand greater mobility to explore the underwaterworld of the seas. This was made possible bydesigning a small compressed air cylinder on theback of the diver which feeds the proper amount ofair regardless of his position. Soon Scuba divingbecome not only a popular sport for many amateurand professional divers, but also a key for exploringthe underwater riches of the continental shelf.Scientists, particularly geologists, marine biologistsand oceanographers learnt Scuba diving to gainfirst-hand knowledge of the undersea world. Mineralprospectors engaged Scuba divers for discoveringnew mineral deposits. Petroleum companiesemployed Scuba divers to repair offshore underwateroil wells. Scuba divers came in handy for manyundersea exploits including salvage operations inship wrecks. Remarkable and useful as the Scubais, it has a serious drawback that, even at a depthof 100 feet man is subject to three times theatmospheric pressure and hence breathes three timesas much oxygen leading to oxygen poisoningresulting in giddiness, nausea and convulsions.Remedy for this is to design a device that wouldregulate and control the intake of oxygen, whatevermay be the ambient pressure. Krasberg, a youngscientists from Harvard, developed an electronicallycontrolled device.

Scuba diving has several handicaps when wehave a deal with a detailed, prolonged study ofunderwater by a team of scientists. For extensive insitu studies involving more scientists, what is neededis a submersible vessel which can withstand thevery high pressures at great depths and at the sametime equipped well with the scientific instruments,cameras etc., for observation and recording.Although it was in late 1920, the American biologist,William Beebe who conceived the idea ofpenetrating the ocean depth, it was only during thelast two decades that scientists and engineers started


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designing and building varieties of modernsubmersible bathyscope vessels ranging from theTrieste I to the latest SEALAB series. Trieste wasthe brainchild of a Belgian scientist August Piccard.The voyage of Trieste to the bottom of the sea wasconsidered a spectacular success. It has dispelledall doubts about the ability of man to reach thebottom of the ocean and even descend below theAbyssal planes to the bottom of the trenches. Underthe leadership of Donald Walsh, Trisete made ahistoric voyage landing on the floor of MarianaTrench some 35,800 feet below the sea level. It washere, for the first time, new forms of life survivingon new forms of plankton unknown to mankindwere discovered. In fact, it was with the help ofTerieste that the dismembered remains of the firstU. S. nuclear submarine Thrasher which sank onApril 10, 1963 were discovered. For the first timeit was demonstrated that, on the large ocean bed,small objects could be discovered by an equallysmall mobile submersible. One of the smaller deep-diving submersible Alvin could locate and retrievethe lost hydrogen bomb in 1965 of the coast ofSpain.

Until the 19th century very crude methods wereemployed for measurement of the ocean depth.During the last few decades, in their efforts toprobe deep into the sea and to tap their richresources, oceanographers are employing a largevariety of new and improved instruments. Almostall the sea-going vessels have invariably sonarsystems which are used to measure the oceandepth, obtain the profile of the bottom of the sea inthe form of charts showing the variation of thedepth with distance. Sonar has undergoneremarkable improvements using the moderntechniques for signal processing for eliminatingambient sea noises in order to make it more sensitiveand to extend the range of the instrument. Powerfulsonars are even able to penetrate the sedimentarylayer of the ocean bottom and delineate the structureof various layers above the hard rock. Sonar hasbeen successfully used by geologists andgeographers to map the bottom of the sea. During

the world war, it has been used by worships todetect prowling enemy submarines. Submarinescan communicate with each other through Sonarsystems. In recent times, Sonar is extensively usedfor locating extensive fish shoals to help the fishingindustry. Underwater sunken ships and oil rigs canbe identified with good clarity using Sonar. Sonarhas also been used select the route for layingunder-sea cables for international communicationand for fixing suitable location for construction ofhighways and tunnels under the sea-bed acrossnarrow channels.

Among the techniques ocean scientists employ,seismic sounding is one of the most ingenuous andhas been extensively used by oil prospectors forlocating oil fields beneath the earth. Maurice Ewingwho headed the famous Lamont-Doherty GeologicalLaboratory of Columbia University extended thistechnique to underwater exploration using two shipsone to set off an explosive change in water tocreate a miniature earthquake-like wave whichpropagates horizontally in the bottom sedimentsand a second ship to receive and record the receivedsignal. By measuring the arrival time of the soundpulse for different distances between the ships, it ispossible to measure the thickness of the sedimentson ocean floor. Seismic sounding has become apowerful tool not only to estimate the thickness butalso to know composition of the sedimentary layers.

Underwater communication is an important areain which considerable work has yet to be carriedout. There is a need for portable walkie-talkie fordivers to communicate with each other usingultrasonic waves. Such portable devices have yet tobe developed. Radio communication withsubmarines is another field which needs specialattention from scientists and engineers. As seawater is a good conductor conventional radiowaveswill get absorbed in the ocean and as such there isneed for a powerful very low frequency (VLF)transmitter at frequencies below 10 Khz forunderwater communication. Perhaps, some dayscientists can control ionosphere at heights of 100km and use it as natural antenna for communicating

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with submarines by using extremely low frequencyradio waves.

Under-sea photography has been in use forprobing the sea nearly a century. During the lastcouple decades the Woodshole OceanographyInstitution developed a technique for automaticunderwater photography which reveals in minutedetail and brilliant clarity the objects on the sea-floor. The major problem in underwater photographyis to produce brilliant flashes of light whichpenetrate the thick dense muddy water on thebottom of the sea. This requires special illuminationtechniques for underwater photography. Both theunderwater camera and television scan have been agreat boon to modern biologists who could sit intheir laboratories watch and study the behavior offish in their natural habitat.

While all these techniques are of great value toobserve understand the ocean and the life within it,scientists do need samples of the water and theearth and rock below the sea-bottom to analyse andunderstand the structure and composition in detail.For collecting water samples Nansen Bottle, namedafter the famous Arctic explorer Fridtz of Nansen,is used extensively. There are several varieties ofcoring devices used to collect the sample into acore pipe which bores through like a drill, cuttinginto the bottom of the ocean. Biologists collectedsample of living creatures by many kinds of nets.Special devices like the Clark-bumpus sampler andHardy Recorder were used to study the tiniest sea-creature, plants, microscopic plankton, etc. Suchstudies have been used to find out the riches of thesea food resources. A host of instruments such asmagnetometers, gravimeters, subsurface currentmeters, bathythermographs, salinity meters and heatprobes were developed to take measurements atgreat depths in the ocean.

Very recently scientists have developed atechnique known as Ocean Acoustic Tomography,the basic principle of which was proposed in 1917by the German mathematician Radon. This principlehas been successfully used widely in medicaldiagnostics. The CAT (Computer Assisted

Tomography) seen employing X-rays passingthrough any part of the body, especially brain, toform a three-dimensional image of ultrasound hasbeen used successfully to give tomographic imagesof liver, kidneys etc. Motivated by a desire to studyocean currents, and following similar principal asCAT Scan,Walter Munk of Scripps Institute ofOceanography and Carl Wunch of MassachusettsInstitute of Technology formulated the basic theoryand design which crystallised as a practicalmeasuring tool. This has now become anindispensable sophisticated instrument in the handsof the modern oceanographer and has been used inocean current studies.

Development of marine instrumentation is stillin its infancy in this country. In view of the needfor specialized instrumentation for oil and mineralexploration, and for new research programes to beundertaken, there is an urgent need to encourageresearch and development and manufacture ofmodern sophisticated ocean instruments, ifnecessary, by adopting liberal and flexible policies.

PHYSICAL OCEANOGRAPHY

Having reviewed the structure and origin of theOcean basins and the modern techniques designedand developed for exploration and scientific studyof the ocean, it is appropriate to examine now someof the physical properties of the ocean and the partplayed by them in ocean currents, ocean energy,coastal erosion, marine life and marine ecosystem.The water wealth of the world is unevenlydistributed with 97.3% in the ocean and the rest2.7% on the land of which almost 85% is contributedby fresh water in glaciers and ice caps which arethe largest fresh water resources on land.Undoubtedly, detailed studies of the spatial andtemporal variations of the basic physical parameters,such as temperature, salinity, density, surface andphysical parameters, such as a temperature, salinity,density surface and deep ocean currents will lead toa better understanding of the physical processestaking place at the interfaces between ocean water,ocean bottom, atmosphere and coastal land.


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To the naked eye, it appears that only thesurface of the ocean is distributed by waves and isin perpetual motion, but the fact of the matter is themass of ocean water is far from being at rest.Indeed the gigantic mass of water in the ocean is inperpetual motion and constitutes a complex systemwith several physical and chemical variableschanging rapidly in space and time. While oceansurface currents are mainly driven by wind at asurface, the origin of ocean currents at differentdepths can be traced to several sources such asrotation of earth, changes in position of moon andsun relative to earth, energy generated by solarradiation, and other additional sources of energylike earthquakes, tsunamies, volcanic eruptions,water and sediment transport from rivers etc.

The characteristic feature of the ocean is itshigh salinity which make it the richest source ofnumerous elements and minerals. Over millenia ofyears, ocean have accumulated salt from the landbrought by rivers and became highly saline. Wateris unique in the sense that it is a good solvent andas such many salts are present in it in a dissolvedstate. However, it is interesting to note that therelative concentrations of various salts remainsurprisingly constant inspite of the systematic andrapid decrease of the total salinity with depth. Thezone up to a depth of 500-1000 feet where there isa continuous decrease of salinity with depth iscalled halocline. Below this depth salinity remainspractically constant. Estimates of salinity of seawaterare make by chloride ion concentration which iseasy to measure in the laboratory or on boardocean-going research vessels.

Salinity of the sea has a profound effect onphysiology of marine organisms which depends onthe nature of the biological members. By a process,known as osmosis the body fluid of the marineorganism interacts with the saline water in the seaand attains an equilibrium, enabling the fish tosurvive the salt water environment. Unless adoptedto the freshwater environment, salt water fish wouldnot be able to survive in low salinity water orfreshwater as it tends to inflate the animal with an

inflow of freshwater in order to equalise theconcentrations.

Sea surface receives enormous quantities ofthermal energies of the sun which varies withlatitude reaching maximum in the tropical waters.The average surface temperature variation withlatitude shows that the sea in the northernhemisphere has generally higher surfacetemperatures than that in the southern hemisphere.This asymmetry is smaller in the northernhemisphere.

Oceans, constitute a huge reservoir for storingenergy compared to the solid earth whose heatcapacity is four times smaller. Consequently, thevariation of temperature on the land is four timesthat on the sea. Examining the spectrum of lightenergy from the sun impinging on the ocean surface,it may be noted that most of the energy which is inthe ocean. In particular, the amount of solar energywhich penetrates below a depth of 100 metres ishardly one-fiftieth of the total incident energy.While the surface of the ocean absorbs andassimilates rapidly almost all the solar energy, butthe mechanism of transfer of this heat into thedepths of the ocean is relatively slow and complex.In fact, deep in the ocean, below a few metresdepth, the diurnal variation of the temperature isrelatively very small, unlike the relatively largervariation observed on the surface. Indeed, at depthsbelow thousand metres, the temperature is of theorder of 1–2°C, which is maintained through thedeep ocean. Surprisingly the temperature at thesedepths even at the equator is largely determined bythe water from the polar region which sinks andgets transported to the temperature and topicalregions.

The surface of the sea is highly saline and hencehas lesser surface tension which makes it easy forthe formation of froth and foam when waves breakup near the coast. The process of formation andbreaking up of waves result in the formation ofenormous quantities of foam and tiny droplets ofwater, containing dissolved salts and organic matter


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from the surface of the surface of the sea. These arecalled aerosols. The wind and the generalatmospheric circulating system carries the aerosolsto high levels and disperses them till they condenseinto tiny crystalline ice particles. It is thereforeobvious that rainfall in coastal areas containsubstantial amount of sodium chloride.

One of the most interesting results of oceanscience is the great abundance of carbon dioxide inthe dissolved gases beneath the surface of theocean, being nearly four times the concentration ofnitrogen and nine times that of oxygen. Thus, eventhough, the atmosphere and ocean constantly interactwith each other, strangely the composition of gasesin the ocean is totally different from that in theatmosphere where nitrogen is four times oxygenand carbon dioxide is an insignificant minorconstituent. Indeed, it is the predominance of carbondioxide in the dissolved gases which explains thegreat abundance of biological life in the ocean ascarbon dioxide is the most vital and essentialingredient for the growth of marine organisms.When this abundant quantity of carbon in the formof carbon dioxide in ocean waters is supplementedby a rich wealth of nutrients, and the entire volumeis illuminated by radiation from the sun, marineplant life multiplies rapidly by photosynthesis andinitiates the series of food chains leading to a richharvest of higher forms of marine life. Oxygen,which is rich in the upper strata of the ocean iscontinuously depleted by marine organisms and assuch the concentration reaches a minimum at alevel where the biological life is in great abundance.

Man has always been fascinated by theinnumerable variety of waves observed on ponds,streams and oceans. Little did we realise that allthese waves have one common feature that they donot transport the water but only the energy.Atmospheric winds interacting with the surface ofthe ocean give rise to complex system of waveswhich propagate over long distances over the oceansurface with little loss of energy. Among the widespectrum of waves thus generated, those with longer

wavelengths travel faster and further than the shorterwaves. Hence, the more complex and high amplitudewaves generated in a thunderstorm arrive at thecoast travelling several thousand of kilometers as a“swell” which contains mainly the long waves, theshorter ones having been dissipated on the oceansurface. Unfortunately, scientists have not yetunravelled the mechanism of the transfer of energyfrom the wind to the surface of the ocean and assuch considerable theoretical and experimentalworks has yet to be done to be able to predictprecisely the high of the “swell” which crosses theshore as a greater storm surge in a severe thunderstorm or a cyclone causing collosal damage to lifeand property.

So far no reliable and simple method formeasuring ocean wave heights was availableparticularly at large distances away from the coast.Recently, a new radio method of estimating thewave heights has been developed using highfrequency radiowaves beamed towards the oceansurface from a high elevation on the coast. Suchradiowaves reflected from the wave fronts reinforceeach other to give a strong return signal when thewavelength of the radiowave is a multiple of half-wave length of the sea wave. One of the latest andimproved versions of this technique, known as thesky-wave radar, enabled ocean scientists to sendradiowaves bouned forward by the ionosphere tostrike the ocean surface at a great distance of 2000-3000 km. These radio signals retrace their path andare received back after reflection from the oceanwavefronts with appreciable single strength at anappropriate frequency of the radiowave. The skywave Radar has enormous potential is a powerfultool for scanning large areas of ocean at greatdistances and measure the ocean wavelengths.Indeed, this technique can also be used formeasuring the wave heights in the cyclonic regionon the ocean and send warning signals to be thelowlying coastal areas in case the wave heights areso high as to give rise to a devastating storm surge.Improved and sophisticated versions of thistechinque could be used to detect and watch


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movements of fleets of vessels which will beparticularly valuable in defence applications.

Unlike the waves, which are purely surfacephenomena, the wind on the surface also generatessurface currents which involve literally the transportof ocean water unlike the waves. Ocean circulationis also influenced by the 24-hourly rotation of theearth and also by the gravitational pull of the sunand the moon. The Coriolis effect of the earth’srotation on the sub-surface currents in the oceanresults in a clockwise deflection in the northern andanticlockwise in the southern hemispheres in thetropical zone.

While every one knows the difference betweenclimate and weather very few, including scientists.realise that a similar distinction applies to oceancurrents. As advanced techniques were not availabletill recently, we have known so far only the averagefeatures of the ocean movements which we maycall “climate” circulation. With the moderntechniques, it was shown that there is a fine structuresuperposed on this chlimate circulation which variesfrom day-to-day like the weather and which cannotbe easily predicted. Synoptic charts of ocean currentsare narrow, fast and winding, while the climaticmaps are smooth, broad and slow. The later areused for long-term studies of the effect of oceancurrents on coastal erosion and climatic conditons,whereas the synoptic maps are used to pilot shipsand submarines to follow the currents to gain inspeed. The current system in the ocean, like thewind system, tends to circulate and form gyreswhich follow generally the wind circulation. Thetheory of ocean circulation developed during lastthirty years, explains reasonably well theexperimental data. Model studies in the laboratoryhelped scientists to simulate the formation ofcurrents like Gulf Stream in North Atlantic,Kuroshio in North Pacific and Agulhas in IndianOcean. Some of the detailed studies on Gulf streamindicated that occasionally the main stream forms asmaller loop of a few hundred kilometers whichbreaks off and separates as an eddy and graduallyweakens. The spectacular discovery involving

sometimes transport of tens of millions of tons ofwater from North Atlantic to sub-tropical regionsalong with its living organisms is of considerableimportance to the biology of the sea. Such eddiesconstituted the biggest natural transport of part ofthe ocean along with its marine organisms andecon-system. Another major finding is that the Gulfstream is not one single stream like a river butconsists of 2–3 filaments each having its own speedof flow. It is like having three rivers in the oceanflowing at different speeds and carrying differentvolumes of water. The fine structure of the oceanweather is a new phenomenon which has no parallelin the atmospheric weather.

Deep sea circulation in the ocean is an importantand interesting phenomenon. Basically the coldcondensed water around the polar caps sinksdownwards and propagates towards the lowerlatitudes along the ocean bottom. In fact, the coldand condensed water from the Antarctic flowstowards the north and even crosses the equator toflow into the northern hemisphere. Such deep seacurrent systems are prominent in the Atlantic seawhere they stretch from the north pole to southpole without being intercepted by any large landmass. On the other hand, the Pacific ocean isalmost cut-off from the Arctic sea by North Americaand East Asia except for the narrow channel knownas Bering Canal. This land mass acts as a barrierpreventing the cold Arctic water moving southwardsinto the Pacific ocean.

One of the obvious effects of ocean currentsnoticed all along certain coastal areas is the erosionand accretion. Over years and perhaps over decades,we witness a continuous erosion of beaches on theshore as sea advances inland threatening the coastaltowns. Such phenomena are noticed in many coastaltowns like Visakhapatnam. A detailed study of thesubsurface ocean currents with special reference tothe speed, direction, volume of flow and diurnaland sessional changes may throw light on theorigin and nature of ocean currents and theirinteraction with the coastal landmass. An in-depthstudy of these physical interactions by


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oceanographers may ultimately lead to a solutionto such problems of great national importance andresult in the saving of valuable property, buildings,structures and even harbours along the coast. Tocite an example, nearly half a centrury ago,engineers noticed rapid silting of the entrancechannel of the natural at Visakhapatnam port andthey were completely baffled by the giganticproblem of clearing the silt from the channel andthe enoromous cost involved in the gigantic task. Itwas late Sir Mokshagundam Visweswarayya whogave an extremely simple solution to this problemby suggesting two condemned old ships to be sunkin the sea a little ahead of the entrance to thechannel with a view to deflect and divert thecurrent systems from entering the channel andblocking its passage with sand and silt. At a timewhen ocean currents and their behaviour was notwell understood for want of data, it was the geniusby Dr. Visweswarayya which found a practicalsolution thus saving crores of rupees of expenditureincurred on clearing almost continuously the harbourchannel of the accumulating silt by specialmechanised vessels.

OCEAN AND THE ATMOSPHERE

The climate of the earth is intimately connectedto the ocean through the atmosphere which servesas the common canopy for both, thus transferringenormous quantities of water vapour, energy andmomentum from the sea to the land. Extensivestudies have been undertaken jointly by themeteorologists and oceanographers on the air-seainteraction with a view to improve our understandingof the world climatic conditions and even to makeshort-term weather forecasts. Such studies willultimately enable scientists to predict climaticchanges over longer periods thus enablinginternational organizations and different countriesto face the challenge of disasters like droughts.Perhaps, the time is not far away when scientificstudies over much longer periods will throw lighton major climatic upheavals like ice ages.

It is now well-established that the ocean surfaceof 1 cm thickness known as surface micro-layer

plays a crucial role in air-sea interaction. Detaliedstudy of this layer is important in meteorology,agriculture and pollution. This micro-layer transfersnot only energy and water vapour but also richnutrients like nitrogen, phosphorous and potassiuminto the atmosphere. Oil spills and other pollutantsover the ocean, concentrate in this micro-layer andfinally enter into the food chain through marineorganism which are eaten by the fish.

Ocean being a large reservoir of momentum andenergy, the response of the ocean to inputs is muchslower when compared to that in the atmosphere.Ocean is therefore referred to as the memory of theatmosphere. It is now generally accepted that theSomai current, flowing northwards along the coastof Kenya and Somali, initiates the summer monsoonone month later. Meteorologists and oceanographershave yet to unravel the cause for the delay. TheSomali current however reverses and flowssouthward during northern winter. It is generallybelieved that the lowering of temperature over theArabian Sea from 28° to 25°C resulting fromSomali current triggers off the summer monsoon,as a significant correlation was observed betweenthe drop in surface temperature of Arabian Sea andrainfall one month later during June-August period.A remarkable new observation by Sri Gilbert Walkerrevealed a world-wide southern oscillation,accompanied by high pressure over the Indianocean associated with low pressure over Pacificand vice versa, the intensity changing from year toyear markedly. This large global oscillation seemedto be linked with El Nino, a recurrent phenomenoninvolving replacement of cold upwelling nutrientrich current by hot tropical current off the coast ofPeru, resulting in failure of normally bountiful fishharvest. It is not clear to what extent El Nino isrelated to the global oscillation, but it is certainlyremarkable that the failure of monsoon in ourcountry in 1972 coincided with the El Nino of 1972indicating the possible connection between the two.

In any study of the ocean currents, one cannotignore the complexity of the pattern of circulatingcurrents which are widely varying from ocean to


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ocean. It may be noted that the climate, marineorganic life, coastal erosion and such other physicalfeatures are largely dependent on the surface currentsas well as ocean bottom currents. A well-knownexample of surface current system is the GulfStream, which has its origin on the surface of warmtropical waters and converges along the Floridacoast as a warm water current system. Proceedingfurther north, the Gulf Stream branches off intoNorth Atlantic current along UK and western Europeand move southwards as Canary current along thecoast of Spain and west Africa. It is well-knownthat the North Atlantic current which brings warmwaters exerts considerable influence on the climateof western Europe, particularly Britain andScandinavanian countries in the winter season.Oceans which are the giant reservoirs of water withall its rich biological and mineral wealth servemankind by providing salubrious climate both inthe hot tropical regions and cold north temperaturezones by the massive transport of cold ocean bottomcurrents from poles to the equator and hot streamnear the surface from equator to the poles. Indeed,nature has its own way of balancing the opposingforces and extremes of climate by a system ofnatural forces which tend to compensate extremitiesin climate. Let me express a word of caution thatany attempt to disturb the natural ocean equilibriumby such grandiose schemes or projects proposedsuch as building a dam across the Bering strait toserve as a major source of energy, may lead toserious imbalances in the climate and oceanecosystem.

One of the greatest challenges posed by theocean is the devastating effects due to cyclones,storm surges and Tsunamis which have their originin the ocean. Different parts of our countryparticularly adjoining the Bay of Bengal aredevastated frequently by cyclones and consequentstorm-surges at various locations on the sea coast.Similarly, every year all over the world hurricanesroaring Atlantic or Pacific Oceans invade the mainland destroying life and property over extensiveareas. The violent and whirling storms known as

cyclones and hurricanes begin as a comparativelysmall storms at sea and gradually begin to grow togiant sizes of the order of 150 kms and move fastas roaring monsters. The world weather watchcentres in various countries trace these events byrecording and studying cloud pictures transmittedby weather satellites such as TIROS and NIMBUS.Thus cyclones and hurricanes brewing anywhereover the vast oceans are detected and early warningis given to all affeted countries. During the last twodecades, cloud seeding attempts were also madesuccessfully to precipitate the clouds in cyclones tominimize their fury. Much of the damage to coastalareas caused by cyclones is due to what is knownas storm surges, giant waves which build up alongshallow coastline areas to great height of 3–10metres and moves like a wall of water inlanddevastating all life and property in its path. Theworst storm surge struck the north coast of Bay ofBengal in 1970 killing 25,000 people. RecentAndhra cyclones in 1979 and 1981 involving stormsurges of 3–4 meters, caused great havoc loss oflife and property. All these storm surges weretracked by satellites, but timely warning could notbe given to the affected areas.

