The hundreds of dead and dying carp washing up along the shores of Lake Spokane are being killed by natural causes, though state wildlife biologists can't pinpoint any, and there is no threat to people.
In a joint press release issued this afternoon, officials from three state departments (Fish and Wildlife, Ecology and Health) stress there is no human health emergency and no evidence of toxic substances in the reservoir popularly known as Long Lake.
Low levels of dissolved oxygen have also been ruled out, confirming an analysis offered to The Inlander earlier this week by two water quality specialists at Ecology. See our story.
The press release says a dead carp was examined by a Fish and Wildlife fish pathologist who could not determine a specific cause of death. Organ and tissue samples were sent to other laboratories for further testing with results not expected for several weeks, the press release says.
Earlier, Ecology water quality specialists Mike Hepp and David Moore said koi herpes virus could be a likely cause of the die-off. It is specific to carp (and no other species in Long Lake appear to be dying in great numbers) and has been responsible for virulent carp die-offs around the country. Spokane Riverkeeper Rick Eichstaedt e-mailed several articles on the same topic:
The Las Vegas Sun reported a year ago that Arizona Game and Fish Department released lab results that showed koi herpes to be responsible for thousands of carp dying in Lake Mead last June. Read their story.
In another story from last June, the Roanoke Times quotes a state biologist saying spring viremia or koi herpes would be the most likely causes of a carp die-off in a Virginia lake. Testing for specific viruses is pretty straightforward, he says. Read the story.
KXLY has video showing goodly numbers of dead carp in Long Lake. Residents appeared queasy about getting in the water, but according to the press release there appears little risk of harm from swimming or other activities. People should take basic hygiene precautions such as washing off after swimming in an area with dead fish or after handling carp carcasses.
The stench is awful, shoreline residents report. State officials say the carp will fully decompose in another week or so, and note that residents can bury the carcasses as state agencies don't have the manpower to remove the dead fish.
In fact, this news broke over the weekend, just as most state agencies were forced to shut down Monday as the first of several "furlough days" to balance the budget. The official response was slow and somewhat confused.