Oxidative stress responses in bivalves (Scrobicularia plana, Cerastoderma edule) from the Oued Souss estuary (Morocco).

The aim of this work was to study the responses of oxidative-stress biomarkers (catalase: CAT, thiobarbituric acid reactive substances: TBARS) in bivalves (Scrobicularia plana and Cerastoderma edule) from the Oued Souss estuary (Morocco). This estuary, subjected to large amounts of sewage discharges and industrial effluents, do not receive since November 2002 any waste outlets due to their connection to a wastewater purification plant. High CAT and TBARS values were recorded in both species collected before the implantation of wastewater treatment. These results confirm that these bivalves were submitted to various contaminants generating oxidative stress and membrane lipid peroxidation. The diminution of these two biomarkers following the setting up of the purification plant indicates probably a reduction in contaminants in the Oued Souss estuary. We recommend the use of CAT and TBARS as oxidative-stress biomarkers in S. plana and C. edule.