Climate change is to blame for falling Chinook and chum salmon populations in Alaska, the National Oceanic and Atmospheric Administration's (NOAA) annual Arctic report card revealed.
The card published Tuesday is the most recent in a series of alarm bells sounded by experts who warn that climate change and global warming are advancing at an unprecedented and dangerous rate.
Climate change has caused negative impacts to the agriculture sector worldwide, and the Arctic is warming four times faster than other areas. Rising water temperatures and drought have contributed to species deaths across the globe, including more than 150 river dolphins that recently died in Brazil. Now, according to the NOAA's report, the warming climate has negatively influenced salmon populations in the Yukon and Kuskokwim rivers—the two longest rivers in Alaska.
This is the first year the NOAA has included a chapter on salmon species vital to Indigenous communities in its annual report, and the data shows a concerning trend. Chinook and chum salmon, which are critical to the Indigenous communities living near the Yukon and Kuskokwim rivers, have declined in population, with heat waves at fault. Chinook and chum salmon are 81 percent and 92 percent below the 30-year mean, respectively.
Newsweek reached out to the NOAA by email for comment.
Not only are the salmons' numbers declining but warming waters are reducing the salmons' size, as well, with adult length decreasing by 6 percent.
"Chinook and chum salmon numbers have declined following recent heatwaves and ecosystem changes in the rivers where they spawn and the ocean waters where they grow to maturity," the report said. "Warming river waters have been linked to heat stress in Chinook salmon, and warmer ocean waters may be contributing to both species maturing as smaller adults."
Meanwhile, sockeye salmon populations in Bristol Bay, Alaska, are thriving with the warmer temperatures.
"Contrastingly, sockeye have been extremely successful under recent warm conditions, which allow them to grow faster in lakes as juveniles and may boost their survival when they migrate to the ocean," the report said. "The diverging impacts are affecting Indigenous communities that depend on the salmon for food, and challenging fishery managers as the different species respond in unique ways to the warming climate."
Experts called for global action after the report was released, urging communities to reduce greenhouse gas emissions to drive down temperatures before more harm is done.
"The overriding message from this year's report card is that the time for action is now," NOAA Administrator Rick Spinrad said in the report.
He went on: "NOAA and our federal partners have ramped up our support and collaboration with state, tribal and local communities to help build climate resilience. At the same time, we as a nation and global community must dramatically reduce greenhouse gas emissions that are driving these changes."
Other aquatic life has responded poorly to warming waters in Alaska, with as many as 10 billion snow crabs dying from marine heatwaves in the Bering Sea between 2018 and 2021.
About the writer
Anna Skinner is a Newsweek senior reporter based in Indianapolis. Her focus is reporting on the climate, environment and weather ... Read more
To read how Newsweek uses AI as a newsroom tool, Click here.