Of all the ocean events the most destructive isthe “Tsunami” (a Japanese word for harbor andwave) which is a giant wave of great heightgernerated by an underwater earthquake. Tsunamishave caused great havoc in Japan and Hawaiinislands. Earthquakes associated with subductionzones on Pacific ocean floor make the incidence ofTsunamis highest there. Tsunami is a phantom atsea consisting of a giant wave, several miles long,which travels at great speeds of the order of 800km per hour. Sailors in the ships and fishermen donot notice this even if it passes right under their seacraft. The destructive power of the Tsunamis isnoted only when it reaches shallow water along theshore and travels inland as great wall of water 10-30 m high leaving death and destruction along itstrail. Recorded evidence exists of Tsunamis of even30 m travelling inland over several miles. Althoughseismic sounders give location of the epicentre of


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the earthquake, this alone is not adequate. Aningenuous electronic wave-guage invented by Greenwas found to be extremely sensitive to detectchanges in water level of 0.02 feet of water. A largenetwork of such guages deployed near knownTsunami centres telemetres the data and warningsignals to main control centres taking prompt action.Ionospheric physicists have also discovered a newtechnique for detecting and tracking the travellingionospheric distrubances induced by the Tsunamis.

Far from the tropical seas Science has found asolution for another sea menace, namely, the largeicebergs drifting slowly along shipping lanes causingdisaster as it happened to Titanic on its maidenvoyage in 1971. It is estimated that almost 7500sizable iceberge breakoff, from Arctic glaciers alongthe coast of Greenland and start their menacingvoyage down south. Today, International Ice Patrolkeeps track of icebergs by Radar and dyeing it towatch its progress. Satellite imagery is also used todetect icebergs particularly during dense fog.

In any study of the ocean-atmosphere interaction,we can not ignore the role of carbon dioxide and itsshort and long range effects on the global climate.The total carbon dioxide in the earth’s presentatmosphere is 2300 billion tons which is 0.03percent of its total mass. However, this quantity isalso dependent on the amount of carbon dioxidewithdrawn or supplied from the oceans, rocks andliving organisms. The total carbon dioxide in theocean is fifty times as much as in the air, but mostof it is present in carbonate compounds. Being arich reservoir, ocean acts as a damper for thefluctuations of carbon dioxide in air. Whenatmospheric concentration of carbon dioxideincreases ocean tends to absorb the excess. When itfalls, the ocean replenishes it. Also volcanoes in theocean replenish it with more carbon dioxide whereasweathering of the rocks depletes it.

It may be of interest of note that ocean comesto the rescue of the atmosphere whenever there isan imbalance in carbon dioxide. In the last 620,000years of current glaciation period, about ten distinct

temperature cycles were observed in oceansediments which can be explained on the basis ofcarbon dioxide exchange between ocean and air. Ifthere is a lush growth of vegetation on land takingup large quantities of carbon dioxide, after sometimeequilibrium with the ocean reduces the atmosphericconcentration to nearly half its original value andthe average temperature or earth falls by 6.9°F.This drop will cause glaciers to spread and oceansto shrink, resulting in slow release of the excesscarbon dioxide from the ocean into the atmosphere.This will again raise the temperature and restorethe carbon dioxide in the atmosphere to the originalvalue. So long as the atmospheric carbon dioxidein the ocean–atomosphere system remains unaltered,these cycles repeat producing the well-establishedtemperature cycles.

During the past century, activities of maninvolving burning of fossil fuels has seriouslydisturbed the carbon dioxide equilibrium of theearth. Annually six billion tons of carbon dioxide isadded to the atmosphere by the fossil fuels andanother 2 billion tons by agricultural operations.The eight billion tons increase in the carbon dioxidecontributes to a large increase in plant life and isalso partly absorbed by the oceans. Theoreticalstudies indicate that the carbon dioxide dissolvedin the ocean establishes equilibrium with the carbondioxide in the atmosphere in approximately 1000years. During this long preiod oceans take up onlyhalf of the carbon dioxide added to the air. Overmuch longer period oceans can take up much largeradditional quantities of carbon dioxide in the formof carbonate compounds before the ocean-air systemattains equilibrium.

Estimates of the fossil fuels consumed in theworld each year show that in the past 100 yearsman has added 360 billion tons of carbon dioxideto the atmosphere resulting in 13% increase incarbon dioxide to the atmosphere. Such an increaseshould raise the average temperatue of the earth by1% F. This is exactly the average increase recordedall over the world during the past century.Extrapolating these figures to the year 2000 A.D.


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the average temperature of the earth should raiseby 3.6% F. If the consumption continues to increaseat the current rate for another thousand years wewould have exhausted all our known reserves ofcoal and oils and the carbon dioxide in theatmosphere would have increased 18 times.However, after ocean-atmosphere system attainsequilibrium, there will be ten times carbon dioxidethan it is today resulting in the earth being 22°warmer than at present. Such a large addition ofcarbon dioxide to the ocean will undoubtedlyincrease the acidity and pH of sea water. This maynot disturb the future marine life, but certainly forman it will be most uncomfortable to live on thisplanet. During the next half a century, it should bepossible to test conclusively the theories of climaticchange and take remedial action if mankind has tosurvive the onslaught of this ecological crisis.

There are several international co-ordinatedresearch programmes such as InternationalGeophysical (IGY), International Quiet Sun Year(IQSY), Middle Atmosphere Programe (MAP),Global Atmospheric Research Programme (GARP)and Garp Atlantic Tropical Experiment (GATE)which undertook world-wide experimentalprogrammes involving ocean-atmosphericinteraction with world-wide coverage. The recentmonsoon experiment (MONEX) in the Indian oceaninvolving participation by several countriessucceeded in obtaining a vast wealth of data whichis awaiting deatiled analysis and study. In most ofthese International coordinated experiments, besidesresearch vessels which are fully equipped withmodern scientific equipment, aircraft were alsoused increasingly to collect data at a faster rate.

CHEMISTRY OF THE OCEANS

The ocean as a chemical system is very complexas it has a very large number of chemicals in theform of salts. Cheimcal oceanographers have beenstudying the various chemical reactions with aview to understand and exploit these rich resources.In spite of the large number of elements and saltspresent, one of the important principles in chemical

oceanography known as Forchammer’s Law ofRelative proportions establishes that ratio of all themajor elements in the ocean remain same,irrespective of where the sample is collected fromthe sea. In recent times, chemical oceanographersare paying considerable attention to investigateocean pollution with special reference to the levelsof pollution, their origin and remedial measures.

At the outset, it will be relevant to outlinebriefly the techniques employed by chemicaloceanographers. Most of the studies made bychemical oceanographers were carried out on seawater samples collected by the Nansen Bottle whichhas special valves at either end and containsthemometres to record the temperature at which thesample is collected. Samples thus collected areanalysed for their chemical composition in thelaboratory in order to understand the chemistry ofocean waters. Chemists now-a-days usesophisticated instruments such as atomic absorptionspectographs for measuring gaseous and organiccontent and amino acid analysers to detect andmeasure protein content. Currently chemicaloceanographers have been able to use extensivelyradioactive isotopes to estimate the rate of depositionof marine sediments.

96.6% sea water is pure water and only theremaining 3.4% contains dissolved salts. The bulkof dissolved salts in sea water consist of six majorelements—chlorine, sodium, magnesium, sulphur,calcium and potassium. Seawater contains also otherelements in minute quantities, the levels ofconcentration being 1–100 parts per million.Strontium, bromine, boron, iron and silicon aresome of the minor elements present in sea water.Trace elements of less than one part per million arecontrolled significantly by biological activity. Aremarkable property of marine organisms is theirability to attract, absorb and assimilate many of thetrace elements in the sea-waters. For example,plankton absorb several trace elements. Somevarieties of sopnges have the ability to concentratenickel in their body.

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Elements, such as carbon, oxygen, nitrogen andphosphorus are indeed essential for the survivaland growth of living organisms as they form thebasic nutrient elements. In fact, these elements areavailable in the form of compounds such asbicarbonates, phosphates and nitrates dissolved inwater. At shallow depths, where there is abundantlight, the basic elements carbon, nitrogen andphosphorus are removed from these compounds byphotosynthesis. In very deep waters, where theamount of light available is negligible, the bacterialactivity comes into play to destroy organic matterwhich is brought back into ionic sea water. In thisway, there is a closed cycle of photosyntheticactivity, followed by bacterial degradation whichessentially maintains the basic ingredient for thesurvival of life in the ocean. No wonder, the organicmatter in the ocean has low concentrations at thesurface and increases with depth.

In view of the continuous contact of theatmosphere with the sea surface, sea water containsseveral gases, especially oxygen, carbon dioxide,nitrogen and noble gases such as argon, helium,neon and radon. Near volcanoes under the sea,hydrogen sulphide is present in abundance. Oxygendissolved in sea water is made available chemicallyby photosynthesis of plants in water at or near thesurface. Oxygen is also consumed rapidly for thedecomposition of organic wastes, plants and animallife that tends to sink to the sea floor. Ocean is therichest source of oxygen for replenishing theatmosphere. On the other hand, nitrogen in the seaplays a vital role as it helps to synthesise complexprotein molecules which are vital for the growthand reproduction of all organisms. Marine organismsalso excrete complex nitrogen compounds whicheventually decompose under the action of bacteriainto simpler chemical compounds. Of all thedissolved gases in the ocean, carbon dioxide playsa very prominent role in the sustenance of life inthe ocean. The oceans contain 130 trillion tons ofcarbon dioxide, of which only a small fraction isdissolved in sea waters, the rest being present inthe form of lime stone, lime sediments, etc. There

is a continuous exchange of carbon dioxide betweenthe atmosphere and the oceans at the air-seaboundary. Living organisms in the oceans needenormous quantities of carbon dioxide of theirsurvival and growth. It was estimated that annuallyabout 200 billion tons of carbon dioxide is extractedfrom the atmosphere by the oceans. It is well-known that carbon dioxide is continuously absorbedby the plants in the sea in photosynthesis, while itsconcentration increases by exchange with theatmosphere and gases released from the volcanoes.While, no doubt 100 million tons of carbon dioxideis depleted from the ocean by the formation offossil fuels, this is a very small fraction (0.2%) ofthe annual production of carbon by photo-synthesis.Scientists have estimated that several hundredmillion years ago, extensive deposits of oil andcoal were formed in the ocean which depletedthousand trillion tons of carbon dioxide from theatmosphere-ocean system.

A new branch of study called the IsotopeOceanography has come to the forefront in recenttimes. Using radioactive elements such as C 14 asa radioactive tracer, oceanographers developed aninteresting method of determining the rate of deepsea circulation. Ocean circulation studies have thusbecome possible by using C 14 as radioactivetracer to estimate the time of traverse. By followingsuch techniques it was found that water at thebottom of the Antarctic which is very cold hastaken nearly 600 years to complete this journeyfrom 60° South latitude to 30° North latitude.Similarly studies have indicated that the averagespeed at deep waters as Pacific is very smalll andis of the order of 1.8 meters per hour which iscomparatively a very slow speed.

In ocean waters, the distribution of isotopesvaries widely depending on the depth and thelatitude. To illustrate this, we shall consider theconcentration of deuterium which is an isotope ofhydrogen and is present as heavy water in the sea.In the equatorial region, where the surfacetemperature are higher, the rate of evaporation of


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water from the surface is more. The heavy water,being slightly heavier than normal water, there isgreater evaporation of normal water on the surfacein the equatoral regions. This results in enrichmentof heavy water in the surface. Comparatively, thetemperature and polar regions are poorer in heavywater. There is similar accumulation onconcentration of an isotope of Oxygen (O18), relativeto (O16). Indeed the ratio (O18/O16) in ancientsediments in pre-historic ages could be used tostudy the fluctuation of temperature during the lastthree hundred thousand years.

One of the most successful applications ofradioactive isotopes is in the age-determination ofdeep sea sediments and also of the rate ofsedimentation. In this estimation of the deep seasediments, isotopes such as proactinum (Pa231) andlonium (Th230) are used.

LIFE IN THE OCEAN

The Beagle expedition of Charles Darwin andthe Challenger expedition in the late 19th centurywere historic expeditions to collect thousands ofmarine organisms. Based on these fabulouscollections a systematic description andclassification of marine plant and animal life wasmade. In the past, marine biologists were largelyinterested in taxonomic studies, but, of late, theyturned their attention to an in-depth study of themarine organisms, their biology and behaviour.

The Marine environment can be broadly dividedinto two principal regions—pelagic and benthic.Those fish which emerge occasionally on the surfaceare called Pelagic fish and those which live in thedeep sea are called Demerish fish. The Benthicregion is divided into littoral, bathyl, abyssal andhadal zones. The littoral region covers the coastalenvironment from the shore up to a water depth ofabout 200 meters. The rest of the huge mass of theocean is divided into three horizontal zones, thebathyl from 200 m to 2000 m the abyssal from2000 to 6000 m and hadal below 6000 m to eventhe bottom of deep trenches. In general thepopulation of marine organisms decreases with

depth with practically very few carnivores in thehadal region where sunlight cannot penetrate.Strangely carnivores in this region survive on deadorganisms sinking to the bottom and oxygen andnutrients brought from great distances by deep-ocean currents.

One method of classification of marine organismsis based on locomotion and habitat :

1. Plankton2. Benthos3. Nekton.

The first group the plankton are floaters orwanderers and have no means of locomotion orself-propulsion. Usually they are carried by theocean current system. In terms of numbers, thePlankton constitute the major population of marineorganisms. Plankton generally live in shallow watersabsorbing sunlight and mineral nutrients. With theexception of jelly fish and brown algae, planktonare usually microscopic organisms. Planktons, arebroadly classified into Phytoplankton andZooplankton. The phytoplankton which includemicroscopic diatoms, live generally in cooler watersand contain a lot of silicon dioxide. Where there isa dense population of phytoplankton in the ocean,the ocean, appears slimy and large quantities ofcalcium carbonate is deposited. Plankton multiplyat a phenomenal rate of 10–1000 million tones perday even in a small sea like the Sargasso Sea.

Zooplankton being a much more evolved speciesare larger and are more complex in structure, feedinghabits and behaviour than Phytoplankton. Theyhave a remarkable ability to adopt themselves todifferent environmental conditions of temperature,salinity, currents, illumination and nutrients. Leavingaside the microscopic varieties, there are two majorgroups called copepods (0.3–10 mm) andcrustaceans which are larger and are commonlyknown as krills (up to 50 mm). The latter serve asfood for certain species of whales.

There are three varieties of bottom dwellingorganisms (Benthos) : Sessile, creeping and


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burrowing. All varieties of sea weeds belong to thefirst category. Corals, barnacles and oysters whichattach themselves to some objects belong to thisclass. The commonly known crabs, lobsters andsnails are creeping variety whereas clams and wormsare burrowing type of benthos. All the evolvedspecies of fish, small and big including dolphins,porpoises and whales are Nektons.

One of the earliest classifications of sea life wasthat due to a Swedish naturalist, Corolus Linnaeus,who evolved a remarkable new scheme ofclassification of animals and plants, based onsimilarities of structure which is well establishedand known to all students of Biology.

The most abundant of the ocean plant life is theprimitive form known as algae which generallysurvive near the surface in ocean waters. Except forone variety of plant called eelgrass, ocean has noadvanced form of plant life. Blue-green algaeobserved in the Indian Ocean are rich in nutrientsand have been successfully used not only inextracting chemicals but also in enriching soilfertility by agricultural scientists working in IndianAgricultural Research Institute. Green algae usuallyconfined to shallow waters are responsible for richlimestone deposits in ocean. Red algae occur invarieties of beautiful shapes and colours and isused as the raw material for extracting agar-agar, asubstance used in food industry particularly forjellies and ice creams. Of all the algae, the mostadvanced is brown algae, familiarly known as kelpwhich settles down on the sea floor in shallowwaters. It is one of the richest sources for iodineand phosphorus.

Diatoms are well known unicellular algaeprotected by bivalved silica shells having a glassyappearance and innumerable perforations throughwhich they absorb gases and nutrients. The silicabox contains chloroplast pigments that absorb thesunlight to convert carbon dioxide and water toorganic matter. Diatoms, which are asexual,multiply at a fast rate by cell division. There is acontinuous division followed by progressive growth

in a healthy environment. Interestingly their life isshort and millions of them sink to the bottom,consolidate in due course to give diatom oozewhich is a useful natural filtering material.

Animal life in the sea is very varied anddiversified than plants in terms of shape, size, formand weight. They also live at different depths in theocean. Strangely, some species of marine animalscan survive at great depths where there is totaldarkness. The variety of animal species in theocean is indeed staggering as the total number of25,000 species range from the extremely smallmicroscopic animals like sarcodina to the giant sizewhales. I shall not attempt to describe such a largeand diverse range of animal species in the ocean.However, I would briefly refer to the crucial role ofbacteria which is one of the earliest forms of lifeknown at dawn of evolution of the earth and playa crucial role in marine ecology not only becauseof its ability to adapt and survive but also becauseof its capacity of bring about chemical and physicaltransformations in oceans and in deep sea sediments.Perpahs, bacteria are the oldest organisms whichare most extensively distributed all over the world.It is one of nature’s greatest wonders that bacteriacan survive even at the deep sea floor where thepressure goes up to thousands of atmospheres.Perhaps, the key to the understanding of the oilwealth in deep sea sediments lies in studying therole of bacteria in the formation of petroleum. Theycan do wonders like producing petrol, limestone,silicate rock and even iron deposits. Mankind’sfuture perhaps will be mainly dependent on theunderstanding and successful utilisation of bacteriain the various development needs.

Recorded evidence of unusual sonar observationsduring last war of unidentified layers at sea bottommoving up during day and down during night,could be now interpreted by scientists as due tohuge shoals of small fish and crustaceans etc.Which move up and down seeking light at thelowest limit of penetration of sunlight penetratingthis layer by using submersibles like Alvin, marine


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scientists discovered new forms of marine life somecarrying their own headlights and some havingluminescent organs. Thus, in deep sea, we findmany fish which have the capacity for self-illumination.

In recent years, several expeditions of marinescientists exploring the deep V-shaped valley ofMid-Atlantic Ridge, East-Pacific Ridge andGalapagos Rift, led to the discovery of many newforms of marine life surviving in the dark depths ofthe ocean by a totally new biological processunknown to man. Setting foot on these unexploredhot volcanic surfaces for the first time, marinebiologists discovered sea life similar to clams,crabs, mussels and unusually long carnivorous tube-worms which constitute an entirely new system oflife perhaps belonging to a new Phylum. In thewarm waters above the ridge hydrogen sulphidegas released from the volcanic rocked supports anentirely new species of bacteria which evolve andmultiply by a process called chemosynthesis processtotally different from photosynthesis. The higherforms of sea life is evolved by a food chain whichstarts from this new species of microscopic bacteria.Although, there were speculations on the existenceof such new forms of life in other planets having atotally different atmosphere, such a possibility isnot even predicted as a possibility on the face ofthis planet. The “Oasis”expedition in April–May,1982, on the East-Pacific ridge off the coast Baja—California, gave ample opportunities to scientistsfrom USA, France and Mexico to extend theseinvestigations and discover many more such newspecies of marine life.

BIOLOGICAL RESOURCES

It may be recapitulated that the earth which hasbeen so lavishly gifted with the most preciousnatural resources is finding it difficult to supporteven the existing population, while the worldpopulation continues to grow and is likely to toucha staggering figure of 11 billion by the year 2100as estimated by the United Nations. Moreover, thepeople of developed societies have exploited some

of the natural resources so indiscriminately thatthey are on the verge of being completely depleted.

In such a situtation, can the sea help mankindfor its biological survival and provide him the life’sessentials so that he can lead a full and rewardinglife. From this standpoint, the importance of oceanin providing food and protein can hardly be over-estimated. If, with the application of Science theTechnology we could usher in an era of greenrevolution and slove the food problem to a greatextent in the Indian context, why can’t we harnessthe potential biological resources of the sea, perhapswith less financial power inputs but with carefulplanning, for providing rich food to millions ofpeople who are still living below the poverty line.Let us not forget that fish protein has a favourablebalance of amino acids and as such is well-suitedfor human diet.

In analysis of the food problem of the humanrace, one should not overlook the fundamental factthat over three-fourths of human settlements arealong the banks of the rivers or the coastline of theocean. Yet it could not harness adequately theocean resources for its food purposes. It is estimatedthat oceans are contributing only to three percent ofthe world’s food consumption. Fish form animportant constituent of our food, rich in proteinand we have known the art of catching fish fromtimes immemoral. However, even with all theadvances in methods of locating, harvesting andcatching of fish, fish contribute hardly to 10% ofprotein to our diet. The remarkable feature offishery resources in that they are renewable,available in abundance and are easily accessible inthat part of the sea in continetial shelf and othershallow waters which occupies only 8% of the totaloceanic area. Available data of fish harvest indicatethat approximately three-fourths of the world’s fishcatch come from the continental shelf. In addition,twenty-four percent of total fish catch comes fromnarrow select regions off the coast where thephenomenon of coastal upwelling is found. Coastalupwelling is a major contributing factor for bountiful


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harvest of fish, but occasionally events like El Ninolead to the failure of fish harvest. The Somali Coldcurrent upwelling, off the north-east coast of Africa,has similar effect of bountiful harvest occasionallypunctuated by a sharp fall. It is striking to note thatrecent experimental studies have established that,by pumping nutrient-rich cold deep water to thesurface, an artificial upwelling can be created forintensifying the fish productivity. By using suchnew scientific techniques, recurrent failure of fishharvest in the well-known upwelling areas couldeasily be avoided or mitigated.

There is a Chinese proverb which says : “If yougive a person a fish a day, you are giving him ameal for the day, but if you teach him how to fish,you provide him meals for the rest of his life”. Thisclearly underlines the significance of the art of fishfarming for intensifying the productivity of fish.The singular factor involving fish farming relatesof the identification of their locational aspect. Theoceans are endowed with about twenty-five thousandvarieties of fish and their number is estimated to beseveral billions. A number of studies conducted onthe different varieties of fish in the context of thefollowing variables : movement feeding andspawning habits and their response to the stimulusby various electrical currents and sound waves,have revealed that it is possible to develop scientifictechniques and devices for havresting them. Whiledeveloping the scientific methods and tools for fishharvesting, we must consider the parameter of cost-benefit analysis and ensure the conservation andmaintenance of our ecosystems. The sound producedby each species in the ocean, if scientificallyunderstood and perfected could perhaps becomeone of the major variable in the process ofidentification of the fish zones. Scientists havediscovered that sea is literally filled with soundproduced by the wide variety of marine species.Experiments in marine laboratories established thatalmost 80–90% of marine fish produce detectablesounds in many ways which can be deciphered inorder to understand the language of the fish. Whenscientists succeed in understanding these sounds

produced by each species, he can put this knowledgeto use in order to attract or drive the fish intofishing boats.

Modern Science had developed specialtechniques using sonars fitted to fishing trawlersfor detecting large shoals of fish to collect a bighaul. According to a well-known observation somevarieties of fish will swim along a course of strongcurrents and are irresistibly drawn towards thecurrent electrode. Fish generally tend to followwarm water currents and as such infra-red detectorscould be used as a handy tool for indicating thepath of fish shoals. In future, it may be possible touse satellites from outer space for locating the fishconcentration in the sea. Researches carried out inthe Woods Hole Oceanographic Institution revealedthat a variety of sounds could be employed duringthe fish catching operations. Say, for example, thesounds which frighten fish especially of predatorscan drive whole shoals of fish towards fishing craftawaiting with their nets. Chemicals could also beused successfully to guide salmon fish to theirspawning grounds in a river. Fish are found to beallergic to air bubbles and this device was usedsuccessfully by many oceanographers to keepmillions of fish in confinement with the aid of anartificial closed curtain of air bubbles. Such airbubble enclosures could be formed even on highseas by floating platforms off the shore.

Scientists, using ultrasonic signals sent throughunderwater sources, have succeeded in establishingcommunication process with the porpoises, dolphinsand even whales. This device has proved to beimmensely useful in the fish catching operations. Itis well-known that dolphins were trained to help inrescue missions to transport tools to divers at workunder sea. Porpoises have been successfully trainedto do acrobatics better than man. Although scientistshave not get perfected such high level training tocommand the services of these mammals, there isgreat scope for research work in this field.Futurologists are speculating on the enoromousfuture potential of ocean ranching of fish of 200-


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300 species, which are presently caught for food,by using dolphins as “aqua-cowboys” to herd shoalsof fish to fertile grazing grounds in the samemanner as well-trained dogs were used on land-based ranches. There are enough evidences toindicate that man has yet to learn the scientificmethods and devices for harvesting the fish in ahealthy fashion. Any attempt on our part to over-exploit them would be likely to endanger thereproduction and ecology of fish species. In such asituation, it is necessary to explore and employappropriate technologies which are ecologicallyoriented to maximizing the fish-farming.

