Annual reports for the Bering Sea, Aleutian Islands and Gulf of Alaska reveal mixed signs for fish stocks in changing conditions

By Yereth Rosen, Alaska Beacon

Lisa Hupp

The waters off Alaska’s Aleutian Islands registered the warmest winter temperatures in over a century, part of a decade-long period of warming, according to a report issued by the National Oceanic and Atmospheric Administration.

The record-high temperatures in the western and central Aleutians moderated later in the year but warmer-than-normal conditions persisted for the rest of the year throughout the waters around the 1,100 mile chain extending from southwestern Alaska, according to the 2023 NOAA Fisheries Ecosystem Status report for the region.

The Aleutians report is one of three annual ecosystem status reports issued by NOAA Fisheries for marine areas of Alaska. The reports, compiled by large teams of scientists, were released earlier this month and presented to the North Pacific Fishery Management Council, the panel that sets regulated commercial fishing in federal waters off Alaska.

The annual reports provide snapshots of current conditions and clues about future conditions in a warming climate, information needed to manage fish harvests and other activities, NOAA Fisheries said in a statement.

“Warming at rates four times faster than the rest of the ocean, Alaska’s Arctic ecosystems are a bellwether for climate change. Now more than ever having ecosystem and climate-related data and information is essential to support adaptive resource management and resilient commercial, recreational and subsistence fisheries, and rural and coastal communities,” Robert Foy, director of NOAA’s Alaska Fisheries Science Center, said in the statement.

The Bering Sea and other marine waters off Alaska produce more than half of the nation’s commercially harvested seafood.

In the Aleutians, the fish most vulnerable to the warm condition are Pacific cod, according to the Aleutian ecosystem status report. There are several reasons for that, NOAA Fisheries biologist Ivonne Ortiz told the council in her presentation of the report.

“Pacific cod has a very narrow range of temperatures for the eggs to hatch,” Ortiz said. That range, from 3 degrees to 6 degrees, has been exceeded in the waters, she said.

Higher temperatures also increase Pacific cod’s energy needs, Ortiz said. “The cost of living is higher, the cost of growing, feeding, pooping, having sex, swimming around is higher, so they need to either consume prey that has higher caloric content or consume more prey to make up for that,” she said. But high-quality food for Pacific cod is less available in the Aleutian region, she said.

Also vulnerable and sensitive to higher temperatures are Atka mackerel, an important species for commercial harvests, according to the ecosystem status report. But pink salmon originating from eastern Kamchatka, on the Russian side of the ocean, appear to be thriving, with the third-highest population on record, the report said.

With warming temperatures come higher risks of algal toxins, and the past year’s record provides evidence of the association. Mussels found in June at Sand Point, Unalaska, False Point and Akutan, communities in the eastern Aleutians or at the western tip of the Alaska Peninsula, had levels of paralytic shellfish toxins that were 47 times the amount deemed safe for human consumption, according to the Aleutians ecosystem status report.