A sample of Atlantic salmon that escaped after a fish farm’s net pen collapsed last summer tested positive for a contagious and harmful virus, according to findings released by the Wild Fish Conservancy on Thursday.
An independent lab at the University of Prince Edward Island found all 19 salmon donated from different sources were infected with Piscine Orthoreovirus (PRV), a virus it says can cause heart and skeletal muscle inflammation and affects a salmon's ability to compete and survive in the wild.
Researchers tested heart, gill, and kidney samples from fish that were caught in the Strait of Juan de Fuca, near Cypress Island, and 50 miles up the Skagit River.
Wild Fish Conservancy also speculated that its sampling is cause to believe that all the escaped fish are most likely infected with PRV.
But there are some holes in the report, according to Washington Department of Fish and Wildlife. Mainly, that in its 120-page report released January 30, the agency essentially disputes the timing of when the Atlantic salmon contracted the virus. On page 98 of that report, DFW says when it examined more than 15 Atlantic salmon shortly after their release, biologists concluded, "The escaped population was healthy at the time of release. No endemic, bacterial, viral, or parasitic pathogens were detected in the group of fish."
On the following page, DFW goes on to say that in the weeks after their release, the Atlantic salmon contracted the virus in the wild, stating, "The fish became susceptible to bacterial infection following anorexia and stress. In other words, DFW says the fish were not when they left the pen, but got sick because they couldn't make it in the wild.
About 260,000 non-native salmon were released into the Salish Sea in August after a net pen failed at Cooke Aquaculture’s Cypress Island fish farm. Cooke was fined $332,000 after the failure.