There is another dimension to the problem whichshould not be overlooked in the developmentalprocess of fish-farming. The problem stems fromthe fact that the mortality rate of fish is highest inany living species. To take an example, the survivalrate of fish from the moment of spawning till theyreach the size of 2′′ in the case of mackerel fish isas 4 in a million. This extraordinarily high mortalityis due to the lack of protection from predators,incidence of disease, non-availability of food andinclement weather on the high seas.

Of all the countries in the world, Japan is themost advanced country in the matter of modernizedfish-farming. It would be appropriate to look atbriefly the mariculture, which has been defined asa technique of cultivation of sea life in confinementprotected from predators and inclement weather.The Japanese and Chinese have used this techniquefor cultivating pearl oysters over several centuries.Mariculture has also been employed extensively tocultivate mussels, scalps, shrimp and a small numberof fish including carp, salmon, trout, catfish, tunaand others. In spite of the new technology,mariculture has not been adopted widely all overthe world. The total worldwide maricultureproduction is only two million tons which is 4% ofthe total world catch. In recent years, the CentralFishery Research Institute at Cochin and the CentralInstitute of Fisheries education at Bombay havesuccessfully reared prawns in salt water tanks. In

Australia, oysters are grown on wooden sticks. InSpain, the mussels are reared on ropes which arehooked and lowered in to the water. It is Interestingto note that given the same kind of care andplanning a brackish pond yields three times aslarge a yield as an acre of land in agriculture.

In all fishing operations, there are innumerablevarieties of trash fish (50%) which are thrown asuseless although they are edible. Scientists havedeveloped a method of making this trash fish intofish protein concentrate (F.P.C.) which is the hopefor the protein-hungry world. This concentrate couldbe in the form of colourless and odourless whitepower-like wheat flour and can be produced at acost of almost one rupee per pound.

In a world faced with a shortage of 20 milliontons of protein, it is possible to produce largesurplus of vital protein which is twenty times thepresent yield by application of scientific methods.The world’s resources of smaller and larger fishwill be approximately 200 million tons. It wasestimated that at the end of the last world war, theworld’s annual catch was 20 million tons whichincreased to nearly 70 million tons by 1970.Thereafter the increase had been gradual. Accordingto UN indicative world plan the annual fish catchby 1985 could be 100–200 million tons. However,the exploitation of fishery resources of our oceans,without taking care of their replenishment shouldnot be overlooked. The artificial hormone treatmentand other methods of fish spawning and piscicultureare imperative not merely for the steady supply offish food but also for the maintenance of a naturalequilibrium in the ecosystem.

The most important fishing areas of the worldare North American waters, North Sea between UKand Europe, South American waters, Indian Oceanand East Asian waters. Of these Waddel sea inScandinavian region, waters off the coasts of Peruand Chile and parts of the Indian ocean areextremely rich in fishery wealth. East Asian watersare the most intensively fished in the world. Theproportionate fish catch in various oceans of the


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world was : Pacific Ocean 53%, Atlantic Ocean40%, Indian Ocean 5% and Mediterranean 2%.Thus, within the total world catch, the major OceansPacific and Atlantic together contribute 93%Although, fortunately, India has a large coastline,the total production of fish in 1981 was only 2.4million tons of which 1.4 million tons is from thesea and 1.0 million tons is from inland waters. Ourexport earnings for the same year is around 290crores for 75,000 tons of fish exported.

Seaweeds which are generally considered anuisance could offer a solution for the hungrymillions as an alternative for food because of theirhigh nutritional value. Seaweeds could be used ina variety of ways for food, pharmaceuticals, textilepurposes. For example, Algin, Carrageenin andagar are three major substances which are extractedfrom seaweed and are used in a variety of ways infood preparation, such as icecream, malted milk,cheese, chocolates, puddings and salad dressingsuch as mayonnaise. Apart from these, there aremany other varieties of seaweeds which can beused as food, fertiliser and even biomass. At present,the cost of harvesting and processing seaweeds ishigh but scientists could find out ways and meansto cut down the cost and increase the availability ofseaweeds. The future of seaweed farming is verybright. Japanese scientists have successfullypioneered sea-weed cultivation extensively usingsimple designs and could harvest as many as sixcrops per year.

It is estimated that the total annual yield ofseaweed in the country is 50,000 tons and mayreach one lakh tons if all the seaweed resourcesalong the coastline are explored and utilised.Considerable work has been done on seaweed inthe Central Salt and Marine Chemical ResearchInstitute and Central Marine Fisheries ResearchInstitute and National Institute of Oceanographyand Andhra University on various aspects ofeconomically useful seaweeds. Scientists in ourcountry should take up urgently development offast-growing, high-yielding and protein rich varieties

of seaweeds suitable for aquaculture. Efforts shouldbe made to prevent pollution of low-lying seaweedgrowing areas. Seaweed industry should beencouraged and be treated as a part of ruraldevelopment programme for poor people livingalong the coast.

Apart from the sewweeds, there is a far richersource of seafood namely plankton, the microscopicplants and animals that abound in sea water inmillions turning it into a rich nutritious soup. Thereare two varieties of plankton—phyto plankton andzooplankton. The most numerous type of thiszooplankton are called copepods. The wide diversityof animal life among the zooplankton is staggering,as such a diversity is not seen in any realm of life.They are enormous in their numbers. The totalnumber of copepods in the world in much morethan all multi-celled creatures combined, includinginsects. These copepods feed on phytoplanktonwhich is the first food chain of the sea. The nextchain is created when small fish eat the zooplankton.The final food chain is the one in which larger fishlike tuna, shark etc. consume smaller fish. There isa colossal loss of food almost 90% at each stagewith, the result a thousand pounds of diatoms willultimately lead to 1/10 pound of tuna.

Detailed and quantitative study of the data ineach stage is useful in estimating regional andglobal food resources. Scientists are now deeplyconcerned about cutting short these heavy losses inthe food chain by evolving methods of directlyturning the plankton into food so that the vorld’sfood supplies may be considerably enhanced andutilised for the grossly over-populated world oftoday. This involves extensive studies in thelaboratory to convert the plankton powder tohamburger-like meat, which may be very tasty. Atthe present stage of progress in plankton-foodtechnology, the cost of such products is high mainlydue to high cost of filtering plankton from seawater. To illustrate, it would be necessary to filterabout 15 million tons of water to get 50 tons ofplankton which is not a cost-effective process.


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Scientists are trying to tackle this problem followingnature’s own system of filtering as it exists, forinstance, the blue whale which needs a millioncalories a day, all of which comes from planktonwhich she picks up as it moves through the water.Perhaps by the end of the decade techniques willbe developed and perfected to collect a steadystream of plankton as the ships move along on highseas. By the end of this century, hopefully, scientistswill be able to perfect these techniques to makeplankton the greatest addition to world’s food supplyfor man as it is estimated that the mass ofphytoplankton in the ocean is approximately 0.2million billion tons which is the largest quantity ofliving species in the ocean.

A remarkable feature of the living species in theocean is the vast diversity in the nature of speciesand the wide range of size, from the microscropicphytoplankton to the giant whale. Whales are sea-mammals widely differing in size, shape, structureand weight. There are about 90 different species ofwhales in the ocean and the adjoining seas. Knownas the largest animal, the size of the whales varyfrom 2 to 35 metres and weight from 1 to 120 tons.While, on the one hand, killer whales are the mostdreaded marine animals, majority of whales arevlunerable and harmless because of their slowmovements. During the last few decades man beganhunting whales as a source of edible oils and fatsfor his personal gain. The ruthless exploitationsand greedy destruction of the whales for selfishends by whale hunters has led to a rapid depletionof these species. There has been a growing concernabout this rapid depletion of these species. Thesehas been a growing concern about this rapiddepletion of certain whale species and nearextinction of eight species of whales which led toa world-wide awakening among the natureconservation and it has become a world-wideecological concern of mankind. The United Nation’sConference on Human Environment held inStockholm in 1972, unanimously recommended aten-year moratorium in world whale hunting. Withthe emergence of a world-wide consciousness and

international controls many countries have stoppedall whaling activities.

A similar situation holds good for porpoises andturtles which are facing ruthless exploitation. Assuch, stringent measures must be taken against thecomplete elimination of these species. Large scaleuse of crocodile skin industry has also attractedattention and steps must be taken for artificialrearing.

In any analysis of the ocean biological resourcesand their development, we should not overlookthat, apart from the source of food, the oceans canbecome rich repositories of our pharmaceuticalindustry. Considering the significance of oceanicresources for the pharmacological purposes a gooddeal of investment is being made by the nationaland international governments. Indeed the marinepharmacology is emerging as an important area ofocean science. Several marine organisms and plantshave been used for medical purposes from timesimmemorial, According to ancient history, watercrabs properly treated were used as antidotes formost poisons. Chinese have used sea weeds fortreatment of throat diseases. Modernpharmacologists are currently investigating manymarine organisms for pharmacological studies. Sea-cucumber is known to be capable of freezing nerveswithout damaging them and the extract from this isan indispensable toxin for post-operative treatmentBarnacles possess a cement which is used as dentalglue because it is water-proof and strong. Thevenon produced by man-of-war fish is used orpreventing heart attacks. Certain varieties of horse-shoe crabs, one of the endangered species at presentrestricted to eastern part of Bay of Bengal, containsa unique substance called lysate which has enormousmedical applications, as it serves as an index forthe bacterial endotoxin in vaccines and serums. Aremarkable observation that sharks can withstandmore brain damage and are also immune to cancermay pave the way for discovering a drug to fightthis deadly disease. Detailed scientific investigationsmust be undertaken or marine pharmacology in

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various universities and national laboratories todiscover new drugs which will be of paramountimportance to the health of our people.

PHYSICAL RESOURCES

In any analysis of the rich resources of theoceans of the world, one is struck by the vastrenewable biological wealth, but it is striking tonote that the physical resources of the oceans areequally staggering. No doubt the majority of thephysical resources barring energy of the waves,wind tide and temperature are non-renewable andas such this would call for a planned and cautiousapproach in exploiting them. The vast mineralwealth in ocean sediments and ocean basins isindeed enormous but the most valuable mobile oreof the oceans is the vast volume of water holdingenoromous quantities of salt, chemicals and gases.Oceans hold 350 millions of cubic miles of water.Each cubic mile of sea water weighing 4.7 billiontons contains 165 million tons of dissolved solidsof which common salt is the most abundant,followed by magnesium, calcium, potassium andbromine. Oceans, as a whole have vast mineralresources to the extent of 50 million billions tons.Besides, the sea floor is covered by manganesenodules which are awaiting to be exploited. Thelast few decades witnessed phenomenal progress inthe exploration and exploitation of oil and naturalgas. As more and more of the land resources aregetting depleted, greater attention is now paid toextracting of several scarce elements and chemicalsfrom sea water and mining of minerals in themanganese nodules on the sea floor and mines atdifferent depths in the sediments of the sea floor.

In a world, facing serious shortage of petroleumfor its various developmental needs, it is necessaryto look for new sources of petroleum using moderngeological and geophysical techniques. It is nowwell-established that organic matter subjected tohigh pressure and chemical actions is responsiblefor the formation of petroleum and other gasproducts. Scientists have not yet unravelled themechanism of the formation of petroleum, but an

approximate estimate indicates that it takes nearlymillion years or so to form petroleum from suchorganic matter. Geological and geophysical studiesrevealed that the petroleum products consisting ofpetroleum and natural gas, usually associated withwater, get trapped in dome-shaped structures or ata junction of a major fault in the earth’s crust.

Deep sea drilling for oil is comparatively recent.Right from the year 1930, geologists andgeophysicists felt certain that there was oil underthe sea, but they felt that in may not be feasible todrill for it because of major technological hurdles.Enterprising engineers, aware of the potential ofthe oil in the offshore, started designing giantmobile and even floating platforms in the sea byingenuous methods in order to conduct deep-seadrilling operations.

With the rapid depletion of resources ofpetroleum on land and with the advancement inmodern techniques of exploring and exploitingoffshore petroleum, there was a global awakeningamong many countries to start exploring forpetroleum in their offshore waters. It was estimatedthat offshore waters, all over the world, have reservesof 85 billion barrel of petroleum. Foremost amongstthe countries which started offshore drillings areUSA, UK, Norway and a few other Europeancountries. It is estimated that nearly 20% of theworld’s known oil reserves come from offshorereserves of oil and gas. Even a modest estimateindicates that the total potential of petroleumproducts in the sea are atleast equal to those on theland. Recently extensive petroleum reserves werefound in the North Sea area between Britain andScandinavian countries. Current estimates of thereserves indicate that this is one of the richestoffshore oil fields of the world. Although theoffshore platforms are currently located in shallowdepths but futures technological developments willcertainly enable the exploitation of petroleumavailable at depths of even 2000 metres.

India is one of the developing countries whichhas started sufficiently early to explore offshore


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areas, for oil prospecting. The success achieved in1980 in Bombay High has opened up a new chapterin the exploration of offshore oil resources to feedthe petrol refineries in our country. It is indeedremarkable that within a period of two years,Bombay High Oil Fields increased their capacity toreach production level of 80 thousand barrels a daywhich is worth about 30 crores of foreign exchangeper year and nearly 10 percent of the present costof import to crude oil. Besides these rich resourcesof oil in the Bombay High, the country is fortunateto have discovered natural gas offshore at AndamanNicobar islands, Godavari and Cauvery basins.

With the explosion in human population, manwill be compelled to turn to the sea for his futureneeds of water. Even a country bountifully blessedas USA with all its large rivers and lakes cannotincrease its water resources without turning to thesea. Out of the water resources estimated to be400,000 million gallons a day, U.S. is using around70% for its daily requirement of agriculutre, industryand domestic use. In India, the total resources ofwater is 177.5 million hectametres of which only26.4 million hectametres is used. Nearly 50% ofour population has no potable water supply.

The three basic ways of separating salt from seawater are distillation, reverse osmosis and freezing.On the high seas, many ships use distillation formeeting its freshwater need, but this is a mostexpensive method for freshwater. The Central Saltand Marine Chemical Research Institute atBhavnagar has set up an experimental solardistillation plant producing a few hundred gallonsper day which is serving the requirements of asmall village. Although inexpensive, in recurringcosts the initial capital cost to set up such a unit ishigh and vast land areas are needed for setting upthe plant. Reverse osmosis is a cheaper and compactmethod for separating salt from sea water using aspecially treated membrane that allows water onlyto pass through. Central Salt and Marine Chemicalsinstitute has also perfected this technique which iscommercially viable. Drought prone areas, located

on the sea coast which have a serious water shortagecould well use this new technique for supply ofpotable drinking water.

A grandiose plan of tugging an iceberg from thearctic region was suggested by John Issac of theScripps institution. It is estimated that in two monthstime an ocean-going vessel can tug a 10 mile longand half mile wide iceberg and tow it into afloating dam to supply 250 million gallons offreshwater. The cost will workout at one-third of acent, per thousand gallons, a minute fraction ofwhat we pay for our drinking water. This ideawould be still more valid for arid zones and vastdesert lands in various countries, particularly inAfrica and Australia.

In any analysis of the rich non-renewableresources which man can exploit in the sea, thebrightest and the most commonly useful for thepresent and the future needs of our economy arethe chemicals from the sea water. Since historictimes, man has been using sea water for extractionof common salt which is a vital ingredient of man’sdiet. The techniques of preparing common salt bysalt pans on the sea-shore are know to mankindperhaps for over thousands of years. Today, almostall countries are extracting varieties of chemicalson a commercial scale from sea water.

Out of 92 naturally occurring elements in theearth, nearly sixty elements can be extracted fromthe sea water which highlights the variety and thewealth of minerals dissolved in the sea water.Unfortunately, most of these elements are presentin infinitesimal amounts which can only be extractedby expensive methods on a very limited scale.

Chemical analysis of the composition of seawater is bound to lead to estimates of the sea watermineral potential which will be high at least in thecase of major constituents considering the fact thatvolume of sea water resource is gigantic. Howeveron economic considerations, very few of theminerals are extracted from sea water commercially.Common salt is the most important and abundant


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of all chemical constitutes being 0.3% of the seawater. The total quantity of salt in the sea is 50trillion tons and if this quantity is spread out dry onthe land, it will cover the globe to a height of 502ft. burying everything on the land in a sea of salt.Looking back at the preindustrial period, salt fromthe sea was used only for human consumption.With the rapid industrialization all over the world,major use of common salt in industries forproduction of chlorine, sodium hydroxide, severalmagnesium salts, bromine and a few othercompounds. Apart from the use of common salt forextracting other elements and minerals, it is useddirectly in many industries like paper, plastic andtextile industries. Magnesium which is a scarcemetal on earth is found in sea water in sufficientquantity, to be a commercially viable propositionfor extraction.

Wayback in 1879, the British oceanographicship H.M.S. challenger, first brought up from thesea floor curious potato-sized lumps of stone nowknown as manganese nodules. Years later, severaloceanographic expeditions dredged more and moreof this rich manganese nodules spread on the surfaceof the sea floor in countless millions in almost allthe oceans. Irregular shaped and varying in sizefrom 1–6 cms they consist of manganese and ironoxides in percentages varying from 10–40%deposited in concentric layers around a nucleus.This discovery is important not so much for itsmanganese and iron content but the ability of thesenodules to scavenge other relatively rare metalslike copper, nickel and cobalt. Till recently, scientistsconcentrated the efforts in understanding the origin,growth, composition and structure of these nodulesas a subject of great scientific curiosity. Theremarkable feature of these nodules is their abilityto grow at an average rate of 1–2 millimetre perthousand years. Estimates of the concentrations ofthese nodules vary widely from place to place.According to one oceanographer Dr. John Mero,the aggregate deposits of the nodules would bearound 1–7 trillion tons containing 400 billion tonsof manganese, 16 billion tons of cobalt. Such vast

and rich deposits of nodules contain metals likecopper, cobalt and nickel whose total oceanresources by far exceed the estimated world’s totalland resource. While these figures indicate enormousand almost unlimited reserves lying to be exploitedon the surface of the ocean, but their distributionover a large area of the ocean bottom makes iteconomically non-viable except in those regionswhere there is an excessive concentration. Scientists,technologists, economists and planners predict thatit is possible to commercially exploit these, onlywhen the land resources get exhausted but it shouldbe stressed that it it not economical to exploit themas most of them are located at great depth. However,extensive studies carried out in recent times, revealedthick solid deposits of over 50 million tons allalong the axial deep trenches in the Red sea whichcan be economically exploited in view of their highconcentration.

Sea floor is indeed a treasure house of exclusivemineral resources which nations can exploit.However, the distribution of these various mineralsvarious widely from region to region among thevarious minerals available in the ocean, one of themost promising are the large beds of phosphaterock, conveniently situated in shallow areas nearthe shore, which is a vital material in themanufacture of chemical fertilizers currently ingreat demand all over the world. Phosphorite depositwere discovered off the coast of several island inthe Indian Ocean. Continental self of Australia isrichly endowed with phosphorite which is beingminded for its domestic and export potential. Whilethe world reserves of phosphorite in sea areestimated to be 300 billion tons, the present worldreserves of phosphates are 50 millions tons ofwhich 98% is held by four countries, namely U.S.A.,U.S.S.R., Tunisia and Morocco.

Another element extensively used in chemicalindustry is sulphur which lies buried within thecontinental shelf and sea floor sediments. Thiselement is usually recovered by pumping hot waterwhich melts the sulphur and brings it to the surface.


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Tin is another industrially useful element whoseland resources are dwindling. Malaysia has largetin deposits and is one of the Asian countriesexporting tin in large quantities. Very recentlyextensive prospecting by foreign firms led to a fewsites offshore Thailand, Laving rich deposits. Ironis certainly one of the most important elementssought after by many industrial countries. Nearly adecade ago, Japan which has a large internalconsumption of iron discovered a fabulously richmine, estimated at 2 billion metric tons, off thecoast off Kyushu which is one of the southern-mostislands. In addition to these abundant, commonlyused and industrially potential metals, oceangeologists estimate the availability of enough copperand aluminium in 40 million and odd square milesof ocean bed which will continuously supply theneeds of man for the next million years at thepresent rate of consumption.

From times immemorial, explores are lured andtempted by bright prospects and exciting possibilitiesof undersea gold and diamond prospecting. Perhapsthe greatest and the most abundant gold mines willbe found underneath the sea in the present and nextcentury, as thereare enough scientific evidences ofgold mines obtained by a new technique ofsurveying the sea bed for ancient river channelswhich are likely to have rich deposits of gold dustand grains. Diamond prospecting was first initiatedby Keeble who believed diamonds could be foundin sands near the mouth of the river. He started apioneering venture using a ship Barge 77 andsucceeded in bringing ashore significant qualitiesof diamonds off the shore of South-west Africa.Indeed, the diamond wealth of the sea is so highthat every thousand pounds of sand was bringing asmany carats of diamond as are million pounds ofmaterial on earth.

ENERGY FROM THE OCEAN

The ocean receives energy from the sun in theform of solar radiation. It also receives the gavitationenergy due to attraction of the sun and the moon onthe earth. In addition, there is a perennial supply of

heat from the molten mass in the interior of theearth. The total energy is accumulated in the oceanin the form of temperature and the kinetic energyof the moving water in the waves, tides and currentsin the ocean. The most spectacular and conspicuousfeatures of the ocean are the waves of varyingheight and length. Waves on the ocean have alwaysimpressed artists, poets and scientists. One of theearliest studies of the waves by German ScientistFranz Gerstner revealed that water particles in awave move in circular orbits. The study of thewave and surf movements is essential for navaloperations particularly during war time. Althoughthe waves on the surface of the ocean carryenormous amounts of energy, it has not yet beenpossible to develop techniques to exploit this sourceeconomically.

While scientists have not been able to develop asimple and efficient machine to extract the waveenergy which was so obvious to the naked eye,energy of the tides could be fully exploited bybuilding giant power stations. The periodic rise andfall of sea level due to the gravitational attractionexerted by the moon on the sea and to a lesserextent by the sun is called the tide. Tides arecomplex phenomena which depend on the positionsof the moon and sun, the uneven distribution of thewater on the earth’s surface and the irregularconfiguration of the ocean base. The complexinteraction of these features results in tides whichvary from place to place, ranging from a few inchesto about 12 meters height. Tidal gauges are usuallyinstalled in most of the harbours to recordcontinuously tidal data which help in navigation.

Tidal motions have so far attracted muchattention from scientists and engineers becausepower generation is possible following theconventional hydro-electric power systems.Normally the tidal range does not exceed 2 to 3meters. However, there are special locations wheretidal range can be as large as 15 metres. There areabout 25 sites all over the world where the tidalrange exceeds 5 metres which is the minimum


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height required for setting up tidal hydro-electricpower stations. The first country which has exploitedtidal power is France which has set up the Ranceriver power plant near St. Malo which is the firstcommercially successful tidal power plant. Thetidal height in this area ranges from 9 to 14 metres.The plant completed at a cost of 100 milliondollars, generates a total of 2,40,000 k. W. ofpower using 24 reversible turbines. In India, thegulf of Kutch and the Gulf of Cambay on the westCoast in the State of Gujarat are the only twoplaces having the potential for setting up tidalhydro-elelctric power stations, which can generatea total tidal power of a few thousands of megawatts.

In recent times considerable interest has beenevinced by scientists and engineers to utilize thevast and almost unlimited ocean thermal energyavailable in the upper layers of the ocean which isconstantly receiving the energy from the sun. Thetemperature of the sea water which is of the order25°C at the surface goes down to 8°C at a depth of450 metres. This difference in temperature betweenthe surface of the ocean and the deep water can beutilized to obtain electric energy by using atechnique which is exactly opposite to the principleof a refrigerator. Designs are well under way togenerate a 1,60,000 k.W. power plant by using theOcean Thermal Energy Conversion (OTEC)Principle near Laccadive islands. It will probablytake several years of research, design anddevelopment before this new and perennial powersupply system could be perfected. Scientists havepredicted that with OTEC electric generators it ispossible to provide continuous energy supply tomankind which is 200 times as great as the estimatesof world’s power requirement in the year 2000.

New methods of generating power arecontemplated by using the salinity gradient whenfreshwater from the rivers flow into and meets thesalt water of the sea particularly in the estuaries oflarge rivers, as scientists have shown in laboratoryexperiments, that considerable amounts of electricpower can be generated when freshwater meets saltwater.

