Factors influencing the occurrence and distribution of Corbicula fluminea (Müller, 1774) in the River Lima estuary

Abstract

This study evaluated the status of the Asian clam Corbicula fluminea (Müller, 1774) in the River Lima estuary (Portugal), which it first invaded in 2002. During the summers of 2004 and 2005, spatial and temporal variations in the abundance, biomass and population structure of C. fluminea were investigated in this estuary. This species was present in a limited intertidal area of the estuary and was rarely found in the subtidal zone. Its abundance and biomass were considerably lower than those found in other estuarine systems. Based on these studies it appears that salinity fluctuations and possibly other factors such as nutrients and environmental contaminants are keeping this invasive species from reaching its full potential. Given the lower abundance and biomass recorded and the restrict distribution of the species in this estuary, the eradication of this nonindigenous invasive species is still possible. The findings of this study may be useful for the management of this species not only in the River Lima estuary but also in other locations it may invade.