Can data collected from marine protected areas improve estimates of life-history parameters?
One of the argued research-related benefits of marine protected areas (MPAs) to fisheries management is that because there is no fishing inside of an MPA, it may be possible to precisely estimate the rate of natural mortality and better determine growth and maturity rates, parameters that are often prespecified in stock assessments. This study assesses the degree to which having an MPA increases the ability to estimate these parameters in a integrated stock assessment model, Stock Synthesis; how long it would take for these benefits to be reflected in improved estimates of management quantities; and the extent to which these improvements will be reduced or lost if there is movement of adults (i.e., spillover) from the MPA to the fished area. A two-area, age- and length-structured simulation model is used to examine these benefits on estimation performance for Stock Synthesis. Given the data and process assumptions explored here, the extent of improvement in estimation of growth and maturity parameters with data collected from MPAs is small, but estimation of natural mortality is substantially improved compared with directly estimating these parameters using fishery data. The extent of this improvement depends on the degree of spillover and the complexity of the assessment model.