Indoor Fish farming | EquipmentPlanningConstructionService

Big Dutchman International GmbHDr. rer. nat. Marco BöerProject Manager Business Unit FishP.O. Box 1163 · D-49377 Calveslage · GermanyTel. +49 (0) 44 47/801-4801 · Fax +49 (0) 44 47/801-5-4801mboeer@bd-fish.de · www.bd-fish.de

Ahrenhorster Edelfisch GmbH & Co. KGHermann Otto-LübkerBornhagenweg 3 · D-49635 Badbergen-Vehs · GermanyTel. +49 (0) 4447/801-4802 · Fax +49 (0) 4447/801-5-4802hotto-luebker@bd-fish.de

Authors: Dr. rer. nat. Marco Böer, Hermann Otto-LübkerLayout, text and typesetting: www.bitters.de

Edition: 2010

DisclaimerThe material presented here has been thoroughly researched and is believed to beaccurate and correct. However, the authors and publishers cannot be held legallyresponsible for any errors. There are no warranties, expressed or implied, made withrespect to the information provided. Neither the authors nor publishers will be liablefor any direct, indirect, special, incidental or consequential damages arising out of theuse or inability to use the content of this publication.

All rights reserved.© 2010 Big Dutchman International GmbH · Business Unit BD Fish3 Equipment

This brochure including all its parts is protected by copyright. Any use beyond thenarrow confines of the copyright law without the author’s approval is illegal and leadsto prosecution. This is particularly true for copies, translations, microfilming, and thesaving and processing in electronic systems.

We would like to thank the German Fish Information Centre “FIZ” (Fischinformations-zentrum e.V.), the German Agricultural Society (Deutsche Landwirtschafts-Gesell-schaft, DLG) and the editorial office of “FischMagazin” for kindly providing graphics.We also thank Mrs Dr Birgit Schmidt-Puckhaber for valuable contributions and sug-gestions during the preparation.

Printed in Germany

Aquaculture What is aquaculture? 6Levels of intensity in aquaculture 6History of aquaculture 6Husbandry systems 6

·································································································································································Global production China no. 1 producer in the world 9

·································································································································································Development fishery World fishery output stagnates 10

and aquaculture The wels catfish has great potential 11·································································································································································

Indoor fish farming Recirculation technology 13technology Cleaning systems 13

The BigPool3 system 13The BigPool3 component parts 13

·································································································································································Conditions for successful What you should know 18

indoor fish farming Water quality und -quantity 19Energy supply 18Emission und immission 19Insulation and room climate 19Discharge water 19

·································································································································································Catfish rearing at Ahrenhorster The wels catfish 20

Edelfisch Husbandry conditions 20Ecologically sound fish production 20Health 20Ways to the consumer 20

·································································································································································Economic efficiency Costs and earnings 22

Production costs for three system sizes 22Calculation of the live fish price 22License 22

Content | 3

4 |

Dear reader | 5

As part of the Big Dutchman Group, the corebusiness of BDFish3 Equipment is the establish-ment of environmentally-sound indoor fishfarms. With Ahrenhorster Edelfisch GmbH &Co. KG we have a strong partner with many

years of experience in indoor fish farming at our side. Our fish farmsare planned considering both the economic and environmental per-formance of the system. For cost-effective operation, automation andcost-conscious management are decisive preconditions. These arethe same principles that Big Dutchman has followed since 1938 inthe development and realisation of feeding systems and housingequipment for modern pig and poultry production.

The Big Dutchman brand symbolises quality, reliability and profi -tability all over the world. Innovative technology, constant furtherdevelopment of systems in response to market needs and customizedsolutions are part of the successful corporate strategy.

Big Dutchman is regarded as market leader in the field of animal hus-bandry equipment: our name stands for reliable quality, quick serviceand unsurpassed know-how on five continents in more than 100countries. Innovation led by our company has significantly influencedmodern livestock management.

We are working on keeping it that way.

Dr. rer. nat. Marco Böer Hermann Otto-LübkerProject manager Consulting

Big Dutchman is

represented in more

than 100 countries

worldwide. The com-

plete product range

for modern livestock

production is sold by

several daughter

companies and inde-

pendent agencies.

