In a year when salmon and steelhead returns were seeing historic lows across the Pacific Basin (2021), Bristol Bay, Alaska noted record high sockeye salmon returns at over 66 million fish, shattering the 2018 record of nearly 63 million. Bristol Bay salmon returns have been studies since the 1940’s and this year was only the third time a sockeye return has broken 60 million fish. Conversely, Alaska’s Yukon River saw some of the lowest Chinook and chum salmon returns on record.
While a number of anthropogenic and environmental variables currently influence Pacific salmon populations, climate change may have played a role in both the record high and low returns.
“Climate warming seems to have actually benefited Bristol Bay sockeye” said University of Washington Researcher, Dr. Dan Schindler. In cold northern climates, warmer water temperature leads to more food and better growth, and the sockeye of Bristol Bay are currently experiencing optimal conditions. The watersheds draining into Bristol Bay are undeveloped, providing optimal physical habitat as well.
Climate models predict range shifts for virtually all species of flora and fauna in North America, and while the Bristol Bay sockeye are booming, salmon and steelhead from California up through Washington are struggling from warming waters and myriad other environmental factors. Because fish populations fluctuate naturally, the sockeye returns to Bristol Bay may not persist at the present exceptional level, but fishery scientists do expect the runs to remain strong for the foreseeable future.
Thanks to habitat and genetic structural diversity in the Bristol Bay tributaries, these sockeye may prove to be one of the few future Pacific salmon strongholds, barring significant or unpredictable changes in ocean conditions.