Monthly Archives: February 2012

Sustainable feed resources

Fish farming is very efficient in terms of the conversion of protein, which means an important ecological advantage in light of the sustainability of fish feed resources.

One of the most-frequently cited issues with the sustainable development of aquaculture is the capture of other fish as raw material to be used as fish feed in the form of fish meal and fish oil. It is seen as an issue because a food production sector is in part relying on a capture fishery for the supply of raw materials for the production of aquaculture feed.

Typically, these other fish species are small, oil-rich, bony pelagic fish that are not normally used for direct human consumption. Two decades ago, the majority of fish meal and oil was used to make feeds for land animal production. At present, over 50 percent of fishmeal and over 80 percent of fish oil is used for aquaculture.

If aquaculture is to fill the gap in demand for seafood, this raises important sustainability issues as to the availability of sufficient feed supply. This is particularly relevant given the fact that fishmeal and fish oil production has been, and is likely to remain, relatively constant at around 6 million and 0.9 million tonnes per year, respectively.

However, as the demand for fishmeal and fish oil in aquaculture has increased, so the price has risen. This has driven both terrestrial agriculture and aquaculture to seek nutritional alternatives to fishmeal and fish oil. This is an on-going process and estimates made by the International Fishmeal & Fish oil Organisation (IFFO) show that the growth of aquaculture and the substitution of fishmeal and fish oil can continue together. The IFFO has started to produce datasheets on fisheries for fish meal and fish oil and these are available at the IFFO web site.

Conversion of caught wild fish to farmed fish

It has been noted that certain types of fish, particularly salmon, are net consumers, requiring in the region of 3 kg of wild fish as feed to produce 1 kg of farmed fish. While it is true that growing high-quality salmon requires considerable amounts of fishmeal and oil, improved technology in fishmeal and oil production as well as better feeding practices on farms have reduced the ratio over time.

Salmon are an exception, because their diets require large amounts of fish oil. For aquaculture overall, the ratio is now well below one: less fish is used for feed than is produced at farms. For carnivorous species, the ratio is still decreasing and expected to reach 1.0 around 2012 (IFFO).

These figures do not include recent gains thanks to the recovery of meal and oil from aquaculture waste. Increasingly in Europe, waste from aquaculture is collected and processed, redirecting around 50 percent of the harvested weight to valuable products.

It should also be noted that wild carnivorous fish also need food. It is estimated that it takes 10 kg of forage fish to produce 1 kg of salmon caught in the wild6. If by-catch values are added to the equation, another 5 kg of forage fish has to be added. Hence, even a 3 to 1 ratio for farmed salmon would be significantly better than a 10-15 to 1 ratio of salmon caught in the wild.

 Efficiency of food conversion in farmed fish

The ‘food conversion ratio’ (FCR) is defined as the weight of food that is required to produce one kilogram of fish. In the early days of aquaculture, farmed fish were fed with whole ‘trash’ fish and FCRs were more than 20 to 1. Through the years, the ratio has dramatically declined. With the advent of dry, pelletised feeds and modern extrusion technologies, FCR levels are now almost 1 to 1. Certain trout and salmon farms achieve an FCR of less than 1:1, making them far more efficient converters of marine protein than their wild counterparts.

As fish feeds represent an increasingly high share of total production cost, fish farmers have every interest in using feeds as effectively as possible, thereby also reducing the potential environmental impacts of non-consumed feeds. Overfeeding or underfeeding would increase the FCR. Therefore, many farms are equipped with underwater surveillance and monitoring systems as well as devices controlling the supply and delivery of feed.

Replacement of marine protein sources by (terrestrial) plant protein

For various reasons, fishmeal and oil are gradually being replaced by plant proteins in feed that is used in fish farms. Plant proteins can be less costly and they are free of potential contaminants like dioxin, PCB or mercury.

However, fishmeal is an important ingredient in fish feed and can only to a limited extent be replaced by vegetable proteins without reducing feed efficiency and growth. After all, carnivorous or ‘piscivorous’ fish naturally feed on other fish. The fatty acid composition in the flesh from farmed fish will also reflect the feed composition and inclusion of vegetable oil will reduce the level of omega-3 fatty acids.

Although the introduction of plant protein into the feed can be seen as a way of reducing the sector’s dependence on fish meal and fish oil, some have questioned the trend because:

  • carnivorous fish do not naturally feed on plants;
  • plant proteins may have anti-nutritional effects on fish;
  • there is a maximum level of replacement, after which the texture and eating quality
  • of the fish is compromised;
  • some plant proteins could be derived from GMOs.

Generally speaking, though, marine plants have enormous potential to act as fish feed ingredients. Initial research has confirmed this potential and our knowledge in this area is starting to build.

Decontamination of fish meal and fish oil
Fishmeal and fish oil are produced from fish that may contain contaminants. Various research projects are ongoing to look into the feasibility of de-contaminating fish meal and fish oil. One such project is carried out at the Fiskeriforskning Institute in Norway.

Fish stocks of concern in the northern European industry are sprat and herring from the Baltic Sea, and herring, sprat, sand eel and blue whiting in the North Sea. The differences in dioxin and PCB levels reflect the general pollution levels in the respective fishing areas and will disfavour the North European fishmeal and oil producers in the world market. This is already the case in aquaculture, where most fishmeal is sourced from the southern hemisphere.

The main objective of the project is to develop a new oil extraction process to reduce the persistent organic pollutants level in fishmeal. The research will aim to identity optimal processing conditions with respect to both decontamination efficiency and preservation of fishmeal and oil quality. The new oil extraction process is expected to have several advantages compared to a standard hexane extraction process. This will include the possibility of easy integration in an existing fishmeal processing line, use of a safe and non-flammable extraction medium and lower investment and operation costs.

Do farmed fish contain artificial colouring?

The natural red/orange colour of salmon results from carotenoid pigments, largely astaxanthin in the flesh. Astaxanthin is a potent antioxidant that stimulates the development of healthy fish nervous systems and that enhances the fish’s fertility and growth rate. Wild salmon get these carotenoids from feeding on small crustaceans, such as prawns and shrimp. Astaxanthin does not naturally occur in fish feeds and thus must be added. The astaxanthin which is added to feed is identical to the natural pigment.

Food miles

In recent years, there has been increasing emphasis on energy resources needed to ship in food from afar. Although the relationship between transport and overall sustainability can be complex, it can be said that where food supply chains are otherwise identical, reducing food transport improves sustainability.

Therefore, generally speaking, European aquaculture production could be seen as more efficient in terms of “food miles” than imports of the same species from countries far away.

However, there is a food mile issue with the use of fish meal and fish oil produced in the southern hemisphere and used in Europe, although this is itself a trade-off of not using fish meal produced in Europe due to issues of species in recovery (e.g. sandeel and capelin) and contamination of fish meal and oil (e.g. Baltic herring).

However, as stated before, comparisons can be complex, involving differences between food supply systems that often involve trade-offs between a diverse variety of environmental, social and economic factors. The impact of food transport can be offset to some extent if food imported to an area has been produced more sustainably than the food available locally. For example, a case study showed that it can be more sustainable (at least in energy efficiency terms) to import tomatoes from Spain than to produce them in heated greenhouses in the UK outside the summer months.

In the case of fishmeal and fish oil, the world’s largest producers of fishmeal and fish oil are in South America. There, fishmeal and fish oil are mass-produced very efficiently and shipped overseas (already with a reduced water content in the case of fishmeal) to Europe to be used as feed in aquaculture. Surely, this has to compare favourably to using airplanes to import fresh fish from Asia or South America.

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Greenhouse with tilapia, lettuce, herbs and cucumbers


A completely integrated food production system using retractable roofs to create optimal growing conditions using the advantages of the natural outdoors and a greenhouse.

Green Sky Growers, a rooftop farm, is located on top of the Garden Building in Winter Garden, Florida, and is the first Certified Green building in the world with commercial-scale, Aqua-Dynamic farming on the rooftop. Green Sky Growers produces tons of fresh vegetables and fish on an annual basis without the use of harmful pesticides.

  • Environmentally friendly growing practices include the harvesting of rainwater that is recycled in the Aqua-Dynamic growing systems.
  • All the growing systems continuously recycle 100% of the nutrients and water.
  • The majority of food produced is available to the local Winter Garden community, thus providing healthy, locally grown and low carbon-footprint food.

    project of NGO


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Should You Attempt Fish Farming?