Thanks to this fine

network, Big Dutch-

man customers profit

from the expertise of

a worldwide orga -

nization.

Aquaculture6 |

What is aquaculture?Aquaculture is the farming of aquatic organismsincluding fish, molluscs and crustaceans, as wellas water plants (FAO). Farming in this context in-cludes any engagement in the manipulation of theenvironment to increase productivity. This includesmeasures such as stocking, feeding and protectionagainst predators for example. In contrast to capturefisherys, in aquaculture the organisms always be-long to and are controlled and provided for by oneperson or corporate body. Wild fish in open waterare ownerless and left to their own resources. Thismakes aquaculture comparable with agriculturalproduction methods.

Levels of intensity in aquacultureExtensive | Cultivated organisms live on the feedwhich is naturally available in their environment,no additional feed is supplied, the input to outputratio is relatively small.

Intensive | Water organisms are kept in high stockingdensities with exclusively artificially supplied feed,the input to output ratio is relatively large.

History of aquacultureThe beginnings of fish farming go back to the cul-tivation of freshwater fish in China during the Han

Dynasty more than 4,000 years ago. Evi-dence of fish farming in Mesopotamia

more than 3,500 years ago has beenfound. In Europe this type of farmingwas introduced with the Roman Em-pire. In Germany, the first ponds forfish farming were described in the

11th and 12th century. They were used

for carp production. In the 1960s, systems for theproduction of Atlantic salmon in marine submer -sible cages were developed, first in Norway, thenin Scotland and later on also in other countries.Closed recirculation systems were developed ap-proximately 30 years ago and have constantly beenfurther developed and improved.

Husbandry systemsIn the course of history, different husbandry sys-tems for aquatic organisms have been developed.A principal distinction is made between systemssuch as natural ponds (banking) or earth ponds(simple excavation) located in the natural environ-ment and artificial and more controllable techno-logies, such as concrete ponds and channels, netcages or recirculation systems.

Pond management | The classic technology for theproduction of fish and seafood is the pond. Pondbased husbandry goes back several centuries.Apart from the rain-fed pond which depends solelyon rainfall, ponds use natural water resources inflow-through systems.

Water rights are required for the use of natu ral sur-face waters for aquaculture purposes. Today it israther difficult to acquire water rights for traditio-nal pond based systems. Existing farms intensifyproduction through better utilisation of the existingwater (air and/or oxygen enrichment, waste watertreatment) or by using high-quality breeding stockand high-quality feedstuffs.

“Against the background of stagnant yields from marineand freshwater capture fisheries, aquaculture is gainingin importance.”

Aquaculture may

use fresh water,

brackish or salt

water.

Production may

take place in cold

or warm water,

with different levels

of intensity and in

different produc -

tion systems.

Illustration below:

Fish bowl approx.

1450 B.C.; Nile

tilapia (Oreochro-

mis niloticus) as

symbol for rebirth.

The Egyptians

believed that this

mouth-brooder

recreated itself

(Egyptian Museum

Berlin).

| 7

Top left: trout pro-

duction in natural

ponds, centre: two

different channel

systems for the

production of sal-

mon; top right and

below: net cage

systems for pro -

duc tion of salmon

in Norway.

Ponds are farmed with different intensities. Carpponds (carp, tench, catfish, pike and pike perch) areoften managed extensively, i.e. only with naturalfeed, whereas some trout farms (trout, sea trout,brook trout) use very intensive management ap-proaches.

Channel systems | Channel systems require largeamounts of water from natural water resources(water rights). Due to their artificial linings (wallsetc.) and the resulting controlled flow rates, muchhigher stocking densities can be achieved compa-red with systems based on ponds with natural sidesand bottoms. Normally, fish in these systems arefed with extruded high-energy feed and the wateris enriched with oxygen. It is possible to achievestocking densities of 80 kg trout per m3. Additionalwaste water treatment in modern systems allowsthe reuse of some of the water.

Net cage management | The fish are kept in anexisting water body (fjord, lake, bay, open water) innets or in cages.

Even though this method is a very economic formof fish production, permits for net-cage farms areissued only in special cases in Germany. The dis -charge of fish excrement and uneaten feed into thewater body is a significant burden on the environ-ment. However, there are new technologies whichoffer diverse possibilities for water treatment andare already in use in several European countries.

