IHN virus was first found on a salmon farm in Bainbridge. (Map: Stock File)
Lethal fish virus first found at salmon farm in Washington state
Monday, May 28, 2012, 23:40 (GMT + 9)
A deadly fish virus has been found for the first time ever in Washington at a Bainbridge salmon farm. All the fish there have been killed and state wildlife experts are on alert for additional outbreaks.
The infectious hematopoietic necrosis virus (IHN) was recently spotted in two British Columbia (BC), Canada fish farms and led to the killing of almost 600,000 fish.
It is believed that the virus spread from BC to the Bainbridge farm.
The virus’s move south to Washington "is a big concern to us," said John Kerwin, the state Department of Fish and Wildlife's fish health supervisor, Kitsap Sun reports.
"Any first time it occurs, you don't fully understand the impact to wild fish," he said. "We know it can impact (farmed) fish. If we move fast, we can try to minimise the amplification."
IHN occurs naturally in wild sockeye salmon and can be carried by other species including herring, which sometimes swim through the net pens at the Bainbridge farm owned by American Gold Seafoods, affiliated with Icicle Seafoods of Seattle.
American Gold Seafoods noticed that fish were dying off at a fast rate in April and testing this month confirmed the presence of IHN virus.
All the fish will be removed by the second or third week of June. The fish will be composted; those fish living will be processed and sold, although most of the fish have not matured to the preferred market size.
"It's a very, very big loss for us," lamented Alan Cook, Icicle's vice president of aquaculture.
The nets from 2 ac worth of pens will be taken off and disinfected.
The farm will resume operations four months later.
American Gold is also worried about another batch of net pens in Clam Bay near Manchester, which is located only half a mile away. Monitoring has increased and the fish at both facilities have been isolated.
The last outbreak of the virus on the US West Coast occurred at a BC fish farm in 2003, Kerwin noted.
The recent outbreaks in Canada have prompted Washington's Wild Fish Conservancy to push for stricter testing rules and limits on net pen salmon aquaculture. The concern is that densely packed fish farms can intensify the virus's spread, encourage its mutation and infect wild fish that swim through or near the pens.
Cook stressed that his company’s choice to remove all the farm's fish is not legally required.
"We're not letting the situation sit and fester and then explode," he said.
- Third fish farm quarantined over virus concerns
- CFIA quarantines another salmon farm in BC
- Mainstream starts depopulating farm after detecting IHNv
By Natalia Real