Detecting a need for improved management in a data-limited crab fishery

A majority of fisheries worldwide lack effective management because of poor quality data and limited resources. Data-limited stock assessments are increasingly used where model-based, data-rich approaches are not possible. However, their widespread use is constrained by several important limitations, especially the inability to estimate biomass or maximum sustainable yield (MSY)-based reference points. Here we applied several data-limited stock assessments and utilized expert opinion to identify early warning signs of depletion in the rapidly growing Southern California (CA) rock crab fishery, a small scale yet economically valuable fishery being managed with relatively limited information. We chose our specific assessment methods with the aid of a decision support tool (FishPath) designed to help identify context-appropriate options for assessing and managing fisheries. Results of five assessments indicated that serial depletion, regional overfishing, and effort creep may be occurring in the rock crab fishery. Expert opinion regarding changes in fishery operations and fishing effort provided vital insights for interpreting assessment results. We illustrate a general path for enhancing understanding of fishery impacts in a data-limited fishery, and sound rationale for proactive management to address warning signs of overfishing in the southern CA rock crab fishery.