AB 14:87-98 (2011)  -  DOI: https://doi.org/10.3354/ab00377

ABSTRACT: Biological effects of pollutants were studied in Carcinus maenas crabs from 3 polluted sites (Bizerte, Teboulba, Gargour) along the Tunisian littoral zone using biochemical biomarkers. A metal contamination gradient was found, Bizerte standing out as the most metal-polluted area. Gargour animals nonetheless showed higher oxidative stress responses, such as glutathione reductase and 6-phosphogluconate dehydrogenase activities, as well as malondialdehyde (MDA) levels in gills. The gills showed higher lipid peroxidation than did the digestive gland, in keeping with their respiratory role. Animals were also exposed for different periods to 2 model pollutants, cadmium and chlorpyriphos-ethyl. Although cadium induces oxidative stress, mainly in gills, thus increasing lipid peroxidation, principal-component analysis indicated that metal content in sediments and crabs from in-field monitoring does not fully correlate with oxidative stress biomarker responses. Catalase and MDA were the most sensitive biomarkers, and gills the most responsive organ. A lower catalase content in gills was linked to higher MDA levels.

KEY WORDS: Biomonitoring · Biochemical effects · Antioxidant enzymes · Lipid peroxidation · Multivariate analysis · Digestive gland · Gills · Metals · Organophosphates · Sediment pollution