Influence of temperature, pH and salinity on the skeletal properties of the Adriatic clam Chamelea gallina

Climate change driven mainly by human activities is causing an increase of temperature and acidification in oceans with negative effects on marine ecosystems. Understanding how marine organisms may respond to environmental changings is crucial when considering future predictions. The Mediterranean clam Chamelea gallina was used in this study as a model organism to investigate the complex interactions of temperature, pH and salinity on its shell biometry and skeletal parameters. Clams of commercial size were exposed for 21 days to eight different treatments resulting from the combination of two temperatures (18 and 22 °C), two pH levels (8 and 7.9) and two salinity levels (35 and 32). During the experiment, the daily mortality rate was assessed, and it resulted to be higher in clams reared in low pH and warm temperature. Despite the short-term exposure, reduced pH and increased temperature and salinity negatively influenced porosity and bulk density by making less dense and more porous shells. Our findings revealed that climate change is likely to affect the health and survival of this species, with significant economic implications for fisheries in the Adriatic Sea, potentially reducing its economic value