Where Have 7 Billion Snow Crabs Gone?

For the first time, Alaska has canceled its winter snow crab season in the Bering Sea because of a shocking decline in the crab population. There were an estimated eight billion snow crabs in 2018, a number that dropped off a cliff to a mere one billion last year.

Where did seven billion crabs go? The likely culprit is climate change, with the cold waters on the floor of the Bering continental shelf warming. This so-called “cold pool” is where young snow crabs normally enjoy plenty of food and few predators. But the pool is shrinking and shifting farther north, and crab-eaters like cod are finding the conditions warm enough to enjoy the buffet.

“From 2018 to 2021, we lost about 90 percent of these animals,” fish and game department biologist Miranda Westphal told the New York Times. She said that in recent years, the Bering Sea “was extremely warm and the snow crab population kind of huddled together in the coolest water they could find.”

The warming water not only made the crabs vulnerable to predators, it also fired up their metabolism, so the crustaceans needed more fuel than normal to survive. “They probably starved to death and there was not enough food,” Westphal said.

The crabs may also have been more susceptible to disease in these conditions, but as Westphal points out, “We don’t know and we are never going to actually know because the crabs are gone.”

The Department of Fish and Game also kiboshed the fall red king crab harvest for the second year in a row, citing the low number of mature female crabs, a red flag for a stock already in long-term decline.

Photo credit: Alaska Department of Fish and Game