Mangroves 3

8/2/2019 Mangroves 3

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Environment Management

Project on

Mangroves around the world

Importance and Why to protect


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MangrovesAn Introduction

A mangrove is a tree, shrub, palm or ground fern,

generally exceeding one half metre in height, that

normally grows above mean sea level in the intertidal

zone of marine coastal environments and estuarinemargins.

A mangrove is also the tidal habitat comprising such

trees and shrubs

The term "mangrove" comes to English from Spanish

word mangueand english word grow


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Ecosystem

Though the trees themselves are few in species, the

ecosystem that these trees create provides a home for

a great variety of other organisms.

Protection from strong winds & waves

Soil stabilization & erosion protection

Nutrient retention and water quality improvement

through filtration of sediments and pollutants Protection of associated marine ecosystems


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Evolution of Mangroves

Evolved around 114 million years ago Indo-Malaysian area is considered as cradle of

evolution of mangrove system

Mangroves of West Africa and Americas contain

fewer but similar colinizing species.

Asia, India, and East Africa contains much full range

of mangove species

At present, Indo-Pacific region is also known asluxuriant Mangroves

Sunderbans of India and Bangladesh forms the single

largest block of mangroves of the world


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Where do Mangroves occur?

The richest mangrove communities occur in tropicaland sub-tropical areas

The best mangroves are found in Asia especially in

India and Bangladesh Sunderbans are the largest forest mangrove in the

world both in size as well as biodiversity

Total area of Mangroves is about 6,740 sq. km7%

of the worlds total area of mangroves 80% of the mangroves are present in the east coast

Remaining 20% are scattered on the west coast fromKutch to Kerela


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Importance of Mangroves

Buffer between land and sea

Play an invaluable role as nature's shield againstcyclones, ecological disasters and as protector ofshorelines

Harbour a variety of lifeforms like invertebrates, fish,

amphibians, reptiles, birds and even mammals liketigers

Save the marine diversity, which is fast diminishing

Purify the water by absorbing impurities and harmful

heavy metals and help us to breathe a clean air byabsorbing pollutants in the air.

Potential source for recreation and tourism

Saviors in todays scenario of global warming


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Mangroves vegetation

The mangrove flora of the world is represented by

about 65 species.

The Indian mangroves are represented byapproximately 59 species (inclusive of some

mangrove associates) from 29 families.


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Few commonly found plant species in

Mangrove ecosystem are:

Rhizophora apiculata (Red Mangrove): It grows well in sheltered areasrather than open seas exposed to the wave action.

Rhizophora mucronata (Red Mangrove): It is often notice as a front

mangrove plant where the shore is well protected. It has a high growth rate

and is economically important. The species is quite similar to R. apetala

Bruguiera gymnorhiza (Broad leaf orange mangrove): Roots arecharacteristically thick, rope-like and filled with air. They are called "cable

roots".

Parviflora (Small leaf orange mangrove): Essentially a back mangrove

species. It is a useful tree for commercial extraction of tannin. The leaves

are supposed to be used for treating high blood pressure. Sonneratia alba (Mangrove Apple): It prefers non swampy intertidal

zones and prefers open areas with some wave action. It has thick, pointed

and long pneumatophores. The apple like fruits are edible and used in

pickles.


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Ceriops tagal (spur mangrove): A widely distributed species with a high

tolerance for salinity.

Avicennia marina: Avicennia spp have the highest salt tolerance of

mangrove trees. One of the dominant species found throughout thecoastline.

Avicennia officinalis: Of the three dominant species of Avicennia this is

the tallest. The wood is used as timber and fuel. Extraction of tannin is still

done at some places. Leaves useful as fodder for cattle.

Acanthus ilicifolius (Shore purslane): One may notice this attractiveplant in the back mangrove zones. Its shrubby nature and spiny leaves

make it an outstanding species.The blue flowers are also a source of nectar

for honey bees. The flowers and leaves are used for decoration in Kerala.