Considerations for Prospective Fish Growers

Louis A. Helfrich, Fisheries Extension Specialist, and George S. Libey, Associate Professer, Aquaculture; Department of Fisheries and Wildlife Sciences, Virginia Tech


Fish farming is an ancient practice that can provide many profitable opportunities today. The raising and selling of fish on a commercial basis has proven to be economically successful throughout the United States. In Croatia, fish farming is growing in popularity. Increasing recognition that fish is a healthy food, low in calories and cholesterol levels, but rich in protein has increased consumer demand in both restaurants and supermarkets.
Fish are excellent animals to rear. They can convert feed into body tissue more efficiently than most farm animals, transforming about 70 percent of their feed into flesh. Fish also have excellent dress-out qualities, providing an average of 60 percent body weight as marketable product and a greater proportion of edible, lean tissue than most livestock. Fish can be intensively cultured in relatively small amounts of water. In Virginia, they can be farmed at densities near 2,000 pounds/acre with careful management. Farm-reared fish offer a new alternative agricultural crop that can potentially replace those which are declining in popularity or profitability. Healthy farm-reared fish, guaranteed free of diseases, pesticides, and other harmful toxicants, are a more desirable substitute for wild fish from potentially polluted waters.

Fish farming is, like most other types of farming, a risky business that requires special knowledge, skills, and careful considerations. Some of the most important factors to consider in determining whether you should begin a fish farming business are listed below. Answering yes to all or most questions does not insure success. Similarly, answering no to all or most questions does not guarantee failure. Individuals with little or no experience in fish farming and few resources available can become successful fish farmers, but they should start small and expand slowly, and be willing to invest lots of time and effort.

Answer Yes or No

Do you have sufficient financial resources available?
2. Do you own suitable land with a good source of high-quality water?
3. Do you own enough land and water necessary for a profitable venture?
4. Is there a high demand and sufficient market for your product?
5. Do you have the equipment and machinery necessary?
6. Is expected profit from fish farming greater than other land uses?
7. Can you really devote the money, time, and labor necessary?
8. Do you know the costs involved with the following items:

Capital CostsLand & buildings
Building ponds/raceways
Trucks & tractors
Plumbing & pipes
Tanks & aerators
Oxygen meters
Nets & boots
Operating CostsPurchasing eggs/fingerlings
Fish feed
Electricity & fuel
Labor & maintenance
Chemicals & drugs
Taxes & insurance
Telephone & transportation

Is there an established market for your fish?
2. Is the market demand sufficient year-round?
3. Do you have an alternative marketing strategy to rely on?

Do you have a continuous source of clean, high-quality water?
2. Does your soil have enough clay content to hold water?
3. Is the water temperature optimal for the fish species reared?
4. Do you have space sufficient to build enough ponds or raceways?
5. Do you have good and easy pond access for feeding and harvesting?
6. Are the pipes sufficient in size for quick draining & easy filling?
7. Is your residence near enough for direct observation and security?
Have you had your water tested (chemical and bacteriological)?
2. Do you have a reliable source of fingerlings or eggs at affordable prices?
3. Do you have a reliable source of feed at reasonable cost?
4. Do you have dependable labor available at affordable wages?
5. How long is your growing season (days/year)?
6. What’s your production capacity (pounds/year)?
7. What’s the best fish species for you to grow?
8. Are you aware of fish reproductive biology and nutritional needs?

Are you aware of the federal and state laws about fish farming?
2. Do you know where to apply for the necessary permits and licenses?
3. Are you familiar with the personal liability concerns involved?

Risk Assessment:
Can you afford to lose your entire fish crop?
2. Can you conduct water quality tests?
3. Is fish-disease diagnostic-help readily available?
4. Do you know about off-flavor and its causes?
5. Is pesticide, metal,or oil contamination possible?
6. Can you deal with poachers and vandals?
7. Do you know where to go for information and help?

Fish Farming Publications

Magazines/ Newsletters
Aquaculture Digest
9434 Kearney Mesa Rd.
San Diego, CA 92126

Aquaculture Magazine
P.O. Box 2329
Asheville, NC 28802

Aquafarm Letter
3400 Neyrey Drive
Metairie, LA 70002
Arkansas Aquafarming
University of Arkansas
Cooperative Extension Service
Box 391
Little Rock, AR 72203

California Aquaculture
University of California
Cooperative Extension Service
Aquaculture Extension
Davis, CA 95616
Canadian Aquaculture
4652 William Head Rd.
Victoria, British Columbia
Canada, V8X3W9

Carolina Aquaculture News
P.O. Box 1294
Garner, NC 27529

Farm Pond Harvest
Professional Sportsman Pub.Co.
Box AA
Momence, Illinois 60954

Fish Farmer
Business Press International
205 E. 42nd St.
New York, NY 10017

Fish Farming International
Heighway House
87 Blackfriars Road
London SE 1814B England

Fish Farming International
110 Fleet St.
London EC4A England

For Fish Farmers
Mississippi State University
Cooperative Extension Service
Mississippi State, MS 39762
Georgia Fish Farmer
University of Georgia
Cooperative Extension Service
Athens, GA 30602

Salmonid Magazine
U.S. Trout Farming Asso.
506 Ferry St.
Little Rock, AR 72203

South Carolina Aquaculturist
Clemson University
Cooperative Extension Service
Room 102, Long Hall
Clemson, SC 29631

Texas Aquaculture
Texas A&M University
Cooperative Extension Service
102 Nagle Hall
College Station, TX 77843

The Catfish Journal
Catfish Farmers of America
P.O. Box 1700
Clinton, MS 39056

Timely Tips-Fisheries
University of Tennessee
Cooperative Extension Service
P.O. Box 1071
Knoxville, TN 37901-1071

Water Farming Journal
3400 Neyrey Drive
Metairie, LA 70002

World Aquaculture News
P.O. Box 150129
Arlington, TX 76015
Journals/ Technical Publications
American Elsevier Scientific Pub. Co.
52 Vanderbilt Ave.
New York, NY 10017
32 issues/yr.–$640/yr.

Aquaculture Engineering
Elsevier Applied Science
52 Vanderbilt Avenue
New York, NY 10017

Journal of Shellfish Research
National Shellfisheries Association
Oyster Biology Section
Gulf Coast Research Lab.
Ocean Springs, MS 39564

Journal of the World Aquaculture Society
178 Pleasant Hill
Louisiana State University
Baton Rouge, LA 70803

Progressive Fish Culturist
American Fisheries Society
5410 Grosvenor Lane, Suite 110
Bethesda, MD 20814-2199

Transactions of the American Fisheries Society
American Fisheries Society
5410 Grosvenor Lane, Suite 110
Bethesda, MD 20814

Selected Fish Farming Books

  • A Guide to Integrated Warm Water Aquaculture. D. Little and J. Muir. Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland.
  • Aquaculture Engineering. 1977. F.E. Wheaton. R.E. Krieger Publishing Company, Kreiger Dr., Malabar, FL 32950.
  • Aquaculture: The farming and husbandry of freshwater and marine organisms. 1972. John Wiley & Sons, Inc. New York, NY.
  • Cage Aquaculture. 1987. M. Beveridge. Unipub, 4611-F Assembly Drive, Landham, MD 20706-4391. Phone (301) 459-7666. ($38)
  • Commercial Catfish Farming. 1973. Interstate Printers and Publishers. Danville, Il.
  • Crustacean and Mollusk Aquaculture in the United States. J.V. Huner and E.E. Brown. AVI Publishing Co., Inc., 250 Post Road East, P.O. Box 831, Westport, CT 06881.
  • Fish Farming Handbook. 1980. AVI Publishing Co., Inc., Westport, Ct. 06881.
  • Fish Hatchery Management. 1986. American Fisheries Society, 5410 Grosvenor Lane, Suite 110, Bethesda, MD 20814.
  • Guidelines for Striped Bass Culture. 1976. American Fisheries Society, 5410 Grosvenor Lane, Suite 110, Bethesda, MD 20814-2199.
  • Principles and Practices of Pond Aquaculture. 1986. American Fisheries Society, 5410 Grosvenor Lane, Suite 110, Bethesda, MD 20814-2199, Phone (301) 897-8616. ($39.95)
  • Principles of Warmwater Aquaculture. 1979. John Wiley & Sons, Inc. New York, NY.
  • Principles of Warmwater Aquaculture. 1979. American Fisheries Society, 5410 Grosvenor Lane, Suite 110, Bethesda, MD 20814-2199. Phone (301) 897-8616 ($39.95)
  • Recent Advances in Aquaculture. J. Muir and R. Roberts. Westview Press Inc., 5500 Central Ave., Boulder, CO 80301.
  • The Aquaculture of Striped Bass. 1984. Maryland Sea Grant Program, 1224 Patterson Hall, Univ. of Maryland, College Park, MD 20742.
  • Trout and Salmon Culture (Hatchery Methods). 1980. California Fish Bulletin Number 164. University of California, Berkeley, CA 94720.
  • Trout Farming Handbook. 1973. Scholtum International Inc. Flushing, NY.
  • Water Quality in Warmwater Fish Ponds. 1984. C.E. Boyd. Auburn University, Auburn, AL 36830. ($8)


American Fisheries Society
5410 Grosvenor Lane
Suite 110
Bethesda, MD 20814-2199

Catfish Farmers of America
P.O. Box 36
Jackson, MS 39205
National Ornamental Goldfish Growers Asso.
6916 Blacks Mill Rd.
Thurmont, MD 21788

National Shellfisheries Association
Edwin Thodes
National Marine Fisheries Service
212 Rogers Ave.
Milford CT 06460

Shellfish Institute of North America
National Fisheries Institute
2000 M Street, NW, Suite 580
Washington, DC 20036

U.S. Trout Farmers Association
515 Rock Street
Little Rock, AR 72202

World Aquaculture Society
341 Pleasant Hall
Baton Rouge, LA 70803

CCRES AQUAPONICS special thanks to Michelle Davis, Research Associate, Fisheries and Wildlife

Virginia Cooperative Extension materials are available for public use, re-print, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.

