DIODATO Soledad Lorena
Integrated Biomarker Response in Mytilus chilensis exposed to untreated urban discharges along the coast of Ushuaia Bay (Beagle Channel, Argentina)
DIODATO S.; COMOGLIO, L. I.; CAMILIÓN, C.; AMIN, O.; MARCOVECCHIO, J.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
The short-term effects of coastal untreated effluents from Ushuaia Bay, Beagle Channel, on the biochemical and physiological biomarkers of Mytilus chilensis were assessed. An Integrated Biomarker Response (IBR) index was calculated as a helpful tool to represent the general stress of the experimental organisms. Cultured mussels were exposed during 96 hours to three coastal sites impacted by sewage effluents. At the beginning (T0) and every 24 hours, mussels were subsampled from each site and different biochemical and physiological biomarkers were determined. There was no mortality registered in the experiments during the 96 hours. However, biochemical and physiological biomarkers presented significant variations. Lipid peroxidation mean levels in mussels decreased in mantle and increased in digestive gland respect to T0 in almost all cases. Acethylcholinesterase activity was inhibited in all sites, reaching a maximal decrease of 35% respect to T0. Catalase remained stable and glutathione-S-transferase was activated. Oxygen consumption and ammonia excretion rates increased in organisms from two sites and consequently, O:N ratio decreased, denoting a symptom of stress. IBR values showed the existence of different stress levels between exposed and unexposed mussels. These results exhibited an alteration of the general metabolism of mussels exposed for a short period of time to untreated coastal wastewater, suggesting the use of these organisms as early indicators of changes in the environmental quality of coastal waters of Ushuaia Bay.