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(80-33) Environmental stress effects in clam, Chamelea gallina, from Adriatic Sea, Italy. Da Ros, Luisa*,1, Pampanin, Daniela1, Nasci, Cristina1, 1 Istituto di Biologia del Mare CNR - Venezia Riva Sette Martiri 1364/A, Venice, Italy ABSTRACT- A number of marine bivalve molluscs are well known as sentinel organisms to be used in monitoring marine coastal environment. In this study the venus clam, Chamelea gallina, has been applied as bioindicator of exposure to/effects of stress conditions in the coastal Adriatic Sea. Due to their characteristics, the infaunal filter feeding organisms are known to be able to provide information about sediment surface layers. Moreover, these clams represent an important economic resource in Italy, where major fisheries are locate along the central and northern Adriatic coastlines, and natural populations have been monitored since the early '90s. This study was focused on the evaluation of the responsiveness to the environmental conditions of a number of cellular and phisiological biomarkers applied in this species. As known, biomarkers could be applied at different levels of biological organization, from cells to population/community, and data obtained at cellular/organism level are the most suitable to point out early signs of stress conditions. Lysosomal latency and digestive cell thickness at cellular level, survival in air and body burden of the protozoan parasites Perkinsus sp. at organism level were used to evaluate physiological status of venus clams collected from four commercial fishing grounds along the western coasts of the Adriatic Sea. Moreover, to a better comprehension of the biological variables, chemical analyses of inorganic and organic micropollutants have been performed in the same samples. Results showed a good relationship between stress condition and physiological status of clams indicating the possible use of C. gallina as a sensitive sentinel organism. In addition, applied biomarkers were able to differentiate sampling sites, Chioggia (North Adriatic Sea) resulting more impacted than the three sites located in the Central Adriatic Sea. Further research should aim at studying the influence of endogenous and environmental variables (reproductive period, temperature, salinity, dissolved oxygen, food availability, etc.) on the biological responses of this venus clam. Key words: biomarkers, Chamelea gallina, Adriatic Sea, bioindicators |
