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(37-08) The use of bioindicators for monitoring the Antarctic environment around the Italian Base at Terra Nova Bay. Regoli, Francesco*,1, Nigro, Marco2, 1 University of Ancona, Ancona, Italy2 University of Pisa, Pisa, Italy ABSTRACT- The use of bioindicators is of particular importance in the Antarctic environment for the possibility to early detect the impact of anthropogenic activities which are progressively increasing in these remote areas. Among the various organisms currently used within the Italian Antarctic Program, the bivalve molluscs Adamussium colbecki has been largely characterized for both the content of various pollutants and for specific biological responses useful as biomarkers of stressful environmental conditions. At the subcellular level, lysosomal alterations have been associated with the first detectable onset of toxicity induced in A. colbecki by different pollutants and such effects appear to be mediated by enhanced formation of reactive oxygen species. The balance between prooxidant factors and oxidative damages has been demonstrated to be of particular interest in Antarctic organisms where antioxidant defenses have a probable adaptive role to extreme environmental conditions. Characterization of antioxidant system and alterations induced by pollutants have been analyzed both in terms of individual antioxidants and of total oxyradical scavenging capacity measured toward hydroxyl radical, peroxyl radical and peroxynitrite. Considering the importance of biological responses which may be used for a rapid detection of both anthropogenic and environmental disturbance in Antarctica and the sensitivity of antioxidant responses for predicting short term effects induced by stressful conditions, the sensitivity of A. colbecki to oxidative stress has been further characterized to assess seasonal fluctuations of these parameters and the possible influence of both biological and environmental factors including reproductive cycle, food availability and exposure to UV radiation. Key words: bioindicator, biomarker, Antarctic, pollution |
