Wildly cyclic but sustainable nonetheless: Challenges for a data-poor crab fishery

The Marine Stewardship Council (MSC) provides principles and process to analyze fisheries in order to evaluate if they are “sustainable” according to numerous criteria that apply to management, ecosystems, and user groups involved. Dungeness crab have been scrutinized for several years to determine if the fisheries can be declared sustainable, but several hurdles have slowed the analyses and final decision. The primary impediment has been the long history of cyclic landings based on a conservative “3S’ management scheme: size, sex, and season. Only males larger than first reproductive size are landed during an intense winter season, and landings have cycled with a 10 year periodicity and a 5-7 fold amplitude. State fishery agencies, with no capacity to survey abundance, view the historic cyclic landings as reflecting a variety of forcing factors that affect recruitment and eventual exploitable biomass. MSC criteria are often based in more detailed fishery assessments including surveys, abundance estimates, target reference points, limit reference points and other metrics more typical of intensely surveyed stocks. MSC assessment scientists, state fishery managers, and industry stakeholders have grappled with means to satisfy critical scoring criteria that are not readily measured in the case of “data-poor” Dungeness crab.