Estimating Survival, Growth, and Morphometric Relationships of Blue Crab (Callinectes sapidus) in North Carolina Using Mark–Recapture and Bayesian Approaches

Several of the North Carolina blue crab’s (Callinectes sapidus) life history parameters such as growth rate, natural mortality, and length–weight relationships would benefit from being updated or localized. To this end, we designed a mark–recapture study of blue crabs using coded wire tags to estimate carapace width (CW)-to-weight relationships, growth, and natural mortality in a North Carolina blue crab population. We used data from captured blue crabs to estimate their CW-to-weight relationships and used recapture data to estimate growth rates via the Fabens method using both frequentist and Bayesian approaches. Additionally, we built a Cormack–Jolly–Seber (CJS) model to estimate apparent survival. Our CW-to-weight estimates fell largely between the CW-to-weight estimates from the Chesapeake Bay and Florida stocks, suggesting possible regional variation. Our frequentist and Bayesian growth rate estimates had higher k values than other estimates based on a limited number of growing recaptures. There was no single CJS model that was strongly supported by data, but we identified important covariates that inform the precision and accuracy of the CJS model for future studies. Our results suggest that coded wire tags can be useful for mark–recapture studies of species without permanent hard parts, but considerable effort may be necessary to produce viable results.