Blue King Crab Fisheries In The Bering Sea Are Struggling

Sep 3, 2019

Blue king crab is considered overfished near the Pribilof Islands as well as St. Matthew Island, according to a recent report from NOAA.
Credit Alaska Department of Fish and Game

Every year, the National Oceanic and Atmospheric Administration (NOAA) reports to Congress on the status of U.S. fisheries. The report breaks the data down by region, and highlights which stocks are in "overfishing" and "overfished" status, as well as which stocks have been rebuilt. 

Krista Milani, a natural resource specialist with NOAA Fisheries in Unalaska, said the  2018 report, released in August, shows the number of U.S. fish stocks subject to overfishing remains at a near all-time low — meaning there are a lot of healthy, sustainable populations. But in Alaska, it's not all good news. 

"For the Alaska region, we didn't have any fisheries that were in overfishing status, but we do have two stocks that are considered overfished," said Milani.  

One of those is Pribilof Island blue king crab, which has been designated as overfished since 2002. The other is the newly-added blue king crab stock around St. Matthew Island, north of the Pribilof Islands in the Bering Sea.

NOAA has two years to put together a rebuilding plan. Then, the Magnuson–Stevens Act gives NOAA 10 years to declare the St. Matthew Island blue king crab stock rebuilt
Credit Celeste Leroux/Alaska Sea Grant

Milani said there's an important distinction to make when it comes to stock status. If a stock is experiencing "overfishing," that means humans are responsible for catching too many of the species. But if it's been designated as "overfished," that does not necessarily mean overfishing occurred. 

"For blue king crab, we're fairly certain that they're declining due to environmental conditions," said Milani. "So things like warmer water, ocean acidification, changing ocean currents — all those things can affect a blue king crab's ability to reproduce and the ability for larvae to mature to adult crab, which of course affects overall biomass of the stock." 

Since NOAA just determined the St. Matthew stock to be overfished, the agency now has two years to develop a rebuilding plan. Milani said that could include reevaluating its management strategies or closing certain fishing areas to avoid blue crab bycatch.  

"Once the rebuilding plan goes into effect — which should be in 2020 — then from the start of that rebuilding date, the Magnuson–Stevens Act gives us 10 years to declare the stock rebuilt." 

But that timeline doesn't always work. For instance, the Pribilof blue king crab stock has been "rebuilding" since 2004, and it's still considered overfished.

Specific changes to the status of stocks in 2018.
Credit National Oceanic and Atmospheric Association

Milani said many crab populations in the Bering Sea/Aleutian Islands region have been declining over the past few years, and it's hard to pinpoint exactly why.

According to data from NOAA and the Alaska Department of Fish and Game, at its peak in the 1980s, the St. Matthew fishery harvested nearly 9.454 million pounds of blue crab each year. In 2015/16, the catch was down to just 0.105 million pounds.  

Going forward, Milani said there's no doubt scientists will have to study climate changes more and more to determine how Alaska's fish stocks will fare in the future. 

Other species added to the 2018 overfished list include Coho salmon in the Puget Sound and Washington coast, Chinook salmon in the Klamath and Sacramento rivers, and Atlantic mackerel in the Gulf of Maine.