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Europska aquakultura

Važnost očuvanja

Provjere od strane službenika za kontrolu ribarstva sprječavaju prekomjerno izlovljavanje ribe.

Ribarska industrija EU-a druga je po veličini u svijetu. Godišnje osigurava oko 7.3 milijuna tona ribe. Ribarstvo i industrija prerade  ribe zapošljavaju više od 400.000 ljudi.

Prioritet ribarske politike EU-a je postići ravnotežu između osiguravanja konkurente ribarske industrije s jedne i održivih ribljih zaliha te održivog pomorskog eko-sustava s druge strane.

Za razdoblje od 2007.-2013. godine, Europski ribarski fond ima na raspolaganju 3.85 milijardi eura koje se mogu potrošiti na prioritete postavljene od strane zemalja članica, temeljene na njihovim vlastitim odlukama o tome što im je naviše potrebno. Novac se može iskoristiti za morsko i slatkovodno ribarstvo, akvakulturu, organizacije proizvođača, sektor procesiranja i marketinga, te za ekonomsku diverzifikaciju u ribarskim zajednicama.

Nužna je dobra provedba

Kako bi osigurala poštivanje ograničenja vezanih za ribarstvo, postavljenih u interesu dugoročnog očuvanja zaliha ribe, EU je 2005. godine osnovala Agenciju za kontrolu ribarstva Zajednice. Agencija, čije je trenutno sjedište u Bruxellesu, trebala bi se u 2008. godini preseliti na svoju stalnu lokaciju u Vigo u Španjolskoj, europsku vodeću ribarsku luku. Agencija koordinira provedbu pravila za sprječavanje prekomjernog izlovljavanja ribe i zaštitu drugih oblika morskog života. Osim toga, ona osigurava obuku za inspektore i organizira zajedničko postavljanje inspektora iz više država članica Unije.

Međunarodna suradnja i pomoć

Ribarski sporazumi sa zemljama izvan EU-a i pregovori unutar regionalnih i međunarodnih ribarskih organizacija osiguravaju sprječavanje prekomjernog izlovljavanja ribe, ne samo u vodama EU-a, već i u onima iz čitavog svijeta. Istovremeno, ribarima EU-a pružaju pristup ribi u udaljenim vodama. Zemljama u razvoju EU plaća za pravo pristupa, a novac dobiven tim putem uvelike se ulaže u ribarske industrije tih zemalja te u izgradnju njihovih ribljih zaliha.

Razvijanje akvakulture

Akvakulturom se može nadoknaditi smanjenje zaliha divlje ribe. Već sada 20% ukupnog izlova Europske unije dolazi iz uzgajališta riba. Mekušci, školjke, potočna pastrva i losos spadaju u najvažnije proizvode akvakulture, no u nekim zemljama važno mjesto zauzimaju i šaran i deverika.

Akvakulturna industrija EU-a raste sporije od industrije ostatka svijeta. Europska komisija razmatra uvođenje dodatnih koraka za razvoj potencijala ove industrije. Ključni izazovi uključuju manjak prostora i vode dobre kvalitete, te visoke standarde zaštite javnog zdravlja i okoliša. Europska aquakultura prednjači u održivom razvoju u svijetu, i po pitanju socijalnih učinaka i učinaka na okoliš, no to otežava tržišno natjecanje s proizvođačima iz drugih zemalja, posebice iz Azije i južne Amerike.

Pomorska dimenzija

EU ima više mora nego kopna te predstavlja najveći svjetski pomorski teritorij. Ima ukupno 1200 luka, a oko 90% ukupne vanjske trgovine i 40% unutarnje obavlja se morskim putem. Trgovačka flota Europske unije najveća je na svijetu.

Pomorske regije sačinjavaju više od 40% bruto domaćeg proizvoda EU-a, a u njima živi 60% populacije Unije. Oko 5% BDP-a dolazi izravno iz pomorskih industrija i usluga. Broj je puno veći kada se uzmu u obzir neizravni doprinosi iz drugih sektora, poput turizma.

Kako su ribarska politika i politika zaštite okoliša već neko vrijeme percipirane kao dvije strane iste medalje, EU sada preuzima šire gledište kako bi obuhvatila sve koristi našeg pomorskog prostora. Cilj je ojačati europska pomorska istraživanja, tehnologiju i inovacije. To se uklapa u Lisabonsku agendu za veći broj kvalitetnijih poslova i rast, te u Unijinu posvećenost osiguravanju da gospodarski razvoj ne ugrožava održivost okoliša. Integrirana pomorska politika obuhvaća pomorski prijevoz, konkurentnost kompanija u pomorskom sektoru, zapošljavanje, znanstvena istraživanja, ribarstvo i zaštitu morskog okoliša.

Kako bi naglasila važnost ovog sektora, Europska komisija je 20. svibnja proglasila Europskim danom pomorstva. Prvi Europski dan pomorstva obilježen je 2008. godine. 


Branka Kalle 

Predsjednica Savjeta 

Hrvatskog Centra Obnovljivih Izvora Energije (HCOIE)

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Quality of life for the planet

Need for high quality water and other resources

Clean water is the primary pre-requisite to successful aquaculture. A clean environment is therefore critical for its commercial success. Any environmental impact that would compromise the quality of the water used on fish farms must be monitored and minimised through appropriate siting (choice of locations) of farms and production processes.


In recent years, the development of aquaculture has raised some associated environmental concerns. Like any farming operation on land, fish farm cages produce waste materials. These fall into three categories – uneaten feed, fish faeces and dead fish. Most of the environmental impacts of aquaculture can be managed and minimised through understanding of the processes involved, responsible management and the effective siting of farms.


Uneaten feed – Should uneaten feed reach the bottom of a cage, processes that break it down can reduce the amount of oxygen in the sediment. In severe cases, oxygen levels in the water above may also decrease, creating “anoxic” conditions in which only a few animal species can survive. Should the feed contain antibiotics used to treat the farmed fish above, bacteria in the sediment and the natural breakdown of waste material might be affected.

In practice, fish farmers do everything they can to prevent such a situation, since the cost of fish feed amounts up to 40 percent of the total production cost. Feed reaching the sediment is lost, and it is in the farmer’s interest to minimise such waste. On well-managed farms, feeding is carefully regulated to ensure that the maximum amount of food is taken up directly by the fish and farmers aim to ensure that less than 5 percent of the feed is wasted. To improve uptake by fish, feed pellets are manufactured to either float or to sink slowly through the water.

Fish faeces – Unlike land animals, fish do not generally produce compact solid faecal material and more often excrete a loose cloud of faecal material that is easily dispersed by water currents. In still conditions, however, faecal material can build up beneath fish cages. It is, however, not in the farmer’s interest to let this happen, since the buildup of faecal material can lead to anoxic conditions which affect the fish above. Fish farmers wanting to ensure the health of their fish will frequently check the bottom below their fish cages to ensure that faecal material is not building up. In addition, in many EU Member States, the government employs diving teams to carry out inspections.
If faecal build-up is observed, farmers will be advised to move their cages, allowing the bottom to recuperate for a short period, however full recovery typically takes between three to ten years. In recent years, improved feed formulations have also been introduced that fish digest more efficiently, producing less waste.

Fish farmers generally avoid overly sheltered and stagnant sites, preferring areas that contain a healthy flow of water through the cages. Such flows disperse fish faeces so it can enter the natural food chain.

Dead fish – Dead fish are a loss to the farmer and a potential health hazard to the stock as well as a source of pollution. Fish farmers will, at all times, endeavour to minimise the number of dead fish on their farms and to remove such mortalities where they occur.

