Bering Sea hybrid crab population surges following snow crab die-off

A massive surge in hybrid crabs has been detected in the Bering Sea, following a catastrophic die-off of snow crabs caused by a marine heatwave in 2018. Research conducted by the National Oceanic and Atmospheric Administration (NOAA) reveals that hybrid individuals—crossbreeds between snow crabs and red king crabs—have increased to more than 13 times their historical average.

The heatwave, driven by greenhouse gas emissions, led to a reduction in sea ice and rising seafloor temperatures. This caused the snow crab population to plummet from an estimated 10 billion to approximately 1 billion, prompting a commercial fishing ban in Alaska from 2022 to 2024.

As the ecosystem shifted, hybrid crabs began filling the ecological niche left by the declining snow crab population. In 2025, hybrids accounted for nearly half of the catchable male crabs, up from a historical rate of less than 10%. Computer modeling by NOAA fisheries biologist Erin Fedewa suggests the primary driver of this surge is the drastic reduction in the original snow crab population.