Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2013, 5(12):1307-1314 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 1307 Heavy metals (copper, zinc, iron and cadmium) in sediments and the small clam (Chamelea gallina) of the coastal area north-east of Morocco *C. Belbachir 1 , A. Aouniti 2 , M. Khamri 1 , A. Chafi 3 and B. Hammouti 2 1 Regional Laboratory of Analysis and Research of Oujda (LRARO), Isly, Oujda 2 LCAE-UARC18, Faculté des Sciences, Université Mohammed Premier, Oujda, Morocco 3 Laboratory of Hydrobiology and General Ecology, Faculty of Science, Université Mohammed Premier, Oujda, Morocco _____________________________________________________________________________________________ ABSTRACT The Moulouya estuary located at the north-east of Morocco between 33° and 35° 30’north latitude and between 2° and 4°30’ west longitude receives the water from Moulouya River. This river can drain various pollutants from the backcountry who knows a strong agricultural activity marked by the massive use of fertilizers and pesticides. These pollutants might disturb the balance of the local marine environment. To measure the extent of this impact, the marine sediments in this area were analyzed to determine the content of heavy metals (Cd, Cu, Zn, Fe) in sediment fraction less than 63microns. We also studied the impact of sediment contamination on the small clam (Chamelea gallina) by the use of sequential extraction method of metal species. The results showed that the content of heavy metals (Cd, Cu, Zn, Fe) in sediments at both stations studied did not exceed the recommended guidelines from the U.S. National Oceanic and Atmospheric Administration levels (NOAA) and the Canadians on the Sediment Quality guidelines. The study of correlation between sediment contamination and that of bivalve showed the possible involvement of sediment contamination in the small clam by Cd, Cu and Fe. This correlation does not seem to be verified in the case of zinc. In order to better understand and assess the impact of sediment contamination on heavy metal levels recorded in the small clam, we expected to study the bioavailability of different metals by using different extraction methods sequentially. The results showed that although the contamination of sediment by iron, zinc and copper is sometimes marked, the forms present are mobilized only in certain percentage. So contrary to what can be concluded from the total digestion, sequential extraction suggests that the risk of this contamination on the small clam (Chamelea gallina) may be less noticeable. Keywords: bivalve mollusks, Microbiological Quality, Mediterranean, Morocco. _____________________________________________________________________________________________ INTRODUCTION Coastal fringes are under increasing pressure from industrial and human activities whose effects are quickly felt. These activities are often the source of anthropogenic releases that end up more or less rapidly in aquatic environments, particularly coastal and estuarine, where they may have adverse short and long term effects [1]. In these aquatic environments, a large part of anthropogenic or natural compounds are adsorbed on suspended particles and then accumulate in the sediments. Thus, the sedimentary deposits at the interface between oceanic and continental areas constitute real filters and tanks for heavy metals and are an important source of contamination [2]. However, the overall behavior of these heavy metals in the aquatic environment is strongly influenced by the metal associations with different geochemical phases in sediments [3].