OLYMPIA - About 70,000 rainbow trout and another 70,000 winter-run steelhead were destroyed after a waterborne fish virus was discovered at the Vancouver Trout Hatchery, according to the Washington Department of Fish and Wildlife (WDFW).
The loss of the rainbow trout can likely be made up from production at other state hatchery facilities in the region. However, there is likely to be a shortfall of approximately 40,000 winter-run steelhead available for release in lower Columbia River watersheds, said WDFW Hatchery Program Manager John Kerwin.
The virus, infectious hematopoietic necrosis (IHN), has no known cure and can be fatal to infected fish, but cannot be passed on to humans. The virus affects both wild and hatchery fish, including salmon and trout species, and is common throughout the Columbia River basin. The virus is spread from fish to fish, but birds can also be a vector.
Kerwin said the shortfall in rainbow trout production at the Vancouver facility will be made up through transfers of fish from the Goldendale and Naches hatchery facilities.
The loss of winter-run steelhead from the Vancouver hatchery can't be fully recovered, Kerwin said, adding that the effects of this year's fish kill will be felt primarily during fisheries in 2005-06. The loss represents a small portion of the overall hatchery winter-run steelhead production in the lower Columbia River basin.
Brown trout and summer-run steelhead that are currently being reared at the Vancouver hatchery are being monitored and have not been affected by the IHN breakout.