Red King Crab
The U.S. federal government through the North Pacific Fishery Management Council (NPFMC) and the State of Alaska jointly manage the Bering Sea and Aleutian Islands crab stocks, whereas the State of Alaska solely manages the Gulf of Alaska crab stocks. Harvest strategies vary among areas and species, but all crab fisheries have minimum size limits, male-only restrictions, and specific fishing seasons (i.e., size, sex, and season, or “3-S” management). Minimum size limits have been enforced to provide at least one opportunity for males to mate with females. Single-sex harvest has been in effect to protect mature females for reproduction and specific fishing seasons are set to avoid harvesting crab during mating and molting (soft-shell) periods. A number of king and Tanner crab fisheries are managed with a guideline harvest level (GHL) determined either from available abundance estimates and appropriate target harvest rates or from historical average catches. The fishery performance within a season is monitored, and if the fishery is expected to exceed the GHL before the declared closure date, then the season is closed by an ADF&G Commissioner’s emergency order. Incidental mortality of crabs in other fisheries (trawl, pot, and dredge) is reduced by enforcing maximum allowable crab bycatch thresholds. Additional management measures include pot limits, permits, onboard observers, registration areas, reporting requirements, vessel tank inspections, legal gear specifications, and provisions for gear placement, removal, and storage.
Six Bering Sea crab stocks are managed by the NPFMC according to fishery management plans with thresholds for overfishing (an excessive annual rate of removal) and overfished (a minimum biomass level). These stocks are Bristol Bay red king crab, Bering Sea Tanner crab, Bering Sea snow crab, St. Matthew Island blue king crab, and Pribilof Islands red and blue king crabs. If the stock declines below the ‘overfished’ biomass level, then the stock is declared overfished, and management actions in the form of reducing fishing mortality or rebuilding plans must be implemented.
In addition to federal management regulations, the ADF&G has developed harvest strategies for king and Tanner crab stocks in selected fisheries of the Bering Sea and Gulf of Alaska. The harvest strategies aim to maintain sufficient spawning biomass for stock productivity by controlling the removal of mature males. Minimum stock size levels (mainly of mature portion) and minimum GHLs (for a few stocks) are estimated for assessing stock viability and for assuring manageability under continued fishing.