Alarm was raised among fishermen and scientists when billions crabs disappeared from the Bering Sea, near Alaska in 2022.

Scientists explained that it was not overfishing, but probably too warm sea water, which caused changes in their metabolism and eventually led to their death by starvation.

The crab die-off is just one consequence of the changes taking place in the region, scientists said in a new study.

According to CNN, research from the National Oceanic and Atmospheric Administration concluded that warmer ice-free temperatures in the southeastern Bering Sea—conditions found in subarctic regions—are 200 times more likely now than they were before humans began they burn fossil fuels that overheat the planet.

The study also highlights how much the Bering Sea ecosystem has changed and warns that “we should expect many more – very warm – years”, while truly arctic conditions will be few and far between.

Snow crabs, a species found in the frozen waters of the Arctic, thrive in areas where the water temperature is below 2 degrees Celsius, although they can survive in water as hot as 12 degrees Celsius.

A marine heat wave in 2018 and 2019 was particularly deadly for the crabs. The warmer water caused the crabs’ metabolism to increase, but there wasn’t enough food to keep them alive.

Billions of crabs eventually starved to death, ruining Alaska’s fishing industry for years to come.

Snow crabs are a commercially valuable species, bringing in up to $227 million annually.

The disappearance of the Alaskan crab signals a broader shift in the Arctic ecosystem as oceans warm and sea ice disappears. The ocean around Alaska is now becoming inhospitable to many marine species, including the red king crab and sea lions, experts say.

A warmer Bering Sea is also introducing new species, threatening those that have long lived in its cold waters, such as the snow crab.