Recirculation systems | Human population growthand economic development will lead to increasedconsumer demand for high quality protein. Due tolimited land and water resources in many parts of

the world, the increasing requirements cannotbe met solely by aquaculture traditional methodssuch as pond or channel systems. That means otherproduction methods such as those based on net-cages or recirculation will have to be used.

Modern methods in aquaculture include farming oforganisms in recirculation systems. Recirculationsystems have the advantage that they simulate thenatural self-cleaning abilities of marine and fresh-water ecosystems.

Global production8 |

“According to information published by the Food & AgricultureOrganization (FAO), aquaculture1 currently produces almost halfof the global seafood production.”

1 including algae

China no. 1 producer in the worldApproximately 500 types of aquatic species andplants are now produced using aquaculture, high-quality products beeing preferret. The most im -portant high-quality products include fish, aquaticplants (algae) as well as shellfish and crustaceans.

According to official FAO statistics the total pro-duc tion of fishery and aquaculture – including the production of algae – has constantly increased in recent years and reached 159.1 million tonnes in2008. This includes 68.3 million tonnes (includingalgae) from aquaculture. That means that aqua-culture makes up for almost half of the global sea-food production.

In 2008, the countries in the Asian-Pacific regionmade up for more than 91,7 % of the worldwideaquaculture production. The largest aquaculturalproducers are China, India, Thailand and Indonesia.In comparison, the EU accounts for only four percentof the world’s entire aquacultural produc tion.

| 9

Norway is placed among the top ten in the globalranking both in fishing and in aquaculture and isthe number one production country in Euro pe, fol-lowed by Spain, France and the United Kingdom.

In the Asia-Pacific region, especially in China andSouth Asia, aquaculture is characterised by theproduction of cyprinids (carp). The most importantfish types in Europe are trout and salmon. The fourmain species of fish produced in aquaculture in Europe (in tonnes) are rainbow trout, salmon, seabream and carp. German aquaculture producesmainly rainbow trout, carp, eel and sturgeon.

Marine andmigratory fish

Freshwater fish

Molluscs

Algae

Crustaceans

According to FAO,

marine fisheries

are exploited so

inten sively that

further increases

in output are not

possible.

1 in

clud

ing

alga

e

Megatons

160

155

150

145

140

135

130

125

120

2002

World capture and aquaculture1 fishery production (FAO 2010)

2003 2004 2005 2006 2007 2008

7%7%

23%

42%

7%1%

19%

Other

The most important aquaculture1 products 2008 (FAO 2010)

quantity in tonnes

10 | Development fishery and aquaculture

World fishery output stagnatesWhile the worldwide aquaculture has grown by7.5 % per year on average since 1970, the harvestof world fishery is stagnating or, for some fishtypes, is receding. This decline of fishery outputcan be traced to inadequate controls on fishing andto pollution (chemical and acoustic) of the ocean.

According to FAO statistics, aquaculture is the fas-test growing primary food production sector. Thisis due to the growing world population and increa-sed nutritional awareness. FAO forecasts that by2020 one half of the worldwide fishery harvest willbe supplied by aquaculture.

FAO forecasts

predict that aqua-

culture production

will rise to 80 mil-

lion tonnes by 2020.

Illustrations from

left: trout, salmon,

carp and sea

bream are the most

popular farmed fish

species on the

European market.

The wels catfish has great potentialThere were four farms producing the wels catfish(Silurus glanis) in Germany in 2008 using recircu-lation systems. They produced a total of 205 tons.

The largest wels catfish producer is located in Bad-bergen-Vehs in the northwestern part of Germany.To meet the increasing demand, the total produc -tion of the fish farm has increased to 115 tons in thelast couple of years.

According to experts, the market potential for welscatfish lies in the region of 4,000 tons plus per year.

Megatonnes per year

90

85

80

75

70

65

60

55

50

45

Development of the production output of fishery and aquaculture1

�� Fisheries (million) �� Aquaculture (million)

1 in

clud

ing

alga

e

2002 2003 2004 2005 2006 2007 2008

“Aquaculture is the fastest growingfood production sector.”