OCEAN ENVIRONMENT

In the present climate of opinion, a good deal ofawareness is being reflected by the nationalgovernments and international agencies includingthe United Nations system, about the conservationand the maintenance of our environmentalequilibrium. This awareness has arisen after thedamage has been caused during the process of ourdevelopment strives made with the application ofScience and technology. A wide variety ofbyproducts and disposable material extremelyharmful to the human system and the biologicalworld as a whole has been discharged into theenvironment and dislocated our natural equilibrium.Most of the environmentalists and ecologists arenow articulating on the top of their voices that manmust learn to live in harmony with laws of nature,but unfortunately what they are missing is of moreimportance. In fact, they are not viewingenvironment in its totality. While studying ourenvironment, we must consider it as the total fluidsystem comprising both of water and air whichenvelopes the earth. It may not be overlooked thatthe interaction of the ocean and atmosphere is sothorough and complete that any deterioration of theocean environment will lead deterioration of thetotal environment. The marine environment to alarge extent dominate that of land. It nourishes andsupports its life which evolved from the sea. Air,water and temperature are necessary conditions forthe evolution and progression of life on this planet.The ocean holds untapped energy resources andmineral deposits of staggering magnitude and alsosupports a global food chain. It is true that theocean has always offered benefit to the mankind inreverse ways and has been a crucial input to oureconomy, defence and aesthetic sensibilities, andyet it is threatened by man’s misuse of hisenvironment.

Perhaps, it is our inability to perceive oceans interms of living organism that we went on disturbingtheir ecosystem and treate them as dumping groundsfor our wasted and disposable materials of everykind from seawage to radioactive waves. It was our


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mistaken belief that they had the capacity to absorbthem, but on the contrary, what has happenedshould not surprise us. This process has contributedto a significant level of pollution not only on thecoastal areas but also in the mid-ocean. There hasbeen a continual deterioration of the oceanenvironment induced largely by man-made processesand occasionally by sporadic natural processes suchas volcanoes and earthquakes. While studying theoceanic environment, it is necessary to understandabout the Physics, Chemistry, Biology and Geologyof the oceans, so that we can reliably assess whathappens to the substances we dispose off daily, inever-increasing amounts, into the oceans. Let usnot forget that the mechanics of dissemination ofpollutants causing damage to the oceanicenvironment are of complex and manifold character,not yet fully understood.

Massive oil pollution of coastal waters is one oftoday’s most alarming sources of hazards. Althoughthere is some pollution danger from offshore drillingoperations, the greatest threat is posed by the hugeoil tankers needed to satisfy our demands for energy.Sewage sludge from secondary treatment plantscan have damaging effects through the accumulationof petrochemicals and of heavy metals in the sludgeis discharged at sea, the toxic materials may beharmful to bottom populations and inhibit thebacterial breakdown of the organic pollutants.Domestic sewage contains fertilizing elements suchas phosphorus and nitrogen which can increaseproductivity in the sea, but when added in excess,they stimulate growth of undesirable phytoplanktonand tend to eliminate species beneficial as food forhigher organisms. Insecticides, such as DDT, usedin agriculture and polychlorinated biphenyls,(PCB’s), used in manufacturing processes, are bothcarried to the sea by the atmosphere or by landrunoff. While concentrations are lower in the openocean than in coastal waters near rivers, scientistshave found them to be surprisingly high, given thetremendous area and volume of the ocean. Heavymetals are being recycled by man at rates severaltimes faster than natural weathering or erosion

processes. The oceans are being polluted throughrivers and atmosphere by these waste products ofman’s civilization and technology.

Amongst the different pollutants affecting ouroceanic environment, perhaps the discharge ofoutflow of oil into the ocean seems to be the majorpollutant. The agricultural, domestic and industrialactivities are also threatening our marineenvironment and the rate of pollution has reachedan alarming degree specially in countries borderingon sea. We do not know the extent of marinepollution in India at the Peninsular Belt, especiallyin the coastal region, Visakhapatnam, Trivandrum,Cochin, Goa and Bombay, but then monitored,perhaps the rate would be quite alarming.

Before considering important pollutants likesynthetic organic compounds, heavy metalhalogenated hydrocarbons, carbondioxide, radio-active wastes, it would be relevant to look at brieflythe pollution caused by oil to our oceanicenvironment somewhat in depth. It would be relevantto recall that oil pollution hit the global newsheadlines as one of the major constituents ofpollution to the oceanic environment, with thedischarge of 34 million gallons of oil on the surfaceof the ocean near Cornwall coast by Liberion shipTorrey Canyon in 1967. Considering the importanceof the oil in the present era, the operational activityof oil tankers has increased considerably. It isestimated that over 3500 oil tankers with an intakecapacity of 1000 millions tons or more are operatingand they are dumping over 5 million tons of oilinto the ocean annually.

Looking at the dynamics of oil pollution inmarine environment, one is struck by the fact thatoil has been indentified as a major threat to theexistence of the fish community. It causes a highincidence of severe neurological disorders followedby death. It indirectly affects the human life andother mammals inhabiting that region. It isunderstandable because once the inhabitants of thatregion take contaminated fish, they fall a prey tovarious physical and mental disorders. In any


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analysis of the oil spills in the ocean, we should notforget that oil is highly toxic and it can endangerthe life of sea birds and lump back whales, andothers. Assuming that some forms of oil spillswould appear to be inevitable as the demand forpetroleum continues to increase in the comingdecades, can we explore ways and means tominimize them, especially the offshore spills? Weshould give top priority to improve our coastalnavigation systems and introduce strict regulationsof marine traffic. The obsolete tankers should bebanned and the new tankers equipped with all thesafety measures should only be permitted to operatein the ocean. The International MaritimeConsultative Organisation and other Internationalagencies should address themselves to this questionseriously and evolve improved standards for thepreservation of healthy oceanic environment whichshould be made mandatory for all involved in thenavigational and transportation activities in the sea.

Another significant pollutant to the oceanenvironment has been identified as radioactivity.The artificial radiation emanating from radioactivenuclei, are manifested in the ocean, followingdischarge of radioactive wastes. The impact of theradioactive hazards to the oceanic environment cameto the notice of public when two atom bombs weredropped in Japanese cities of Hiroshima andNagasaki in 1945. Since then, we have witnessed aproliferation of nuclear experiments, which havebeen carried out in the atmosphere, undergroundand undersea.

The major sources of ocean contamination byradioactive material are fall-outs from nuclearexplosions, effluents and waste products fromnuclear power plants and nuclear driven ships.Since oceans are enormous in the size, volume anddepth, it is taken for granted that they are the safestrepositories for radioactive wastes. Radioactivesubstances from nuclear plants enter the oceanchiefly in packaged disposal dumped to the deepseafloor. Nuclear driven ships discharge radioactivematerial in the ocean through various leakages. Infact the radioactive material goes to the sea through

various channels and contaminate the oceansignificantly. It is difficult to say with any degreeof a authenticity about the impact of radioactivematerial on the marine life but the available data isa clear index of their significant impact onmutational changes and as such change in thegenetic spectrum.

Another significant variable which is contributingto the pollution of oceanic environment are heavymetals. Heavy metals such as lead, copper, zinc,cadmium, nickel, chromium, mercury areresponsible for degrading the quality of environmentand extinguishing a number of marine organisms.It is interesting to observe that worst type of marinepollution due to heavy metals was observed amongstthe inhabitants on the shore of Minamata Bay in1953 and Niigata Island in 1965, due to the releaseor mercury through inland channels. Manyorganisms absorbed heavy metals in their bodiesand later passed these through the food chain toman. Metals are often associated with chlorinatedhydrocarbons. Finally, heavy metals are alsosupplied to the ocean from mine residues, whichare carried by streams and rivers. Some heavymetals may come from the crude or heavy fuel oilleaks (or spills) from ships, pipelines, offshorewells, and refineries. Vanadium, manganese, cobaltand nickel are found in crude oils as non-volatileporphyrins. Oceanic pollution is more concentratedalong coastal zone primarly because of highpopulation concentration and heavy density ofindustrial complexes. It is along the coastal zone,that factories, power stations, refineries, harbourinstallations are established, which discharge highlytoxic materials contributing to the degradation ofthe oceanic environment. The major sources of thisdegradation are the municipal wastes and industrialeffluents. Methyl mercury chloride had beenidentified as the causal toxin, which contributes topollution in the marine organism. It is byproduct ofthe manufacture of polyvinyl chloride resin, octanoldioctiol pthalate with acetaldehyde as the initialmaterial.


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It may be recalled that the chemical pesticideswhich are being used extensively for acceleratingthe pace of agricultural production are provingdangerous to the health of ocean. DDT which wasfound to be a useful compound for controllingmalaria has adversely affected the marine life, sayfor example, the residues of DDT in the seaenvironment are selectively absorbed by planktonswhich in turn are taken by small fish, thus eventuallyit gets transferred to higher organism including theman.

Though all the chlorinated hydrocarbons,synthetic organic chemical compounds aredischarged into the sea all along the industrialcoastalline all over the world, the process by whichthey can be removed from the seawater are not wellunderstood. We need more information of potentialtoxic matters in successive levels of food webs toavoid any future disasters to organic life in theocean.

The effect of pollution on marine organismscannot be evaluated unless normal functioning ofthe healthy organisms is known. This requires alarge amount of basic research work about themarine organisms and their response to marineenvironmental changes and chemical pollutants.Such experiments have to be carried out in theirnatural habitat encircling portions of the sea waterrather than in the laboratory.

Assuming that much of the pollution to theoceanic environment is the result of our industrialdevelopment, the solution to the problem does notlie, in calling for a moratorium on the industrialdevelopments. In fact, we cannot afford to slowdown the pace of our development task and alsocannot wait any longer from harnessing the resourcesof the ocean for developmental purposes, to satisfythe needs and requirements of our explosivepopulation living in impoverished conditions.

Perhaps, we have to evolve a coherentenvironmental policy for conserving and maintainingthe marine ecosystem without causing anydislocation to our industrial and agricultural

developmental activities. It is possible to controlthe oceanic pollution by promoting multi-disciplinary studies and working out operationalstrategies and modalities of action through whichwe can efficiently and effectively control thepollution. The first task would be to identify variouspathways by which pollutants enter the ocean andlater an analysis of the behaviour of the individualpollutants. These are essential for recommendingremedial measures against hazards in the oceanicsystem. Once we realize that oceans are repositoriesand the necessary pre-requisite conditions for themaintenance and the sustenance of life in thisplanet, then our task would be to treat them in sucha fashion that the equilibrium in the oceanicenvironment is not dislocated

RESEARCH, TRAINING AND MANPOWERPLANNING

Implicit in the preceding analysis is the generalassumption that ocean development is crucial forhuman and social development and as it is absolutelynecessary to accelerate the pace of education,training, research and development activities invarious areas of ocean Science and technology.Educational activity is a vital input in anydevelopmental process and must be organized inthe context of social, political, economic, cultural,environmental and technological demands of anysociety for facilitating an integrated developmentof man and society. As such there is an urgent needfor promoting an efficient and effective educationaltraining programme linked to a coherent policy formanpower planning for identification anddevelopment of ocean resources.

Though India has a long and rich coastline, wehave not been able to exploit our ocean resourcesfor our development due to various factors. Wehave not succeeded in our efforts to establish thenecessary infrastructure, collect data and build themanpower needed for carrying out this task. Verylittle has been attempted on the survey front forcollecting the basic knowledge and informationabout the sea and the sea bed. The data on ocean


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dynamics, currents, coastal upwellings, waves,marine chemicals, biological and physical resources,mineral mapping, their delineation and assessmentis totally inadequate for taking up any meaningfulprogramme of development. It is rather unfortunatethat we have not been able to prepare realistic man-power projections and to train skilled personnel invarious priority areas of ocean development due tolack of a realistic plan of ocean development basedon data of our resources. To cite a few examples,we have a serious shortage of ocean engineersurgently needed for our offshore oil installations.In the area of marine pharmacology, physicaloceanography, monsoon dynamics, ocean pollutionand ocean mining, we do not have adequatelytrained staff both for developmental and researchactivities.

It may be recapitulated that the United NationsConvention on the Law of the Sea has recognizedIndia as a “pioneer” investor in ocean mining andperhaps this imposes a heavy responsibility on usfor organizing an efficient educational and researchinfrastructure in the area of oceanography for thepreparation of highly skilled manpower to meet thedemands of the country as well as of the developingsocieties which might have to draw upon ourresources in the forseable future.

The picture that emerges of our universities inregard to the training and man-power facilities inthe area of oceanography does not seem to besatisfactory. Andhra, Annamalai, Cochin universitiesand I.I.T. Madras are offering educationalprogrammes in marine science and engineering.The courses offered no doubt need to be updated inthe context of various scientific and technologicalbreakthroughs in the different disciplines ofknowledge. Marine science being an inter-disciplinary subject, it has to be organized in acoordinated fashion involving scientists having ininter-disciplinary approach.

The vastness and complexities of the oceanenvironment calls for a coordinated, centralizedand highly sophisticated research programmes. This

should be also based on adequate knowledge of allcommercially exploitable ocean resources. The mainthrust of such a programme should be on theoptimum utilization of living resources like fishand seaweeds, exploitation or non-living resourcessuch as marine chemicals, oil, manganese nodulesand harnessing of renewable resources like thermalwave and tidal energies. This is not the place ofidentify the frontier areas on which we shouldconcentrate—the issues have been specified andidentified in each of the preceding section but thepoint which I intend to make is that the basicresearch is of utmost importance in any scientificarea and perhaps more important than the appliedone. It is the basic research which provides supportto the applied research. The knowledge which weare applying to some of the most urgent problemsof marine environment is applied from the basicresearch work done during the past.

At the same time, let us not overlook thefundamental fact, that marine development is heavilydependent on technological achievements. Muchmore needs to be done for the development ofindigeneous technology for the exploitation ofvarious development resources from the ocean. Infact, the technologies, which need to be developedshould be ecologically balanced, self-reliant andemployment-oriented.

There is another direction to the problem whichshould not be overlooked in any process of teaching,training and research particularly in Ocean Science.Paracelsus once remarked “No man can find ateacher in the class room nor his master by thefireside”. Ocean Science being largely a field-oriented subject, no man can be a goodoceanographer by learning in the classroom orlibrary. It would be wrong for an ocean scientist tobelieve that he can do advanced research withoutadequate training and experience on a researchvessel. Many of our Ocean Science trainingprogrammes in our universities and nationallaboratories suffer from lack of training on board aresearch vessel equipped well for all types of ocean


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studies. If our ocean scientists have to carry outadvanced research as well as train our youngresearchers, adequate infrastructure and support inthe form of ocean-going research vessels has to beprovided particulary to the university sector.

If our oceans have to become potential sourcesof food, energy and chemicals and to provide analternative source to our land resources which aredepleting fast, there is no way out, but to train ourscientists in this area in a big way. While trainingour scientists in this area we should not forget thatthe problem of the ocean development is of aglobal character and it needs a global solution, andtherefore we must work out a global marine policyand ocean management programmes while keepingin mind our national interests.

MANAGEMENT AND CONSERVATION OFTHE OCEAN RESOURCES

The issue of management and conservation ofthe ocean resources — food, minerals, energy andmarine environment — for the developmental taskshas assumed considerable importance in the presentclimate of opinion. This is a staggering problemand beset with a set of challenges. The majordifficulty stems from the fact that the size of theoceans is so vast, covering roughly two-thirds ofthe earth’s surface and touching the boundaries ofapproximately one hundred and fifty countries whichare independent nations.

Considering the importance of oceans for thedevelopment of their economy, most of theseindependent countries are putting forth their claimsfor portions of the ocean as part of their territorialjurisdictions. The difficulty is further compoundedby the fact that over 85 percent of oceanic territoryfalls outside the jurisdiction of all nations. In sucha situation, who should have the legitimate right toexploit the resources of the ocean is a problem ofproblems which only the United Nations systemcan tackle with some degree of firmness andforesight.

The complex programme that ocean developmententails will require well designed management,

institutional infrastructure, basic knowledge andinformation about all aspects of the ocean includingits resources. It would also involved a detailedsurvey and sampling in the regions of exclusiveEconomic Zone and the adjacent ocean to locateand evaluate the rich and economically viableresources. The integrated management of oceanresources would call for the new technologicalcapabilities which must be continuously revisedand updated. Preserving simultaneously the marineenvironment to avoid the undesirable consequencesof hasty decisions made on the basic of inadequateunderstanding and to proceed in an effective way,it is imperative that we improve our communicationssystem, global cooperation and coordination.

It is essential that ocean-oriented lawyers,economists, business experts, sociologists and othersshould be involved in the decision making process.To put the issue a little explicitly, the entire processof development will involve the blending ofoceanography with public policy which could beviewed from the two perspectives : the first concernswith the decision making process and the secondconcerns with the substance or the issues nowdevolving in oceanography. The integratedmanagement of the ocean resources will also callfor a clearer and coherent legislation on the part ofnational government’s and international bodies.What is really needed in a statutory dedication ofnational government and international bodies forevolving a rational and just legal political frameworkfor exploring the minerals and others resourcesunderlying the high seas.

This is not the place to examine, in historicalperspectives, the conflicts amangst various countrieswhich took place during the different periods ofhistory, but the point which I intend to make is thatissues relating to ownership of resources, territorialclaims and marine environment are being debatedcurrently in the international Laws of the sea. TheUnited Nations Laws of the sea convention whichhas been the subject of great debate and controversyis likely to open a new chapter in the foreseeable


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future in the international law and globalcooperation. In 1958, over 81 countries took part inthe Geneva conference, and four importantconventions, which have since been ratified byseveral other nations, adopted :

1. the convention on the Territorial Sea andContiguous Zone;

2. the Convention on the Continental Shelf;

3. the Convention on the High Seas; and

4. the Convention of Fishing and Conservationof the Living Resources of the High Seas.

If would be relevant to examine each of thembriefly.

TERRITORIAL SEA AND CONTIGUOUSZONE

According to the convention on the territorialsea and the contiguous zone, each nation will havethe sovereign power to a band of sea adjacent to itscoast (the territorial sea) and to the air space overthe territorial sea as well as to its bed and subsoil.

Opinions were divided about the width of theterritorial sea. The zone exists within the twelvemiles from the baseline that makes the point fromwhich the extent of territorial sea is to be measured.The convention also stipulates that each coastalnation would have a right within its contiguouszone to carry out immigration, customs, and sanitarypolicies.

THE CONTINENTAL SHELF

The convention on the continental shelf envisagesthat shelf is defined as “the sea bed and subsoil ofthe submarine areas adjacent to the coast but outsidethe area of the territorial sea to a depth of 200metres or beyond that limit, to where the depth ofthe super adjacent water admits of the exploitationof the natural resources of the said areas, as well asthe sea bed and subsoil of similar submarine areasadjacent to the coasts of islands.” The conventionprovides to each coastal nation sovereign right overthe continental shelf for the purposes of explorationand exploitation of its natural resources.

THE HIGH SEAS

According to the convention on the high seas,the high seas encompasses all portions of the seaoutside territorial seas or the internal waters of anation. The high seas belong to all nations and aretherefore under no jurisdiction of an individualnation. Naturally, every coastal and non-coastalnation has got an access to the high sea. Theconvention guarantees freedom of navigation,fishing, construction of submarine cables andpipelines and flight.

FISHING AND CONSERVATION

The convention on fishing and conservation ofthe living resources of the high seas provides thatall states have the duty to adopt or to cooperatewith other states in adopting such measures fortheir respective nationals as may be necessary forthe conservation of the living resources of the highseas.

While assessing the contributions of the UnitedNations towards the establishment of an internationallegalist framework for harnessing the rich potentialsof the oceans resources, we must, consider, indetail, the historic Malta Resolution which wasgeared to give the United Nations a greater role inmanaging the world’s oceans, particularly theresources of sea bed and subsoil which fall beyondnational jurisdiction. Another related developmentoccurred almost simultaneously. In August 1967,the United Nations was confronted with animaginative proposal by the government of Maltaof turning over to the United Nations all the mineralresources of the deep sea. This proposal immediatelyraised the legal question of who owns the sea bed.The United States was surprised at Malta’s initiative.Ambassador Arthur Goldberg went to the UnitedNations in October 1967 with a three-part proposal;first, to re-enunciate a concept the government hasadopted, that there be no colonial race with regardto the sovereignty of the deep sea bed; second, thatthe United Nations establish a committee on theoceans; and third that the nations of the world worktogether to find out resources are in the oceans.


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Space and time does not permit to discuses, indetail, about finding of various conferences,seminars and symposia organized under the auspicesof national and international agencies, especiallyby the United Nations for working out a globalpolicy and an international legal and politicalframework for exploring the vast potential resourcesof the oceans. However, I would like to focus onthe United Nations Law of the Sea conventionwhich was signed on December 10th, 1982 byIndia and 116 other countries at Montego Bay inJamaica. This convention unfolds a new chapter inthe evolution of any growth of international lawand global cooperation.

It gives special recognition to the leading role ofIndia in exploiting deep sea bed resources. Thenations and the international consortia with pioneerstatus are to be given priority being allocated arefor sea bed mining under the convention and theyin turn will have to share their technology with aninternational body, to be known as Enterprise, whichwill exploit the resources as a common heritage ofmankind.

Indian Law Minister Jagannath Kaushal, whoattended the final session of the nine years longU.N. Law of the sea conference at which theconvention was signed, had said, that India wasgrateful for the recognition as a pioneer. This, hesaid would boost the morale of the other developingcountries as well. Mr. Kaushal also said that Indiahad fulfilled the conditions, such as the carryingout of surveys and making a minimum investmentfor exploiting the sea bed resources to qualify forthis status. The president of the conference, Mr.Tommy Koh of Singapore warned the countriesboycotting the convention; ‘any attempt by anystate to mine the resources convention will earn theuniversal condemnation of the internationalcommunity and will incur the gravest political andlegal consequences’.

The lengthy detailed document of the conventionlays down the law for virtually all aspects pertainingto the sea. It allows a 12 nautical miles-wild

territorial zone along the coast and a 200 mileswide exclusive economic zone in which coastalstates control all resources, such as fish andpetroleum. The treaty also demarcates thedelineation of sea boundaries and provides forpeaceful international navigation. The United Statesand other developed nations accepts this provisions.The controversy, however, centres around therecognized by the convention that all countrieshave a right to the natural resources in the watersbeyond the exclusive economic zone. Theconvention provides for setting up an Internationalsea bed authority to regulate the mining and othereconomic exploitation of the resources with“Enterprise”.

The adoption, by an overwhelming majority ofnations of the convention of the UN conference onthe law of the seas will unfold a new opportunityin the realization of the goal of a new internationaleconomic order, and global co-operation.

It is heartening to note that our country has beenrecognized as a pioneer investor in ocean miningby the United Nations and has thus been entrustedwith a heavy responsibility for the development ofnecessary technological infrastructure and capabilityfor the exploitation of the resources of the oceanwhich belong to the entire population on the globe.This is unique challenge and a rewardingopportunity for us.

Considering the crucial importance of the oceanresources for development in an ecological fashionby developing appropriate technology and capability,the Government of India has set up the Departmentof Ocean Development (DOD) to carry out themanifold broad objectives of policy-planning,coordinating with various agencies and monitoringand implementing various developmentalprogrammes on the ocean Science and technology.It is one of the major governmental agency entrustedwith the overall management of ocean and relatingmatters. It is also coordinating its activities withother federal agencies including the Department ofScience and Technology, CSIR and its laboratories,


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the Department of Environment and the UniversityGrants Commission for carrying out both basic andapplied research and developmental activities.

THE FUTURE SCENERIO

While presenting an overview on newdevelopmental advances in oceanography, withinthe national, international, legalistic, political andsocio-economic frameworks, I was primarily movedby one consideration as to how oceans can transformthe face of this planet by eliminating hunger, squalor,disease, imbalances and grim poverty in theemerging and foreseeable future. Whether oneadmits it or not, they are the last frontiers ofknowledge and human and social developments,holding a rich promise for the establishment of anecologically balanced human a rich promise for theestablishment of an ecologically balanced humanenvironment and rich quality of life. To put theissue little explicitly; for me, the human developmentand ocean development at this critical hour of ourhistory are interlinked and we should endeavour toaccelerate the pace of their development in anintegrated fashion.

A close look at the literature on variousdevelopmental activities reveals that rarely ourexperts in various disciplines of knowledgeendeavour to provide objective projections into thefuture. But what does the futurologists tell us? It isinteresting to observe that, in the sixties, most ofthe futurologists presented a picture, a vision of thefuture of an unending explosion of knowledge andaccomplishments in diversified developmental areas.Surprisingly, these very prophets of optimism arecurrently predicting a global crisis, a highlytechnological and nightmarish society animated byhuman and artificial robots. It is not an exaggeratedstatement, if I am permitted to say, that theseprophets of gloom and doom are presenting thefuture scenerio in terms of total despair and eventhe extinction of human life on this planet. Some ofthe indications are

1. explosion of population;2. imbalanced development amongst the

developed and developing societies;

3. impairment of the biosphere;4. stagnation and inflation eroding the world

economy;5. military expenditure reaching a new appalling

record of 450 billion per year;6. rampant social ills of poverty, injustice and

intolerance; and7. an absence of meaningful dialogue between

east and west.