Fish farms are required to report significant fish deaths when they occur and are inspected by state agencies at least twice a year.

Shellfish cultivation

Shellfish such as oysters, mussels and clams are filter feeders and take their food directly from the water in which they live. This means that they do not require supplementary food and, if anything, actually improve the quality and clarity of the water. Shellfish farming can only provide the best quality products if practiced in pristine environments with the highest water quality.

Environmental problems can arise on shellfish farms where the animals are held at overly high densities, leading to depletion of food in the water and build-up of faeces below the holding areas. Both effects will harm the outcome for the farmer and hence shellfish farms are generally sited where water exchange is high and the stock is kept at densities that are compatible with the level of water exchange. In many cases, stocking densities on farms are lower than those of clusters of shellfish (e.g. mussels) that occur on natural beds.

Shellfish farms have been thought to disturb wildlife habitats by taking up space on a beach where wading birds feed. It has been shown, however, that wading birds and oyster farms can exist side by side. The fallen oyster or mussel can have a positive impact on a bird’s feeding pattern.

Other potential impacts include the importation of parasites, pests and diseases onto the shellfish farm which would then spread to other areas. The microscopic oyster parasite Bonamia ostrea, for example, gradually spread through Europe with the spread of oyster farming. Oyster farmers have responded by significantly reducing the density at which their shellfish are farmed.

Some people complain of “visual pollution” caused by large numbers of floating barrels or shellfish trestles in otherwise unspoilt areas. Low-profile and dark-coloured floats have recently been developed to minimise the visual impact.

Pond fish farming

Fish pond systems represent the oldest fish farming activity in Europe, at least dating back to medieval times. Ponds were built in areas where water supply was available and the soil was not suitable for agriculture. The wetlands of Central and Eastern Europe are good examples of this. The total European production from pond farming is approximately 475,000 tonnes. About half of this production is cyprinid fish, such as common carp, silver carp and bighead carp. The main producer countries are the Russian Federation, Poland, Czech Republic, Germany, Ukraine and Hungary.


Typical fish ponds are earthen enclosures in which the fish live in a natural-like environment, feeding on the natural food growing in the pond itself from sunlight and nutrients available in the pond water.

In order to reach higher yields, farmers today introduce nutrients into the pond such as organic manure. This is accompanied by stocking of fingerlings and by water being flushed through the pond. Fish pond production, however, remains ‘extensive’ or ‘semi-intensive’ (with supplementary feeding) in most countries, where semi-static freshwater systems play an important role in aquaculture. Chemicals and therapeutics are not usually used in such ponds. Hence the main environmental issue is the use of organic fertilisers, which may cause eutrophication in the surrounding natural waters. The use of organic fertilisers is regulated at national levels.

Extensive fish ponds are usually surrounded by reed belts and natural vegetation, thus providing important habitats for flora and fauna. They play a growing role in rural tourism. Many pond fish farms have been turned into multifunctional fish farms, where various other services are provided for recreation, maintenance of biodiversity and improvement of water management.

In areas where water is scarce, some farm systems recirculate, treat and re-use their water. Such systems are generally self-contained and therefore pose little threat to the environment. Solid waste material produced in such systems is rich in organic compounds and often used as a fertilizer elsewhere. Alternatively, new hydroponic systems have been developed to grow vegetables and other food crops in the nutrient-enriched water. There is much interest in these systems, but their economic viability remains challenging.

Trout farming in flow-through systems


The most widely-practiced form of inland aquaculture in Europe is trout farming. Water is taken from the river, circulated through the farm and treated before being released downstream. All water in the farm is renewed at least once per day. Where more than one farm exists on the same river, it is in everyone’s interests that the quality of the outflowing water from one farm is good, as this then becomes the inflowing water for the next farm. Other water sources include spring water or drilled and pumped ground water. In some countries, heated industrial water sources (such as electricity generating plants) are used to increase the water temperature (by heat exchange)
used in the farm, thereby saving energy costs to heat the water. Geothermal water also provides naturally warmed water, thus allowing the farming of new fresh water species (especially eel, sturgeon, perch and tilapia) with low environmental impact.



trout farm

Recirculation Aquaculture Systems

Recirculation Aquaculture Systems (RAS) are land-based systems in which water is re-used after mechanical and biological treatment so as to reduce the needs for water and energy and the emission of nutrients to the environment. These systems present several advantages such as: water and energy saving, a rigorous control of water quality, low environmental impacts, high biosecurity levels and an easier control of waste production as compared to other production systems. The main disadvantages are high capital costs, high operational costs, requirements for very careful management (and thus highly skilled labour forces) and difficulties in treating disease. RAS is still a
small fraction of Europe’s aquaculture production and has its main relevance in The Netherlands and Denmark. The main species produced in RAS are catfish and eel but other species are already being produced using this type of technology such as turbot, sea bass, pikeperch, tilapia and sole.


Other environmental impacts of fish farming – the case of escaped fish

It is inevitable that fish farmed in net pens in either fresh or salt water will sometimes escape into the wild. In some cases, there will be a small but steady release of fish. Sometimes, large numbers will escape due to severe damage to the net pen by way of storms, predator attacks or vandalism.


There has been vigorous debate on the potential impact of escaped farmed fish, in particular salmon, on wild populations. On the one hand, it has been suggested that escaped farmed salmon could compete for living space, breeding partners and food resources, spread disease, or interbreed with wild fish, causing “genetic pollution” and thereby weakening the wild strain and reducing its ability to survive . On the other hand, scientists have argued that farmed salmon, which are bred for fast growth in perfect conditions, are less able to compete for food, territory and mate in the wild than their wild colleagues. Therefore, a limited escape of farmed fish would be unlikely to have a serious effect on wild fish populations. Only if very large numbers of fish escape into a small area, would interbreeding occur and the fitness of the local population potentially be reduced.


In its Aquaculture Europe 2005 conference, the European Aquaculture Society invited the North Atlantic Salmon Conservation Organisation (NASCO) to hold a special workshop on the interactions between wild and farmed salmon. The summary report of this event “Wild and Farmed Salmon – Working Together” drew the following main conclusions:

Through the use of single bay management, single generation sites and synchronised fallowing, real progress is being made in relation to minimising impacts of diseases and parasites, which are key issues for wild fish interests. The development of third-party audited containment management systems may represent a significant step forward. The liaison group should look more at the possibilities of rearing all-female triploid salmon, which could eliminate genetic interaction with the wild stocks, but which need to be balanced by the production cost of these fish, as well as consumer resistance to what could be seen as genetic manipulation.

Restoration programmes can benefit from fish farmers’ expertise, but habitat protection and restoration have equal or greater importance in species restoration than stocking programmes alone.



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CCRES AQUAPONICS Cooperating Institutions


 CCRES AQUAPONICS Cooperating Institutions
International Fish Farming Technologies provides a novel technology for the inland production of seawater fish. IFFT’s innovative and environmentally friendly Closed Loop Mariculture (CLM) offers an alternative to conventional fish farming. By uncoupling from the environment and under stable rearing conditions they present the new perspective for sustainable and environmentally friendly fish farming.
Agro Ittica Lombarda S.p.A. : CALVISIUSâ Original Caviar Malossol is the registered trade mark of Agroittica Lombarda’s farmed White Sturgeon Caviar. Agroittica Lombarda, based in Brescia (Italy) runs the largest sturgeon farm in Europe producing 500 tonnes/year of meat and 20 tonnes/year of top quality caviar. Experienced since 1991 in farmed caviar processing, Agroittica has gained a worldwide reputation for the freshness, granulometry (min.2.8mm) flavour and hygiene of its sturgeon roe: a real Malossol with a very low salt content. This has been made possible because CALVISIUSâ is extracted from October through March thus avoiding high salting for longer preservation.
We, the Acadian Sturgeon and Caviar Inc. , produce and sell sturgeon stocking material – Atlantic (Acipenser oxyrhynchus) and shortnose sturgeon (Acipenser brevirostrum) for aquaculture, restocking and research. We also offer consulting and R&D services in the field of sturgeon aquaculture and ecology. We are developing the production of sturgeon meat and caviar as well as a gene bank for both those sturgeon species in Carters Point, New Brunswick, Canada.
The GoConsult is an independent consultancy involved with ship-mediated biological invasions and species introductions for aquaculture purposes since 1999. Dr. Gollasch was chairman of the ICES Working Group on Introductions and Transfers of Marine Organisms (2001-2006). This group commented on the project to re-import sturgeons from North America to the Baltic countries and also monitors through country reports the importation of life specimens for trade and aquaculture, including sturgeons. Today’s work is focussed also on the development of risk assessment and ballast water management scenarios for Europe as well as on specific efficacy tests of ballast water treatment systems.
The Holsten-Stör Fishfarm produces caviar from the Siberian sturgeon, Acipenser baeri, in closed recirculating systems. The caviar is sold under trademark “Baerioska”.
The main objectives of the International Sturgeon Research Institute (ISRI) in Rasht (Iran) relate to conservation and sustainable use of sturgeon stocks in the Caspian Sea while also fostering regional and international cooperation to conduct sturgeon research in joint projects along the following thematic subject areas:

A) Specific Research topics:

  • Sturgeon Ecology in natural waters and under ponds conditions
  • Controlled reproduction, Sturgeon rehabilitation and restocking of sturgeon populations
  • Stock assessment and improved catch technology
  • General physiology and biochemistry of sturgeons
  • Genetics and breeding, biotechnology and population genetics of sturgeons
  • Sturgeon aquaculture
  • Ecotoxicology studies using sturgeons as target species
  • Processing technology and development of sturgeon products
  • Sturgeon pathology and disease control

B) Involvement in Regional and International Cooperation:

  • Cooperation with international organizations to conserve valuable stocks of sturgeons in the Caspian Sea and other endangered populations of sturgeon species in the world. eg. CITES ( Asia representative in Animal Committee), IUCN (Chairman of Sturgeon Specialist Group), Member of Foundation Committee and Board in WSCS
  • Exchange scientific and technical information as well as research experts with other organizations and universities
  • Conduct long term and short term training courses at different academic levels
  • Hosting international conferences on management and conservation of sturgeon stocks. (Chairman of ISS5)
The North Atlantic Salmon Conservation Organization (NASCO) is an international organization established under the Convention for the Conservation of Salmon in the North Atlantic Ocean which entered into force on 1 October 1983. The objective of the Organization is to contribute through consultation and cooperation to the conservation, restoration, enhancement and rational management of salmon stocks subject to the Convention taking into account the best scientific evidence available to it. The Convention applies to the salmon stocks which migrate beyond areas of fisheries jurisdiction of coastal States of the Atlantic Ocean north of 36N latitude throughout their migratory range. Contracting partners include Canada, Denmark, the European Union, Iceland, Norway, Russian Federation and the United States of America. NASCO has three regional commissions. NASCO can be contacted through the Secreatariat at NASCO / 11 Rutland Square / Edinburgh, EH1 2AS / United Kingdom
CRM-Coastal Research & Management is a private association of experts in the fields of Marine Research and Environmental Consulting, Integrated Coastal Zone Management and Marine Biotechnology. CRM elaborates science-based planning and decision tools, that help to avoid ecological or economical failures. Since 1993 CRM’s interdisciplinary team supplies services for coastal industries (aquaculture, harbor, shipping, tourism) and is partner in international scientfic projects. The first seaweed farm in Germany was established by CRM in order to develop new value added products for cosmetic, medical and biotechnological use.
Leibniz Institute for Zoo and Wildlife Research (IZW) of the Forschungsverbund Berlin e.V. The IZW conducts integrated biological and veterinary research on wildlife. Our work is focused on the mechanisms and functions of evolutionary adaptations that ensure the survival and reproduction of individuals in free-ranging and captive populations of wildlife, and the limits that may affect the viability and persistence of such populations. For this purpose, we study the behavioural and evolutionary ecology, wildlife diseases, and reproduction of mostly larger mammals and birds. A special group around Dr. A. Ludwig studies in particular sturgeon genetics in relation to their phylogeny and distribution but also in light of trade control of caviar. The institute was recently the co-organizer of the 2nd Status Workshop on Identification of Acipenseriformes Species in Trade
Department of Ecotoxicology (Institute for Ecological Research and Technology, Technical University of Berlin. Major research areas are: Fisheries and ecological status of habitats. Effects Monitoring (freshwater and marine) and the study of detoxification processes using modern methods to assess DNA damages (Genotoxicity, Xenoestrogens, Immunosuppression, Phagocytosis). Development of modern bioanalytical systems and (on-line) monitoring systems, entire cell bio-sensors. Development and testing of cost efficient screening methods (genotoxic potential, endocrine effects and immunosuppression) in inland and coastal waters. Landscape scale ecotoxicology in respect to the Water Frame Work Directive and REACH. Risk assessment, -communication and -management in constructions and materials.
The European Aquaculture Society (EAS) is an international non-profit association that promotes contacts and disseminates information among all involved or interested in aquaculture in Europe. EAS has members in more than 60 countries and participates in various initiatives to contribute to the sutainable development of European aquaculture.
From the start DIECKMANN & HANSEN has always been and still is a caviar import/export company and has therefore global experience in this trade and its quality control. DIECKMANN & HANSEN was founded in 1869 and is the oldest existing caviar trading company worldwide.
Polar and Marine research are central themes of Global system and Environmental Science. The Alfred Wegener Institute conducts research in the Arctic, the Antarctic and at temperate latitudes. It coordinates Polar research in Germany and provides both the necessary equipment and the essential logistic back up for polar expeditions. Recent additional research themes include North Sea Research, contributions to Marine Biological Monitoring, Marine Pollution Research, Investigation of naturally occuring marine substances, marine aquaculture and technical marine developments.
The European Association of Fish Pathologists was established on 25th October 1979 in Munich, Germany. it is an interdisciplinary society, embracing all aspects of aquatic disease in fish and shellfish, in aquaculture and in wild stocks. Members come from all disciplines, biologists, microbiologists, veterinarians, fish farmers and aquaculture engineers. The objective of the EAFP is to promote the rapid exchange of experience and information on aquatic disease problems and related topics. These aims are pursued mainly through regular regional and international meetings, support for training courses in laboratory techniques and the publication of the Bulletin of the European Association of Fish Pathologists, a fully citeable journal listed in ASFA, Current Contents and Science Citation Index.
Blackwell Publishing Germany Blackwell Verlag is the German subsidiary of the company Blackwell Publishing whose headquarters are located in Oxford, UK. At the heart of Blackwell’s publishing service is an organisation with international reach, publishing over 660 journals and collaborating with more than 500 learned societies. In 2002 Blackwell published over 600 books. With revenues of approximately 230 million euros, Blackwell is the largest privately owned publisher world wide.
Leibnitz-Institute of Freshwater Ecology and Inland Fisheries The Leibniz Institute of Freshwater Ecology and Inland Fisheries is one of the principal German centres for research on limnic ecosystems, and unites hydrologists, chemists, microbiologists, fish ecologists and fish biologists. A combination of fundamental and applied research supports our long-term goal of management of aquatic ecosystems, via restoration, development and protection. Our research activities are primarily oriented to the analysis of the widespread structures and functions of freshwater ecosystems. Our subsidiary focus is the study of unique regional environments such as the Berlin river-lake system where numerous shallow lakes are interconnected by dominant rivers, and turbulence is a major influence.
Sander Ozonizers Erwin Sander Elektroapparatebau GmbH: Ozone Generators for Laboratory and Industry – Typical Applications: Potable Water, Waste Water, Waste Air, Bottling Industry, Sterilisation, Swimming Pools, Laboratories, Material Tests, Petro Chemistry, Bio Chemistry, Water Chemistry, Climatic Technology, Cooling Towers, Test Cases, Aquaculture, Public Aquaria, Medicine, School, University
Global Information System FishBase FishBase is a relational database with information to cater to different professionals such as research scientists, fisheries managers, zoologists and many more. FishBase on the web contains practically all fish species known to science. FishBase was developed at the WorldFish Center in collaboration with the Food and Agriculture Organization of the United Nations (FAO) and many other partners, and with support from the European Commission (EC). Since 2001 FishBase is supported by a consortium of seven research institutions.
Deutsche See Deutsche See is the market leader for fish and seafood in Germany. Pleasure oriented foods and excellent service are the core competences – and this is demonstrated to customers and partners everday. The real cornerstones lie in the international sourcing of fresh and carefully selected products, their processing in the custom built “Deutsche See” factory in Bremerhaven and the groundbreaking Quality Management. Furthermore, “Deutsche See” offers a high degree of local presence and delivery all over Germany through a network of 26 “Deutsche See” branches.
aquafuture aquaFUTURE e.K. – Aquaculture Equipment, Consulting, Fishfarming, Recirculated Systems
Vancouver Island University Vancouver Island University  Known as a centre of excellence for teaching and learning, Vancouver Island University (VIU) is producing high calibre graduates who are in demand by employers across the country and around the world. Through its ongoing evolution and growth, VIU is proud to have contributed to the development of Vancouver Island and British Columbias culture, economy and knowledge base. VIU, formerly Malaspina University-College, has evolved from a small community college to a dynamic, internationally known university supporting a student population in excess of 18,000 full-and part-time learners and employing over 2,000 faculty and staff.
Society to Save the Sturgeon e.V. Founded in 1994, the Society to Save the Sturgeon is engaged in the restoration of the European sturgeon Acipenser sturio. Scientists, fishfarmers und nature conservationists work closely together in this ambitious project, supported by international experts and organisations, aming at the reintroduction of the species in the mayor German rivers. Accompanied by international cooperations, these stocks should be expended to neighboring areas. On our homepage, we want to give experts and interessted layman some insights to the project and the sturgeon – its biology and its way of life.
Freshwater Fisheries Society of BC The Freshwater Fisheries Society of B.C. (FFSBC) is a non-profit society that delivers all of the services formerly provided the by Provincial Governments Fish Culture Section (Provincial Hatcheries). The society works in partnership with the province to deliver the provincial fish stocking program as well as providing conservation fish culture services that support steelhead and sturgeon recovery programs. The Freshwater Fisheries Society is also responsible for the promotion and marketing of freshwater fishing in the province. One of the main objectives is to offer anglers the most comprehensive website for lake and stream sports fishing information in British Columbia.
fishartgallery Teom Lim is an award winning carver with a unique perspective. He is an artist, avid fisherman and fisheries biologist rolled up in one. His meticulous attention to detail and university background produces carvings that are beautiful and anatomically correct. These attributes coupled with his love for fishing have enabled Teom to create pieces of art that capture a moment in nature.
Sturgeon AquaFarms Sturgeon AquaFarms, LLC (SAF) is a company that is dedicated to restoring the world’s resources of sturgeon. The company was established in order to start an aquaculture operation in Florida, USA that would farm various sturgeon species for commercial production of sturgeon meat and caviar – beluga, osetra, sevruga.
Sturgeon AquaFarms, LLC. was established in order to farm sturgeon species Huso huso, Acipenser gueldenstaedtii, Acipenser stellatus, Acipenser baerii, and Acipenser ruthenus. The company has been researching this proposal for the past seven years. During that time we have negotiated with the United States Department of Agriculture, Division of Aquaculture, Food & Drug Administration, Conservation Commission, Department of Fisheries, Water Management organization and Aquatic Services. We have corresponded with these agencies in an attempt to successfully fulfill all requirements for our proposal.
AquaBioTech Group AquaBioTech Group is a leading independent aquaculture, fisheries and environmental consulting, development, testing, research and training company operating throughout the world.