Significant reduc tions in

fishery yields, the bad

management of wild

fisheries and an increasing

scarcity of high-quality

water resources have

contributed to the strong

growth of aquaculture

in the last decade.

| 11

Indoor fish farming technology12 |

MMS (multi-measuringsystem)

waste watertreatment

O2 pH NH4 NO3

“With its modular system for innovative fish farming, BDFish³Equipment offers a solid package of field-proven technology forcompletely healthy fish!”

| 13

Recirculation technologyIn Germany, recirculation systems are used mainlyfor the farming of warm-water species. In order tobe able to re-use the process water, specially adap-ted water treatment systems are used. Normallythe treatment systems consist of biological and me-chanical cleaning stages for the removal of suspen-ded material and excrements.

Cleaning systemsTwo broad categories of systems are used:

External cleaning system | The equipment for themechanical and biological treatment of circulationwater are located outside of the pond.

Internal cleaning system | The holding pond andthe equipment for the mechanical and biologicalwater treatment are integrated in one large vessel.

The BigPool3 systemBDFish3 Equipment uses an internal cleaning systemin its recirculation systems. The cleaning system isintegrated into the holding vessel and includes bio-lo gical treatment of the holding water and sedimen-tation. Outside cleaning systems have high opera-ting costs due to the high energy requirements forthe additional pumping required. The internal cle-aning system from BDFish3 Equipment is charact-erized by its low energy consumption and high efficiency which are both very important factors forthe profitability of an indoor fish farm.

The BigPool3 component partsA BDFish³ Equipment indoor fish farm is made upof the following technical components:

Pond• Fish pond• Biological cleaning stage (bioreactor)• Sedimentation

Pipe systems for• Water• Aeration• Wastewater

Control and monitoring• Harvesting, weighing and sorting• Feeding• pH-value• Fresh water supply• Process air supply• Climate and heat control• Central water analysis

Energy supply• Co-generation plant and alternative

energy source• Various heat exchanger and heat recovery units

Air supply • Roots blowers

Fresh water supplyFeed unitHarvesting, weighing and sorting equipmentWaste water treatment system and container forfish slurry

In general, the fish ponds are divided in three parts(holding tank, bioreactor, sedimentation).

Each module consists of several ponds, their num-ber depends on the production capacity.

BigPool314 |

Ponds are first stocked with young fish with anave rage weight of 90 g. These are regularly sortedaccording to growth rates in order to maintain anoptimal stock of uniform fish in each pond. In or-der to provide the fish with optimum conditions,the water must be cleaned. Underneath the biolo-gical filter, large amounts of air enter the systemthrough a special ventilation system. The air lifts thewater column in the bioreactor and thus creates acurrent in the pond. This also supplies the micro-organisms with oxygen. A longtitudinal current isgenerated throughout the fish pond creating anoptimum uniform distribution of all solutes (oxy-gen etc.). The modular construction of the systemallows water to be exchanged between the pondsby means of a bypass. Thanks to this, all the waterin a module can be circulated in 2.5 hours.

The pond, as well as the water pipes, air duct anddrainage network are made of hard-wearing andfood-safe plastic.

The core of our recirculation systems is the bio -reactor and the ventilation. Thanks to the biologi-cal treatment of the production water, the fish areprovided with ideal growth conditions. Inside thebioreactor, the nitrogen excreted by the fish as am-monia is oxidized to nitrate via nitrite by meansof micro-organisms (nitrification), similar to thebiological processes in natural waters. The micro-organisms accumulate on the substrate of the fixed-bed bioreactor and form a so-called biofilm. Theentire bioreactor unit is called the bio-package.

Recirculation systems are not completely closed. Inorder to prevent the accumulation of certain sub-stances (such as nitrate) and thus provide optimum

“The daily water renewal rate is five to ten percent of the total capacity including evaporation.”

water conditions for the fish, a certain amount ofwater is removed from the system and replaced bymake-up water. The water renewal rate of our indoorfish farm system is between five and ten percentper day including evaporation. The daily withdrawalof water is mainly attributed to the dis charge ofsludge arising from fish excrement and uneatenfeed.

Through settling, waste feed and excrement collectin funnels in the sedimentation section which ma-kes up the third unit of our ponds. The sediment isautomatically transferred to a waste water treat-ment system by means of an air lift pump whichtransports the sediment from the funnels.