Aegiceras corniculatum (River mangrove): A densely flowering shrub.

Salt tolerance of this species is comparatively low and grows only in theareas where there is good mixing of freshwater at least for a few months. It

seeds profusely between January and March and fruits are curved and very

finely pointed. The nectar produces fine quality honey.


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Phoenix padulosa (Sea Date): This palm species is also called as sea date

and is a relative of the common date. In Sunderbans, this species forms a

major zone along the upper reaches of the delta. It is used as a fuel and its

trunk is used for constructing traditional hutment. It grows naturally onlyon the East Coast.

Nypa fruticans (Golpatta): This is a characteristic palm species and

resembles a shrunken coconut tree. It prefers well consolidated but moist

tidal zones with a low to medium level of salinity preferably with

freshwater mixing. Heritiera fomes (Sundari): This plant is locally called as sundari in W.

Bengal. The name Sunderban perhaps has been derived from the abundance

of this species in the Gangetic delta. It produces timber of excellent quality

which is said to be more expensive than teak.


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Coastal Regulation Zone (CRZ) Rules 2011.

CRZDefinition

Coastal regulation zone is the boundary from the high tide line up to 500min the landward side area between the low tide line. In the case of rivers,

creeks and backwaters, the distance from the high tide level shall apply to

both sides and this distance shall not be less than 100m or the width of the

creek, river or backwater whichever less is.

There are four categories of CRZs.CategoryI (CRZ I)

Areas which are ecologically sensitive and important such as national

parks, areas close to breeding and spawning grounds to fish and other

marine life. Historically important and heritage areas, area rich in genetic

diversity, areas likely to be inundated due to rise in sea level consequentupon global warming and such other areas as notified by government from

time to time.


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Mangroves around the world

The countries with the largest area of mangroves are:

1) Indonesia

2) Brazil

3) Australia

4) Nigeria

5) Mexico

Estimates of mangrove diversity indicate that there are 16-24

families and 54-75 species worldwide. The greatest mangrove

species diversity exists in SE Asia.

Only 12 mangrove species are found in the Americas, with 4

of these occurring along portions of the SE USA (Florida)

coast.
http://mangroveactionproject.org/mangroves/origin-of-mangroveshttp://mangroveactionproject.org/mangroves/origin-of-mangroves


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Sundarban Forest The Sundarbans is the largest mangrove forest in the world

300 species of trees and herbs

425 species of wildlife including the Royal Bengal Tiger exist.

It lies in south-east of Calcutta .

It covers some 10,000 sq.km. of mangrove forest and water (of which some

40% is in India and the rest in Bangladesh)

It is a part of the worlds largest delta (80,000 sq. km.) formed fromsediments deposited by three great rivers, the Ganges, Brahmaputra and

Meghna.

The three sanctuaries are intersected by a complex network of tidal

waterways,

mud flats, small islands of salt tolerant mangrove forests.

The area is flooded with brackish water during high tides which mix with

freshwater from inland rivers.

The Sundarbans has experienced balanced growth of flora and fauna in

association with the fresh water of the Ganges and the salty sea water of

theBay of Bengal.


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The Sundarbans mangrove area of India and Bangladesh when

taken together forms one of the worlds largest single patches.

Tidal waves are a regular phenomenon and may be up to 7.5m

high About half of the Sundarbans is under water and the rest of the

landscape

Rainfall is heavy and humidity high (80% on average) due to

proximity of the Bay of Bengal. The entire mangrove forest extends over an area of 4,262

sq.km. of which 2,320 sq.km. is forest and the rest is water and

it is called Sundarban, locally known as sundari.

It is classified moist tropical seral forest, comprising beachforest and tidal forests.


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This mangrove forest generally bears the salt-tolerant

forest ecosystem excepting some amongst which

about 856.7 million Sundari (Heritiera fomes) trees

are less salt-tolerant.

