A new report from the National Oceanic and Atmospheric Administration (NOAA) found that the ocean's influence on salmon populations varies from different rivers and regions.
In a Jan. 20 release, the disparity of 2021 returns among West Coast and Alaska fish populations was affected by an ocean's temperature, currents, prey availability, and nutrients that were experienced before returning to rivers to spawn.
“Salmon scientists have long recognized the prominent but highly variable effects of ocean conditions on salmon and steelhead," NOAA said in its release.
Specific numbers found that steelhead returns to the Snake River and Chinook and chum salmon runs on the Yukon-Kuskokwim River in Alaska in 2021 were among the lowest on record, with steelhead returns to the Fraser River in Canada falling close to extinction levels, NOAA said.
However, Bristol Bay in Alaska recorded the most significant return of sockeye salmon on record. This disparity between fish populations returns in 2021 among West Coast, and Alaska salmon and steelhead directly reflects ocean conditions' tremendous influence on fish survival. Better conditions in the ocean for salmon allow more efficient returns to rivers for spawning, affecting the likelihood of recovery for more than 25 species of threatened and endangered salmon and steelhead on the West Coast.
