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Decades Of Trawl Surveys Help Bering Sea Climate Change Research

May 8, 2017

 

Maps show changes in where Bering Sea Pollock are from year-to-year.
Credit Graphic courtesy NOAA/Alaska Fisheries Science Center

There’s a new tool to help scientists and others interested in monitoring how Bering Sea fisheries respond to a changing climate.

Biologist Steve Barbeaux of the Alaska Fisheries Science Center has created hundreds of graphics mapping where 22 species of fish spend their time during different life stages.

The data comes from annual trawl surveys dating back to 1984, but Barbeaux says that information was hard to analyze as a whole.

“To understand the true impacts of climate change we have to look across all of these life stages to get a true picture of what’s going on,” Barbeaux said. “It potentially could be beneficial at one stage of life, but harmful at another stage of it’s life.”

Barbeaux started small — looking at greenland turbot, a species that is greatly impacted by temperature changes. When the fish develop from larvae to juveniles, they depend on a cold pool in the Bering Sea. But without it:

“You get high natural mortality,” Barbeaux said. “So for [the greenland turbot] the impact really is at that settlement stage. Versus pollock where that impact has more potentially to do with their midlife stage.”

The graphics Barbeaux created allow him to see the distribution of the greenland turbot through time and location or through temperature and depth.

When other scientists saw what he’d done, they wanted it for their species too. Now the tool is available for 22 species in the Bering Sea. Barbaeux plans on updating the document as long as annual surveys continue.