A quarter of salmon in seas off Norway are escapees from fish farms, threatening the survival of their wild cousins in a cautionary tale for fish farmers worldwide, the WWF conservation group said on Thursday.
OSLO A quarter of salmon in seas off Norway are escapees from fish farms, threatening the survival of their wild cousins in a cautionary tale for fish farmers worldwide, the WWF conservation group said on Thursday.
"The wild races of salmon off Norway are threatened by escaped fish. We suspect this is an issue for every country where salmon are farmed," said Simon Cripps, director of the WWF's Global Marine Programme.
About half of all wild Atlantic salmon are born in Norwegian rivers, with lesser populations of the prized fish from Scotland to the United States. Fish farm breakouts in recent years are adding to threats ranging from pollution to dams.
"Around half a million farmed fish, both salmon and trout, escape from fish farms in Norway every year," Cripps told Reuters.
Fugitive farmed fish, which make up about a quarter of salmon caught in seas off Norway and 9 of 10 in some fjords, compete for food and can spread parasites to wild fish.
When farmed fish mate with wild cousins, the hybrids dilute the genetic pool of up to 400 races of salmon in Norway's rivers. In turn, that could make the overall species less resistant to disease, a WWF salmon report said.
Flabby farmed fish that manage to leap up rivers to lay eggs often do so after wild fish, sometimes displacing wild eggs from river beds. Wild salmon are born in rivers, swim out to sea and then return 1-4 four years later to spawn.
Cripps said the WWF was worried that escapees from other fish farms, like for cod, could also hit depleted wild stocks. The world cod catch tumbled to 890,000 tonnes in 2002 from 3.1 million in 1970.
The WWF urged Norway to tag every farmed salmon, to step up security at farms and to keep farms further from spawning rivers. In Maine in the eastern United States, it said at least one fish farm clipped identity tags to fins.
"Tagging would put pressure on the bad fish farms by showing where escaped fish come from. It would let consumers choose," Cripps said. He had no estimate of the extra cost.
In 2003, the percentage of fish farm escapees among salmon in Norwegian seas was 24 percent, according to Norwegian statistics quoted by WWF. The overall figure was down from a peak above 40 percent in the late 1990s, when big storms hit.
Cripps said stricter Norwegian rules, including placing fish farms in more sheltered areas, were not enough.
Norway, the top Atlantic salmon farming nation, exported 424,000 tonnes of salmon and trout last year and promotes fish as a safer, healthier alternative to meat and a better choice than fish caught from wild stocks.
Apart from escapes, the industry has problems including consumer worries about cancer-causing dioxins in the flesh and anti-dumping duties imposed by the European Union. Norway says the fish is safe to eat and denies giving subsidies.