Granted that we are passing through crucialtimes, I have a firm faith in the human will and itscapacity to meet these challenges withdetermination. The very fact that our presentsituation is likely to end in global disaster shouldprovide us with new opportunities and an newcommitment to transform it is so that it may becomean exceptional opportunity. Let us not forget thatthere is a close co-relation between crisis andcreativity and this could be amply substantiatedfrom the study of the lives of great men.

There are enough evidences, based on scientificresearches and speculative thinking, which clearlysubstantiate that the following are frontier are aswhere major breakthroughs in oceanography arepossible in the foreseeable future. These are

1. revolutionary developments in the area ofremote sensing technology for prospectingoil and material and biological resources ofthe sea with the use of satellites, specialaircraft, and research vessels;

2. development and deployment of oceanmonitoring equipment extensively forcollecting, analyzing data on the marineenvironment;

3. innovative developments in the frontier areaof underwater archeology;

4. exploration into the behaviour pattern of sealife with the help of underwater acousticaltechniques;

5. a foreseeable possibility of revolutionarybreakthroughs in the areas of marinepharmacology;


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6. understanding of the genetic behavior of sealife relation to their immunity to fatal diseaseslike cancer;

7. a new possibility of understanding theevolution of life in other planets, based onthe discovery of entirely new marine life,surviving on toxic volcanic effluents in thebottom of the sea;

8. establishing innovative technologies forunderwater communication system andlinking it with the land-based communicationnetwork;

9. building a new complex and sophisticatedsystem of transportation which will be self-sufficient and immune from disasters; and

10. an emerging possibility of colonization onthe sea floor by human population living onfloating or submergible vehicles with anaccess to modern facilities.

Considering the strategic importance and urgencyof exploiting the vast ocean resources, scientistsand technologists would be working on newer andmore sophisticated electronic remote sensingtechniques for locating, identifying and estimatingthe vast reserves of oil well, mineral deposits andbiological wealth of the oceans, particularly in theshallow zones of the continental shelf. Satelliteshave already been put to use to locate and followoceans currents like gulf stream, ocean bottomprofiles showing the path of rivers flowing into thesea. Acoustical and radio sounding techniques wouldundoubtedly be improved and perfected to identifyand delineate the large oil wells besides vast depositsof natural gas, manganese nodules, precious goldand diamond and rate elements like nickel andchromium, etc.

To ensure a balanced development of the marineenvironment, it is absolutely necessary that weshould give top priority to monitor the ecologicalcharacteristics of the ocean by an extensive use ofhighly sophisticated instrument packages locatedon floating buoys deployed at specific points on theoceans for collecting scientific data. This processwill also involve the establishment and the use of

highly sophisticated computer systems which willbe located in the world ocean data center toconsolidate the wealth of data, store and analyseand present the results in the form of weatherprofile map. Apart from yielding meaningful resultsin the various dynamics of the oceans, this processwould enable us to produce and publish oceanweather maps along with the meteorological mapsin the dailies. They would aim at enhancing theaccuracy of prediction of our weather, both on theland and in the ocean.

Another unique and an exciting possibility whichneeds to be exploited at an optimum level relates tothe development of underwater archeology. Theestablishment of an underwater, archeology is likelyto bring about a major breakthrough in theidentification of many new cities, towns andcivilization which existed and flourished during thepre-historic times. At the same time, we will beable to develop innovative methods and techniquesto be employed by historians for understanding thehistorical processes and developments of humancivilizations.

A new understanding of the extraordinarycapabilities of the ocean life may enable mankindto design and develop new instruments. Say forexample, the discovery of radar was based on theauditory capability of bats to fly in total darknessavoiding all obstacles. In a similar way, we couldvisualise the possibility of several breakthroughs inthe area of instrumentations during the process ofour study of the behaviour characteristics of the sealife.

The marine pharmacology is another vital areain which we are likely to witness severalbreakthroughs. In any analysis of the developmentof oceanic resources, we should not overlook thefundamental fact that the ocean biological wealthabounds in innumerable species which are totallyresistant to fatal diseases like cancer, epilepsy andheartattacks, etc. An analysis and understanding oftheir genetic and other characteristics may unravelthe new and exciting possibilities of developing


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new diagnostic and treatment methods. It may beadded that very little work has been done on thegenetic studies of marine organism. We can envisagethe possibility of relating genes structure of sea lifewith its behavourial characteristics and to specialcapacity of resistance to various diseases which areafflicting mankind. These new discoveries willadvance the frontier of knowledge in the areas ofmedical sciences and improve the diagnostic andcurative aspects of various ailments.

A new possibility of understanding the evolutionand development of life in our neighbouring planets,based on the recent discovery of a new form of life,surving on toxic effluents in volcanic regions at thebottom of sea could be visualized. It is interestingto observe that the recent discovery of new formsof life without having any access to oxygen andcarbon dioxide in the volcanic regions at the bottomof the ocean, — which is nourished by the newtype of bacteria fed on hydrogen — might enableus to identify and understand the evolution ofvarious types of life in our neighbouring planets.The study of these new forms of life has to bepursued relentlessly from a changing perspective.Such studies will produce meaningful results inour biological knowledge.

We are on the verge of witnessing a revolutionarybreakthrough in the area of underwatercommunication systems. While we have the sonarsystems for communication between ships and sub-marines, it is almost impossible for two submersibleor two diverse vessels to communicate with eachother in view of the ineffectiveness of radiocommunication and constraints in soundcommunication systems. If mankind has to realizethe dream of colonization on the ocean bottom, itis absolutely necessary to accelerate the pace ofresearch and development in this area.

While mankind has been using the seacraft foradventuring and commercial purposes for overseveral centuries, we have not yet witnessed anymajor breakthrough in the area of oceantransportation. This is an area where revolutionary

designs of new transportation system are likely tobe evolved which will be highly stable and dynamic.These large ocean–going vessels will have theintrinsic merit of being self-sufficient in terms offood, energy, communication and other physicaland recreational amenities, etc.

Looking at the phenomenal explosion of globalpopulation, mankind may have to look forcolonization of the ocean areas by building townsand cities under the sea. It should be noted that theenvironment on the sea bottom is more congenialas the temperature is moderate and does not undergoan appreciable daily or seasonal changes. Thegreatest obstacle for man is to find the enormousresources of oxygen necessary for living under thesea and also to move from place to place. Man’sexploration of the sea has always been limited bylack of oxygen which he has always to carry on hisback in the form of a tiny cylinder. Is it possible tomake a synthetic gill imitating what the livingtissues of fishes gill do? Scientists haveexperimented on many materials and perhaps arenearer the solution to have a thin membrane ofpolyestrine and rubber silico, which will permitoxygen to prevent the water to flow in. While airhas 200 c.cs. of oxygen for every litre, sea has only9 c. cs. of dissolved oxygen. Although this amountis small, it is enough to supply man’s needs. Thefuture possibility of extracting oxygen from sea-water through special membranes must be explored.

Hopefully, these possibilities would soon becomerealities with the advancement of our knowledge inoceanography in the near future and ultimatelywould enable mankind to survive in the oceans.Granted that with the exploration of moon, wecould not succeed in migrating our expandingpopulation to the moon but I am confident that acolonization of oceans by the people of the earth isan emerging possibility in the near future.

Meeting of such creative minds in the city ofLord Venkateshwara—the seat of knowledge—forlooking forward towards the solution of manifoldproblems, which are making the human race


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uncomfortable, reminds me that most of our creativeworks have been accomplished at sacred places. Infact, the birth of our scientific knowledge can belocated in our philosophical and spiritual traditions

It is fascinating to note that during the post-Newtonian period we have witnessed thefragmentation of knowledge in diverse disciplines,leading to the emergence of the Cartesian divisionand the mechanistic world view. They have beenextremely successful in the advancement of ClassicalPhysics and technology but had many otherimplications on the development of man and society.The twentieth century Science which originated inthe Cartesian division and the mechanistic worldview is now trying to overcome the fragmentationand leading us back to the idea of unity expressedin the Greek and Eastern philosophies. One runsinto many statements by the distinguished physicistsof our century about the radical transformation ofour whole world view, based on ecological ideas ofinterconnections and interdependence. Here is aninsight from Julius Robert Oppenheimer.

The general notions about human understanding... which are illustrated by discoveries in AtomicPhysics are not in the nature of things whollyunfamiliar, wholly unheard of, or new. Even in ourown culture they have a history, and in Buddhistand Hindu thought a more considerable and centralplace. What we shall find is an examplification, anencouragement, and a refinement of old wisdom.

What Neils Bohr had to say on the subject isequally relevant for our purpose. He writes.

For a parallel to the lesson atomic theory ... (wemust turn) to those kinds of epistemologicalproblems with which already thinkers like theBuddha and Lao Tzu have been confronted, whentrying to harmonize our positions as spectators andactors in the great drama of existence.

Please permit me to invoke Lord Venkateswara’sblessings that he should provide us a creative sparkand guide us during the deliberations in the nextfew days. Hopefully, the deliberations will generate

ideas on diversified areas of development and fosterthe spirit of cooperation and collaboration amongstvarious countries on many experimental areas for aquantum leap forward in the area of oceanography.

I express my sincerest thanks to our distinguishedPrime Minister for inaugurating the Sciencecongress and for continuously providing us adynamic leadership in the development of Scienceand technology in general, and Ocean Science inparticular. The creation of the department of theOcean Development clearly indicates hercommitment to the advancement of the last frontiersof knowledge.

SOURCES CONSULTED

Alexander, L. M., (Editor), The Law of the Sea :National Policy Recommendation, Proceedings ofthe Fourth Conference on the Law of the SeaInstitute, University of Rhode Island, 1970.

Baker, J. M. (Editor), Marine Ecology and AirPollution, New York: Wiley, 1976.

Bardach, J. E., Ryther, H. E. and McLarney,W.O., Aquaculture, New York: Wiley, 1972.

Bardach, J. E., Harvest of the Sea, John Dicken,1968.

Barlett, Jonathan (Editor), The OceanEnvironment, New York: H. M. Wilson 1977.

Bascom, W., Waves and Beaches : The Dynamicsof the Ocean Surface. Garden City N. Y. Doubleday,1964.

Bates D. R., The Earth and its Atmosphere,New York Basic Books, inc.

Bhatt J.J., Oceanography — Exploring the PlanetOcean.

——, Environmentology : Earth’s Environmentand Energy resources, Cranston, Rhode island:Modern Press, 1975.

——, Oceanography : Exploring the PlanetOcean, D. Van. Nostiand Co. 1978.

Broecker. W. S., Chemical Oceanography, NewYork : Harcourt Brace Jovanovich, 1974.

Brown, Seyan, Marine Resources.Burke, C. A., and Drake, C. L. (Eds), The

Geology of Continental Margins, New YorkSpringer, 1974.


286

Carlisle Noman, Riches of the Sea, PhoenixHouse, 1958.

Carson, Racbel (Editor). The Sea Around Us.

Chapman, V.J. Seaweeds and Their Uses, secondedition, London : Methuen. 1970.

Champman A.R.O., Biology of Seaweeds,Edward Arnord, 1979.

Church T.M. (Editor). ACS Symposium Series,Marine Chemistry in the Coastal Enviroment.

Coker R.E., The Great and Wide Sea, NorthCarolina Press. 1954.

Colman John. S., The Sea and its Mysteries,G. Bell & Sons. 1958.

Cowen R.C., Frontiers of the Sea, 1960.Cronan D.S., Underwater Minerals, Academic

Press, 1980. This is part of Ocean Science Resourcesand Technology—An intermational Series.

Cushing, D.H., Marine Ecology and Fisheries,London : Cambridge University Press. 1975.

——, Fisheries Resources of the Sea and theirManagement, New York : Oxford University Press,1975.

Duxbury A.C., The Earth and its Oceans,Reading, Massachusetts : Addison-Wesley, 1971.

Fanbridge R.W., The Encyclopedia ofOceanography.

Friedman, W.A., The Future of the Oceans,New York : Dobson, 1972.

Firth F. E. (Editor), The Encyclopedia of MarineResources, 1969.

Garstang Walter, Larval Forms.Gullin A. (Editor), User of the Sea, Englemann

Cliff.Gaskell, T. F., The Gulf Steam, London : Cassel,

1972.Greon, P., The Waters of the Sea, New York :

Van Nostrand Reinhold, 1967.Hanson J. A. (Editor), Open Sea Mariculture,

Drowden, Hutchinson and Ross, inc. 1974.Heezen, B. C. and Hollister, C. D., The Face of

the Deep, London : Oxford University Press, 1971.Hardy, Sir Alister, The Open Sea, 1971.———, Great Waters, Harper Row, 1967.

Hill P. J. and Hill, M. A. The Edible Sea. NewYork. Barnes and Noble, 1976.

Hill M. N. (Editor). The Sea Volume–1. PhysicalOceanography

Volume–2. Composition of Sea—Water—Comparaitive and Descriptive Oceanography.

Volume–3. The Earth Beneath The Sea, 1956.Johan Hyort and John Murray, The Depths of

the Ocean. 1956.Jackson Daniel F., Algae and Man, Plenum

Press, 1964.Jones, O.A., and Endean, R. (Eds), Biology and

Geology of Coral Reefs., New York : AcademicPress, 1973.

Kinsman, Blair, Win Waves : The Generationand Propagation on the Ocean Surface, EnglewoodCliffs, New Jersey : Prentice-hall. 1965.

King. C. A. M. Beaches and Coasts. SecondEdition. London, Edward Arnold, 1972.

King, Otto. (Editor)., Marine Ecology : AComprehensive, Integrated Treatise on Life inOceans and Coastal Waters, New York : Wiley.1975.

Komar. P. D., Beach Processes andSedimentation, Englewood Cliffs, New Jersey :Prentice-hall. 1976.

Larsen Egon, Men under the Sea. Phoenix House.Loftas Tony., Wealth From the Oecans, Phoenix

House.Madal, A. B. (Editor) : Environment.Margaret Deacon : Scientists and the Sea 1650-

1900, A study of Marine Science.Mary Sears and Daniel Merriaman :

Oceanography, the past.Martin, D.F. Marine Chemistry, Volume–2 :

Theory and Application, New york : Marcel Dekker,1970.

Mathews, W.I.T. Smith, F. E. and Goldberg,E.D. (Eds), Man’s impact on Terrestrial and OceanicEcosystems. Cambridge, Massachusetts : M.I.T.Press, 1972.

Mc. Lellan. J., Elements of PhysicalOceanography.


287

Mc. Connaughey. B. N. Introduction to MarineBiology. Second Edition. 1974

Menzies, R. J., George, R. Y. and Rowe, T. R.,Abyssal Environment and Ecology of the WorldOceans, New York : Wiley 1973.3

Mero J. L.. The Mineral Resources of the Sea,New York : Elsevier, 1965.

Miller, Robert C., The Sea. 551-46.Nelson-Smith, A. Oil Pollution and Marine

Ecology, New York : Plenum, 1973.Norman Carlisle : Riches of the Sea — The New

Science of Oceanology.Palmer Muyvin C., Algae and Water Pollution.Parsons, T. R. and Takahasl. M., Biological

Oceanographic Processes, Oxford : Pergamon,1973.

Pell, Clarborne, Challenges of the Seven Seas,910—02166, P 38.

Piccard Auguste, Earth Sky and Sea, OxfordUniversity Press.

Pirie, R. G., Oceanography: ContemporaryReadings in Ocean Sciences, New York: UniversityPress, 1973.

Rilley, J. P. and Chester, R., Introduction toMarine Chemistry, New York : Academic Press,1971.

Robert C. Cowen, Frontiers of the Sea — TheStory of Oceanographic Exploration.

Robison, Allan R. (Editor), Wind Driven OceanCirculation, 1963.

Sapr J. Earth, Sea and Air : A Survey of theGeophysical Sciences, Addison-Wesley PublishingCo.Inc. 1962.

Saunder T. (Editor), Ocean Resources and PublicPolicy.

Schlee, Susan, The Edge of Unfamiliar World:A history of Oceanography. New York : E. P.Dutton, 1973.

Schmitt Walter R. and Wick Gerald, L.,Harvesting Ocean Energy, Unercu Press, 1981

Shapley Harlow (Editor), Climatic Change :Evidence, Causes and Effects, Harvard UniversityPress, U. S. A.

Shephard, F. P., Sumarine Geology, ThirdEdition, New York Harper, 1974.

Shepard F. P., The Earth Beneath the Sea, JohnHopkin Press.

Smith F. G. W., The Seas in Motion, New York :Growell, 1973.

Smith J. L. B., The Search Beneath the Sea.Spar, J., Earth, Sea and Air: A survey of the

Geophysical Sciences, Reading, Massachusetts :Addison - Wesley, 1973.

Sullivan, Walter., Continents in Motion : Thenew Earch Debate, New York : Mc.Graw-Hill,1974.

Sverdrup, H. U., Johnson, M. W. and Fleming,R.K., Oceans: Their Physics, Chemistry and GeneralBiology, Englewood Clieffs. New Jersey : Prentice-Hall.

The Open University : Oceanography —Introduction to Oceans.

Thorson, Gunner, Life in the Sea, New York :McGraw Hill, 1971.

Tsunami: U. S. Coast and Geogetic Survey 1956.The Story of the Seismic Sea Wave Warning System.

Turekian, L. K., Oceans, Second Edition,Englewood Cliffs, New Jersey, 1976.

Urey H. C., The Planets, Their Origin andDevelopment. Yale University Press, 1952.

Von Arx, W. S., An introduction to physicalOceanography, Readings Massachussets: AddisonWesley, 1975.

——, Introduction to Physical Oceanography,Second Edition, Reading Massachussets, Addision-Wesley, 1975.

Walford L. A., Living Resources in the Sea.,Ronald Press.

Wenk, Edward, Jr., The Politics of the Ocean,Seattle: University of Washington Press, 1972.

Williams, Jerome, OceanographicInstrumentation, Annapolic, Maryland: NavalInstitute Press, 1973

Yorge C. M. and Russell F. S. The Seas — OurKnowledge of Life in the Sea and How it is Gained,Frederick Wame Co.Ltd., 1958.


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BIOLOGICAL RAIN - A NEW WINDOW FOR HARVESTINGATMOSPHERIC MOISTURE

A. K. Srivastava* and Yogranjan**

Recurrent droughts in several regions of the world and its disastrous impacts on survival oflife have necessitated to look for a viable option for harvesting atmospheric moisture. Humanefforts have been made to make rain artifically through physical and chemicals means.Recently, in addition to these two, biological agents are also being exploited at experimentallevels for harvesting atmospheric moisture. The biological alternative specifically termed as“Bioprecipitation” proved to be economically feasible and practically viable.

* Department of Physics & Agrometeorologyemail:[email protected]

** Department of Biotechnology, College of Agriculture, J.N.Agricultural University, Tikamgarh (M.P.), India-472001

INTRODUCTION

W ater/moisture is the foremost necessaryclause for existence of life on any

planet. Earth and its atmosphere have enough water/moisture to support life, but still there is severescarcity of water in several regions and due towhich habitat suffers a lot. Ways and means havebeen exploited from time immortal by a number ofcreatures including human in search of water/moisture to sustain their life. Establishment ofmany ancient cities on the bank of rivers to haveeasy and economic access of water exemplifited thehuman efforts in the history. Consequent uponindustrial revolution and intensive agriculture,demand of water has increased exponentially thatmade the scenario for natural rainfall as insufficientto fulfill this demand. All these led to put pressureon human to invent methods to harvest availableatmospheric moisture or create rain artifically.

The harvesting of atmospheric moisture/waterhas been a major challenge in arid and semi-aridregions of the world where water level is abnormally

low on account of scanty rainfall. Therefore, aneasier and less expensive way has to be ascertainedto get moisture/water. During the last two decades,a number of atmospheric moisture harvestingexperiments has been tried and attempts weredemonstrated to sustain the habitats’ life. Theseexperiments mainly encompassed use of chemicalnucleators and other machines and biologicallyactive microorganisms and plants. Chemicals suchas Silver Iodide, finely powdered Sodium Chloride,solid CO

2 mediated artifical rain experiments and

were successfully demonstrated the possibility ofharvesting atmospheric moisture, but proved to bequite expensive and have some harmfulconsequences to human and environment also,therefore not much preferred. Many plant pathogensand plant surfaces have cutting edge over chemicalmeans owing to their economical and eco-friendlyapproach. Numerous plant pathogens and plantsurfaces have super-hydrophilic or hygroscopicproperties and are thus likely to be able to absorbwater from atmosphere. The bacteria Pseudomonassyringae and Pseudomonas fluroescens migla (plantpathogen) and the bromeliads (plants ofBromeliaceae family) are among the best knownexamples. These biological classes that make raingiven way to a novel concept of Bioprecipitation.


289

PHYSICS OF PRECIPITATION

Clouds are aggregate of minute water dropletssuspended in the atmosphere. Droplets producedby the condensation process are indeed very smallin size, averaging less than 10 micrometer indiameter, seem to float in the air. Rain drops havediameters ranging from about 200 microns upto700 microns. The drops larger than this upper limit(500 microns) have capability to fall against airupdraft motion. The cloud droplets to join togetherto from large rain drops capable of failling to earthas precipitation. In certain type of clouds, the waterdroplets do not tend to coalesce and all the timethey are kept floating in the air and no precipitationis released from them. On the contrary, in certaincloud froms, the droplets have a tendency to jointogether and big size rain drops develop and theyare producers of precipitation. Two mechanismshave been proposed to explain these processesnamely ice-crystal theory of Bergeron (for clodclouds) and Collision-coalescence theory of Bowen(for warm clouds). Either to condense, to grow orto coalescence, a hygroscopic nuclei is required tobe present in the atmosphere.

RAINFALL AND ICE CREATING BACTERIA

Atmospheric moisture vary between 0.2 to 4 percent and harvesting it through experiments otherthan chemical means viz; water house, wind turbineand bacterial use are some of the recent developmentin the field of research aiming to achieve artificalrain. Looking to the severity of demand and itseco-viable vista, research efforts leading to microbesmediated artificial rain or very specificallybioprecipitation has fetched wider global attention.The first ever concept of bioprecipitation wasenunciated by David Sands et al1.

The concept of biological rain through bacteriamaterialized from the basic natural phenomenonthat, before a cloud can produce rain or snow, raindrops or ice particles must form. This requires thepresence of tiny particles that serve as the nuclei

for condensation. Traditionally minerals werethought to be the dominant ice nucleators in theatmosphere, however, airborne microbes likebacteria, fungi or tiny algae can do the job just aswell2. Unlike mineral aerosols, living organismscan catalyse ice formation even at temperaturesclose to 0°C. The new research finding also supportthat a large variety of macroorganisms includingbacteria, fungi, diatoms and algae, persist in theclouds can be used as precipitation starters.

A few physiologically distinct groups of bacteriaassociated with plants are reported to be capable ofice nucleation “in vitro” and “cause” frost injury ofplants3. Some of the Bacteria like Pseudomonas

syringae, P. fluorescens migla and Erwinia herbicolaserve as effective ice nucleators even at relativelyhigh temperatures of – 1 to – 2 degree Celsius.There is also a remarkable fact that, most knownice-nucleating bacteria are plant pathogens. A recentstudy confirmed that the rain making bacteria thatlive in clouds might have evolved the ability toimpel showers as a way to disperse them worldwide.

Some very potent ice nucleators in decayingplant matter were found that made the surprising

discovery that they came from microbes4. A fewyears later, the bacteria Pseudomonas syringae was

identified as the source of these nucleators5;parallelly, Deane Arny discovered that more frost

formed on plants infected with P. syringae.

The rain making potential of bacteria lies on a

mechanism that the bacteria produce a specialprotein, InaZ, which can act as an ice nucleus at the

relatively warm temperature of – 2°C, probablybecause its repetitive shape is just right for coaxing

water molecules into a crystalline arrangement. Air,including clouds, is usually full of micro-organisms

like bacteria and fungi, some of which produceice-nucleators. Ice crystals which form in cloudswill grow until they are big enough to fall as eitherrain or snow depending on whether they melt on


290

the way down. Researchers have detected P. syringae

in fresh rain, snow and ice from a wide range of

locations including Louisiana, the French Alps and

even Antarctica. Another team of researches found

that one-third of the ice crystals in clouds over

Wyoming had formed around biological particles.