ABT Aquaculture is a leading aquaculture consulting and technical support company that forms part of the AquaBioTech Group. The company has grown to become one of the largest dedicated independent aquaculture consulting company`s operating on a truely global scale. With clients and projects in over twenty-nine (29) countries and a team of over twenty-five (25) highly qualified and experienced staff and personnel, the company draws on a wealth of experience and expertise covering all aspects of aquaculture planning, feasibility, development and operation.

ZwyerCaviar LLC ZwyerCaviar LLC is an family owned enterprise, seated in the heart of Swiss alps. As an innovative company we are determined to succeed and differentiate ourselves in the highly competitive and growing luxury fine food market worldwide. We are socially and ecologically conscientious of everything we do. Our approach is led by sustainability. Caviar is about trust. ZwyerCaviar comes from a sustainable controlled and responsible aqua farming environment and meets the highest health and quality standards in the world. A high priority is given to the protection and conservation of the sturgeon species in the wild. The sturgeons of ZwyerCaviar live in an untouched natural reserve, far from civilization and pollution. ZwyerCaviar is a clima-neutral company and proud member of the World Sturgoen Conservation Society eV.

Apart from the corporate website there is a blog named Caviarist you may want to visit, which is a mix between a corporate (of ZwyerCaviar LLC) and a privat (Roger Zwyer) blog.

Aller Aqua Group Aller Aqua Group:  With more than 40 years in the sector, Aller Aqua is one of the most experienced suppliers of fish feed for freshwater and saltwater species.
Aller Aqua has a wide range of fish feed for freshwater and saltwater fish  for example fish feed for carp, catfish, rainbow trout, cod, turbot, rockfish, salmon, seabass, seabream and sturgeon.

All our fish feed products are produced by means of extrusion. The fish feed must cover the basic metabolism of the fish and ensure healthy growth. In order to meet these requirements the fish feed composition must meet all needs for nutrients, vitamins and minerals. Aller Aqua fish feed meet all these requirements and have been adapted to various sizes of fish and feeding strategies. The feed have been developed in cooperation with customers and undergo continuous tests, in selected test stations and fish farms.
Fish feed from Aller Aqua are produced at our factories in Denmark, Poland and Germany.

Fish Farm Giaveri Rodolfo The Fish Farm Giaveri Rodolfo  was created in 1979 as an eel farm. Thanks to realization of an efficient system of modern aquaculture, with an advanced plant, it has become the leader in this field among the top European fish farms. For almost 30 years the focus of the farms eel production has been to satisfy traditional kitchen requests in the South of our Peninsula and Sardinia, while trade in the foreign market has been mainly in smoked eel. Furthermore, already in the early 80’s, the breeding was diversified introducing alternative species as Carps, Tenches and especially the Sturgeon. At the beginning, bred for sport fishing and then for its meat, it became the new and real protagonist of Giaveri production. Sturgeon inspires a lot of interest for the high quality of its resulting caviar also covering a particular role for variety of exemplars of Acipenser which are present in the plant.
Empirika Empirika
Mottra Caviar MOTTRA Ltd  are the purveyors of exceptional quality farmed black caviar from Latvia. Established in 2002 and founded by a group of Russian and Latvian caviar experts, MOTTRA combines a new environmental and scientific approach resulting in the production of the purest CITES certified caviar that will delight the most discerning connoisseur.

Mottra produces Osetra (Acipenser baerii) and Sterlet (Acipenser ruthenus) caviar all year long, no matter what the season, due to the Mottra caviar pools being totally enclosed and insulated under carefully controlled temperatures using unique technology. This allows Mottra to be in full control of the process of caviar ripeness as the water at the farm is not susceptible to climate change and the caviar can be collected when it is at its best. Mottra does not use any preservatives, chemical or medical additions to the fish nor to the caviar; only salt is added. The caviar is malossol, grain-to-grain. Unlike many farms, the Mottra sturgeon are “stripped” of their eggs and are allowed to mature rather than being culled, as for each year that the fish lives the superior the quality, and thus all round caviar experience.

Tropenhaus Frutigen The Tropenhaus Frutigen  represents a new tourist attraction in the Bernese Oberland. 100 litres of mountain water flows out of the Ltschberg Base Railway Tunnel every second. This heat energy is put to good use in the Tropenhaus: Fish and plants that love a warm climate are cultivated in the extensive facility, which is open to the public, and the Tropenhaus has around 80 employees from the local area. The facility is run by the Tropenhaus Frutigen AG, with Hans Peter Schwarz as the Chairman of the Board of Directors.

The Tropenhaus Frutigen is an attractive excursion destination for both individuals and groups. Visitors experience at first hand how the waste heat from the Ltschberg Base Tunnel is made use of: Exotic plants thrive in the Tropenhaus, while heat-loving fish swim about in the large basins. The food that is produced on-site comes fresh onto the tables of the operations own restaurants. The Tropenhaus is also a suitable location for events of all kinds, such as wedding receptions, company events or meetings. A wide range of tourist attractions are also available in the immediate vicinity.

TU Berlin Department of Ecological Impact Research and Ecotoxicology Berlin Institute of Technology (BIT) Department Ecological Impact Research and Ecotoxicology  Research for a Sustainable Future of our Ecosystems: Our research line in the field of ecological impact research and ecotoxicology aims to understand changes in an ecosystem from molecule, cells, organisms up to population effects and landscape structure. Within this goal the aquatic-terrestrial connectivity is one of the main back bones. Beside anthropogenic caused changes, we are investigating natural compounds, such as cyanobacterial toxins, which also cuase changes in an ecosystem.

A sustainable protection of our ecosystems can only be achieved, if single ecosystem function are investigated in order to help achieving the goal to protect the ecosystems.

Fischzucht Rh�nforelle GmbH & Co. KG Fischzucht Rhnforelle  is among the pioneers of sturgeon farming in Germany. In 1990 Peter Gross imported the first thousand small Siberian sturgeon juveniles from Konakowo (Volga River) to Gersfeld (Germany). Since than, he gradually converted the former trout farm into a sturgeon farm. Today, the Siberian sturgeon is reproduced year round and fertilized eggs are exported world-wide, including to the former origin in Russia. Today, juvenile production includes the highly endangered species Huso huso.
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Species protection and conservation



Fish farming can contribute to the protection and restoration of endangered fish populations living in the wild through the efficient provision of juveniles for release or stocking.

