Scientists see serious threat to dwindling wild stocks; saboteurs blamed
by Craig Weatherby
As if to underline the threat that salmon farming poses to wild stocks, thousands of farm-bred Atlantic salmon escaped a farm in New Brunswick, Canada earlier this month, just as local wild Atlantic salmon were beginning to breed.
Thanks to over-fishing at sea, and pollution and stream blockage on land, Atlantic salmon are either extinct or highly endangered throughout their natural range, which stretches from the New England states to Labrador in Canada.
In an ironic coincidence, the number of escaped salmon—about 100,000—approximates the number of Atlantic salmon that persist in the wild.
Farmed fish may interbreed with wild salmon; offspring proven fragile
The farmers claimed that the fish were sexually immature and incapable of interbreeding with the wild salmon.
However, scientists at the Atlantic Salmon Federation (ASF) in New Brunswick say that 43 of the 45 escaped salmon found so far were sexually mature and capable of breeding with the small populations of wild fish in the rivers. They fear the escapees could have a serious impact on depleted wild salmon populations in U.S. and Canadian rivers that feed into Passamaquoddy and Cobscook bays.
The ASF and other groups boost salmon stocks in some streams with captive-bred fish, but these programs are carefully designed to maintain specific local populations of salmon, which return to their own streams to spawn because they develop genetic characteristics adapted to each stream.
Escaped farm fish do not thrive in the wild. Some streams in Norway are now populated entirely by descendants of farmed fish, but they are fragile and would disappear absent continual replenishment by fresh escapees.
As noted in a press release by the ASF, “Mr. Cooke’s statement that the escapees will not cause any harm because they are ‘wild cousins’ has been refuted over and over again by scientists, who have documented the weakened ability to survive in the wild of offspring from wild and farmed salmon mating.”
The escape, which occurred at Cooke Aquaculture on Deer Island in the Bay of Fundy, was no accident. It was the third time this year that nets at Cooke salmon farms were deliberately slashed. Police suspect disgruntled former employees. Regardless, the numbers of fish freed by these incidents of sabotage pale in comparison with the huge numbers that escape every year with no human help.
Fortunately, the situation for Alaska salmon is much better. Alaska wild salmon stocks remain robust and the state has banned salmon farming from its waters. The best thing consumers can do to stem the spread of salmon farming is to choose sustainably harvested wild salmon whenever possible, and encourage stores and restaurants to do the same.