MICROBE WATER CYCLE AND BIO-PRECIPITATION

Like natural water cycle there exists microbe

water cycle also, but in this cycle microbes (Bacteria,

Fungi) do not change their physical status. These

bacteria and fungi are found as high as 30,000 feet

in the atmosphere. The researchers found air mass

and hurricanes that spew these bacteria from water

and land surfaces into atmosphere. It was observed

that mostly marine bacteria, and terrestrial bacteria

were originated over water and land. These bacteria

were dynamically mixed with other particles and in

terms of distribution, there were about 144 bacteria

cells found in every cubic foot of air. Reported

information suggests that the bacteria gets out of

clouds and back to Earth and on plants through rain

and thus complete the cycle.

Similar to the natural phenomenon,

bioprecipitation also requires a source of nucleation;

such sources exist both outside and within plants.

Outside sources of nucleation include dust particles,

organic matter, bacteria and even gas bubbles. These

bacteria populate on the surface of many plants

species, and frost formation on such plant surfaces

bears a logarithmic relationship to the number of

ice nucleating bacteria on the plant surface. A

reduction in number of such bacteria on plant

surfaces reduces the threshold temperature for frost

formation. The same bacteria that cause frost

damage on plants can help clouds to produce rain

and snow. Studies on freshly fallen snow suggest

that ‘bio-precipitation’ might be much more

common than was suspected.

HARVESTING MOISTURE THROUGHPLANT BREEDING AND LANDMANAGEMENT

Plants harbor large numbers of microogranismson their surfaces. Cultivated plants, in particular,are considered to be a major source of themicroorganisms – and especially the bacteria.Canopies of snap bean, for example, harbor INAstrain of bacteria Pseudomonas syringae in strengthof about 30 bacteria/m2/Sec in the air. Sands andcolleagues proposed the existence of a biologicalcycle whereby colonization of plants by INAbacteria contributes to enhanced precipitations whichin turn augment plant and microbial growth andcontributes to the dissemination of bacteria to newplants1. Thus plants could be considered to becloud seeders. Attempts must be made to widen thehost range of the crops suitable for bacterialcolonization by specific strain. Future selectivebreeding followed by effective selection would offerthe potential for plant evolution to support highnumbers of INA bacteria. For maximizing INAbacteria anchorage on plant surface, selection forspecific canopy properties may be one possibleavenue. It will of course be important to establishthat newly introduced or selected crop cultivarswith increased harboring efficiency should at leastmaintain yields of existing varieties and ideally beresistant to the pathogenicity of INA bacteria. Plantbreeding and agronomic strategies that enhancethese forms could be investigated to reduce thespread of plant pathogenic INA bacteria. Aconsiderable knowledge base integrating researchin agronomy, microbiology, meteorology, physics,sociology and economics will be needed to bringus to the point of such choices.

ENVIRONMENTAL EFFECTS OFHARVESTING RAIN THROUGH BACTERIA

Artificial rain produced by several chemical viz;Silver Iodide (costly) or solid carbon dioxide oreven finely powdered Sodium Chloride (cheaper)leads to accumulation of these chemicals in plant


291

and animal bodies which could create argyria,anaemia, weakness and loss of weight. Similarlyadverse health implications were also reported fromthe study conducted at the “Bangalore Universitywhich revealed that the first rains of summerencompassed high level of pathogens includingStreptococcus spp, Staphylococcus aureus,Enterococcus spp, Actinomyces spp, Bacillussubtilis, Neisseria spp, and Mycobacterium sp inaddition to E coli.” These fungal species can causeinfectious disease, have acute toxic effects, andgive rise to allergies and cancers. However, thereseem viable preventive as well as remedialalternatives available for microbial borne diseasesas compared to that of chemically induced.Therefore, despite to the risk involved inbioprecipitation, the option is quite preferableconsidering economical, environmental and remedialaspects.

CONCLUSION

Demand of water has increased tremendouslyand in some regions natural precipitation is notenough to sustain lives. The artificial rain makingis a tool and possesses the potential to fulfill, tosome extent, the demand of water, but is quite

expensive and has limited applicability due to itsenvironmental effects. Bio-precipitation emergedout as a new hope for water harvesting, though it’spro and cons have not been fully evaluated, butseems to be economically feasible and practicallyviable for water harvesting. However, beforematerializing the concept, a scientifically soundrisk-benefit assessment must be executed leading toan explicit prospect of Bioprecipitation.

REFERENCES

1. D.C. Sands, V. E. Langhans, A. L. Scharen,Smet G. de J. Hungarian MeteorologicalServ. 86, 148-152, 1982.

2. C. Brent Christner, Cloudly With a Chanceof Microbes, Microbe 7.2 : 70-75. ChristnerResearch Group. Louisiana State University.Web. 28 Oct. 2012 <http://brent.xner.net. >.

3. S.E. Lindow, Annu. Rev. Phytopathol. 21,363-384, 1983.

4. R. C. Schnell, and G. Vali, Nature, 236,163-164, 1972.

5. L. R. Maki, E. L. Gaylan, M. M. Chang-Chien, D. R. Caldwell Appl. Microbiol.28, 456-459, 1974.


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DIABETES AND MEDICINAL PLANTS

R. U. Abhishek, D. C. Mohana*, S. Thippeswamy and K. Manjunath

Diabetes mellitus is a metabolic disorder characterized by chronic hyperglycemia or increasedblood glucose levels, resulting from insufficient or inefficient insulin secretion, with alterationsin carbohydrate, protein and lipid metabolism. Type 2 diabetes is the most prevalent form, ofthe total diabetics about 90% have type 2 diabetes, which is characterized by post-prandialhyperglycaemia (increase in blood sugar level after a meal). Many medicinal plants arereported to have insulin-mimetic effect, modulation of insulin secretion and inhibition ofcarbohydrate digesting enzymes.

* Department of Microbiology & Biotechnology, JnanaBharathi, Bangalore University, Bangalore- 560056, E-mail: [email protected]

INTRODUCTION

S ince ancient times, plants have been anexemplary source of medicine. Ayurveda

and other Indian literature mentioned the use ofplants in treatment of various human ailments. InIndia, indigenous plant remedies have been used inthe treatment of Diabetes mellitus since the time ofCharaka and Sushruta (6th century BC)1. Plantshave always been an exemplary source of drugsand more than 80% of the currently available drugshave been derived directly or indirectly from them.Medicinal plants have the advantage of having noor only few side effects. Some of them are beingused in traditional systems of medicine fromhundreds of years in many countries of the world.Metformin is an oral antidiabetic drug used for thetreatment of non-insulin-dependent diabetes mellitus(NIDDM) patients. Metformin is now believed tobe the most widely prescribed antidiabetic drug inthe world; it was first derived from a medicinalplant Galega officinalis, which was historicallyused for treatment of diabetes in medieval Europe2.There are many antidiabetic plants which mightprovide useful sources for the development of drugs

which can be used in the treatment of diabetesmellitus. The literature on medicinal plants withantidiabetic activity is vast, so a few commonlyused plants have been discussed here.

WHAT IS DIABETES ?

Diabetes mellitus is a complex metabolic disorderresulting from either insulin insufficiency or insulindysfunction. The disease is primarily classified intoinsulin-dependent diabetes mellitus (type 1 dabetes,IDDM), non-insulin-dependent diabetes mellitus(type 2 diabetes, NIDDM) and Gestational diabetesmellitus (GDM). The prevalence of NIDDM isincreasing globally. Of the total diabetics, about90% have NIDDM3, which is characterized bypost-prandial hyperglycaemia (PPHG) andassociated with post-prandial oxidative stress. PPHG(increase in blood sugar level after a meal) plays animportant role in the development of NIDDM, aswell as in complications associated with thecondition, including micro-vascular and macro-vascular diseases.

Most of the food we eat is broken down intosimple sugar glucose, which is the main source offuel to get energy for the body. After digestion theglucose reaches our blood stream where it isavailable for the cells to utilize for energy, but


293

insulin is needed for the uptake of glucose into thecells. Insulin is a hormone secreted by the pancreas,it has to be secreted in adequate amount to transportglucose from blood into different cells of the body.If the insulin is not produced sufficiently or theproduced insulin does not work efficiently, theglucose is not taken into the body, remains in theblood. This makes rise in blood sugar level causeshyperglycaemia. If a diabetic person has high bloodsugar, either because the body does not produceenough insulin, or because cells do not respond tothe insulin that is produced. This high blood sugarproduces the classical symptoms of polyuria(frequent urination), polydipsia (increased thirst)and polyphagia (increased hunger)4.

Pancreatic α-amylase is a key enzyme in thedigestive system and catalyses the initial step inhydrolysis of starch to a mixture of smalleroligosaccharides. These are then acted on by α-glucosidases and further degraded to glucose whichon absorption enters the blood-stream. Degradationof this dietary starch proceeds rapidly and leads toelevated PPHG (post-prandial hyperglycemia).PPHG can be controlled by delaying the absorptionof carbohydrates from the gastrointestinal tract byinhibiting digestive enzymes. Foodstuffs which arerich in phenolic compounds are known to inhibitdigestive enzymes, most of the phenolics of millets(finger millet or ragi) and grains are concentratedin the seed coat5. Many plants (Indian gooseberry,guava, and pomegranate), vegetables (cauliflower,garlic, onion) and leafy vegetables (amaranth,punarnava) are reported to have hypoglycaemicactivities. An herbal formulation containing thethree medicinal fruits Phyllanthus emblica (Amla),Terminalia belerica (Bibhitaki) and Terminaliachebula (Haritaki) named Triphala (Sanskrit, tri =three and phala = fruits), is traditionally usedmedicine for the treatment of diabetes.

TYPES OF DIABETES6

Type 1 diabetes is called as insulin-dependentdiabetes mellitus (IDDM), immune-mediated or

juvenile-onset diabetes. It is caused by an auto-immune reaction where the body’s defense systemattacks the insulin-producing cells. This diseasecan affect people of any age, but usually occurs inchildren or young adults. People with this form ofdiabetes need injections of insulin every day inorder to control the levels of glucose in their blood.

Type 2 diabetes is called as non-insulin-dependent diabetes mellitus (NIDDM), and accountsfor at least 90% of all cases of diabetes. It ischaracterized by insulin resistance and relativeinsulin deficiency, either of which may be presentat the time that diabetes becomes clinically manifest.The diagnosis of NIDDM usually occurs after theage of 40 but can occur earlier, especially inpopulations with high diabetes prevalence. It ischaracterized by insulin resistance and impairedbeta cell function.

Gestational diabetes (GDM) is a form ofdiabetes consisting of high blood glucose levelsduring pregnancy. It develops in one among 25pregnancies worldwide and is associated withcomplications in the period immediately before andafter birth. GDM usually disappears after pregnancybut women with GDM and their offspring are at anincreased risk of developing NIDDM later in life.Approximately half of women with a history ofGDM go on to develop type 2 diabetes within fiveto ten years after delivery.

DIABETES COMPLICATIONS4,5

One of the long-term complications of NIDDMis hypertension or high blood pressure. Hypertensionand NIDDM are interrelated metabolic disorders.Persistent hypertension is one of the risk factors forstrokes, heart attacks, heart failure and is a leadingcause of chronic renal failure. Thoughpathophysiology of diabetes remains to be fullyunderstood, experimental evidences suggest theinvolvement of free radicals in the pathogenesis ofdiabetes and more importantly in the developmentof diabetic complications. Free radicals are capableof damaging cellular molecules, DNA, proteins and


294

lipids leading to altered cellular functions. Manyrecent studies reveal that antioxidants capable ofneutralizing free radicals are effective in preventingexperimentally induced diabetes in animal modelsas well as reducing the severity of diabeticcomplications. For the development of diabeticcomplications, the abnormalities produced in lipidsand proteins are the major etiologic factors. Indiabetic patients, extra-cellular and long livedproteins, such as elastin, laminin, and collagen arethe major targets of free radicals. These proteinsare modified to form glycoproteins due tohyperglycemia. The modification of these proteinspresent in tissues such as lens, vascular wall andbasement membranes are associated with thedevelopment of complications of diabetes such ascataracts, microangiopathy, atherosclerosis andnephropathy. During diabetes, lipoproteins areoxidized by free radicals. As diabetes is amultifactorial disease leading to severalcomplications, and therefore demands a multipletherapeutic approach.

DIABETES AND INSULIN

Even insulin therapy does not reinstate apermanent normal pattern of glucose homeostasis,and carries an increased risk of atherogenesis andhypoglycemia1. Regardless of the type of diabetes,patients are required to control their blood glucosewith medications and/or by adhering to an exerciseprogram and a dietary plan. Insulin therapy byinjection is given to those with IDDM and also tosome patients with NIDDM when oralhypoglycaemic drugs fail to lower blood glucose.Due to modernization of lifestyle, NIDDM isbecoming a major health problem in developingcountries. Patients with NIDDM are usually placedon a restricted diet and are instructed to exercise,the purpose of which primarily is weight control. Ifdiet and exercise fail to control blood glucose at thedesired level, oral antidiabetic medication isprescribed. Several plants have been reported fortheir insulin stimulation and mimetic activities(Table 1).

S. Botanical nameNo.

1. Aloe vera

2. Amaranthus caudatus

3. Boerhaavia diffusa

4. Azadirachta indica

5. Caesalpinia bonducella

6. Ficus benghalensis

7. Glycyrrhizae radix

8. Gymnema sylvestre

Table-1Some important medicinal plants with antidiabetic properties6,8,9

Common names

True aloe, Ghritakumari

Amaranth tender, Chaulaisag

Hogweed, Punarnava

Neem

Yellow nicker, Kantkarej

Indian banyan, Indian fig,Bengal fig

Liquorice root, Mulethi

Gudmar, Madhunashini

Family

Liliaceae

Amaranthaceae

Nyctaginaceae

Meliaceae

Caesalpiniaceae

Moraceae

Fabaceae

Asclepidaceae

Beneficial effects

Hypoglycemic, wound healing indiabetics

Hypoglycaemic activity

Increases plasma insulin concentrationand insulin sensitivity

Hypoglycemic, reduces peripheralutilization of glucose and glycogenolyticeffect

Hypoglycemic, insulin secretagogue,hypolipidemic activity

Hypoglycemic, hypolipidemic, inhibitsinsulinase activity from liver and kidney,Insulin mimetic activity

Hypoglycemic activity

Stimulation of repair or regeneration ofbeta cells, anti-hyperglycemic effect,hypolipidemic


295

SYNTHETIC DRUGS AND HERBALMEDICINE

Oral antidiabetic agents exert their effects by

various mechanisms: (1) stimulation of β-cells in

the pancreas to produce more insulin (sulfonylureas

and meglitinides), (2) increasing the sensitivity of

muscles and other tissues to insulin

(thiazolidinediones), (3) decreasing gluconeogenesis

by the liver (biguanides), and (4) delaying the

absorption of carbohydrates from the gastrointestinal

tract (α-glycosidase inhibitors)6.

A major effort was directed toward discovery of

novel antidiabetic agents, which resulted in the

discovery of several patented compounds:

cryptolepine, maprouneacin, 3β, 30-dihydroxylupen-

20(29)-en-2-one, harunganin, vismin, and quinines7.

Galegine was isolated as an active antihyperglycemic

agent from the plant Galega officinalis L. used

ethnomedically for the treatment of diabetes.

Galegine provided the template for the synthesis of

metformin and opened up interest in the synthesis

of other biguanidine-type antidiabetic drugs2.

Since the hydrolysis of dietary carbohydratessuch as starch is the major source of blood glucose,it is believed that the inhibition of the carbohydratehydrolytic enzymes may be a promising strategyfor the management of NIDDM. Phytochemicalssuch as phenolics with strong antioxidant propertieshave been reported to be good inhibitors of theenzymes linked to NIDDM. Phenolic extracts ofplants were found to be effective inhibitors ofintestinal α-glucosidase and are being used tocontrol NIDDM. Some polyphenolic compoundsfrom plants are known to cause insulin like effectsin glucose utilization in mammals. Aloe vera, bittergourd, guduchi, Gymnema sylvestre (gudmar), neem,methi, Syzygium cumini (jamun) and pomegranateetc. are some most commonly used plants whichhave antidiabetic properties7,8. Several mechanismshave been investigated to explain theantihyperglycemic action of medicinal plants, whichinclude modulation of insulin secretion, insulin-mimetic effect and inhibition of intestinalglucosidase activity7,9. Some important commonlyused medicinal plants having antidiabetic propertiesand their beneficial effects are presented in Table 1.

Beneficial effects

Insulin mimetic activity

Decreases lipid peroxidation, antioxidant,hypoglycemic

Antioxidant, anti-hyperglycemic effect

Hypoglycemic, insulinogenic-enhanceinsulin release

Hypoglycemic, anti-oxidant activityty, α-glucosidase inhibitory activity

Stimulates insulin release from islets

Hypoglycemic, antioxidant, hypolipidemicactivity

Hypoglycemic, antioxidant, hypolipidemicactivity

Anti-hyperglycemic, stimulates insulinrelease from islets

Hypoglycemic activity, stimulates insulinrelease by islet cells

Family

Cucurbitaceae

Phyllanthaceae

Lythraceae

Fabaceae

Myrtaceae

Gentianaceae

Combretaceae

Combretaceae

Menispermaceae

Leguminosae

Common names

Bitter melon, Bitter gourd

Indian gooseberry, Amla

Pomegranate

Indian kino tree, IndianMalabar, Vijaysar

Jambul, Jamun

Indian gentian, Chirayata

Bahera, bastard myrobalan,Bibhitaki

Myrobalan, Harra, Haritaki

Amrita, Guduci

Fenugreek, Methi

S. Botanical nameNo.

9. Momordica charantia

10. Phyllanthus emblica

11. Punica granatum

12. Pterocarpus marsupium

13. Syzigium cumini

14. Swertia chirayita

15. Terminalia bellerica

16. Terminalia chebula

17. Tinospora cordifolia

18. Trigonella foenum-graecum


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DIABETES AND DIET

The uncontrolled diabetes can lead to long-termorgan damage, resulting sometimes in heart disease,stroke, vision loss, kidney failure, foot amputationor death, studies show. The diet frequentlyrecommended for people who suffer from diabetesis one that is high in dietary fibre, especiallysoluble fibre, but low in fat (especially saturatedfat) and sugar. Highly processed, calorie-dense,nutrient depleted diet leads to exaggerated increasein blood glucose and lipids that induces immediateoxidative stress5,10.

A statement of American Diabetes Associationrecommended the medical nutrition therapy (MNT)for diabetics. MNT is important in preventingdiabetes, managing existing diabetes, and preventing,or at least slowing, the rate of development ofdiabetes complications. MNT is an integralcomponent of diabetes self-management at all levelsof diabetes prevention4.

The MNT recommendations include4

(a) Energy balance, overweight, and obesity:

● In overweight and obese insulin resistantindividuals, modest weight loss has beenshown to reduce insulin resistance. Thus,weight loss is recommended for alloverweight or obese individuals who have orare at risk for diabetes.

● For weight loss, either low-carbohydrate orlow-fat calorie-restricted diets may beeffective in the short-term (up to 1 year).

● For patients on low-carbohydrate diets,monitor lipid profiles, renal function, andprotein intake (in those with nephropathy)and adjust hypoglycaemic therapy as needed.

● Physical activity and behavior modificationare important components of weight lossprograms and are most helpful in maintenanceof weight loss.

(b) Primary prevention of diabetes

● Among individuals at high risk for developing

NIDDM, structured programs emphasizing

lifestyle changes that include moderate weight

loss (7% body weight) and regular physical

activity (150 min/week) with dietary strategies

including reduced calories and reduced intake

of dietary fat can reduce the risk for

developing diabetes and are therefore

recommended.

● Individuals at high risk for NIDDM should

be encouraged to use dietary fiber (14 g

fiber/1,000 kcal) and foods containing whole

grains (one-half of grain intake).

Inhibition of pancreatic α-amylase could result

in the abnormal bacterial fermentation of undigested

carbohydrates in the colon and therefore mild α-

amylase inhibition activity is useful. Plant derived

compounds are reported to have strong inhibitory

activity against α-glucosidase and mild α-amylase

inhibition. High fibre content may further improve

the satiating effect of the diet and a diet rich in

soluble fibre, including oat bran, legumes, barley

and most fruits and vegetables, has the most

beneficial effect on blood lipids and blood pressure

levels10. Pulses are important in the diet as their

effect on blood glucose is less than that of most

other carbohydrate containing foods. Green leafy

vegetables rich in fiber help to lowering down the

blood sugar levels and thus are healthy.

REFERENCES

1. J. K. Grover, S. Yadav and V. Vats, Journal

of Ethnopharmacology, 81, 81-100, 2002.

2. C.J. Bailey and C. Day, Practical Diabetes

International, 21, 115-117, 2004.

3. National Diabetes Information

Clearinghouse (NDIC), National Institutes

of Health (NIH), USA, 2013.


297

4. American Diabetes Association, Standards

of Medical Care in Diabetes-2010, Diabetes

care, 33, 11-61, 2010.

5. F. B. Hu, Diabetes Care, 34, 1249-1259,

2011.

6. T. Pullaiah, K. C. Naidu, “Antidiabetic Plants

in India and Herbal Based Antidiabetic

Research”, Regency Publications, New

Delhi, pp.04-52, 2003.

7. A. Noor, V. S. Bansal and M. A.

Vijayalakshmi, Current Science, 104, 721-

727, 2013.

8. S. Chakrabarti, T. K. Biswas, B. Mukherjee,“Antidiabetic Plants: scientific Appraisal ata Glance” in ‘Recent Progress in MedicinalPlants”, Vol 18, Natural Products II, Editors-J.N. Govil, V.K. Singh and N.T. Siddiqui,Stadium Press, LLC, USA, pp. 275-309,2007.

9. M. Modak, P. Dixit, J. Londhe, S. Ghaskadbiand T.P.A. Devasagayam, Journal ClinicalBiochemistry and Nutrition, 40, 163-173,2007.

10. S. Pal, A. Khossousi, C. Binns, S. Dhaliwaland V. Ellis, British Journal of Nutrition,105, 90-100, 2011.


298

INTRODUCTION

A biofilm is a complex aggregation of microorganisms growing on a solid

substrate, varying in thickness from a mono celllayer to 6-8 cm thick, but mostly on an average ofabout 100 µm in thickness. Biofilms arecharacterized by structural heterogeneity, geneticdiversity, complex community interactions and ahydrated extracellular matrix (ECM) of polymericsubstances1. The first colonists facilitate the arrivalof other cells by providing more diverse adhesionsites and building the matrix that holds the biofilmtogether. Only some species are able to attach to asurface on their own. Others usually anchorthemselves to the matrix or directly to the earliercolonists. Once colonization has begun, the biofilmgrows through cell division2. A single bacterialspecies can form a biofilm, but in natural

FORMATION AND IMPORTANCE OF BIOFILM

Aryadeep Roy Choudhury*, Mayukh Chakraborty,Samadrita Bhattacharya

Biofilm can be defined as microbial communities attached to a surface. Biofilm-associated cellsare differentiated from their planktonic (free-swimming or suspended) counterparts bygeneration of an extracellular polymeric substance (EPS) matrix, reduced growth rates, andthe up- and down-regulation of specific genes. An established biofilm provide an optimalenvironment for the exchange of genetic material between cells. They also show greaterresistance to antibiotics since they present penetration barrier to such agents. Biofilms affectpublic health because of their role in certain infectious or chronic diseases and in a variety ofmedical device-related infections. This review focuses on the process of biofilm formation, theirdistribution, along with their industrial and clinical significance. A greater understanding ofbiofilm processes would lead to novel, effective biofilm-control strategies and a resultingimprovement in patient management.

environment, it often comprises various species ofbacteria, fungi, algae, protozoa and debris alongwith corrosion products2.

