In recent years, the ocean surrounding Alaska has seen a significant decline in the number of snow crabs. Scientists have now determined that the probable cause of this disappearance is the warmer ocean temperatures, which have likely led to the crabs starving to death.
This revelation comes shortly after the Alaska Department of Fish and Game announced the cancellation of the snow crab harvest season for the second consecutive year, attributing it to the vast number of missing crabs in the Bering Sea’s typically cold and treacherous waters.
A study released by the National Oceanic and Atmospheric Administration (NOAA) has established a notable connection between the marine heatwaves in the eastern Bering Sea and the sudden decline in snow crab numbers, which became evident in surveys from 2021. Cody Szuwalski, the study’s lead author and a fishery biologist at NOAA, expressed his shock upon receiving the 2021 survey data, hoping it was an anomaly. However, the situation did not improve in 2022.
The research aimed to determine whether the crabs had migrated or died. After extensive analysis, the scientists concluded that it was unlikely the crabs had moved, pointing towards a significant mortality event as the primary reason. The study found that the crabs’ increased metabolic needs due to warmer waters and the disrupted food web in the Bering Sea made it challenging for them to meet their caloric requirements.
Furthermore, other species, such as the Pacific cod, took advantage of the situation. Typically, a temperature barrier prevents these species from accessing the crabs’ extremely cold habitats. However, during the heatwave, the Pacific cod ventured into these warmer waters, preying on the remaining crab population.
The Arctic region has experienced temperatures rising at a rate four times faster than the rest of the world. This rapid warming, especially in Alaska’s Bering Sea, has led to a significant reduction in sea ice, further exacerbating global warming effects.
Szuwalski highlighted that the drastic changes in the snow crab population are evidence of the accelerating climate crisis and its impact on livelihoods. While such changes were anticipated, the speed at which they occurred was unexpected. As the ice continues to recede due to climate change, it is projected that the snow crab population will migrate north, leading to a potential decline in their presence in the eastern Bering Sea.