ASSESSEMENT OF METALLIC CONTAMINATION OF THE NORTHEN ATLANTIC COAST OF MAURITANIA (COASTAL FRINGE “LEVRIER BAY”), USING PERNA PERNA

This work presents the results of a seasonal survey during 32 months from January 2013 to October 2016 of heavy metals accumulated in the soft parts of the body mussel Perna perna at four sites in the Lévrier bay (Mauritania). The pattern of the metal levels at all the sites studied followed Zn>Cu>Cd>Pb>Hg in soft body tissues. So, this study shows that high values of heavy metals in P. perna were recorded in the cold season, while during the hot season all metal levels were relatively low. The concentrations of Hg recorded in P.perna soft tissues were the lowest of all metals, whatever the site and the season. Mean concentrations of all heavy metals in this study were in most cases lower than those in other North African areas. Seasonal variations could be explained by the presence of upwelling currents that predominate in the cold season, and further by the life cycle of mussels that have their maximum spawning period in autumn. The maximum values of each metal analysed in P. perna soft tissues no exceeding the European Union (EU) limit at all sampling sites except for Zn in COMECA. These results show that P. perna may be used as a bioindicator of heavy metals and the concentrations found in this work could be used as baseline values.