Billions of precious Alaskan crabs suddenly and mysteriously 'disappear'

Billions of snow crabs have gone missing around Alaska in recent years. Scientists have pinpointed the cause: Warming ocean temperatures may have caused them to starve.

The discovery comes after Alaska officials announced the cancellation of the snow crab harvest for the second year in a row, due to low crab numbers.

Scientists at the National Oceanic and Atmospheric Administration (NOAA) found in surveys since 2021 that there is a link between the temperature of the Bering Sea and the sudden disappearance of snow crabs.

'When I got the first survey results for 2021, my mind was blown, ' said lead author of the study, NOAA fisheries biologist Cody Szuwalski. 'Everyone was hoping that there was an error in the survey and that there would be more crabs next year.'

That year was the first year that the snow crab fishery in Alaska was closed. Fishermen blamed the decline on overfishing.

But this activity has been controlled by conservation measures, so it cannot fully explain the reason for the large number of Alaskan crabs disappearing.

Climate change is really disrupting planning, models and management systems, says researcher Szuwalski.

Warmer temperatures are linked to more deaths among adult crabs. (Source: NOAA).

In the study, scientists analyzed what might have happened to the crab population since 2020. They divided it into two scenarios.

1. First , the crabs have moved elsewhere.
2. Second , they are dead.

After analyzing the northern Bering Sea, western Russian waters, and even the deeper layers of the ocean, they concluded that there was no possibility that the crabs were moving. The only thing left was that they were dead.

Warmer temperatures and population densities are linked to more deaths among adult crabs . And the root cause is a lack of food.

Snow crabs live in cold waters with temperatures below 2 degrees Celsius. Warmer seawater can wreak havoc on the crab's metabolism and increase its calorie needs.

But warming seas are also disrupting the food chain in the Bering Sea, leaving snow crabs unable to find food to meet their caloric needs.

Scientists say temperatures around the Arctic have been warming four times faster than the rest of the planet. Climate change is causing sea ice in the Arctic region to melt rapidly, especially in Alaska's Bering Sea.

'2018 and 2019 were extremely unusual years for ice in the Bering Sea, something we've never seen before,'  said biologist Szuwalski.

What happened to the Alaskan crab is evidence that the climate crisis is accelerating and affecting the survival of many species and humans, he added.

Although he knew this situation would happen sooner or later, he did not expect it to come "so soon".

He said this is a sudden and dramatic change in the crab population. In the long term, snow crabs are expected to move north as the Bering Sea ice melts. And people will no longer see them as much.