The occurrence and spatial distribution of pesticides in sea water of the Agadir bay (South of Morocco)

The Agadir Bay is one of the most important economic centers of Morocco, but it is the site of several pollutions due to the various anthropic activities (agricultural, industrial, tourism), the bay opens onto the plain of Souss which is a highly developed agricultural region. The intensification of modern agriculture in Souss Massa region, especially for vegetable crops destined mainly for export, has been accompanied by the extensive use of pesticide in order to increase yields. In order to assess the contamination by pesticides in sea water of Agadir bay, the water samples are collected, seasonally, between winter 2009 and autumn 2010. The concentrations of pesticides in water, were analysed by gas chromatography using electron capture detector (GC/ECD). Among 32 investigated pesticides, only seven molecules (vinchlozolin, endosulfans, lindane, dichlofluanide, bupirimate, aldrin and tetradifon) have been detected. The total concentration of pesticides residues detected in the different sites shows that the waters of the two estuaries and Anza beach are more polluted compared to the beaches of Aghroud and Cap Ghir The level of contamination of water by total pesticides presented a seasonal variation for all sites, the highest concentrations are obtained in spring and the lowest in the autumn, also the results shows an increases contamination from north to south of Agadir bay. The results obtained in this study show a presence of the pesticides residues during all sampling season, this contamination could be related to the most intense use of this product in agriculture of Souss Massa region.