The fish excrement and unused feed pass from thefish pond sedimentation equipment via the drai-nage network to the waste water treatment system.In this special reactor, decomposition of nitrogenfrom the nitrate (denitrification) and organic con-stituents (carbon decomposition) take place. In afurther stage, phosphorus is removed from thewaste water. The resulting purified water can be dis-charged to the municipal sewer system or a recep-tion pond. The fish slurry produced during this pro-cess is transferred to a storage container from whe-re it can be taken and used as fertilizer for agricul-tural purposes.

The so-called fish slurry is pumped into a large sto-rage pond from where it can be taken and used asfertilizer for agricultural purposes. By flowingthrough an aerobic and an anaerobic biologicalchamber, discharging water is cleaned and canthen be released into a reception or refining pondor into the municipal sewer system.

| 15

High-Rise-System BigPool3

BigPool316 |

Air is supplied to the fish and microorganisms inthe fish pond by means of roots blowers. Dependingon the size of the farm, one or more roots blowersshare the provision of air. Another blower with thesame performance specifications supports the sys-tem in stand-by operation in order to supply thesystem with air in the event of mechanical failure.In the event of a power failure, an emergency powerunit guarantees the continued operation of theroots blowers and hence the supply of air to thefish and microorganisms.

The entire production control, monitoring and do-cumentation as well as targeted alarms is carried outby the process control Fish Management and Con-trol System FIMACS based on pre-set managementparameters. This process control system has beenspecially-developed by BDFish³ Equipment softwareengineers.

Feeding system | To reduce the work involved in aBDFish³ Equipment indoor fish farm, the feed issupplied to the fish automatically on a daily basis.The automated feeding system consists of fivecomponents: a feed container capable of storinglarge quantities of feed, a vehicle to a first dispen-ser, another vehicle which transports the feedthrough the system, and one or more automatedfeeders which deliver the feed to the fish. Feed hasa decisive effect on economic viability in indoorfish farming, so in developing the feeding systemgreat value was attached to accurate dosage andminimal mechanical disturbance due to the tech-nical feed transportation method. To avoid puttinga strain on water quality – due to possible "over-feeding" – a feeding system should have a mecha-nism for monitoring the feed intake of the fish, andgreat value was also attached to this in developingthe BDFish³ Equipment feeding system.

Production output (t/a) 30 60 135Number of ponds 12 24 48Number of modules 2 4 8Water volumefish ponds (m3) 10 10 10Water volumetotal system (m3) 210 420 840Maximumwater demand/24h (m3) 21 42 84Requiredspace (approx. m2) 500 800 1300Energy demandElectricity demand (kW) 10 18 35Heat demand (kW) 26 48 96Biological dataMean weightfor initiation (kg) 0.09 0.09 0.09Mean stockingdensity (kg/m3) 90 90 90Feed conversion ratio (FCR)for European Catfish(Silurus glanis) 1 1 1Growing cycle (month) 9 9 9Economic dataMean saleable weight (kg) 1.9 1.9 1.9Manpower requirements 0.4 0.6 1.0

The BigPool³

system has been

developed under

production prac -

tice conditions

and has been used

successfully for

several years.

“The advantage of the modular design lies in theability to adapt the system capacity to customerrequirements.”

Harvesting and sorting equipment | Fish grow atdifferent rates during the growing cycle. To achie-ve uniform results, they have to be sorted. To thisend, a BDFish³ Equipment indoor fish farm uses anautomated harvesting and sorting unit. For sortingor harvesting, the water is drained from the pondinto a collection tank. From here, the fish are trans-ferred individually to an automatic weighing andsorting system. After sorting the fish are allocatedto their respective ponds via a system of pipes. De-pending on the development of the fish, the sorting procedure is carried out 2 to 3 times pergrowing cycle. For harvesting, the fish passthrough the weighing and sorting system again.Market-ready fish with an average weight of 1.9 kgare sorted out automatically and transferred to anappropriate transport container via a system of pipes.

| 17

The modular farm system allows

adaptation of the number of ponds

to the particular customer needs.

