| Summary: | ICAWA : International Conference AWA, Dakar, SEN, 13-/12/2016 - 15/12/2016 The analysis of the seasonal variation of copepods in the Senegal-Gambia maritime area, using a comparative approach (cold season (May) and warm season (November)) was carried out using data collected during ecosystem cruises aboard the Norwegian vessel Fridtjof Nansen in November 2011 and May 2012. Zooplankton samples were collected between 0 and 50 m depth using a multinet of 80 ?m mesh, towed obliquely behind the vessel, over the continental shelf. Post processing of the samples (n = 34) were made in laboratory by microscopy and the copepod were identified to the lowest possible taxonomic level and counted, using appropriate identification keys. Paracalanus parvus was dominant with 22 % followed by Oncaea venusta (19 %) and Temora stylifera (12 %) in the cold season. In contrast, in the warm season, these two species (P. parvus O. venusta) still dominant with 26% and 13 %, respectively. A total of 34 species of copepods were identified during the cold season, compared with 27 species during the warm season. In one hand, during the cold season, an area of high concentration of copepods was found off the mouth of the Casamance River. On the other hand, during the warm season, two areas of high concentration were identified off the peninsula of Cap-Vert and Casamance. The copepod group which represents 2/3 of the zooplankton would be an ideal indicator for the identification of signatures of changes in phenology and / or latitudinal displacement of species in relation to climatic variations. All of these aspects reflect the interest of this study in improving knowledge of the responses of marine organisms to climate change in the south part of the west African east border upwelling.
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