Phytoplankton community in the maritime area of Aglou « South of the Agadir Bay,Morocco» [Le peuplement phytoplanctonique de la zone maritime d'Aglou «Sud de la Baie d'Agadir,Maroc»]

For assessing the specific diversity of phytoplankton,a monthly monitoring of the composition and distribution of phytoplanktonic communities,at the level of three stations (s1,s2 and s3) of a radial of coast 3km,in the coast of aglou,has been carried out during the spring 2013. the systematic study of samples has highlighted an important specific richness within the ecosystem with 83 phytoplanktonic species whose two (scripseillasp and rhizosolenia styliformis) very common,10 communes and 71 accessories. three classes are represented: diatoms (21 families),followed by the dinoflagellates (16 families) and the silicoflagelles (2 families). the evolution of the specific diversity of phytoplankton,estimated by the index of shannon-weaver (h'),is quasi-similar to the level of the three stations with low values in april and the high values in june. the station s2 has registered the lowest and the highest value (h'= 1.25 in april and 2.52 h'= in june). the indices of similarity of sorensen (qs) between the three stations taken two by two are relatively low: 0.33 between s1and s3,0.31 between s1 and s2 and 0.25 between s2 and s3.