In a troubling development for Alaska's fishing industry, an estimated 10 billion snow crabs have vanished from Bering Sea waters between 2018 and 2021, leading to the closure of fisheries and threatening the state's economy. Scientists believe they have now uncovered the cause behind the mass disappearance, pointing toward extreme ocean heat triggered by marine heat waves, which are becoming more frequent due to climate change.

A study recently published in the journal Science highlights how climate change-induced marine heat waves can disrupt ecosystems and pose a significant threat to human livelihoods that depend on ocean resources. The researchers suggest that the snow crab population crash, which followed its highest-recorded level in 2018, serves as an alarming example of how quickly the outlook for a species can change.

Snow crabs, known for their preference for cold water, typically seek refuge in a cold pool on the Bering Sea floor during the summer, located between Alaska and Siberia. However, during the years 2018 and 2019, marine heat waves severely depleted the cold pool, making it virtually nonexistent.

Given that the metabolism of snow crabs is temperature-dependent, the sharp increase in water temperatures likely led to a significant surge in the crabs' caloric needs. This occurred when the population was heavily concentrated on the seafloor, ultimately resulting in mass starvation.

The research team ruled out other potential factors for the population crash, such as trawling, predation by other species, and disease. While it is possible that the crabs migrated elsewhere on the seafloor, survey ships have been unable to locate them in other areas.

The disappearance of snow crabs has had a devastating impact on Alaska's economy, as the industry was valued at approximately $132 million in 2020, with around 60 crab ships involved in the harvest. The snow crab fishing season was forced to shut down during the winter of 2022-2023 due to the mass die-off.

The situation remains dire, as the snow crab population remains too low to sustain fishing activities. In an announcement earlier this month, the Alaska Department of Fish and Game and the National Marine Fisheries Service confirmed that the snow crab season will remain closed this winter, setting the stage for another challenging season for the crab fishing industry.

The disappearance of 10 billion snow crabs underscores the urgent need for addressing climate change and its impact on marine ecosystems. It serves as a stark reminder that the health and livelihoods of both wildlife and humans are inextricably linked and require immediate attention to preserve these valuable resources.