Thousands of salmon escaped an Icelandic fish farm. The impact could be deadly

 “Look,” he shouts above the howling wind whipping our faces, pointing at one salmon. “It’s an intruder.”

Sure enough, it has a rounded tail and torn fins: signs of a farmed salmon. He suspects it’s a fugitive from an open-net pen where just last month, on 20 August, thousands of fish grown in pens from a Norwegian strain escaped. They have since been found upstream in rivers, endangering the wild salmon population and hitting the headlines in Iceland.

Suspected escapees have now been found in at least 32 rivers across north-west Iceland, according to unconfirmed social media posts, one of which showed fish covered in sea lice, a parasite that can be lethal to wild fish. Iceland’s Marine and Freshwater Research Institute (MRI) confirmed the farmed fish have been found in multiple rivers.

 ...It is not the first big escape: just last year, another salmon farming company, Arnarlax, was fined £705,000 for not reporting an escape of 81,000 fish in 2021.

...“This is an environmental catastrophe,” he says. “If they breed, the salmon will lose their ability to survive.”

Indeed, studies have shown interbreeding between farmed and wild fish produces offspring that mature faster and younger, undermining the ability of the species to reproduce in nature...more