Depending on the fish output

required, plants with

12 ponds (30 tons per year)

24 ponds (60 tons per year) or

48 ponds (135 tons per year)

can be supplied. The modules can,

of course, be expanded anytime.

Storage tank for residual slurry

(fish slurry)Waste water

treatment

Reception pond

Treated water

Storage

Sorting & harvesting

Storage

Sorting & harvesting

Storage

Sorting & harvesting

Office & lab

Feed dosage

Computer equipment & control box

Machine room

Co-generation plant (container)

Feed storage

Heating & dosage

Changing room, WC/shower

Office & lab

Feed dosage

Computer equipment & control box

Machine room

Co-generation plant (container)

Feed storage

Heating & dosage

Changing room, WC/shower

Office & lab

Feed dosage

Computer equipment & control box

Machine room

Co-generation plant (container)

Feed storage

Heating & dosage

Changing room, WC/shower

Conditions for successful indoor fish farming18 |

What you should knowFish farming is considered to be a part of agricul-ture. One of the main differences is the mediumwhich is used for the production of livestock. Forthis reason, the farmer is confronted with certainknowledge requirements such as the biology offish and knowledge of the medium in which theyare farmed.

In order to familiarize our customers with the ope-ration of a BDFish³ Equipment indoor fish farm, weoffer training at Big Dutchman in the technologyand management.

Water quality and -quantity | Aquatic ecosystemsare complex with many water quality variablessuch as temperature, oxygen content, pH-value,nitrite and nitrate contents, alkalinity and manyother parameters. These parameters may also in-fluence each other. This means that the evaluationof water supplies in terms of quality and quantitymust be done on a case-by-case basis.

A sufficiently dimensioned pump and a well shouldbe available for the supply of water to the fish farm.

“Although the old saying ‘The eye of the master fattens the cattle’is true, the control system and the overall management is also decisive for the success or failure of modern fishfarming.”

Successful indoor

fish farming is

based on a combi-

nation of extensive

know-how of plant

engineering for

live stock produc -

tion and years of

practical experien-

ce; this is what you

as customer will

profit from.

| 19

Energy supply | The energy supply (electricity andheat) is important to the profitability. There are different models of energy supply for an indoorfish farm available:• local electricity and gas network• all types of combined heat and power systems• wood chip heating

The least-cost energy supply depends on the localconditions and must therefore be selected indivi-dually for each farm. The process water is heatedusing a heat exchanger which is installed conve-niently to the fish farm. Electricity is mainly neededfor the roots blowers used for ventilation of the hol-ding water.

Emission and immission | The term emission refersto the release of substances, light or noise from thesystem into the environment. Connected to emissionis the immission, which describes the impact thatthe condition of the external environment has onthe system through pollution, noise or irradiance.Fish have very sensitive lateral line organs withwhich they perceive even the smallest pressurefluctuations – caused by sound waves – to whichthey react with a flight reaction. Very noisy locationsare disadvantageous for indoor fish farming.

Insulation and room climate | In order to keep ther-mal losses to a minimum, the facilities have to bewell insulated. A well sealed space is also requiredto be able to efficiently use the air conditioningtechnology for heat recovery developed by BDFish3

Equipment.

Discharge water | Indoor fish production results indis charge water which flows through a specialwaste water treatment system and can then be dis-charged into the municipal sewer system or the reception ponds.

Advantages of indoor fish farming• High productivity through high growth

rates and short production cycles• Control over the entire production cycle• Free choice of location• Low water consumption• Control over water quality• Protection against diseases and parasites• Control over the low amounts

of discharge water

Through the con -

trol of production

cycles, water qua-

lity and discharge

water, indoor fish

farming contributes

to sustainability

and protects natu-

ral resources.

Catfish rearing at Ahrenhorster Edelfisch20 |

The wels catfishThe wels catfish (Silurus glanis) is the second lar-gest freshwater fish in central European waters af-ter the sturgeon. It can reach five meters in length,300 kg body weight and live up to 80 years. In thefirst years of life, the catfish eats mainly crustace-ans, insects etc. From the second year on, it eatsmainly fish, especially percids, gobies, roach etc.

