Email a Friend
Printer Friendly

Ecologists warn of the dangers of GM fish

June 17, 2003

The aquaculture industry will do increasing ecological damage around the world unless urgent action is taken by national and international policy makers, a new report by the British Ecological Society has warned. The report - written by experts from University College Cork, the University of Glasgow, Germany and Sri Lanka - argues that while attention is being paid to the sustainability of capture fisheries in the North Sea, the Atlantic and elsewhere, the aquaculture industry is also becoming ecologically unsustainable.

According to the report, Aquaculture: the ecological issues: "Aquaculture was originally regarded as a benign activity. Three decades ago, images of 'farming the seas' were viewed as positive when set against the relentless overfishing already shown by many capture fisheries. However, as the industry has become increasingly competitive and intensive, concerns have arisen, many of ecological significance."

The report cites a number of serious ecological problems caused by some parts of the aquaculture industry, and makes a number of practical recommendations. The authors are particularly concerned about the impact that aquaculture is having on: fragile habitats such as mangroves; the spread of disease and alien species; the impact of industrial fishing to produce so-called "aquafeed" for the farmed fish on fish stocks, birds and mammals; and the genetic impact that escaped fish have on native wild populations.

Industrial fishing for fishmeal production, for example, can have a catastrophic impact on sea birds and mammals. When capelin fish stocks in the Barents Sea collapsed in the mid-1980s and early 1990s, starving arctic seals invaded Norwegian coastal waters in search of food, and 90% of common guillemots starved to death in 1986-87 because they could not find alternative food. "There have to be serious reservations about the long-term ecological sustainability of aquaculture practices that are so dependent on industrial capture fishing," the authors say. The authors are also concerned about the possible effects of feeding fishmeal to herbivorous fish. "There are possible comparisons with the BSE crisis in cattle, which was caused by an increased use of foodstuffs from higher up the trophic pyramid," they say.

To illustrate habitat loss caused by aquaculture, the report reveals that, in the Philippines alone, 250,000 hectares of mangrove (more than half the area that existed 80 years ago) has been destroyed, and 60% of this loss is attributed to coastal culture of prawns and milkfish.

The report makes a number of recommendations that would reduce the ecological impact of aquaculture and make the industry more sustainable, including:

* Regulations to prevent the escape of farmed fish into the wild. This is particularly important as transgenic (genetically modified) fish - containing genes from other species to boost their growth - are beginning to appear on the market. Ecologists argue that these transgenic fish are likely to be less fit in the wild, so escapes of genetically modified fish could seriously damage wild populations.

* Stronger quarantine and inspection regulations to avoid transfer of alien species (a classic case of alien "hitchhikers" is the slipper limpet, which was introduced to Europe from the USA in the 1880s in consignments of oysters and which has since become a major pest of oyster beds).

* A switch in "aquafeed" production from industrial fisheries to soya proteins or discards and offal from human consumption fisheries. In 1995, the 3 million tonnes of fish and crustacea produced by the aquaculture industry required inputs of fishmeal and oil from more than 5 million tonnes of pelagic fish, yet 25 million tonnes of fish are discarded worldwide each year because the facilities to collect and convert these to fishmeal are rarely available.

British Ecological Society (BES)

RSS Feeds

Ecologists warn of the dangers of GM fish

Science Research Departments