The invasive bag mussel Arcuatula senhousia is a CO2 generator in near-shore coastal ecosystems.
Secondary production, respiration and CaCO3 production by the invasive Arcuatula (Musculista) senhousia (Bivalvia, Mytilidae) were calculated to assess the role of bag mussel productivity on the inorganic carbon budget of the Sacca di Goro (Italy). A. senhousia sequestered 46.04 g C m-2 yr-1 for shell formation, but CO2 fluxes due to respiration and calcification resulted 50.4 and 11.74 g C m-2 yr-1, respectively. The bag mussel is therefore a CO2 generator. Net CO2 production of the A. senhousia population could then represent up to 5-6% of the CO2 fixed by phytoplanktonic production of that area. The introduction and establishment of calcifying invasive species in new habitats likely increases biological CO2 production due to biocalcification and, consequently, increases CO2 evasion from the water into the atmosphere.