Long Lake Carp Die-Off May Be Natural Occurrence
Spokane-area anglers may have noticed the recent die-off of carp in Long Lake, also known as Lake Spokane. What’s causing it? Is it a sign of a larger problem? The Washington Department of Fish and Wildlife says probably not.
According to a WDFW press release, the cause of the carp die-off is still unknown, but it may be a natural occurrence. The fish carcasses are expected to decompose completely within a few weeks, and although people should take basic hygiene precautions, there’s nothing to suggest that this is a human health emergency.
The WDFW may not know the cause of the die-off, but they do know what isn’t causing it. The Washington Department of Ecology has ruled out both toxic substances in the water and low levels of oxygen as potential causes. DOE expert Mike Hepp explains: “All the species of fish in Lake Spokane would have been affected if there were toxic pollutants,” he said. “In addition, we would see small fish dying as well as larger fish, and that’s not the case here.”
So what is causing the die-off? According to WDFW district fish biologist Chris Donley, it may be a combination of spawning patterns and unusual temperature fluctuations.
“Since all the dead carp appear to be adult fish, it’s highly possible they came near shore to spawn when it was cool a few weeks ago, waited around for the warmer water temperatures they prefer, then were stressed with very elevated water temperatures very quickly, and became susceptible to natural pathogens like bacteria or viruses,” Donley said. “Things like this happen more often than most people realize, usually with fish carcasses either sinking to lake bottoms or decomposing in remote areas where no one sees them.”
One thing’s for sure: Local anglers should avoid Long Lake until the problem has been resolved, and Long Lake homeowners are encouraged to safely and hygienically bury any carcasses they find.
