Historical Perspective on Habitat Essential to Bristol Bay Red King Crab

Abstract

The Alaska red king crab, Paralithodes camtschaticus, has one of the most information-rich assessment and exploitation histories of any species in the eastern Bering Sea. Yet unsound assumptions and misconceptions persist as to the species’ basic biology, ecology, and habitat requirements. These include (1) temperature is the dominant factor governing the distribution and abundance of red king crab, making them so unpredictable in their movements that no particular habitat can be designated as more essential than another within their 150,000 km 2 Bering Sea range; (2) early no-trawl refuges (e.g., the Japanese Broodstock Sanctuary and the Pot Sanctuary) were implemented to resolve fishing-gear conflicts rather than to protect red king crab from trawling; (3) protection from bottom trawling is more important for juvenile red king crab than for the multiparous broodstock with its relatively high reproductive value; (4) all male red king crab with a carapace length of 120 mm or greater, regardless of their molt status, are capable of mating with one or more females each year; and (5) the Bristol Bay red king crab stock is assumed to be regulated largely by compensatory mechanisms that cause reproductive success to be highest when spawning-stock abundance is lowest, thus ensuring that the stock will recover from overfished abundance levels once fishing is halted. This paper uses information from surveys conducted as early as 1941 to examine these assumptions and to provide the detail and