Mystery of 10 Billion Snow Crab Deaths in Alaska Solved

In a new study, scientists examined the mass death event and concluded that it was more than 98 percent likely caused by humans.

Researchers from NOAA Fisheries found that the sudden extinction of snow crabs (Chionoecetes opilio) in the Bering Sea was a direct consequence of human-induced climate change causing an ecological shift from Arctic to sub-Arctic conditions in the southeastern Bering Sea.

As reported by IFL Science , snow crabs are a cold-adapted species that are extremely well adapted to living in cold Arctic conditions.

Young crabs grow in cold water, a layer of water with a temperature of less than 2°C (35.6°F) located on the seabed left behind by melting sea ice.

The nearly frozen layer of water acts as a barrier against predators, allowing the young crabs to develop in peace.

However, these cold pools are shrinking rapidly, putting their populations under severe pressure. Warming temperatures are causing their environment to undergo a process of borealization, a transition from Arctic conditions to boreal conditions typically seen in northern areas with coniferous forests.

“What is particularly noteworthy is that boreal conditions associated with snow crab mortality are more than 200 times more likely to occur in the current climate,” said Mike Litzow, lead author and director of the Kodiak Lab at the Alaska Fisheries Science Center, in a statement.

“What is even more concerning is the condition of the Arctic. The ability of snow crabs to maintain their dominant role in the southeastern Bering Sea is expected to continue to decline in the future,” Litzow said.

(wbs)