Husbandry conditions | For the production of uni-form high-quality meat, optimum water conditionsand high-quality feed must be provided. The bree-ding fish are housed in ponds in which a rapidchange in season is simulated by manipulating thewater temperature. In this way it is possible to pro-duce a fresh brood every eight weeks by stripingoff the milters and spawners. It is necessary to beable to identify all breeding fish individually. Be-cause of the high numbers of breeding fish, theyare identified using microchips.

Ecologically sound fish production | Catfish are keptin large ponds with optimum water quality toachieve the best growth results. Thanks to the so-phisticated circulation technology with internalbiological treatment, the water quality stays thesame throughout the production cycle. Drawing

on many years of experience, the quantity of waterrequired can be reduced to a minimum at Ahren-horster Edelfisch GmbH & Co. KG. The small amountof excrement that arises can be used to fertilisecrops. Use of antibiotics or growth promoters is notpermitted.

Health | Apart from its excellent taste, the filet of thewels catfish also brings health benefits. The com-position of fatty acids of the farmed catfish showsa significantly higher share of essential Omega-3fatty acids compared to wild catfish which meansfarmed catfish constitutes a good dietary alternati-ve to mackerel, herring or salmon.

Omega-3 fatty acids are known to have a beneficialeffect on the cardiovascular system in humans. Ingeneral and according to statements issued by theFAO, fish is considered to be a valuable foodstuffand is thus a good source for vitamins, mineralsand essential proteins and fatty acids.

Ways to the consumer | The sale of filets throughwholesale markets lies at the core of catfish basedfish farming. Correspondingly, 95 % of the produc -tion volume of Ahrenhorster Edelfisch GmbH &Co. KG goes to Bremerhaven and only 5 % is solddirectly to caterers, hotels or private customersthrough the farm shop.

Illustration right:

The meat of the

wels catfish is

white and almost

boneless. Due to its

relatively high fat

content of approx.

11 % it is very suit -

able for frying, broi -

ling and smoking.

Illustrations above:

The four stages of

wels catfish pro -

duc tion: hatching

in zuger glass jars,

production of young

fish, production

of food fish and

filleting.

| 21

“Ahrenhorster Edelfisch GmbH & Co. KG: The Otto-Lübker family hasbeen farming the wels catfish since 1991. The inside of the buildingswere completely remodelled to meet the requirements of fish farming.Thanks to Hermann Otto-Lübker’s long experience he succeeded inproducing the wels catfish from breeding to filet and has developedthe market.”

Economic efficiency22 |

Costs and earningsThe economic performance of our modular farmsystem are a combination of evaluations by our co-operation partner "Ahrenhorster Edelfisch GmbH& Co. KG" made in almost twenty years of practicalexperience and new scientific findings that weregained at the Big Dutchman in-house research fa-cility (Technikum).

Production costs for three system sizes | The farmsize has a decisive influence on the productioncosts, particularly technology and managementcosts.

Calculation of the fish price | The price for filet onthe wholesale market is influenced by seasonal flu-ctuations. For a given filet price, the value of fish isdetermined by processing, packaging and trans-port, administration and the yield of the filet.

License | Apart from planning permission which isrequired for a new building or the conversion of anold building, special permits for the use of groundwater and the release of discharge water into themunicipal sewer system or the reception pondsmight also be required.

| 23

“To ensure that indoor fish farming does not remain a mystery, weprovide on-site training at our in-house research facility. We willremain at your side once the farm has been erected and will supportyou in any way during the construction and familiarisation phase.”

Compared with

field-grown wels

catfish, farm-

grown wels cat-

fish has a signi -

ficantly higher

content of Omega-

3 fatty acids. For

this reason the

meat of the wels

catfish is rightly

considered to be

especially bene -

ficial to a

healthy diet.

Kapitel24 |

Big Dutchman International GmbH

Business Unit BDFish³ Equipment

P.O. Box 1163

D-49377 Calveslage

Germany

Tel. +49 (0 ) 44 47/801-0

Fax +49 (0 ) 44 47/801-237

info@bd-fish.de

www.bd-fish.de

■ Applying for planning permission■ Applying for licences■ Comprehensive advice during

planning and construction■ Delivery and installation■ Staff training in the Calveslage research facility ■ Biological knowledge■ Technical support

Ref.-

Nr.:

Bro

schü

re-B

DFis

h_10

10_V

1_en