The Alaska Department of Fish and Game has set the 2021-22 catch limit of snow crab to 5.6 million pounds - down 88% from last season. 

Scientists who study snow crabs attempt to understand what happened to the crabs, native to shelf depths in the North Pacific Ocean. 

They discovered that sea bottom warmed, pushing the crabs farther to the northwest and deeper waters. But scientists, in testimony to the North Pacific Fishery Management Council last week, noted there has also been a massive downturn in the population - not just migration out of survey zones. 

"We really do think that … some sort of mortality event did occur," said Katie Palof, an Alaska Department of Fish and Game biologist who advises the council.