An increasing number of fish are finding their way onto the CITES lists of endangered species. The production of juvenile fish and shellfish in hatcheries is far more efficient (in terms of survival) than in the wild. These juveniles may not only be grown on as food, but also for the conservation and restoration of fish populations (through release or restocking) and the provision of fish for angling.


This technique, also known as “stock enhancement” or “enhancement aquaculture” has an economic advantage in that production costs are much lower, and has proven to be successful for a variety of marine fish species, mainly in Norway, Japan and the USA.


Sturgeons are among the world’s most valuable wildlife resources and can be found in large river systems, lakes, coastal waters and inner seas throughout the northern hemisphere. For people around the world, caviar, i.e. unfertilized sturgeon roe, is a delicacy. Sturgeons are also a major source of income and employment, as well as an important element of the local food supply. Current trends in illegal harvest and trade put all these benefits at risk. Since 1998, international trade in all species of sturgeons has been regulated under CITES owing to concerns over the impact of unsustainable harvesting of and illegal trade in sturgeon populations in the wild.




Photo: Juvenile sturgeon for restocking.
Source Aquaculture Europe Vol 32 (3). September 2007. Courtesy M. Chebanov.


The Ramsar Declaration on Global Sturgeon Conservation recognises the importance of aquaculture in the preservation of sturgeon species, specifically mentioning the importance of captive broodstock programmes to prevent loss of genetic variety; the monitoring of stocked juvenile fish to assess the cost-effectiveness of stocking strategies; the cultivation of sturgeon for meat and caviar products – especially with due involvement of the lowincome local fishing community who need alternative livelihoods; and the need for internationally agreed standards on culture technology and general husbandry, adequate nutrition, disease prevention and product quality control.


More information is available at – the site of the World Sturgeon Conservation Society.


Different trout species have been restocked in Europe’s rivers for decades. Prior to the Second World War, the UK production of trout juveniles was exclusively to stock rivers in England and Scotland to support natural populations and for recreational fishing. It was only in the 1950s that technology was introduced to produce fish for the table. This is the case across much of Europe, where trout remains the top aquaculture production species within European Member States, and where restocking accounts for a significant proportion of total trout fry production.




Photo showing 2007 re-population in the river Nivelle in the Basque region of France.
Photo courtesy of Dr. Jacques Dumas, INRA.




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Health and welfare of farmed fish & shellfish


Farmed fish are contained – in ponds, tanks or cages – as with all farmed animals. Just as in land-based farming, farm managers increasingly choose stocking densities and handling practices that optimize growth and health status while avoiding unnecessary suffering.

Questions are sometimes raised about welfare aspects of aquaculture production. Usually, such questions focus on three issues: stocking densities, the possibility to have ‘free-range’ aquaculture and the way farmed fish is slaughtered at harvest.

There are many definitions of animal welfare. One definition is based upon the Farm Animal Welfare Council’s “five freedoms”:

  • Freedom from thirst, hunger and malnutrition
  • Freedom from discomfort due to environment
  • Freedom from pain, injury and disease
  • Freedom to express normal behaviour for the species
  • Freedom from fear and distress.

Scientific studies have identified operating indicators of fish welfare so that producers are able to measure the welfare status of their stock. The Freedom Food certification scheme of the RSPCA in the UK is a very good example of a welfare standard that has been built by on-farm dialogue with producers and which is now available for salmonid species.

Stocking Density

Many species of fish, such as herring and mackerel, live in large shoals in the wild and are therefore used to very high densities. Keeping such fish in high densities on a farm will only become a problem if the water quality deteriorates, or if the fish are deprived of oxygen or exposed to disease. Fish farmers do their best to prevent such conditions since they will reduce production.

Fish farms holding fish at high stocking densities carefully monitor the oxygen in the water and maintain it at the optimum level for fish growth. Every effort is made to ensure that fish are kept in a healthy condition and that disease is prevented wherever possible, or identified and treated should it occur.

Stocking density has often been proposed as an indicator to measure welfare and there is considerable debate about its value. Also, since the 1980’s the volume of cages used for salmon culture in Northern Europe has increased considerably – in some cases more than 200 times, reducing densities and enhancing the ability for the fish to show natural behaviour. However, as land animals that are kept within fences, some limits on behaviour are necessary in farmed fish production.

Free-range aquaculture

“Freerange” aquaculture exists in several forms – for example in “ranching” of salmon and lobster, in “organic” salmon production and in shellfish farming.


Photo: Juvenile lobsters reared for restocking Copyright: The AquaReg Lobster Project

– is an aquaculture technique whereby fish and shellfish are bred in captivity and then released into the wild to complete their life cycle before being harvested at some time in the future. Ranching has effectively been applied to Atlantic and Pacific salmon production, whereby juvenile fish have been reared from wild-caught eggs and sperm, raised in hatcheries and then released into specific rivers as smolt, allowed to migrate to sea and recaptured on their return to their river of origin.

Lobster ranching has also been tried on a number of commercial lobster beds in the past, with juvenile lobsters being raised in shore-based hatcheries and then placed on the seabed in sheltered rocky habitats where their chance of survival is thought to warrant the expense of production.

“Organic” salmon farming is conducted according to agreed codes of organic production. Rearing takes place in large, open water floating pens where conditions are as close to the open ocean as possible. Stocking densities are reduced to allow the fish to grow and develop in as natural a way as possible and the only feed used comes from sustainable fisheries. Because of lower stocking densities and open water conditions, the fish tend to be less prone to disease and therefore the use of medicines can be kept to a minimum. Increased production cost for “organic” fish is recouped with higher prices on the marketplace.

Shellfish farming, such as the laying of oysters and mussels directly on the seabed or the hanging of mussels on suspended ropes, can be said to be “free range” in so far as it is allowing the shellfish to grow in identical conditions to those they would encounter in the wild.

Slaughter methods

Recent studies suggest that fish, like warm-blooded animals, can experience fear and pain, leading to justifiable concern that codes of practice for the welfare of warm-blooded farm animals should be extended to cover farmed fish.

Accordingly, a four-step process for the humane slaughter of farmed fish has been developed similar to the European Directive covering warm-blooded animals. It covers transport and live storage, restraining, stunning and slaughter.

The process decrees that, to spare fish avoidable trauma, stunning prior to slaughter should induce immediate (within one second) and permanent loss of consciousness or, where loss of consciousness is not immediate, it should be without any avoidable excitement, pain or suffering.


Photo: Electrical stunning of Atlantic Salmon in Tasmania. Systems identical to this are currently being
installed in Norway, so that all farms are equipped by July 2008. Photo courtesy of Bruce Goodrick.

Farmers currently employ any of three ways to reach this goal: electrical stunning (passing a current through the animal); mechanical stunning (a captive needle destroys the brain) or chemical stunning (adding a food-grade substance like eugenol, based on clove oil, to the water in which the fish are held.)



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Croatian Center of Renewable Energy Sources (CCRES)

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Safe and affordable seafood products


Aquaculture produces safe,
high-quality food

Just as with wild-caught fish, farmed seafood represents an excellent source of nutrients important for human health. There is hard evidence that regular consumption of fish lowers the risk of coronary heart diseases because of high concentrations of omega-3 poly unsaturated fatty acids. Other important nutrients in farmed fish are vitamins A and D for maintaining healthy bones, eyes and skin. Farmed fish is also a rich source for iodine, important for the proper functioning of the thyroid gland, and selenium, which is an important anti-oxidant.

Because farmed fish and shellfish are produced under controlled conditions, it is possible to maintain the highest quality standards from the egg to the plate. In the same way that business processes may be certified to meet standards (e.g. ISO), aquaculture production also has certification schemes. They are increasingly supported by various codes (of conduct and of good practice), developed at national and European levels.

Production of fish and shellfish on farms allows for consistent and even enhanced levels of the elements in seafood that do us good. For example, the level and balance of omega fatty acids, vitamins and minerals such as iodine and selenium can all be influenced through specially designed fish feeds.

What are the health benefits of seafood?

Much of the importance of fish in health has come from research into long-chain polyunsaturated fatty acids (PUFA) of the n-3 family. Other abbreviations used are omega-3 and n-3 fats. Fish is a rich source of two important PUFA: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). PUFA are present in both wild and farmed fish. DHA and EPA are found in abundance in the flesh of oil-rich fish but they are also present in lean fish.

The effect of PUFA on coronary heart disease has been extensively studied. The human body cannot make PUFA. There is strong evidence from many scientific studies that PUFAs from fish play a major role in protection against heart disease . PUFAs may also help prevent other illnesses, such as arthritis, Alzheimer’s disease, some types of cancer and asthma. Extensive research to confirm these relationships is ongoing.