BACTERIAL BIOFILM

In their natural environment, biofilm commonlyconsists of aggregates of bacteria, encased in amucoid polysaccharide structure, often growing aspopulations attached to surfaces. It representsmicrobial societies with their own defense andcommunication systems. It may be a pure culturederived from a single type of microorganism ormore often, a mixed culture of multiplemicroorganisms3. Bacterial biofilms formed byPseudomonas aeruginosa, P. fluorescens,Escherichia coli, Staphylococcus and Vibriocholerae have been studied in some details. Insome hardy microbial communities, bacteria likenontuberculous mycobacteria, Pseudomonasaeruginosa, Legionella pneumophila etc. not onlysurvive but proliferate and wait for susceptiblehosts4. A number of mechanisms, including drug

* Post Graduate Department of Biotechnology, St. Xavier’sCollege (Autonomous), 30, Mother Teresa Sarani, ParkStreet, Kolkata-700016, West Bengal, India, E-mail :[email protected]


299

efflux pumps, drug diffusion and penetration throughthe ECM, have been proposed as mechanism forthe resistance of bacteria, growing as biofilm5.However, none of these mechanisms alone canexplain the phenomenon of increased resistanceassociated with biofilm. Other studies have identifiedgenetic components required to form single-speciesbacterial biofilm or quorum sensing signals (acyl-homoserine lactone) in P. aeruginosa biofilm6.

DISTRIBUTION OF BIOFILM

Biofilms are common in nature and appear inour everyday life in more than one form, sincebacteria commonly have mechanisms by whichthey can adhere to surfaces and to each other1.Recent advancements in technology have broughtto use a plethora of devices, so that many humanswill host a biomaterial, and will therefore be at riskof biofilm infection. The surfaces for biofilm growthinclude rocks in water, food stuff, teeth and variousbiomedical implants like artificial hearts, jointreplacements, orthopedic implants and otherprosthetic devices, contact lenses, heart valves,vascular prostheses, dental implants, intrauterinedevices, temporary-indwelling, intravascularcatheters and reverse osmosis membrane filters1,7.These devices are mostly made of inert metals,vitallium (cobalt-chromemolybdenum), titanium,stainless steel, plastics and other synthetic productslike polyethylene, polyethylene terepthalate(dacron), polymethyl methacrylate, silicone rubber,polytetra fluoroethylene (teflon) andpolyvinylchloride. After the biomaterial is implanted,either tissue cells or microorganisms will begin tocolonize it. If the tissue cells colonize first, theimplant will most likely be successful. If the bacteriacolonize first, many microorganisms can adhere tothe surface of the implant, leading to colonization8.Microbial infections can form on biomaterials thatare totally inside the human body or partiallyexposed to the outside. In industrial environment,biofilms are encountered on the interior of slime-clogging drainpipes9.

BIOFILM FORMATION: FACTORS ANDMECHANISM

Biofilm development is conceived as adevelopmental process in which free swimmingcells attach to a surface, first transiently and thenpermanently, as a single layer. This monolayer ofimmobilized cells gives rise to larger cell clustersthat eventually develop into a three-dimensionalstructure, consisting of large pillars of bacteria,interspersed with water channels10. Comprehensivestudies in recent times have been made with respectto V. cholerae. The V. cholerae monolayer, a distinctstage in biofilm development, requires a combinationof pili, flagella and exopolysaccharide. Theenvironmental signals, bacterial structures andtranscription profiles that induce and stabilize themonolayer state are unique. The cells in a monolayerare specialized to maintain their attachment to asurface. The surface itself activates mannose-sensitive haemagglutinin type IV pilus (MSHA)-mediated attachment, which is accompanied by therepression of flagellar gene transcription11. Incontrast, the cells in a biofilm are specialized tomaintain intercellular contacts. The progression tothis stage occurs when exopolysaccharide synthesisis induced by environmental monosaccharides. Thus,the proposed model for biofilm development innatural environment is (i) cells form a stablemonolayer on a surface, (ii) when biotic surfacesare degraded with the subsequent release ofcarbohydrates, the monolayer develops into abiofilm12.

Regarding the biofilm production in the laboratory,the pioneering studies were made by Cholodny,Henrici and Zo Bell, more than 50-60 years ago.Usually the methodology involved was unmersionof glass slides into natural environments andobserving the biofilm developed, under microscope.The adhesion and attraction of the bacteria to thesurface may be brought about by differentmechanisms, including surface charge, gravity,Brownian motion and chemo attraction, provided


300

the surface has nutrients. After attraction, theattachment of bacteria to the surface occurs by atwo-step process, comprised of reversible binding13.The reversible binding is usually brought about byweak Van der Waals forces to hold the bacteriumclose to the surface, before a stronger attachmentcan arise by a combination of both physical andchemical forces. The production of exogenouspolysaccharides, containing the material exuded bybacteria, is one of such chemical substancesimplicated, also called as the glycocalyx. Thebacteria divide and grow freely within thisglycocalyx to form microcolonies, eventuallyforming a biofilm3. The biofilm formation ispartially controlled by quorum sensing, aninterbacterial communication mechanism dependenton population density.

The adhesion capability of the invadingmicrobe(s) depends on the nature and type ofsurface/environment, surface-shape/homogeneity,charge/lack of surface charges, electrolyteconcentration, hydrophobicity, flux materials,hydrodynamics/flow characteristics, nutrientavailability at the surface, nutrient concentration,proper pH and temperature availability etc14. Theusual surface types that facilitate biofilm formationinclude high surface energy materials (for instance,negatively charged hydrophilic materials like glass,metal or minerals) or low surface energy materials(low positively- or low negatively- chargedhydrophobic materials like plastics made up oforganic polymers)15. A higher surface energydenotes higher activity, leading to more adsorptionof dissolved solutes or nutrients, which in turn,affects the rate of bacterial colonization of thesurface16. On the other hand, the rate of biofilmgrowth is governed by factors like rate-limitingnutrient penetration (culture and environment-dependent), nature of anaerobic and aerobic areaswithin the biofilm and heterogeneous versushomogeneous populations17.

The sequences of events that occur during biofilmformation can be summarized as follows: (i) one ormore bacterial organisms are attracted to a surface,influenced by the factors as mentioned above, (ii)The primary colonizing bacteria attaches to thesurface and multiplies, producing an alteredmicroenvironment around the established microcolony by its metabolic activity, (iii) homogeneousenvironment is converted to a heterogeneous one,which, in turn, attracts other bacterial species, (iv)A succession of colonizing bacteria attach on to thesurface, resulting in the formation of a biofilm,until a series of complex communities result2,13.

BIOFILM FORMATION OFFERS SELECTIVEADVANTAGE TO THE CONSTITUENTMICROBES

The adhesion to the surfaces providesconsiderable advantages for the sessile biofilm-forming bacteria, as compared to the planktonicgrowth. These advantages include innate protectionfrom antimicrobial agents and exchange of nutrients,metabolites or genetic material between themicroorganisms. Such syntrophism actually benefitsthe growth and survival of the participatingbacteria18. Each bacterial community either helpsthe other with metabolic by-products or being helpedin return, since they are held together by theglycocalyx.

(i) Protection from antimicrobial agents : Theantimicrobial agents are capable of easily eradicatingplanktonic population of bacteria, as compared tothe sessile forms. Previously, the exopolysaccharideglycocalyx was considered to be the physical barrier,not allowing the antimicrobial agents to reach themicrocolonies of sessile bacteria. However, analysisby confocal scanning laser microscopy (CSLM)and Fourier transmission infrared spectroscopy(FTIR) have helped to develop a variant concept ofbiofilm and sessile bacteria. At the University ofCalgory, a FTIR study undertaken by Jana Jass andcolleagues showed that although the antibiotics areable to penetrate the biofilm rapidly and reach the


301

surface below the film, they are incapable topenetrate effectively the sessile cells located inclumps or microcolonies3. The antibiotics beingeffective against the planktonic population and afew sessile cells on the outer edges of microcolonies;the inner cells remain viable after cessation of theantibacterial treatment. Biofilm-sessile organismscan require 50 to 600 times the planktonic minimalbactericidial concentrations (MBC) to control aninfection19. An earlier observation has clearly shownthat the biofilm inhibitory concentrations (BICs)were much higher than the correspondingconventionally determined minimal inhibitoryconcentration (MICs) for the beta-lactamantibiotics20. The repeated use of antimicrobialagents can cause bacteria within the biofilm todevelop an increased resistance to biocides. As arule, slow growing or dormant microorganisms arefar less susceptible to antimicrobial agents, ascompared to viable, log-stage growth cycles, foundusually in liquid culture of free cells19. In the lattercase, the cells experience uniform exposure to orphysical contact with the antibiotics. The drasticallyenhanced resistance of Candida biofilm againstmost antifungal agents (with the exception ofechinocandins and lipid formulations ofamphotericin B) contributes to the persistence ofthis fungus, despite antifungal therapy21. However,countering the theory of impaired antibiotic access,alternative explanations have been offered by otherscientists, on the basis of possible physiologicaldifferences between sessile and planktonic bacteria,such as growth rates and adherence-dependentdifferential gene expression. In fact, researchershave now shown that a bacterium which attaches toa surface “turns on” an altogether different set ofan array of genes, which makes it effectively asignificantly different organism to deal with22.

(ii) Nutrient exchange : The concentration ofavailable nutrients in the biofilm directly affects thegrowing cells within it. The polyanionicexopolysaccharide matrix, surrounding themicrocolonies of sessile bacteria, serves as an ion-

exchange column, concentrating nutrients and ions,especially cations, from the surrounding fluid,leading to an increased availability of nutrients forgrowth23. The presence of concentrated nutrients inthe biofilm helps the sessile bacteria to tide overadverse bulk fluid conditions which directly hamperplanktonic growth. The multispecies microconsortiafacilitate interspecies substrate exchange or removaland allocation of metabolic products.

(iii) Dehydration-free : The presence of highlyhydrated glycocalyx, which binds water molecules,protects the sessile bacterial cells within it from theeffects of desiccation23. The same safeguard isunavailable to the planktonic bacteria, which aredirectly dependent on the availability of water inthe immediate surrounding.

(iv) Higher metabolic activity : It wasdemonstrated by M. Fletcher at the University ofMaryland that bacteria attached to a surface aremore metabolically active than planktonic bacteria.A consortium of bacterial species within the biofilminteract with each other in several ways, such asremoval of toxins produced by one species,degradation of complex substrates or compoundslike cellulose to be utilized as an energy or carbonsources, recycling of substances produced on lysisor death of cells etc24. Close proximity of differentmicrobial colonies ensures combined metaboliccapabilities in bringing about rapid substratedegradation, leading to the enhancement ofpreviously mentioned advantages of a sessile modeof growth. It also warrants transfer of plasmidDNA and acquisition of new genetic trait, therebyconferring beneficial capabilities to the recipient.The altered gene expression and increasedopportunities for horizontal gene transfer arerecognized as consequences of the association ofmicrobes with surfaces25.

SIGNIFICANCE OF BIOFILM

A. Positive effects : Although biofilm normallycause infection, they can sometimes be beneficial.


302

For example, biofilm can be used for watertreatment, in that they can break down undesirablecompounds, thereby purifying the water26. Manysewage treatment plants include a treatment stage,in which waste water passes over biofilm grown onfilters, which extract and digest harmful organiccompounds. A biofilter is one of several air pollutioncontrol technologies that use microorganisms totreat odorous air. The biofilter has fans, ducts,media support, air plenum and biofilter media. Theventilation wall and pit fans blow air from thebuilding and pit through ducts into the plenumbelow the biofilter media27. The air passes from theplenum through the biofilter media where themicroorganisms treat it before it exhausts to theatmosphere28. A well-managed biofilter can reduceodor emissions by 85%, hydrogen sulfide by 90%and ammonia by around 60%. The emissionreductions can vary widely from 20% to nearly100%29. The biofilter media moisture content andresidence time (the time required for the air to passthrough the biofilter media) are the key factors thatregulate effectiveness.

B. Negative effects :

i. Industrial problems : As already mentionedearlier, the physical presence of biofilm eitherdamages surfaces or causes obstruction so that theefficiency of the surface is reduced. This kind ofsurface damage is collectively termed as“biofouling”. It causes corrosion or deterioration ofthe interior of metal pipelines, storage tanks orvessels, computer chips, contamination of food,pharmaceutical and medical products, equipmentfailure, energy loss through inefficient energytransfer and decreased productivity27,30. The biofilmson floors and counters can make sanitation difficultin food preparation areas. Biofouling is alsocommonly found in the shipping industry. Themicroorganisms like bacteria or algae can form amicrofilm on the hull of a ship. This biofilm canthen serve as an attractive substrate for the

attachment of macroorganisms like seaweed orbarnacles. This macrocoating fouls the hull, andcan retard the efficiency of the vessel31.

(ii) Clinical disasters : Transitioning from acuteto chronic infection is frequently associated withbiofilm formation. Biofilm colonizing and spreadingalong implanted tubes can lead to perniciousinfections in patients. Due to resistance toantimicrobial agents, biofilm often cannot beremoved from biomedical devices, causingsignificant morbidity or occasional mortality32. In amedical set-up, a range of apparatuses, which arein contact with water, find several applications. Thecommon examples can be water filter systems,used in dialysis units or elsewhere, dental units,section apparatuses, artificial ventilator pipes, gastubes etc. The usual spectrum of problems, whichbacterial biofilm present in the above mentionedsystems, include insulation against heat exchange,reduction of fluid/water flow and harboring water-borne potential pathogenic microorganisms. Suchprocesses are seen to occur in most of the systemswhere the ambient physical conditions favor thegrowth of microorganisms. An additional problemis the development of encrustation and consecutiveobstruction in the biomaterials like central venouscatheters33. The body surfaces, especially skin, havea wide range of microbial flora, being dominatedby Staphylococcous epidermidis. Such bacteriaquickly invade the implants and form extensivebiofilm. Occasionally, the infection may reachgrevious proportions and cause severe complications,such as Staphylococcus aureus infection ofintravascular catheter, leading to heart wallcolonization and endocarditis34. This colonizationmay present the need for additional operations,amputation, or it may even lead to death.Pseudomonas aeruginosa or S. aureus biofilms arethe predominant cause of chronic airway infectionin cystic fibrosis18. The dental plaques or dentaldiseases are another common clinical sign of theoccurrence of biofilm.


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The modification of the biomaterial surfaceseems to be the most promising prevention strategyfor bacterial biofilm. The factors governing theeradication of a biofilm is a function of theorganisms in the biofilm, biofilm age, theantimicrobial agent used and the dwell/duration ofthe treatment35. The most effective antimicrobialagents are those (i) that are less affected by theEPS matrix of the biofilm, (ii) that have a morerapid bactericidal effect, or (iii) for which themechanism of action is not dependent upon thegrowth rates of the organisms19. The prophylacticuse of antibiotics at the time of insertion of suchimplants is indicated to reduce the rate of infectionand limit the secondary infection arising out of theprosthesis or eliminate any contaminating bacteriaat the time of insertional surgery. The currentantibiotic therapies are reported to have limitedeffectiveness in resolving biofilm infection.Strategies such as the antimicrobial lock treatment(ALT) have often been used for treatment. Thisapproach involves the instillation of highconcentrations of the antimicrobial agent directlyinto the biofilm-containing catheter, allowingsufficient exposure (i.e., dwell) time to eradicatethe biofilm36. However, fungal biofilms have provento be much more difficult to treat using the ALT,though newer fungicidal drugs such as theechinocandins hold promise in this regard37. Anotherserious drawback with the ALT is the potential forthe development of resistance. The promisingtechnologies that incorporate novel approaches suchas ultrasound, bacteriophage, quorum-sensinginhibitors, or enzymes may provide usefulapproaches in future. Model systems should bedeveloped and used to study biofilm processes onseveral indwelling medical devices. Acomprehensive study of the cell signaling processor molecular responses, at the level of generegulation might also provide better knowledge ofthe mechanism of biofilm formation, enabling moreefficient prevention in future.

REFERENCES

1. R. M. Donlan, Emerg. Infect. Dis. 8, 881-890, 2002.

2. V. Deibel, J Food Safety. 1, 6-7, 2001.

3. A. Kumar and R. Prasad, JK Sci. 8, 14-17,2006.

4. P. S. Stewart and J. W. Costerton, Lancet.358, 135-138, 2001.

5. T. R. De Kievit, M. D. Parkins, R. J. Gillis,R. Srikumar, H. Ceri, K. Poole, B. H. Iglewskiand D.G. Storey, Antimicrob. AgentsChemother. 45, 1761-1770, 2001.

6. D. G. Davies, M. R. Parsek, J. P. Pearson,B.H. Iglewski, J.W. Costerton and E. P.Greenberg, Science. 280, 295–298, 1998.

7. R. M. Donlan, Emerg. Infect. Dis. 7, 227-281, 2001.

8. J. W. Costerton and H. M. Lappin-Scott, In:H. M. Lappin-Scott and J. W. Costerton(eds.), Microbial biofilms, CambridgeUniversity Press, Cambridge, UnitedKingdom, pp. 1-11, 1995.

9. P. L. Bishop, Water Sci. Technol. 36, 287-294, 1997.

10. J. W. Costerton, Z. Lewandowski, D.E.

Caldwell, D. R. Korber and H. M. Lappin-Scott, Annu. Rev. Microbiol. 49, 711-745,

1995.

11. S. Moorthy and P. I. Watnick, Mol. Microbiol.

52, 573-587, 2004.

12. E. M. Davey and A. G. Otoole, Microbiol.

Mol. Biol. 64, 847-867, 2000.

13. H. F. Jenkinson and H. M. Lappin-Scott,

Trends Microbiol. 9, 9-10, 2001.

14. K. C. Marshall, Curr. Opin. Biotechnol. 5,296-301, 1994.


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15. W. A. Corpe, In : G. Bitton and K. C.Marshall (eds.), Adsorption ofmicroorganisms to surfaces, John Wiley &Sons, New York, pp. 105–144, 1980.

16. K. C. Marshall, In: D. C. Savage and M.Fletcher (Eds.), Plenum Press, New York,London, pp. 131-61, 1985.

17. K. C. Marshall, Adv. Colloid Interface Sci. 1,59-86, 1986.

18. R. M. Donlan and J. W. Costerton, Clin.Microbial. Rev. 15, 167-193, 2002.

19. P. Gilbert, J. Das and I. Foley, Adv. Dent.Res. 11, 162-167, 1997.

20. J. L. Burns, L. Saiman, S. Whittier, J.Krzewinski, Z. Liu, D. Larone, S. A. Marshalland R. N. Jones, Diagn. Microbiol. Infect.Dis. 39, 257-260, 2001.

21. P. Vandeputte, S. Ferrari and A. T. Coste, Int.J Microbiol. 2012, 26, 2012.

22. M. E. Davey and G. A. O’ Toole, Microbiol.Mol. Biol. Rev. 64, 847–867, 2000.

23. A. W. Decho, Oceanogr. Mar. Biol. Annu.Rev. 28, 73-153, 1990.

24. R. Amann, J. Snaidr, M. Wagner, W. Ludwig, K. H. Schleifer, J. Bacteriol. 178,3496–3500, 1996.

25. J. W. Coserton, D. E. Lewaldowski, D. R.Caldwell, D. R. Korber and H. M. Lappin-Scott, Annu. Rev. Microbiol. 49, 711-745,1995.

26. J. C. Nicbel, Infect. Urol. 11, 169-175, 1998.

27. Z. Lewandowski and H. Beyenal, Water Sci.Technol. 51, 181-192, 2005.

28. H. C. Flemming, Water Sci. Technol. 27,1-10, 1993.

29. J. H. Choi, Y. H. Kim, D. J. Joo, S. J. Choi,T. W. Ha, D. H. Lee, I. H. Park and Y. S.Jeong, J. Air & Waste Manage. Assoc. 53,92-101, 2003.

30. S. E. Coetser and T. E. Cloete, Crit. Rev.Microbiol. 31, 213-232, 2005.

31. I. B. Beech, J.A. Sunner and K. Hiraoka, Int.Microbiol. 8, 157-168, 2005.

32. J. W. Costerton, P. S. Stweart and E. P.Greenberg, Science. 284, 1318-1322, 1999.

33. T. S. J. Elliott, H. A. Moss, S. E. Tebbs, I.C.Wilson, R. S. Bonser et al., Eur. J. Clin.Microbiol. Infect. Dis. 16, 210-213, 1997.

34. I. I. Raad, M. F. Sabbagh, K. H. Rand and R.J. Sherertz, Diagn. Microbial. Infect. Dis. 15,13-20, 1992.

35. G. Owusu-Ababio, J. Rogers and H. Anwar,J. Controll Release. 57, 151-159, 1999.

36. Y. Qu, T. S. Istivan, A. J. Daley, D. A. Rouchand M. A. Deighton, Med. Microbiol. 58,442-450, 2009.

37. J. Chandra, G. Zhou and M.A. Channoum,Curr. Drug Targets. 6, 887-894, 2005.


305

INTRODUCTION

I n contrast to the pock-marked Moon-likesurface, the surface features of the planet

earth, investigated in detail by geologists, show

completely dissimilar characteristics. While earth-

like crustal features have also been detected in

some of the inner or terrestrial group of planets, the

solid crusts of the outer planets in general have

remained concealed under the thick veil of dusty or

cloudy matter. The outer planets, also known as

giant or gas planets are, nevertheless, additionally

endowed with a spectacular ring system around

their equatorial plane. Besides, planets and planetary

moons, which are basically of spherical shape,

large number of objects of smaller dimension and

SURFACE STRUCTURE OF PLANETARY BODIES—THE MOON

Subhasis Sen*

Excepting the planet earth, which has been studied primarily by the geologists and geophysicists,for explaining surface characteristics of all other planetary bodies, including the pock-markedstructures prominently preserved over the surface of the Moon, mostly astrophysicists have so fartaken the leading role for explaining the relevant features. Most scientists consider that the pock-marked structures over planetary bodies are formed due to impact of external objects like meteoritesof various shapes and sizes. The impact theory has been considered to be more convincing because ofthe fact that meteorites do strike over the surface of the earth, as well as, other planets and planetarybodies, sometimes in the form of showers. Despite the fact that meteorites sometimes strike theplanetary surfaces, such phenomenon cannot be taken for granted for producing pock-marks for thesimple reason that the impacted objects, under such circumstances, would be pulverized and, also, inmost cases, would thoroughly deform the surrounding zones around the point of impact. In this paperformation of perfectly circular depression, often with a peak formed precisely at the geometricalcentral point of the depressed circles of various sizes, have been considered to be the impression of a

silicate melt undergoing rapid cooling at the penultimate stage of solidification.

* Plot–10, Purani Layout, Bharat Nagar, Nagpur – 400 033.E-mail address : [email protected]

of irregular shape that revolve around the Sun,occur in the asteroid belt. These are usually

characterized by smooth surface invariablyassociated with potholes or pitted structures. It has

been taken for granted by most scientists that thepock-marks observed on the surface of the Moon

has been caused by impact of meteorites of variousshapes and sizes. The evidences in support of such

impacts that resulted in formation of the pock-marks are considered to be impact melt pools and

breccias, complex morphology of the structuresassociated with a central peak and malty-ring basins

etc. The author argues that the evidences that haveso far been put forward in support of impact

phenomenon are in fact caused due to solidificationof the of the surface of the Moon from its original

stage when it was a silicate melt and cannot beformed due to impact of meteorites.


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POCK-MARKED PLANETARY SURFACES

Presence of numerous circular pock marks arevisible over the surface of the terrestrial Moon andmany other planetary objects of the Solar System.These features, commonly observed over thesatellites of planets or small-sized planetary bodies,have been considered by most scientists to becaused due to impact of external objects ormeteorites falling over the surface of the relevantplanetary bodies. This theory has been consideredto be more convincing because of the fact thatmeteorites do strike on earth and other planets,sometimes in the form of showers. Despite the factthat every now and then meteorites strike theplanetary surfaces, such phenomena cannot be takenfor granted to be responsible for producing allpock-marked surfaces1,2. It is reasonable to thinkthat very large size circular marks - which arecommon in many planetary bodies - cannot becaused by bombardment of very large size meteorsfor the simple reason that such events would eitherpulverize the striking planetary object or thoroughlydeform it. In support of these views example of theplanetary satellite Mimas, one of the large moons

after the distinguished scientist. Compared to 394km diameter of Mimas, Herschel crater’s diameteris 130 km while its depth is 10 km. If the impactcrater theory is correct, how the satellite Mimascan retain its perfect spherical shape, despite ameteor of such gigantic dimension fell over it?Further, it is also unreasonable to think that undersuch circumstances all impact marks wouldessentially show perfectly circular outline as hasbeen found in Mimas.

