Hundreds of pink salmon were found dead in the Buskin River of Kodiak, Alaska. The Kodiak Fish & Game also discovered dead silver salmon, rainbow trout, and dolly varden. The cause is thought to be warmer water temperatures, as this is affecting other waters in the area. Salmon dying before spawning is negative for salmon populations as well as future sportfishing.
Warmer Water Temperatures
Kodiak sportfish biologist, Tyler Pollum said about the dead salmon, “It looks really consistent with what’s happened the last couple of years in various rivers around here and other places in the state.” The Buskin River has been around 60-65 degrees, which is warmer than usual. Warmer water is unable to hold as much oxygen as colder water, and that combined with low water levels is a deadly situation. “It’s pretty likely that the dissolved oxygen in the water just got so low that they died of suffocation basically,” Polum said. Rivers across Kodiak have been low and warm, causing salmon deaths over the last couple of years.
Even the Yukon is Being Affected
The Koyukuk River is a large tributary of the Yukon River. Last year at least 1,364 chum salmon were found dead. University of Alaska Fairbanks professor, Peter Westley, studied the salmon deaths in relation to the 2019 heatwave. “All of these signs point to these types of events becoming more frequent and potentially of greater magnitude as things warm up,” Westley said. “So in some ways, it’s surprising when it happens, but I think we’re going to get to the point where we are not surprised.”
Future Effects of Warming Waters
How will heat stress affect salmon in the future? The answer to this question is uncertain… but salmon dying before spawning is never a good thing. Tyler Polum said it could impact future sport fishing opportunity in the Buskin River for years to come. More and more research is being done on salmon deaths in order to truly understand what is happening. Peter Westley said, “What we do have the control of is the protection of these habitats and allowing fish to find places in rivers, as much as possible, that might be refuge.”
Check out the original article on this topic at Alaska’s News Source.