Norway - the rising tide of fish farming

Posted: 19 November 2003

Author: Joanna Benn

Long gone are the days when the salmon on your plate was wild caught. The demand for fish and shellfish as a healthy alternative to meat has encouraged intensive fish farming, now set to overtake cattle ranching by the end of this decade. But the environmental threats caused by the world's fastest growing food sector worth US$56 billion, are a cause for concern. Joanna Benn reports from Norway.

Aquaculture or farming at sea of both fish and shellfish provides one-third of the fish people consume. However, as production rises, so too does aquaculture's impacts on the environment.

Salmon demand

Escape of farmed fish from pens. © WWF-Canon / Michel Roggo
Escape of farmed fish from pens. © WWF-Canon / Michel Roggo
Escape of farmed fish from pens is threatening already endangered wild salmon stocks.© WWF-Canon / Michel Roggo

Norway is one the world's largest providers of farmed salmon. An aerial view attests to this. Hundreds of large metal or plastic cages are scattered along the coastline. Norway has a rich tradition of fisheries experience. Ice-free throughout the year, its long coastal zone can be fished perennially.

Furthermore, with the inflow of meltwater, Norway's deep fjords and rivers have been a breeding ground for salmon throughout the ages. The growing demand for salmon, one of the western world's luxury foodstuffs, led to the development of the first salmon hatcheries here in the 1960s. Today, almost 4,000 people are employed in fish and shellfish farming in Norway and fish farming's income revenue is second only to oil and gas.

"Fish farms are here to stay and farming the marine environment is a good thing," says Doctor Peter Andreas Heuch of the Norwegian Veterinary Institute, "but we also need to monitor this to see if there are impacts on the environment that we don't want."

A major concern for environmentalists is the contamination of vulnerable marine and coastal areas by fish farming through the release of nutrients, pathogens, and chemicals. Discharges from fish farms have already led to serious local habitat damage in parts of Scotland and Norway. WWF is calling for vulnerable species and habitats to be identified and sufficiently protected before there is any new aquaculture development. Additionally, it says that Environmental Impact Assessements (EIA) should be conducted for large scale projects and for regions where several smaller projects are operating in close proximity. To date, these assessments are still not compulsory and have not been used adequately in Norwegian coastal zones for siting aquaculture operations.

Genetic contamination

The problems related to fish farming are not only about where the farms are built. Farmed salmon often escape. Unlike their wild cousins, farmed salmon have been genetically altered to grow faster, taste better and provide increased health benefits. In Norway last year, a total of 630,000 farmed salmon escaped. That's more than the total number of spawning wild Atlantic salmon in Norwegian rivers. In some areas, the percentage of escaped fish in the fjords was over 90 per cent.

When farmed fish mix with wild salmon, they compete and interbreed, which can have major impacts on the lifecycle and genetic makeup of wild salmon. During their early years, wild salmon live in streams and rivers before migrating to the sea for food and to grow into adulthood. They return to the river to spawn - the same place they were born. The salmon's unique homing ability is the basis for the classification of the stocks. These stocks have developed different inherited characteristics and become adapted to their watercourse.

Long term, this genetic contamination from mixing with farmed fish can destroy the wild salmon's natural migrating and breeding patterns, creating an unnatural "fake salmon" that might take over.

Farm Villa Leppefisk in Norway. © WWF-Canon / Jo Benn
Farm Villa Leppefisk in Norway. © WWF-Canon / Jo Benn
Farm Villa Leppefisk in Norway is on the path to sustainability.© WWF-Canon / Jo Benn

Solutions to the problem of escaped salmon are fairly simple to implement. Johan Solgaard, a fish farmer and marine biologist works on a salmon farm called Villa Leppefisk. He says he tries to run the farm to be as sustainable and environmentally friendly as possible.

"To prevent escapes, you need to be really careful when handling the fish and you need to protect the propeller on the boats so they don't damage or rip the cages" Johan says. "On this farm, we also have divers every month to look for holes in the cages, and if they find a hole, they mend it."

Parasite infections

Another problem with aquaculture operations is the potential of farmed fish to spread parasites, such as sea lice. The migration of wild salmon between fresh and salt water normally keeps these salt-water parasites at bay. Farmed salmon spend all year in coastal areas - which increases their chances for getting parasites. More fish farms mean more hosts for parasites. And just ten to fifteen lice can kill a fish. Two years ago, more than 90 per cent of migrating wild salmon died in one Norwegian fjord because of sea lice infections.

One innovative approach to prevent sea lice is the use of "wrasse" or cleaner fish to eat sea lice off the salmon. This little brown fish is caught locally and then thrown in the salmon pens. One 5-cm wrasse fish, when analysed, contained over 200 sealice in its stomach. The use of "wrasse" is an effective way to deal with sea lice and is not harmful to the environment, as the other chemical options can be. However, "wrasse" are still underutilized in fish farming operations to combat the sea lice problem.

Fish feed

Another growing problem that the fish farming industry faces is the sustainability of fisheries used to feed farmed salmon. Most fish feed is made of wild caught fish in the form of fish oil and fishmeal. It normally takes about four kilos of wild fish to grow one kilo of farmed salmon. In this way, instead of relieving pressure on the marine environment, fish farming is actually contributing to the overfishing crisis that plagues the world's fisheries.

"Aquaculture can play an important role to provide an adequate supply of fish to consumers, but it must happen in tandem with sustainable fisheries and sustainable sourcing, rather than its current status as one of the primary contributors to fisheries decline," says Dr. Simon Cripps, Director of WWF's Endangered Seas Programme.

Farm Villa Leppefisk provides clues that some in the industry are moving on the path to sustainability. This farm is taking steps to address problems associated with both fish feed supply and waste. It uses fish feed that contains less wild fish and more vegetable products, which helps decrease pressure on fisheries. Additionally, the farm uses an automatic feeder that has a sensor at the bottom, so that the feeder only releases food once the fish have already eaten what's there.

Rasmus Hansson of WWF Norway says, "Fish farming needs to accept it should stay out of areas that need environmental protection. Secondly, fish farming needs to stop all escapes. And finally fish farming in Norway produces large amounts of parasites and diseases that seriously impact wild salmon. These things must stop before the Norwegian fish farming industry can call itself sustainable."

Approximately 50 local stocks of salmon in Norway have already become extinct and the numbers are decreasing globally as well. WWF is calling for governments to establish farm free zones and marine protected areas to protect important salmon rivers and areas of outstanding biodiversity. In addition, the conservation agency wants fish farmers to adhere to a Code of Conduct for Aquaculture and an approved set of best environmental practices.

In the meantime, consumers, too, have a choice.... They can look for eco-labeled, organic, or certified salmon in the stores. And they can urge their supermarkets to stock only salmon from well-managed fish farms.

Joanna Benn is TV Producer at WWF International.

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