How much seafood should we eat?

Different values exist in the scientific literature for what is the “ideal” daily or weekly intake of EPA and DHA for human health. Government advice varies considerably between countries. However, as a general rule, a healthy diet is generally assumed to include 1-2 fish per week, especially fatty fish.

The International Society for the Study of Fatty Acids and Lipids (ISSFAL) suggests an uptake of 500 mg of EPA + DHA per day or 3.5 g per week provides enhanced cardiac health in adults.

In its 2004 report “Advice on Fish Consumption – Benefits and Risks”, the UK Scientific Advisory Committee on Nutrition (SACN) concluded that the majority of the UK population does not consume enough fish, particularly oily fish, and should be encouraged to increase consumption. The Inter-Committee Subgroup endorsed the Committee on Medical Aspects of Food Policy (COMA) 1994 population guideline recommendation that people should eat at least two portions of fish a week, of which one should be oily. Consumption of this amount would probably confer significant public health benefits to the UK population in terms of reducing cardiovascular disease (CVD) risk and may also have beneficial effects on foetal development.

Current advice from the UK Food Standards Agency suggests a weekly intake of up to four 140g portions of oily fish for men, boys and women over reproductive age, with the caveat that girls and women of reproductive age should only consume two portions of oily fish per week2.

Safe seafood products

Because it is a controlled food production process, fish farming can include safeguards to protect its product from contamination. Ironically, the main source of contaminants in farmed fish (such as trace amounts of dioxins, PCBs and mercury) is fish feed composed of wild fish. However, because this food can be sampled and analysed prior to feeding, maximum limits of contaminants in fishmeal and fish oil used in aquaculture have been established by international law.

Photo: Courtesy of Vidar VassvikData from the official controls of the fish feed ingredients and analysis of the farmed fish itself are available for consumers, authorities and industry alike.

Strategies to minimise contamination of farmed fish by way of feed derived from the wild are in place and can include; careful selection of the fish oil source, purification of fish oil prior to its inclusion in fish feed, and partial replacement of fish oil by vegetable oils.

A number of factors have combined to make us more aware than ever of the safety of food. Firstly, increasingly accurate measuring techniques allow us to detect even the lowest levels of contaminants. Secondly, increasing media focus on food safety has highlighted issues such as BSE, dioxins and salmonella, and ‘food scares’ have become regular features of news broadcasts. For food to be acceptable, it must be proven to be safe to eat.

Food safety standards have been developed giving clinically proven safe levels of food constituents that may at higher levels provide a risk to health.

Contaminants and health risks

Contaminants in fish derive predominantly from their diet. Whilst it is not possible to control the diet of wild fish, the levels of contaminants and some nutrients in farmed fish may be modified by altering their feed.

Strict EU regulations (e.g. Directive2002/32/EC) and controls by food
safety authorities ensure that contaminants are kept well below dangerous
levels in farmed fish. Emerging technologies allow fish feed producers to
purify fish meal and oil before it is incorporated in the feed.

 The retention of dietary mercury by fish is dependent on dietary concentration and the duration of exposure to the contaminant. Methylmercury (the toxic form of mercury in fish) is present in higher amounts in large predatory fish such as swordfish and tuna. High consumers of such top predatory species, such as pike or tuna (especially fresh or frozen bluefin or albacore tuna), may exceed the provisionally tolerable weekly intake (PTWI) of methylmercury.

The greatest susceptibility to the critical contaminants (methylmercury and the dioxin-like compounds) occurs during early human development. For a developing human foetus, this means that the risk comes from the amount of these compounds in the mother’s body.

Furthermore, EU maximum limits exist for a range of contaminants in food such as dioxins, dioxin-like PCBs, mercury, lead, cadmium and polyaromatic hydrocarbons (the maximum level is for one PAH, BaP). These limits include food of farm origin and other foods such as fish from capture fisheries.

Monitoring programmes exist to document the levels of contaminants in wild and farmed fish to fulfil a need for independent data for consumers, food authorities, fisheries authorities, industry and markets.


As in land farming, fish farming benefits from traceability technologies to monitor and follow the production cycle through its entirety. While traceability itself is not a guarantee of safety, it is essential in pinpointing problems, should they occur, throughout the whole production chain. This is not just limited to producers, but encompasses their suppliers, processors and distributors. Such “full chain traceability” is most effective when all links in the chain have the same principles and use the same (or at least compatible) tools.

In 2002, an EU-funded concerted action initiative called “TraceFish” ( produced three consensusbased standards for the recording and exchange of traceability information in the seafood chains.

One of these is a standard for farmed fish. The basic element in the system is a unique identification number to be placed on each lot of products in such a way that traceability can be transmitted electronically. The system is voluntary.

Traceability tools are being continuously improved and are major monitoring components of various labelling and certification schemes for aquaculture products.

An example of this is the TRACE initiative ( that is using 5 case studies in food to improve traceability parameters and measure food authenticity. This last point has specific interest for fish products and TRACE is developing generic low cost analytical tools for use in the traceability infrastructure that verify geographical origin, production origin and species origin.

Affordable seafood products

As fish species become scarcer in the oceans, they will become less affordable to consumers.

All of the approximately thirty species of fish in European aquaculture production have shown a decrease in farm gate price as their production volume has increased, while improvements in production techniques have resulted in ever-increasing quality.

Figure 5: EU production and price trends – for several aquaculture species produced in Europe.
Data from FAO FishStat 2006. Note prices in US Dollars.

Atlantic salmon and rainbow trout are almost exclusively farmed. They are now comparable in price to land farmed produce such as chicken and pork.

The availability of ‘new’ farmed species (sea bass, sea bream, cod, sole, scallops, octopus etc.) has the potential to provide this increase in affordability to all consumers.

Quality of life of aquatic animals


Infectious diseases are encountered in all food production. Fish and shellfish may be more under threat from disease than land animals or plants because germs survive longer and can spread more effectively in water. The rapid identification and treatment of bacterial and viral infection is therefore crucial in aquaculture. While best management practice remains the preferred option for producers, the use of therapeutic agents may sometimes be necessary.

National and international regulations have been implemented to approve veterinary medicines that do not compromise food safety. An example of this is the so-called ‘withdrawal period’, defined as the minimum time to elapse between termination of the treatment and harvest of the animal. Withdrawal periods are specific for each drug and each utilisation of that drug, for example to treat bacterial disease.

It is important to note that the use of veterinary medicines such as antibiotics has greatly decreased in many types of aquaculture. For example, in Norway the use of antibiotics in salmon and trout farming has been negligible for the last 10 years due to the use of better vaccines. In 2004, Norway produced 23 times more salmon and trout than in 1985; in the same period, the use of antibiotics dropped by a factor of 25.

Figure 6: Antibiotics used in Norwegian farming of trout and salmon 1980-2004.

The principal challenges in aquaculture are now related to viruses and parasites. For example, “sea lice” threaten farmed salmon in temperate waters. However, non-medicinal and environmentally friendly lice treatments are being developed. In Norway, for example, wrasse, another fish, is used to eat the lice from infected salmon.

With the adoption of tighter laws and regulations, and with the difficulties of drug companies registering new treatments for aquaculture, the availability of medicines to treat aquaculture species becomes increasingly unsure. More and more, research is therefore turning towards prophylaxis as a solution.

Parasites are common in wild fish, too

Parasites are not unique to farmed fish, but in the wild they obviously go untreated. Parasites fall into two main groups – ectoparasites, which affect the skin and external organs, and endoparasites, which invade the body and attack the musculature and internal organs.

Ectoparasites include several types of sea lice, crablike creatures that eat the skin and flesh of the fish. If left untreated, they will cause considerable suffering to the fish and open wounds on the skin of the fish that may become sites for disease.

Endoparasites include nematode worms that enter the body of the fish through the mouth, infest the gut and can then burrow into the flesh of the fish. As well as reducing the fish’s ability to regulate the amount of salt in its body by perforating the gut membrane, they also reduce the saleability of the flesh, since fish infested with nematode parasites are not saleable for human consumption.

As on land-based farms, when animals are held at higher densities parasites can infect a stock relatively rapidly. Because unhealthy fish mean substantial loss to the farmer, however, it is uncommon in modern fish farms to find harmful burdens of parasites. Outbreaks are controlled by modern farming practices and the use of medicines that authorities have deemed safe to the fish, to consumers and to the environment.

(1) Simopoulos, A.P. “Essential Fatty Acids in Health and Chronic Disease”. Am J Clin Nutr 2000; 71 (suppl): 5065-95.


part of NGO

Croatian Center of Renewable Energy Sources (CCRES)

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