Wednesday, September 23, 2020

NOAA plans ecosystem-based fisheries management study for Gulf of Alaska

NOAA Fisheries research biologists say they are embarking on a new ecosystems-based fisheries management study on the Gulf of Alaska, with a focus on the fisheries and coastal fishing communities.

The new project, to run for three years, is funded by the North Pacific Research Board in Anchorage and internal funds from NOAA’s fisheries and climate program, said NOAA Fisheries researcher Martin Dorn, the project lead. 

The Gulf of Alaska study comes on the heels of the Bering Sea ecosystem-based fisheries management study, said fellow NOAA Fisheries researcher Kirstin Holsman.  Both are with NOAA’s Alaska Fisheries Science Center.

While the Gulf project will closely follow the one done in the Bering Sea, it is designed to address some of the environmental and management issues important in the Gulf, Dorn said.

“It is essentially trying to project what the future might look like for the Gulf and try to figure out what implications are for marine resources in the area and how that might affect fisheries and fishing communities,” Dorn said. “We are trying to bring that whole big package together.”

In the wake of the heat wave that hit the Gulf from 2013 through 2016, causing the crash of the Pacific cod population in the Gulf, researchers want to better understand how that heat wave affected the overall ecosystem and whether that type of marine heat wave will occur in the future, he said.

Researchers will also study another aspect unique to the Gulf, that the Gulf has the third largest accumulation of glaciers in the world after Antarctica and Greenland. Projections are that glaciers that surround the Gulf will be retreating and melting, bringing fresh water into the ocean, and there will be greater runoff, Dorn said. Researchers want to know how this will impact the ecosystem, along with aspects of climate change, including overall warming, decreased oxygen in the water and ocean acidification.

Other questions they hope to answer are how these changes will impact halibut, Pacific cod, Alaska Pollock, black cod and other species. While fish populations have the ability to adapt to certain changing conditions, fish in the Gulf are essentially in a bowl with land all around, and there is no way for them to escape to cooler waters, as fish in the Bering Sea can do, he said.

There are also concerns that the Gulf may be subject to invasions of populations from further south, like Pacific whiting or hake, and some rockfish populations might move northward too, Dorn said. Rockfish would potentially compete for food and that would cause a shift in the populations, he said. 

Black cod are another story. “That population is increasing now and it seems a lot of that came about from recruitment to the population during the heat wave,” he said. “We don’t have any proof, but it is possible that sablefish do better under those conditions.”

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