1. Introduction Effectiveness of Marine Protected Areas as a tool for restoring marine resources: Estuarine West African experience Oumar Sadio a, Jean-Marc Ecoutin b, Luis Tito de Morais c, Monique Simier d, Jean Raffray c and Raymond Laë e a : IRD, CRODT/LEMAR (UBO/CNRS/IRD/Ifremer), BP 1386, Dakar, Sénégal. b : IRD, LEMAR (UBO/CNRS/IRD/Ifremer), Avenue Jean Monnet, BP 171, 34203 Sète Cedex, France. c : IRD, LEMAR (UBO/CNRS/IRD/Ifremer), BP 70, 29280 Plouzané, France. d : IRD, EME (UM2/IRD/Ifremer), Avenue Jean Monnet, BP 171, 34203 Sète Cedex, France. e : IRD, LEMAR (UBO/CNRS/IRD/Ifremer), Bd Sidi Abderrahman Ain Diab, Casablanca, Maroc Faced with the growing threat of alteration and overfishing of marine resources by human and climatic pressures steadily increasing, the establishment of marine protected areas (MPAs) appears to be a response to the conservation or restoration of biodiversity (Ecoutin et al. 2014). Bamboung MPA was created in 2004 by the Senegalese government (Breuil 2011). This MPA is protected from all fishing activities. The objective of this study is to evaluate the effectiveness of Bamboung MPA as a tool for restoring marine resources by comparing it to Sangako bolon which is an area opened to all forms of fishing activities. Materials and methods The two areas are in the Sine Saloum estuary in Senegal (West African tropical zone) (Fig. 1). The temporal sampling plan took into account the existence of three major hydro-climatic seasons across the Sine Saloum (Diouf 1996; Simier et al. 2004). Fish sampling was performed using a purse seine net with the same methodology in the two areas. Three surveys were conducted annually from 2008 to 2011. Fish were identified by species and then counted and weighed by species to the nearest gram for each seine haul. A subsample of up to 30 individuals per species per haul was measured to the nearest mm. Observed species were classified into bio-ecological categories end by trophic group. The bioecological indicators and the physico-chemical parameters measured were compared between the two areas. Results The physico-chemical parameters did not differ between the two areas. Between 2008 to 2011, 54 species belonging to 28 families were identified in the AMP against 47 species belonging to 23 families in the fished area. Median abundance and richness observed are higher in the unprotected area while the estimated biomass, the trophic level, the average size and maximum size are in favor of AMP (Tab. 1). These results corroborate those of many authors (Halpern 2003, Lester et al. 2009). The size spectra is different between the two areas (Fig. 2). According to the analysis of ecological guild, species fulfilling all their life cycle in the estuary are less present in the MPA (Fig. 3). The trophic composition analysis of the settlement of MPA highlights a major role given to the predatory and predatory especially high-level component (Fig. 4). Tableau 1: Comparison of bio-ecological indicators by catch per unit. BBG, Bamboung MPA and SNK, Sangako bolon, from 2008 to 2011. Bioecological indicators Area Number of observations Mean Coefficient variation (%) MedianMinimumMaximum Abundance BBG6067638135019127 SNK7231020910003929 Biomass (g) BBG602473027871760387410 SNK72105891336059070415 Richness BBG607556117 SNK729359019 Trophic Level BBG593.1183.234 SNK712.7162.824 Mean size (mm) BBG591784315482362 SNK711452214596252 Maximum size (mm) BBG5942850390821055 SNK7132132285113635 Discussion et conclusion Both areas have similar water body. Then, the differences are due to the protection effect of Bamboung Bolon. Total species richness is higher in the MPA than in the fished area. From 2008 to 2011, the MPA has a positive effect on biomass, trophic level and size, and a negative effect on the abundance and richness. Estuarine affinity species lose their importance in the MPA while marine affinity species strengthen their central role in the MPA. The results clearly reflect the attraction effect of an MPA and therefore we can confirm that AMP is an effective tool for restoring marine biodiversity. Acknowledgments The results presented here are from the multidisciplinary program-related projects: Narou Heuleuk (FFEM / AFD / NGO Oceanium / IRD), AMPhore (ANR Biodiversity), CEPIA (AFD / CSRP / IUCN / IRD). The authors want to thank the fishermen and their team leader Mbaye Mbengue and the crew from research vessel Diassanga and its captain F. Sanseo. Without their help, these results could not have been obtained. Figure 4: Size spectra of piscivorous, 2008 to 2011. BBG = Bamboung MPA (blue line) and SNK = Sangako bolon (red line). Figure 3: Size spectra of strict estuarine species, 2008 to 2011. BBG = Bamboung MPA (blue line) and SNK = Sangako bolon (red line). Figure 1: Location and map of the delta of Sine Saloum (Senegal). Location of the Bamboung AMP and the Sangako bolon with position of their sampling area. Figure 2: Size spectra of the fish assemblage of Bamboung MPA (blue line) and Sangako bolon (red line) from 2008 to 2011.