Marine reserves have become an important tool advocated to protect diversity, habitat or to restore depleted fish stocks. However, the links between reserve effect and temporal variability of assemblages remains equivocal. The present study presents the results obtained in a long-term series of annual surveys in the Scandola Marine Reserve (Corsica, North-western Mediterranean). An underwater visual census was performed on Posidonia oceanica seagrass beds. Species richness and density of target fish were positively affected by fishing prohibition in the no-take zone. The whole assemblage density and density of non-target and prey fish, prevailing in the seagrass bed, were not or negatively affected by fishing prohibition. Concomitantly, temporal stability was positively related to fishing prohibition. This stabilisation of the fish assemblage in the no-take zone had not been observed over rocky reefs in previous studies. This outcome may be linked to wandering predators of rocky areas, preying upon seagrass fish assemblages. In addition, the complete fishing ban appeared to be to only effective tool in restoring target fish stocks and maintaining a higher stability of the fish assemblage whereas partial fishing prohibition failed to meet this goal.

Seytre, C., and Francour, P. 2009. The Cap Roux MPA (Saint-Raphaël, French Mediterranean): changes in fish assemblages within four years of protection. – ICES Journal of Marine Science, 66: 180–187. In recent decades, marine reserves have been established to protect ecosystem structure and biological diversity, or as management tools to combat the overexploitation of fish stocks. The Cap Roux Marine Protected Area (MPA) was established by professional fishers in December 2003, in the French Mediterranean between Cannes and Saint-Raphaël. It was implemented to enhance target fish stocks for local fisheries. The objective of this 3-year study was to investigate the initial responses of fish assemblages, using complementary methods: experimental net fishing performed by a professional fisher and underwater visual census. Within 3 years, this study detected early changes in the fish assemblages. The methods also detected an increase in abundance and diversity of fish, but also a decrease of seasonal fluctuations of the assemblage structure, which was characterized by winter values close to summer values in the protected zone but not outside of the MPA. These results helped clarify the dynamic by which fish assemblages respond to fishing prohibition in a newly created protected area.

-In recent decades, marine reserves have been established either to protect ecosystem structure and biological diversity or to serve as management tools to counter the overexploitation of fish stocks. The Cape Roux marine protected area (MPA), in the Mediterranean Sea, was established in December 2003 for the management of artisanal fisheries and enhancement target fish stocks. Monitoring of littoral fish assemblages (0-30 m depth) in this zone began one year after the MPA was set up. The survey was conducted at 6 stations, located inside and outside the MPA, using three methods: underwater visual census (UVC) on transects, UVC using a new fish assemblage survey technique (FAST), and experimental net fishing performed by a fisherman. The FAST indices were derived from visual censuses, performed along a random pathway, scoring species on a presence/absence basis and size on a 2-class basis. Indices were calculated seasonally, by applying "weights" according to species and size. This study presents results obtained between October 2005 and June 2007. In the protected area, the experimental fishing yielded significantly higher abundance and species richness, and the FAST method highlighted a decrease in seasonal fluctuations. These two complementary methods (UVC and experimental fishing) revealed the early changes in fish assemblages in response to protection. The FAST method employed here seems to be relevant for the study of artisanal fishery target fishes, as a low-cost and sensitive UVC method.Key words: Small-scale fishery / Fish diversity / Underwater visual census methods / Marine protected area / Mediterranean Sea Résumé -L'aire marine protégée du cap Roux (Saint-Raphaël, Méditerranée) est-elle un outil efficace pour soutenir la pêche artisanale ? Premières indications obtenues par comptages visuels et pêches expérimen-tales. Au cours des dernières décennies, des réserves marines ont été créées pour protéger la structure des écosystèmes et la diversité biologique ou comme outil de gestion des pêches pour contrer la surexploitation des stocks de poissons. L'aire marine protégée du cap Roux (Méditerranée, Saint-Raphaël) a été créée en décembre 2003, dans un but de gestion de la pêche artisanale afin de reconstituer des stocks exploités. Le suivi des peuplements de poissons de la zone littorale (0-30 m de profondeur) a débuté un an après la mise en place du cantonnement de pêche et sur 6 stations réparties à l'intérieur et à l'extérieur de la zone protégée. Trois méthodes sont utilisées : des comptages visuels en plongée sousmarine soit le long de transects, soit selon une nouvelle méthode dite : « Fish Assemblage Survey Technique (FAST) », ainsi que des pêches expérimentales au filet tramail, effectuées par un pêcheur professionnel. L'indice FAST est calculé de façon saisonnière sur les peuplements de poissons ciblés, en fonction des espèces, selon leur présence/absence, et selon 2 classes de taille. Cette étude présente les résultats obtenus entre octobre 2005 et juin 2007. Dans la zone protégée, la...

ABSTRACT1. Assessing both direct and indirect effects of fishing, i.e. effects extending to two or more trophic levels, is becoming a key issue in restoration ecology. The present study compared the Cap Roux no-take area (NW Mediterranean) with the surrounding non-protected areas.2. Direct effects of fishing were investigated using experimental net fishing and underwater visual census (UVC) specifically to survey species targeted by commercial fishing and angling. Indirect effects of fishing were deduced from predation and density of sea urchins.3. Observations showed higher biomass and abundance (from catch rates) inside the MPA and differences in size composition (from UVC). The effect of protection from fishing was rapid, with differences apparent within 5 years of protection, and was most evident for highly targeted fish.4. Rates of predation on two species of sea urchin (Paracentrotus lividus and Arbacia lixula) were dependent on protection level and season. This pattern was consistent with the presence of large Diplodus spp., known sea urchin predators, observed inside the reserve only in winter. However, the density of the sea urchins did not differ between the MPA and adjacent fished areas.