Growth and extremely high production of the non-indigenous invasive species Corbicula fluminea (Müller, 1774): Possible implications for ecosystem functioning

The Asian clam Corbicula fluminea (Mu¨ ller, 1774) is a major component of the River Minho estuary, almost completely dominating the benthic biomass. As part of a major study into the ecology of C. fluminea, benthic samples were collected monthly from January 2005 to August 2006. These data were then used to estimate the abundance, biomass, growth, and growth and elimination production of this nonindigenous invasive species. Corbicula fluminea growth was continuous throughout its life span. The annual 2005 growth production was estimated to be 463.778 g AFDWm 2 year 1, and the mean annual biomass was 160.651 g AFDWm 2, resulting in a P=B ratio of 2.89 year 1 and a turnover time of 126.4 days. In the light of these results, C. fluminea is a fundamental element in the River Minho estuary, possibly sequestering a large portion of the carbon available for benthic production and altering the ecosystem functioning. This species should be considered when modelling the nutrient cycles and energy flow in aquatic ecosystems.