Clam farming generates CO2: A study case in the Marinetta lagoon (Italy)

Respiration and calcium carbonate (CaCO(3)) production by the farmed short-neck clam Ruditapes philippinarum were calculated to assess their importance as carbon dioxide (CO(2)) sink/source in a lagoon of the Po Delta River (Italy). Biomass and calcimass were established by monthly harvests during a 1-year period (2009). The ratio of CO(2) released to CaCO(3) precipitated was calculated as a function of the near-bottom temperature. From our estimates, R. philippinarum sequestered [Formula: see text] for shell formation, but the CO(2) fluxes due to respiration and calcification resulted 22.7 and 5.56 [Formula: see text] , respectively. Clam farming seems therefore to be a significant additional source of CO(2) to seawater.