The Collapse of Eastern Bering Sea Snow Crab


Photo: C-World Limited

Rising temperatures in the North Pacific could exacerbate the situation for the remaining crustaceans.

Snow crab (Chionoecetes opilio) is one of the most abundant and widely distributed species in the benthic ecosystem of the eastern Bering Sea.

The species is a valuable object of fishing. Therefore, researchers from different countries conduct constant monitoring of its populations.

Since 2018, more than 10 billion snow crabs have disappeared from the eastern Bering Sea, and the population collapsed to historical lows in 2021. We link this collapse to a marine heatwave in the eastern Bering Sea during 2018 and 2019, the study said.

Alaskan fishermen noted a significant decrease in the eastern Bering Sea snow crab population in May this year. Media at the time quoted a professor at the School of Aquatic and Fishery Sciences in Seattle as saying:

 Fish metabolism depends very much on water temperature, and with warmer water, fish need more food to maintain their bodies and grow. On the other hand, ecosystems change with warmer water, and there may not be sufficient prey around.

Scientists then suggested that it would take more than a year to restore the snow crab population in the Bering Sea. However, the danger of another powerful heatwave would complicate the process.

New research from scientists at the National Oceanic and Atmospheric Administration (NOAA) links the collapse of the snow crab population to a marine heatwave in the eastern Bering Sea during 2018 and 2019. According to scientists, climate change has led to the demise of more than 10 billion snow crabs. The study is published in Science.

Calculated caloric requirements, reduced spatial distribution, and observed body conditions suggest that starvation played a role in the collapse. The mortality event appears to be one of the largest reported losses of motile marine macrofauna to marine heatwaves globally, the scientists said.

The team of scientists conducted monitoring of snow crab (Chionoecetes opilio) populations living in the American part of the Bering Sea. The above-mentioned conclusions were achieved based on those observations.

The scientists added that the increasing frequency and intensity of heatwaves and rising average temperatures in the North Pacific could significantly exacerbate the situation for the remaining clusters of C. opilio in the coming decades. Therefore, this should be taken into account when developing conservation measures and setting the quotas for snow crab fishing.