BAINBRIDGE ISLAND — A deadly fish virus has been detected in Washington state waters for the first time, forcing a fish farm to kill its entire stock of Atlantic salmon.
Tests this month confirmed the presence of an influenza-like virus called infectious hematopoietic necrosis at a salmon farm off Bainbridge Island across from Seattle on Puget Sound, the Kitsap Sun reported.
The virus, or IHN virus, does not affect humans. It occurs naturally in wild sockeye salmon and can be carried by other fish, such as herring, which sometimes pass through fish net pens.
John Kerwin, fish health supervisor for the Washington Department of Fish and Wildlife, said the virus is a big concern.
“Any first time it occurs, you don’t fully understand the impact to wild fish,” Kerwin told the newspaper. “We know it can impact (farm) fish. If we move fast, we can try to minimize the amplification.”
Seattle-based American Gold Seafoods plans to remove more than a million pounds of Atlantic salmon from infected net pens in Rich Passage off the southern tip of Bainbridge Island. In April, the company noticed that fish were dying off at a fast rate. Test results this month confirmed the virus.
American Gold Seafoods, affiliated with Icicle Seafoods of Seattle, operates two hatcheries near Rochester, Wash., and has 120 pens off Bainbridge Island, Port Angeles, Cypress Island and Hope Island in Puget Sound.
“It’s a very, very big loss for us,” Alan Cook, Icicle’s vice president of aquaculture told the Kitsap Sun. “We’ll clean up and start again.”
The company plans to remove all dead or dying fish by the end of June. Nets from two acres worth of pens will be removed and disinfected. The fish farm could be running again in four months.
Cook said the company has increased monitoring of net pens in Clam Bay near Manchester in Puget Sound, which is about a half-mile from the infected pens.
The IHN virus recently appeared in two British Columbia fish farms, forcing the destruction of nearly 600,000 fish there, the newspaper reported.
The recent outbreaks have prompted Washington-based Wild Fish Conservancy to call for tougher testing rules and limits on net pen salmon aquaculture.
Even though the virus occurs naturally in Northwest salmon, the group worries that densely-packed fish farms can amplify the virus’ spread, foster its mutation and infect wild fish that pass in or near the pens.
Cook said his company is taking the virus seriously, and its plan to remove all the farm’s fish is not required by law.
“It’s good husbandry to limit the risk to other fish,” he told the Kitsap Sun. “We’re not letting the situation sit and fester and then explode.”