Evaluation of closed areas for fish stock conservation.
A quantitative approach to estimating the effects of potential closed areas on fish spawning biomass and yields is presented. The focus for evaluation is the biomass of the mature component of the population. Egg production is almost directly proportional to mature biomass, so the mature biomass is taken as an indicator of the reproductive potential of the population. The application of the model is demonstrated with an example from the sole fishery of the Bristol Channel, UK. The conservation benefits for other commercial and non commercial species of the closure of the Trevose fishing grounds are considered. Conclusions are drawn about the general conservation benefits of closed areas for typical European fisheries and the conduct of investigations needed to justify closures.