Climate change due to global warming is predicted to

cause an annual temperature rise of 0.4 degrees

Celsius in Bangladesh and result in greater frequencyand intensity of cyclonic storms.

The sea level is also predicted to rise by 4 millimetres

every year. These phenomena will result in an

increase in salinity and a decrease in the sweet waterflow in the Sundarbans.

But the balance is now being threatened and siltation

is increasing due to decreasing downstream flow of

rivers running through and around.


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Goa Mangroves

Out of Goas total land area of 370000ha, the mangrove area is500 ha having declined sharply from a recorded 20 000 ha in

1987. Some 178 ha of the best mangrove area at Chorao, Goa

has been declared as Reserved Forest under the Indian Forest

Act, 1927 to protect and conserve the mangrove forests. In 1988, this area was declared a bird sanctuary under the

Wildlife (Protection) Act, 1972.

Afforestation work to restore degraded mangrove areas started

in Goa in 1985-1986; By the end of 1996-1997 the programme had covered 876 ha.


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Andaman and Nicobar islands

It comprise 572 islands in the Bay of Bengal, with a total area

of about 825 000 ha. The coastline is about 1 962 km. The areaunder mangroves is 96 600 ha (Government of India, 1997).

The Middle Andaman Islands comprise an area of 99 800 ha,

of which 23 400 ha or 23.4 percent are covered with

mangroves Limited extraction did not cause any damage to the

government mangrove forests, but in the revenue areas (areas

managed in such a way as to allow local people to benefit from

extraction of forest products) the destruction of mangroves isconspicuous.

In 1987, the Andaman and Nicobar Administration has

banned extraction of mangrove wood due to growing

awareness about conservation of mangroves.


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Mangroves in mumbai

Major mangroves are seen today in Mumbai are

Vasai Creek,

Thane Creek,

Manori and Malad,

Mahim - Bandra,

Versova,

Siwari,

Mumbra - Diva

and few more places.


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Importance of Mangroves for Mumbai

Mangroves represent the spirit of Mumbaithey are plucky

survivors.

But each day, millions of citizens in Mumbai pass these

hardy plants imagining they are little more than dirty,muddy weeds growing pointlessly along the shoreline.

Mangroves maintain the integrity of Mumbais shoreline

The Koli community in Mumbai worships mangroves


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Mangrove Destruction in Mumbai

Rapid developments like housing, industrialization,pollution and increasing population of Mumbai has resulted

into degradation of mangroves.

There are two important creeks, Vasai Creek towards north

and Thane Creek toward south where luxuriant mangrove

patches are still left.

Mumbai High Court has ordered freeze on destruction of

mangrove forests in Maharashtra and has banned

construction within 50 metres of them


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Protection is possible only through the participation

of the local community and by building up pressure

groups for ensuring management of this ecosystem

and strict implementation of the legal provisions bythe Government.

Residents associations & NGOs in Mumbai are

coming together to spread this awareness


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Threats to Mangrove ecosystem

Land reclamations for construction activity, aquaculture,agriculture, tourism

Industrial and domestic pollution

Port development

Dumping of all kinds of waste and debris

Deforestation for fuel wood

Over harvesting of marine resources


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Recommendations

The existing forest rules should be strictly enforced tomangroves in order to avoid exploitation.

Collection of mangrove products may be regulated byappropriate rules.

Conversion of mangrove lands for other purpose mustbe strictly prohibited.

Coastal Area development should be associated withmangroves land.

Budgetary provisions may be provided in themaritime states for surveillance, watch and ward ofwetland ecosystems.


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Regular monitoring of the state of art of mangroves

by government organization, Universities and similar

agencies.

A forestation program may be maintained for

transplantation in the appropriate areas.

National Policy on mangrove ecosystem management

may be strengthened/ formulated for protection ofmangroves.

Awareness campaign on conservation and

management of mangroves. Mangroves should be a part of curriculum/syllabus of

education at various levels.

Mangroves 3

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