Before–after control–impact (BACI) assessment of the effects of a deep-water no-take fishery reserve to recover Norway lobster (Nephrops norvegicus) overfished populations and coexisting megafauna

Abstract

AbstractOne of the main drivers of marine ecosystem change is fishing activity, bottom trawling being the most intensive fishing practice affecting benthic ecosystems worldwide. In the western Mediterranean Sea, Norway lobster stocks present signs of overexploitation due to trawling pressure, as their biomass and abundance have decreased abruptly during the last few years. No-take fishery reserves, a type of marine protected area where fishing is prohibited, could be efficient management measures to recover Norway lobster overexploited populations and coexisting demersal megafauna. Adopting a BACI (before–after control–impact) approach, we performed experimental fishing surveys before and after 4 years of the implementation of a deep-sea no-take reserve in the northwestern Mediterranean. After 4 years of closure, the Norway lobster population increased in abundance, biomass, body size, and trophic level in the no-take reserve. Our approach also revealed an increase in Norway lobster biomass beyond its boundaries, suggesting a spillover effect. Other demersal fish species also increased in biomass and abundance in the no-take reserve. Based on the results of this study, we suggest that no-take reserves might be an effective measure for recovering the Norway lobster stock and some species present in the same habitat.