Preliminary analysis of spatio-temporal fish assemblage variations of Gandoule Marine Protected Area in Senegal

Abstract

The study investigated the spatial and temporal fish assemblage structure in relation to the abiotic factors in the Gandoule Marine Protected Area (GMPA) in Sine-Saloum Estuary. Samples were collected in four seasons (cold season, transition from cold to warm season, warm season and transition from warm to cold) from seven stations with a beach seine in 2017. Environmental parameters such as temperature, salinity and pH were measured during each season at all stations. Overall, the fish assemblage of GMPA consisted of 35 species belonging to 20 families. The most abundant species were Ethmalosa fimbriata, Gerres nigri, Mugil curema, Neochelon falcipinnis and Mugil bananensis, accounting for 63.58% of the total abundance. In terms of ecological and trophic guilds, the fish assemblage was dominated by species with estuarine affinity and herbivorous species. The results of similarity analysis showed a significant difference between sampling seasons and stations. The similarity percentage analysis revealed that similarity among seasons was between 7.65% and 13.27%, whilst similarity between stations ranged from 9.51% to 15.24%. The canonical correspondence analysis indicated that temperature and salinity were the main drivers influencing the distribution of species such as Chelon dumerili, Mugil bananensis, Mugil curema, Coptodon guineensis, Neochelon falcipinnis and Ethmalosa fimbriata.