The Real Price of Farmed Salmon

Salmon aquaculture is devastating the world's oceans and an international coalition of scientists, Canadian First Nations and tourism operators have called for a global moratorium.

"We've seen a regional collapse of all sea life in the 20 years since the salmon farms moved in," said Chief Bob Chamberlin of the Kwicksutaineuk Ah-kwa-mish Canadian First Nation in the province of British Columbia on Canada's west coast.

Scientific studies have linked sharp declines in wild salmon populations in British Columbia to disease and parasites originating in open-ocean salmon farms. Millions of non-native salmon have escaped ocean net-pens in Chile and have become an invasive species, transforming the ecology of local river systems.

There is little debate that salmon aquaculture is both unsustainable and environmentally destructive. Three or more kilogrammes of wild fish is needed to produce one kilo of farmed salmon. The ocean bottoms under and around the open-ocean net pens are usually devoid of any life, buried under the excrement of up to a million salmon overhead.

"Salmon farm 'shadows' can extend three or four kilometres depending on the current," said Wolfram Heise, director of the marine conservation programme at the Fundación Pumalin (Pumalin Project), a private conservation initiative in Chile.

These shadows are dead zones where there is nothing but mud and faeces along the bottom of the ocean. "Oxygen levels in the water are so depleted it sometimes forces the farms to move to new locations," Heise told IPS from Puerto Varas, located 1,000 kilometres south of Santiago.

Like land-based factory farms where far too many animals are being raised in confined quarters, heavy doses of antibiotic drugs and hormones are fed to the fish. Despite this, a potent virus swept through Chile's salmon farms last year and has cut production in half. Unable to stem the outbreak, the farms simply moved to new locations hundreds of kilometres away, abandoning their local employees and the contaminated waters and seabed.

On Canada's west coast scientists have connected the decline in wild salmon stocks to the region's 100-plus salmon farms. After publishing their research in the prestigious journal Science, marine biologists warned that one wild salmon species will be extinct by 2011 because of infestations of parasites that originate in salmon farms. More than 80 percent of the annual pink salmon in the Broughton Archipelago, 300 kms north of the city of Vancouver, has been killed by these parasites since 2001.

North America's northwest coast is home to several species of wild salmon that remain one of the natural wonders of the world and are a key part of the coastal ecosystem. After spending two or more years feeding in the open ocean, they return to their natal streams and rivers to spawn and die. Many species, including eagles, bears and wolves, feed on the dying or dead salmon. They also bring large quantities of salmon carcasses into forests, which decay, enriching the soil and feed many plants, including the region's giant red cedars and sitka spruce trees.