Thousands of Atlantic salmon escape from fish farm into Pacific

Company admits it doesn’t know how many of its 305,000 fish are left after a net ‘failure’ amid concern about the impact on native species

Thousands of Atlantic salmon may have escaped into Pacific waters after a net pen holding 305,000 of the fish was damaged at a farm in Washington state, leading wildlife officials to call for anglers to catch as many of the fish as possible.

The fish farm’s owner, Cooke Aquaculture, said on Wednesday that several thousand Atlantic salmon may have ended up in the waters around the San Juan Islands after part of a net suffered a “structural failure”.

The Canada-based company – which purchased the 30-year-old farm last year – blamed Saturday’s incident on “exceptionally high tides and currents coinciding with this week’s solar eclipse”.

The company initially told wildlife officials that an estimated 4,000 to 5,000 of the fish in the net pen had escaped, but said that the exact number would be determined once tidal conditions improved enough to allow divers to fully assess the farm. On Wednesday, the company told the Canadian Broadcasting Corporation that the number could be “much higher”.

“It appears that many fish are still contained within the nets,” the company said in a statement. “Farm crews are on site, working to stabilize the farm and to recover as many fish as possible, when conditions permit.”

Fishermen in the region – out hoping to catch Chinook salmon in recent days – said the Atlantic salmon had already been turning up in their nets. “It’s a devastation,” Ellie Kinley, whose family has fished Puget Sound for generations, told the Associated Press. “We don’t want those fish preying on our baby salmon. And we don’t want them getting up in the rivers.”

Despite being listed in Washington State as an invasive species capable of preying on native populations of fish and spreading disease, Atlantic salmon are a major aquaculture species in Washington state as well as in British Columbia.

Washington state’s fish and wildlife department said it was working closely with the company to address the incident. On Tuesday the department encouraged anglers to join them in the effort by catching as many of the fish – which weigh up to 4.5kg (10lb) as possible.

“Our first concern, of course, is to protect native fish species,” Ron Warren of the department said in a statement. “So we’d like to see as many of these escaped fish caught as possible.”

As environmentalists voiced concerns that the Atlantic salmon could crossbreed with the Pacific salmon or compete with them for food, researchers were divided on the potential impact.

“These things are kind of couch potatoes,” Michael Rust of the National Oceanic and Atmospheric Administration told the Seattle Times. “They are domesticated. Imagine a dairy cow getting lost out in the Serengeti. It doesn’t last very long.”

Others warned that there was not enough research to confidently predict what might happen next. “Everybody wants to know, what does it mean? And the honest answer is we don’t know,” said John Volpe, a University of Victoria professor who has studied Atlantic salmon released in the Pacific. “Impact is definitely on the table. But it runs from something quite modest all the way to something very serious.”

He pointed to research he had done more than a decade ago which suggested that Atlantic salmon was capable of surviving, spawning and producing viable offspring in Pacific waters. But a dearth of research in recent years meant little was known about how well the fish had managed to establish themselves in the wild.

This weekend’s escape was large, but not unprecedented, he said, pointing to the deliberate release of Atlantic salmon on the west coast in the early 1900s. A 2001 memorandum from the National Oceanic and Atmospheric Administration noted that during a three-year span in the late 1990s, some 600,000 Atlantic salmon had escaped into the Pacific.

But this latest incident is different, said Volpe, as it comes at a time when many Pacific salmon populations are struggling to survive against a backdrop that includes urbanisation and climate change.

“The last thing they need is yet one more challenge to their long term viability,” he said. “Given the very precarious state of most Pacific salmon populations – they’re basically teetering on the edge – you don’t need some catastrophic event to push them over. All they need is a nudge.”