Atlantic Salmon Escape Farm Pens In Puget Sound -- Nets Tear As Fish Are Being Moved To Escape A Deadly Algae Bloom
Up to 100,000 salmon from a farming operation near Bremerton died late last week from an algae bloom, and another 100,000 may have escaped into Puget Sound over the weekend after several mesh pens ripped during an urgent effort to move the fish.
Global Aqua USA was relocating about 2 million farm-bred Atlantic salmon from Rich Passage to Vashon Island over the weekend when at least five pens caught on chains attached to anchors and broke open in Puget Sound.
The algae bloom killed up to 100,000 fish, making them unable to breathe through their gills. About 100,000 more escaped after the pens were ripped, said Pete Granger, executive director of the Washington Farmed Salmon Commission.
"It's very hard for us to estimate (how many were freed) because we can't get into the pens and actually count," said Morten Blomso, president and CEO of Global Aqua USA. "It could range to over a hundred thousand fish."
Blomso said the fish are disease-free and do not pose a health threat to native salmon stocks. He also said the Atlantic salmon do not breed with local strains and are two years shy of sexual maturity anyway.
But one conservationist is alarmed by the accident, fearing the freed fish will compete with already endangered Puget Sound salmon.
"We have very low populations of native fish," said Lorraine Bodi, co-director of the Northwest Office of American Rivers. "If we add to competition from non-native stock - through crowding out and competing for food in places where the habitat is not rich - it could be a problem."
The emergency move began Friday when Global discovered an algae bloom in waters close to the Atlantic salmon farm. Algae compete with salmon for oxygen. Global was forced to tow more than 60 nylon-mesh pens across Puget Sound to Vashon Island, but at least five pens broke open near Manchester.
Each pen contained 5,000 to 100,000 fish weighing between one-quarter of a pound and 25 pounds, Blomso said.
Granger said many of the salmon that escaped were juveniles incapable of spawning.
"As far as we know, there's never been a case of a farm Atlantic salmon reproducing on their own or with wild salmon in local streams," he said.
By late afternoon yesterday, most of the pens had reached the west side of Vashon Island, Blomso said. He estimated that less than 5 percent of the farm's 2 million salmon had died.
Blomso said a similar algae bloom threatened Global Aqua USA's farms in 1990. The fish were moved for 10 days, but there was a much higher mortality rate, he said.
Atlantic salmon have been farmed in saltwater pens in Puget Sound and other state waters since 1985. More than 11 million pounds of the fish are bred yearly in Washington.
The loss to Global could amount to hundreds of thousands of dollars, Granger said.
Atlantic salmon are not a game fish, he added, so it's unclear if anglers can keep them if caught. "But they are a heck of a sport fish," he said. "They take hook like crazy."
That aggressiveness worries Bodi.
"We don't want Atlantic salmon becoming a population that spawns in our rivers," she said. "These are fairly tough, territorial fish.