The effects of protection measures on fish assemblage in the Plemmirio marine reserve (Central Mediterranean Sea, Italy): A first assessment 5 years after its establishment

This 2-year study was aimed to investigate the early effects of protection measures on fish assemblage in the Plemmirio marine reserve and to evaluate its level of enforcement. Sampling was carried out by means of underwater visual census techniques in four sampling sites within the reserve boundaries and eight outside the reserve. Results showed significant inside/outside differences in the multivariate abundance of fish assemblage. These results were confirmed and exemplified by significant univariate differences between locations for total abundance, Species Richness and diversity of the fish assemblage; values of these metrics were higher inside the reserve than outside. Small fish size and species of low and medium fishing value did not display significant inside/outside differences in abundances whereas medium, large size fish and high value species showed abundances significantly higher inside the marine reserve. Protection effects were particularly evident for large specimens of high fishing value, most of which were exclusively found inside the reserve (Diplodus puntazzo, Epinephelus costae, Mycteroperca rubra, Scorpaena scrofa, Spondyliosoma cantharus, Sciaena umbra and Epinephelus marginatus). The present study provides evidence of a reserve effect on fish populations after only five years since its establishment. This is an extraordinary result likely due to the high level of enforcement observed inside the Plemmirio MPA.

► We censused fish assemblages inside and outside a Mediterranean marine reserve.
► Statistical analyses showed significant inside/outside differences.
► Results provided evidence of a reserve effect on fish populations
► Large size fish and high value species were more abundant inside the reserve.
► The observed reserve effect was likely due to the high level of enforcement.