Increasing CO2 atmospheric concentration produced by human activities is responsible for both global warming and progressive acidification of oceans. Ocean acidification may affect calcareous structures of organisms, and modify their physiological performance, in particular survival, growth, feeding, and physiological pH. Adults of the mussel Mytilus galloprovincialis were used to investigate the cumulative effects of pH, temperature, and salinity, as predicted in possible climate change scenarios, on physiological parameters, such as clearance and respiration rates. An experimental flow-through system was setup to test simultaneously effects of different temperatures (22 and 28 °C) and pH (8.1, 7.7, and 7.4). Three experiments were performed at 28, 34, 40 psu salinity, and physiological responses of mussels were measured after 7 days exposure. At 28 psu, the highest temperature (28 °C) affected negatively mussel clearance rate, at each pH value tested. Respiration rate increased with decreasing pH, reaching a peak at 7.4 pH and 28 °C. At 34 psu, mussels exposed at 7.7 pH and 22 °C showed a marked increase in clearance rate, respiration rate remaining at control values. An opposite situation was observed at 28 °C. Increased respiration rates were also observed at 7.4 pH and 28 °C. Lastly, at 40 psu, the highest clearance rate was recorded at 8.1 pH and 22 °C, whereas the highest respiration rate was observed at 7.4 pH and 28 °C. Overall, results obtained demonstrated that among salinities, 28 and 40 psu seem to discriminate better differing experimental conditions tested, the former in terms of clearance rate, the latter of respiration rate. Acknowledgements: This work was funded by the Italian Ministry for Environment, Land and Sea (IMELS) in the frame of the CIRCLE-MED Project “The integrated impacts of marine acidification, temperature and precipitation changes on bivalve coastal biodiversity and fisheries: how to adapt (ACIDBIV)”.
Chinellato, A., Munari, M., Matozzo, V., Bressan, M., & Marin, M. G., 2010. First attempts in evaluating acidification effects on physiological responses in Mytilus galloprovincialis. Comparative Biochemistry and Physiology – Part A: Molecular & Integrative Physiology 157(1):S19. Abstract (subscription required).
