Integrated assessment of biochemical responses in Mediterranean crab （Carcinus maenas） collected from Monastir Bay, Tunisia

The biochemical response of Mediteranean Crab (Carcinus maenas) collected at five stations of Monastir Bay and from Kuriat station as control was studied using a set of complementary biomarkers.The catalase,glutathione S-transferase,lactate dehydrogenase,acetycholinesterase activities;and metallothionein and malonediladehyde levels in gills were evaluated.Results revealed differences among sites in relation to each specific biomarker.Hence,a suite of biomarkers can be used to discriminate sampling sites according to types of pollution,reflecting differing conditions of anthropogenic impact.Based on Integrated Biomarker Response,the highest values and critical biochemical alteration were observed at Khniss and Ksibat in response to urban and industrial discharges and the lowest IBR value was found at reference site.The current study has shown clearly that a biomarker-based index is usefulness tool in the monitoring Tunisian coast using C.maenas as sentinel specie.Further studies in progress to investigate the seasonal variations of IBR levels and its relationship to pollutants concentrations in the sediment,gills and digestive gland of Carcinus maenas from Monastir Bay.