The red king crab (Paralithodes camtschaticus) is one of the ocean’s most iconic crustaceans — and the subject of one of Alaska’s most famous and precarious fisheries. With leg spans reaching nearly 6 feet and weights up to 28 pounds, king crabs are the giants of Alaska’s seafloor.
Life on the Bottom
King crabs spend their lives on the seafloor, foraging for food with powerful claws capable of crushing hard-shelled prey. They are omnivores and detritivores — eating whatever the seafloor offers, including clams, worms, sea stars, and organic debris. This scavenging role makes them important components of benthic ecosystem function.
The Mating Migration
One of the most dramatic events in Alaska marine life: red king crabs undertake annual mass migrations — “pod walking” across the Bering Sea floor in dense aggregations of thousands of individuals. These migrations are linked to mating behavior and are one of the most spectacular phenomena in Alaska’s shallow seas.
Collapse and Concern
The Bristol Bay red king crab fishery — once one of the most valuable fisheries in the world — collapsed catastrophically in 2021-2022, with surveys finding populations at less than 10% of historical levels. The fishery was closed for the 2022-2023 and 2023-2024 seasons for the first time in history.
The cause is complex and debated, involving:
- Ocean warming in the Bering Sea reducing cold-water refugia
- Trawl bycatch impacts on juvenile crabs
- Starvation of displaced juvenile crabs in warming waters
- Ecosystem shifts driven by climate change
The collapse represents one of the most dramatic examples of climate-driven fisheries disruption in Alaska history.
At the Alaska SeaLife Center
Red king crabs are among the most popular invertebrates in our exhibits — giving visitors an up-close view of one of Alaska’s most ecologically and economically important species, and the opportunity to learn about the ongoing conservation challenges facing this iconic creature.