This story originally appeared in High Country News and is part of Climate desk Cooperation.
Every June, Serena Fitka goes home to her Yup’ik community in St. Mary’s, Alaska, near the confluence of the Yukon and Andreafsky rivers in the southwestern part of the state. Usually she helps her family catch salmon and store it in the smokehouse for the leaner winter months. But this year it didn’t happen: this year there were no salmon to catch.
“I could feel the loss,” she said. “I didn’t know what to do with my days, and I could tell it was like that for everyone along the Yukon River.”
There are five types of salmon in Alaska: Chinook, sockeye, chum, coho and pink. Chum is the most harvested fish in the Yukon, but both chum and chinook are essential to the life and culture of the approximately 50 communities around Alaska that depend on the river and its tributaries for their livelihoods.
Around the state, chinook numbers have been declining for a decade, but this year’s run is the lowest ever recorded. Chum counts took a dive in 2021, and this year’s count is the second lowest ever; as a result, state and federal fisheries managers have closed companion fisheries on the Yukon. This will affect more than 2,500 households in the region who rely on a friend to feed their families. “The annual harvest is gone,” said Holly Carroll, a Yukon River subsistence fisheries manager for the US Fish and Wildlife Service. Scientists haven’t figured out why chum and chinook runs have been so poor in parts of western Alaska, but many theorize that warming ocean conditions are affecting the salmon early in their life cycle — and some local subsistence fishermen believe that commercial fishing in other parts of the state could also contribute.
Warmer waters have caused a decline in chinook and chum across the Pacific, and these changes are also hurting salmon in the Yukon. In a study of chum, the researchers found that the fish were eating things outside of their usual diet, like jellyfish, and because of that they probably didn’t have enough energy stored in their bodies to survive the winter. “It’s associated with these marine heat waves that we’ve seen in the Bering Sea as well as in the Gulf of Alaska,” said Katie Howard, a fisheries scientist with the Alaska Department of Fish and Game Salmon Ocean Ecology Program. During marine heat waves, mate eats prey that is easier to catch but often less caloric. Drought in the spawning areas of Interior Alaska and Canada can also contribute to lower numbers of chinook as it leads to lower water levels and makes the water warmer.
Meanwhile, nearly 400 miles south in Bristol Bay, a warming climate may actually help salmon run instead, said Jordan Head, a state biologist who works in the region. Bristol Bay fishermen have over harvested 57 million sockeye this yearwhich broke the all-time record of 44 million fish set in 1995. The region has seen over 74 million sockeye returns so far this season, the largest number in the history of the fishery. With the warmer temperatures, the lakes are frozen for less time, and the juvenile sockeye may have been able to grow larger and be more competitive once they enter the ocean, thereby increasing their chances of survival. But as the Bering Sea continues to warm, it could also see the same salmon declines as the Yukon.