CRUST FORMATION OF PLANETARYBODIES – FLUID TO SOLID STATE

To a geologist for studying structural features ofthe crust, in addition to the associated characteristics,the sequence of events that have taken place sincetheir formative stage are also significant. Analysisof such events gives a completely new turn in ourunderstanding on the pock-marked surfaces ofplanetary bodies. The planetary bodies areconsidered to have passed through a boiling statebefore attaining its present condition characterizedby solid crustal surface. For example, in case of theterrestrial Moon it is reasonable to consider that ittoo had to pass through a boiling condition beforeattaining its present state. Under such condition ofpassing phases from liquid to solid, innumerablemarks with perfectly circular outline would beproduced over the magma surface. These marks arecaused by boiling of the magma in a rapidly coolingenvironment associated with widespread degassingor escape of volatiles. Many interpreters on originof planets, especially the earlier ones, consideredthat in the formative stage, the planets were in afluid and super-heated state. Because of coolingdue to loss of heat from the initial gaseous condition,the planetary bodies gradually passed in to a liquidstage, eventually turning into solid units. Thesechanges, manifested mainly on the rocky planets,appear to be particularly relevant to the upper-mostcrustal parts and mantle. In the penultimate andfinal stages of boiling and gas emission, the mediumwould become semi-fluid with production of large

of the planet Saturn which is, in most cases, pittedwith relatively small pock marks although anexceptionally large crater is also found on thesatellite’s surface, which has been named Herschel,

Figure 1, Typical pock-marked structures exhibited onthe surface of the Moon (Credit NASA). Note the perfectlycircular outline with raised circular ring forming theboundary in all pock marks. Such marks cannot be causeddue to impact of meteorites.


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numbers of perfectly circular marks over it whichwould be preserved when its surface finally turnedinto solid, retaining the perfectly circular outer wallas well as a minute peak or blob at the geometricalcentre of these circular structures. It can beinterpreted that the boiling marks were initiallycropped up as minute blobs but with time, facilitatedby escape of volatiles, their dimension continued togrow outwardly keeping their circular outline intact.The emission of volatiles would significantlyaccelerate due to the gravitational force exerted byan external object which in case of Moon wasobviously the planet earth.

The pock-marked Moon surface, shown infigure 1, reveals that :

(1) There are innumerable numbers of pock-marks over the surface of the Moon. Theseare found to occur in diverse dimensions,varying between the sizes of very small orificeand large epicontinental or inland sea whichare known as maria.

(2) All these openings over the planetary bodiesare perfectly circular in shape.

(3) Close observation reveals that relativelysmaller pock marks are occurring over thebigger ones while the reverse is not true.

(4) Smaller the marks, their circular shape arebetter preserved. With increase in size of thepock-marks, the circular shape are retainedalthough not as sharply as in the smallerones.

(5) Smaller the size of the circular basins, theirrelative depths are more in comparison to thebigger ones and are generally conical inshape.

(5) The floors of the bigger basins are flat,relatively shallow and appears to be raised.

(7) Overlapping of the smaller pock marks overthe peripheral border of larger ones has been

observed whereas the smaller ones cut by thebigger marks is totally absent.

(8) Large size depressions or marias are markedby indistinct and distorted borders, withinwhich smaller pock-marks and smallprotruded hillocks are occasionally present.

(9) The hillocks are located closer to theperiphery of the mare and appear to bebroken and disjointed parts of peripheralborder of maria.

(10) Typical geological structures, as observedover the surface of the earth, such as, foldsand faults are generally absent over the pock-marked surface of the Moon and otherplanetary bodies.

CONCLUSION

The above mentioned characteristics of the pock-marked surfaces can be interpreted in the followingmanner :

These structures appear to mark the concludingand penultimate stages of solidification of the thicksemi-fluid magma that formed the crustal layer ofthe Moon and can be considered to be formed bysomewhat similar process like boiling of fluidobjects, fluid food or similar items. With the processof boiling of the semi-fluid magma, when it reachesthe final stage of solidification, a number of smallorifices started to pop up over their surfaces andtend to enlarge in dimension keeping their circularshape intact. Through these orifices volatiles readilyescaped enhancing the process of solidification. Incase of planetary bodies, it is most likely that theprocess of ejection of volatiles was greatly facilitatedby the gravitational attraction of external planetarysources which also enhanced the dimension of thecircular orifices or basins. The lava emission wouldcontinue to extrude or rise up through the orifice ofthe large-sized basins, thereby raising the basinfloor, in consequence of which it attained a flat


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appearance. In case of very large basins of the sizeof epicontinental sea, their peripheral walls may beweakened and broken down due to outwardlydirected pressure exerted in consequence of increaseof size of the circular depression. The detachedbroken parts would be embedded in the interiorparts of the circular basin to form hillock-likestructures while their original wall-like circularfence, would continue to widen with some gapsformed due to detachment of the broken parts oftheir wall. With complete solidification of the uppermost crustal part of the planetary bodies, the above-

mentioned structures would be perfectly retainedover their surface.

REFERENCES

1. Subhasis Sen, Decoding the Solar System,AuthorHouse, London, 2011

2. Ambalika Niyogi and Jyanta K. Pati,Spherules do not lead to impact cratersalways!, National Conference on Green Earth,Pre-Conference Volume, Indian GeologicalCongress and Wadia Institute of HimalayanGeology, p. 52-53, October, 18-19, 2012.


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KNOW THY INSTITUTIONS

NATIONAL INSTITUTE OF INTERDISCIPLINRYSCIENCE & TECHNOLOGY, THIRUVANATHAPURAM

National Institute for Interdisciplinary Science& Technology (NIIST) located at Industrial Estate,Pappanamcode, Thiruvanathapuram, Kerala is oneof the major research laboratories of Council ofScientific Industrial Research (CSIR), whichundertakes R&D projects of both basic and appliednature in a number of areas of fundamentalimportance to the country. Founded as a RegionalResearch Laboratory, the Institute acquiredexcellence in may frontier areas of research andgained multi-disciplinary expertise andinfrastructure. The institute has accomplishednational visibility and international presencejustifying its diverse mandates, which includedevelopment of technologies for the effectiveutilisation of regional resources, generation ofscientific knowledge pertaining to basic and appliedsciences, dissemination of information and human

resource development. Scientists of the institutehave bagged many national and international awardsalso.

It got renamed as National Institute forInterdisciplinary Science & Technology (NIIST) in2007 in view of its orientation towardsinterdisciplinary character. At present, the instituteis well poised to meet the challenges of globalizedeconomy, while continuing to cater the regionalneeds in agro products, materials and energy. NIISTis in the path of becoming a ‘Centre of Excellence’of international standard, piloted by a vision-enabledstrategic plan under the dynamic leadership ofthe present Director.

The institute was established as CSIR -Trivandrum Complex in October 1975 based on arequest from Kerala Chief Minister, Shri C. AchuthaMenon in 1971. As suggested by the Chief Minister,


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Erstwhile Industrial Testing and ResearchLaboratory (ITRL) at Thiruvananthapuram wastaken up by CSIR to establish the complex. Later,based on the recommendations of the ExecutiveCommittee of the CSIR -Trivandrum complex, theGoverning Body of CSIR approved renaming thecomplex as Regional Research Laboratory,Trivandrum (RRL-T) on 6th October 1978. RRL,Trivandrum in its infancy had four Divisions namelyMaterials, Glass & Ceramics, Food & Spices andSystem Planning and Research Management andthe Laboratory took up research in areas based onmineral, agricultural, forest and marine resourcesof Kerala, which were not receiving adequateattention in the other existing laboratories of CSIR.RRL, Trivandrum scaled new peaks under the ableleaderships of its Former Directors Prof. P. K.Rohatgi, Dr. A. D. Damodaran, Dr. G. Vijay Nairand Prof. T.K. Chandrashekhar.

The Laboratory has five major divisions namelyAgro-processing & Natural products, Biotechnology,Chemical Sciences & Technology, Material Sciences& Technology, Process Engineering &Environmental Technology. NIIST takes up ContractProjects (Sponsored, Collaborative/Consultancy) aswell as testing and analysis from industries. NIISThas several national and International linkagesbonded through R&D, Academia and industrychains. The Laboratory has many high impactPublications, Potential Patents and illustriousTechnology Transfers to its credit. It also plays asignificant role in the Human Resource Developmentarena by training Post Graduate students andgenerating PhD Personnel.

SOCIETAL PROGRAMMES

The institute has an active programme targetingsocietal development. Recently CSIR has identifiedCSIR-800 as a thrust area with a vision of inclusivegrowth and improvement in the quality of life ofthe 800 million people at the bottom of economicpyramid, through S & T interventions. Under thisscheme NIIST has taken up a project named Green

Enterprises for Micro-Sector (GEMS). A numberof technologies that have the potential to crategreen micro-enterprises that generate income andemployment for low income groups and are at thesame time beneficial to the environment, have beenidentified, namely (i) environment friendlyextraction of natural fibers, (ii) natural fiber basedbiodegradable household articles, (iii) value additionof under-exploited and underutilized agro products,(iv) agro-technologies for cultivation and postharvest management of medicinal, aromatic plantsand (v) development of green household sanitationdevices. Linkages are being built up with NGOsand appropriate Governmental bodies for deliveryof the technologies in a way that would benefitlarge number of people in the low income groupThe institute has also been supporting in KeralaTile Sector in modernization of infrastructure,training manpower and setting up quality controllaboratories. Studies on industrial feasibility forpreparation of coir and banana fiber reinforcedpolymer composite panels and building componentshave also been conducted.

AGROPROCESSING AND NATURALPRODUCTS DIVISION

The mission of Agroprocessing and NaturalProducts Division is to provide innovative highquality Scientific and technical solutions in thefield of process and product development andknowledge generation in the areas related to lipidscience, spices & flavors and natural products .Thedivision’s core competence is on process and productdevelopment and on the transformation of suchprocesses into fully engineered technology packagesfor commercial exploitation for the benefit ofsociety. The division has set up large number ofcommercial plants in many states and extendedtechnical expertise in making policy decisions inrelevant areas by governmental and non-governmental agencies. More recently the divisionhas been focusing on exploitation of the herbalwealth of the region. Concerted effects are on to


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create the required infrastructural facilities andstrengthen intellectual capabilities for undertakingchemo and bio-evaluation of herbs and naturalproducts in order to develop neutraceuticals,phytochemicals and functional food products. Thedivision has well trained manpower, pilot plantfacilities and sophisticated instrument to undertakeresearch programmes in partnership with industries.

BIOTECHNOLOGY DIVISION

The mandate of the Division is to conduct highquality R & D in specific frontier areas ofBiotechnology. Significant emphasis is put inexploration and value addition of regionalbioresources while ensuring environmentalsustainability. The divisional R & D and industrialconsultancy activities are linked with programmesof national importance through networking withnational and international organizations.Collaborative research and linkages with reputednational and international institutions is a majorstrength of division. The current focus areas of thedivision are (i) bioprocess and product development(ii) energy and environment and (iii) health andgenomics, which are well aligned with prioritysectors of CSIR such as Affordable health care,Energy and Chemistry & Environment. In the areaof bioprocess and bioproducts, the division’semphasis is on production of industrial enzymes,biopolymers and amino acids. Considerable successhas been achieved in developing microbial-basedeco-friendly process for production of bioethanolfrom lignocellulose feed stocks. Under the energysector, the main focus is on developing microbialbased polymers such as PLA and PHB using agroresidues as feed-stocks available in the country,which focus on multi feed based processes. A pilotplant is being established for the lignocellulosesbioethanol programme. Microbes have been isolatedfrom the Western Ghats in Kerala and deposited inthe NII Culture Collection, which is a registereddepository for the culture collection having ~1200actinomycetes, Yeast, bacterial and fungal cultures.

CHEMICAL SCIENCES AND TECHNOLOGYDIVISION

The vision of the division is to be internationallyrecognized for excellence in discovering newknowledge on functional materials and naturalproducts/bioactive molecules and to develop suchmolecules/materials for industrial applications usinginnovative cost competitive and environmentallyacceptable processing technologies. This divisionhas the following sections : Photo sciences andPhotonics, Inorganic and Polymeric Materials andOrganic Chemistry. The activities of the Divisionare related to (i) working on fundamental andapplied aspects of Photochemistry and related areaswith the purpose of developing photonic materialsfor applications in solar energy harvesting, electrooptical devices and photo medicine, (ii) design anddevelop inorganic materials and polymers forapplications in areas relate to energy storage,lightning and molecular sensing for imaging anddiagnostics and (iii) to isolate/synthesize newbioactive molecules and to develop state of the artsynthetic organic methodologies for the finechemical industry.

MATERIALS SCIENCES AND TECHNOLOGYDIVISION

The mandate of the materials Division isdevelopment of materials for strategic and societalapplications. The division has activities related tonano-ceramics, electronic materials, superconducting and magnetic materials, alloys andcomposites. Under the nano-ceramics activity, sol-gel based processes have been developed forproduction of nano-rare earths phosphates andoxides, based on which a pilot plant has been setup at M/s Indian Rare Earths Ltd. Kollam (Kerala).Processes for fly ash, red mud and new clay mixeshave been successfully transferred to variousindustries. Nano-lithium dioxide coated ceramictiles with self cleaning and anti algal activities havebeen prepared based on which a plant has been setup by BHEL in Bangalore for preparation of Water


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treatment membranes. The electronic materialsactivity lays emphasis on communication andenergy. The super conducting and magneticmaterials group has fabricated long length high Tcwires and tapes for cryogen free magnets andfusion magnets. The division has successfullydeveloped materials and components for space,defence and for societal applications such as highstrength aluminum and magnesium alloys withconsiderable grain refinement. Under the mineralsarea an environmentally safe process of syntheticrutile was developed and transferred to industry.

PROCESS ENGINEERING ANDENVIRONMENTAL TECHNOLOGY

This division has four sections viz, (i)Environmental Technology (ii) ComputationalModeling and Simulation (iii) Chemical and ProcessEngineering and (iv) Dioxin Research. Theenvironment technology group is engaged in thedevelopment of processes for odour control,anaerobic treatment for solid waste treatment,industrial water purification and activities related toEnvironment Impact Assessment (EIA) etc. TheComputational Modeling and Simulation groupcarries out research work for developing softwaretools for casting in foundries, modelling of chemicalreactions, rotary klin reactors and works related torational design of molecules and materials. TheChemical and process Engineering group is engagedin the development of mineral beneficiation flow

sheets and also reverse flow dryers for the ruralsector. The Dioxin Research Unit is focusing on themonitoring, control and phase out of persistentOrganic Pollutants (POPs) with special reference todioxins and furans from various industrial and non-industrial activities in Southern states of the country.Some recent R & D achievements of this Divisionare : (i) Setting up of odour control plants in rubberand fish meal factories using gas biofilter technology& anaerobic leach bed technology for productionof white pepper (ii) software for casting simulation‘virtual casting’ and simulation of micro porosityin Aluminium castings for General Motors, USA(iii) Simulation for rotary klin for manufacture ofsynthetic rutile, (iv) Investigation of industrial andnon-industrial sources of Dioxin and furans insouthern states as a first step for the implementationof Stockholm convention in India (v) Process andflow sheet development for KCCP China clay,Guda clay, GMDC clay and silica sand etc. anddevelopment of reverse flow dryers for copra,ground nut, pappad etc.

Contact :The DirectorNational Institute for InterdisciplinaryCouncil of Scientific andThiruvananthapuram–695 019, KeralaTelephone : +91-471-2515220/2490674Fax : +91-471-2491712/2491585Emial : director[at]niist.res.in,sureshdas[at]niist.res.in


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Conferences / Meetings / Symposia / Seminars

The 19th International Symposium on Endoscopic Ultrasonography, 18-20 September2014, Chennai, India

Participating endosonographers will learn from :

● Live demonstrations of basic and advanced EUS procedures

● State-of-the art lectures

● A half day program specially designed for beginners

● A special focus on EUS-related cytopathology

● International experts will debate controversial areas and hot topics

Contact : Kenes India Conferences Pvt. Ltd., Aggarwal Complex, 301, 3rd Floor, LSC, A-l/B, Janakpuri,New Delhi-110058, Tel : +91 1145199100 Fax : 91 1125513052

Contact Person : Suraj Singh, Email: [email protected]

3rd International Conference on Advanced Oxidation Processes (AOP 2014), 25-28September 2014, Munnar, India

Topics :

● Advanced Oxidation Processes and Technologies for the treatment of air, water, wastewater, groundwater,and solid waste

● Advances in photocatalysis, UV/H2O2, Fenton, photo-Fenton, electro-Fenton, sonolysis and ozonolysisin solution state; Synergy Effects

● Oxidative Biodegradation

● Radiation chemical reactions leading to the degradation of organic pollutants

● Fundamental understanding of oxidative degradation by pulse radiolysis studies

● Photochemical degradation/fundamental understanding by laser spectroscopy

● Gas phase oxidation of organic pollutants

● Degradation of Emerging Pollutants

Contact : Prof. (Dr.) C.T. Aravindakumar Convener, AOP - 2014, School of Environmental Sciences,Mahatma Gandhi University, Kottayam, Kerala, India - 686 560, Ph : +91-9447779269, +91-9447391168,+91-481-2732120, Fax : +91-481-2731009, E-mail: [email protected], Website: http://www.ctamgu.in/aop2014


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S & T ACROSS THE WORLD

STUDY SAID TO EXPLAIN GIANTUNDERWATER WAVES

You can’t see them on a turbulent ocean surface,where they produce a rise of just inches. Butinternal waves, hidden totally within the ocean, cantower as high as skyscrapers, with profound effectson climate and on ocean ecosystems, scientists say.

Now new research, both in the ocean and in thelargest-ever laboratory experiments to investigatethem, is said to solve a longstanding mystery aboutjust how the largest known internal waves, in theSouth China Sea, form, They’re shaped like surfacewaves. But instead of forming where water meetsair, they form where different layers of water meet.The difference between an underwater wave andthe water around it is its density, due to temperatureor salinity differences that cause ocean water toform layers.

Instruments can detect the boundary betweencolder, saltier water below and warmer, less-saltywater above. That boundary can resemble theocean’s surface, producing waves that reachtowering heights, travel vast distances, and canplay a key role in the mixing of ocean waters,helping drive warm surface waters downward anddrawing heat from the atmosphere, scientists say.

The new findings come from a team involvingthe Massachusetts Institute of Technology and otherinstitutions, and coordinated by the U.S. Office ofNaval Research. Because internal waves are hard todetect, it’s often hard to study them directly in theocean. Thomas Peacock, a mechanical engineer atMIT, joined other researchers in the study, publishedin the journal Geophysical Research Letters. Theydid laboratory experiments to study the productionof internal waves in the Luzon Strait, betweenTaiwan and the Philippines. “These are the most

powerful internal waves discovered thus far in theocean,” Peacock said. “These are skyscraper-scalewaves.”

The solitary waves have been measured to reachheights of 170 meters (more than 550 feet) and cantravel at a leisurely pace of a few centimeters persecond. “They are the lumbering giants of theocean,” Peacock said.

The large-scale laboratory experiments on thegeneration of such waves used a detailed model ofthe Luzon Strait’s seafloor, mounted in a 50-foot-wide rotating tank in Grenoble, France, the largestsuch facility in the world. The tests indicated thewaves are generated by the entire ridge system onthat area of seafloor, and not a localized hotspotwithin the ridge.

The last major field program of research oninternal-wave generation took place off the coast ofHawaii in 1999. In the years since, Peacock said,scientists have come to a greater appreciation of thesignificance of these giant waves in the mixing ofocean water—and therefore in global climate. “It’san important missing piece of the puzzle in climatemodeling,” Peacock said. “Right now, global climatemodels are not able to capture these processes,” hesaid, but it’s important to do so: “You get a differentanswer ... if you don’t account for these waves.” Tohelp incorporate the new findings into these models,the researchers plan to meet this month with aclimate-modeling team as part of an effort sponsoredby the National Science Foundation to improveclimate modeling. These waves may be “the keymechanism for transferring heat from the upperocean to the depths,” Peacock said.

Internal waves have been known for well over acentury, Peacock said, but remained poorlyunderstood because of the difficulty of observations.Among the new techniques that have helped is theuse of satellite data: While the submerged wavesraise the water surface by less than an inch, long-


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term satellite data can clearly discern this difference.“From 15 years of data, you can filter out thenoise,” Peacock explains: Many locations, such asthe Luzon Strait, generate these waves in a steady,predictable way as tides flow over submerged ridgesand through narrow channels. A resulting 12-hourcycle is clearly visible in satellite data, he added.Internal waves can also play a significant role insustaining coral-reef ecosystems, by bringingnutrients up from ocean depths, Peacock said.

SCIENTISTS DECODE OLDEST DNA OFEXTINCT HUMAN

Researchers say they have decoded a key part ofthe DNA for a 400,000-year-old extinct humanrelated to a species of ancestral humans calledDenisovans. The scientists were able to study DNAso old that previous samples of similar age couldonly be retrieved from permanently frozen ground.This sample instead came from a cave in NorthernSpain.

The researchers said they determined the almostcomplete “mitochondrial genome,” a large sectionof human DNA which isn’t enclosed in the cellnucleus like most of the rest. Mitochondrial DNAis maternally transmitted and commonly used forancestry studies. The Spanish cave, known as the“bone pit” or Sima de los Huesos, has yielded theworld’s largest assembly of ancient human fossilsfrom the Middle Pleistocene era. Matthias Meyerand colleagues of the Max Planck Institute forEvolutionary Anthropology in Leipzig, Germany,developed new methods for decoding highlydegraded ancient DNA. They then teamed up withSpanish paleontologist Juan-Luis Arsuaga and usedthe techniques on a cave bear from the site. Laterthe group sampled some bone powder from a thighbone of a hominin, or extinct human relative, foundthere. They compared its mitochondrial DNA withthat of Neanderthal people, Denisovans, present-day humans, and apes.

Based on “missing mutations,” the researcherscalculated that the Sima hominin lived about400,000 years ago and shared a common ancestornot with Neanderthals but with Denisovans— anextinct group from Asia related to theNeanderthals—about 700,000 years ago. The resultis also “unexpected” since the skeleton showsNeanderthal-like features, said Meyer. The bones,attributed to a species known as Homoheidelbergensis, may be related to the populationancestral to both Neanderthals and Denisovans, hesaid. This “points to a complex pattern of evolutionin the origin of Neanderthals and modem humans,”added Svante Pa..a..bo, director at the Max PlanckInstitute.

The findings are published in the Dec. 4, 2013issue of the research journal Nature. “Our resultsshow that we can now study DNA from humanancestors that are hundreds of thousands of yearsold,” Pa..a..bo said. “This opens prospects to studythe genes of the ancestors of Neanderthals andDeni-sovans. It is tremendously exciting.”

GALAXY GROWTH EXAMINED LIKE TREERINGS

Watching a tree grow might be more frustratingthan waiting for a pot to boil, but luckily there aretree rings. Beginning at a tree trunk’s compact coreand moving out to the soft bark, concentric ringsmark the passage of time, revealing chapters of thetree’s history.

Galaxies outlive trees by billions of years. Butlike biologists, astronomers can read the rings inthe disk of a galaxy to unravel its past, a studysuggests. Using data from two NASA telescopes,scientists have gained more evidence for an “inside-out” theory of galaxy growth, showing, they say,that bursts of star formation in central regions werefollowed one to two billion years later by star birthin the outer fringes. “Initially, a rapid star-formingperiod formed the mass [material] at the center of


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these galaxies, followed later by a star-formingphase in the outer regions. Eventually, the galaxiesstop making stars,” said Sara Petty of Virginia Techin Blacksburg, Va. She is the lead author of a paperon the work in the October 20B issue of TheAstronomical Journal. “This later star-forming phasecould have been caused by minor mergers withgas-rich neighbors, which provide the fuel for newstars.”

The discovery may also solve a mystery ofelderly galaxies, she said. The galaxies in the study,known as “red and dead” for their red color andlack of new star births, have a surprising amount ofultraviolet light emanating from the outer regions.Often, that light comes from hot, young stars, butthese galaxies were considered too old to hostmany of those, Petty explained. The solution to thepuzzle is likely hot, old stars, according to theresearchers. They used a new approach analyzing

light at multiple wavelengths, or “colors,” to showthat the unexplained ultraviolet light seems to becoming from a late phase in the lives of older stars,when they blow off their outer layers and heat up.

The astronomers used two NASA telescopes,the Wide-field Infrared Survey Explorer and GalaxyEvolution Explorer. The first sees the infrared lightcoming from older stars, whereas the other issensitive to ultraviolet. Both are forms of light inenergy ranges, or “colors,” invisible to the unaidedeye. Both telescopes have large fields of view,allowing them to easily capture images of entiregalaxies. “The synergy between GALEX and WISEproduces a very sensitive measurement of wherethe hot, older stars reside in these red-and-deadgalaxies,” said Don Neill, co-author of the paperfrom the California Institute of Technology,Pasadena. “This allows us to map the progress ofstar formation within each galaxy.”

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