Temperature-Dependent Growth of Juvenile Red King Crab (Paralithodes camtschatica) and its Effects on Size-at-Age and Subsequent Recruitment in the Eastern Bering Sea

Abstract

A temperature-based growth relationship was derived for juvenile red king crab (Paralithodes camtschatica) from published data. Growth of annual cohorts of crab was simulated at various locations in Bristol Bay, AK, using long-term water temperature observations, and the resulting mean sizes were compared with those observed by the annual National Marine Fisheries Service eastern Bering Sea crab survey. Results indicate that mean age-at-recruitment is 3–5 yr greater than previously estimated, and has decreased from 9.5 to 7.5 yr over the past decade as a result of increasing sea temperature. Single year-classes require 3–5 yr for complete recruitment to the 'mature' size interval, and recruitment in any year may consist of crabs from four to five year-classes. The high landings and subsequent crash of the Bering Sea red king crab population during the late 1970's probably originated from one or more adjacent strong year-classes in the late 1960's which recruited over a period of several years, followed by a period of recruitment failure and high mortality. Future stock–recruitment studies should account for the effects of multi-year recruitment and year-class overlap.