Billions of snow crabs have mysteriously vanished from the waters of the eastern Bering Sea, causing significant disruption to Alaska's crab fishing industry, slashing jobs, and threatening the survival of coastal communities. Scientists estimate that approximately 10 billion snow crabs disappeared between 2018 and 2021, a period marked by an unprecedented marine heat wave that drastically altered ocean conditions.
This collapse has contributed to a five-year decline in Alaska's commercial fishing workforce, with harvesting employment reaching record lows in 2024, according to the Alaska Department of Labor. The sector has seen its lowest employment levels since state tracking began in 2001.
Researchers suggest that warmer ocean temperatures increased the snow crabs' metabolism, leading to a higher demand for food. With billions of crabs concentrated in a shrinking cold-water habitat, widespread starvation is believed to be a primary factor in their disappearance. "It's a fishery disaster in the truest sense of the word," said Cody Szuwalski, a fisheries biologist at NOAA's Alaska Fisheries Science Center and lead author of a study on the phenomenon.
The snow crab fishery has historically been one of Alaska's most valuable, typically generating around $150 million in annual revenue. However, during the 2021-2022 season, revenue plummeted to approximately $24 million as crab numbers reached historic lows. This forced regulators to close the lucrative Bering Sea snow crab fishery for two consecutive seasons.
The closures have had a profound impact on fishing communities and have been a significant storyline for the Discovery Channel series Deadliest Catch, which has documented Alaska's crab fleets for two decades.
Normally, snow crabs thrive in the cold waters formed by melting winter sea ice, which creates a cold layer across the seafloor. However, a severe marine heat wave in 2018 and 2019 prevented sufficient sea ice formation, eliminating critical cold-water habitat.
Scientists analyzed temperature records, fishing data, and crab population surveys. Their findings indicate that the unusually warm water likely triggered the collapse indirectly. While laboratory studies show snow crabs can survive warmer temperatures than experienced during the heat wave, the rising temperatures nearly doubled the animals' calorie requirements. Simultaneously, the crabs were forced into a smaller area, intensifying competition for limited food resources. Survey data also revealed that surviving crabs weighed less than normal, further supporting the theory of widespread starvation.
Christopher Harley, a marine ecologist at the University of British Columbia, noted that the collapse highlights how climate change is generating environmental shocks that scientists are only beginning to comprehend. "It's just yet another example of something we didn't expect, but now we have to live with," Harley said.
The economic repercussions extend beyond the crab boats themselves. Alaska has lost more than one-third of its commercial fishing jobs over the past decade. State economist Joshua Warren cited a combination of challenges facing fishermen, including rising operating costs, declining seafood prices, climate change impacts, processing plant closures, and increased foreign competition. "There's increased cost, competition in international markets, drop in prices," Warren told KUCB. "A lot of different things can cause someone to choose to fish or not to fish."
Warren also stated that climate change is exacerbating the situation, leading to more unpredictable fish runs and forcing fishery closures in some regions. Despite these challenges, he expressed optimism that the industry will endure, stating, "I don't think I'm terribly worried there won't be fishing in the future. We're just seeing a lot of negative factors right at the moment."
While the Bering Sea snow crab fishery reopened in 2024 with significantly reduced catch limits following some stock recovery, scientists caution that marine heat waves are becoming more frequent due to global warming. This trend suggests that Alaska's fishing industry may face similar crises in the future unless marine ecosystems can adapt.
