Abundance and growth of the invasive Asian clam, Corbicula fluminea, in the lower Columbia River, USA

The Asian clam, Corbicula fluminea , is a broadly distributed and abundant invasive species, yet many aspects of its biology are not well understood. Based on previous research by other investigators, we hypothesized that abundance, population growth rate, and individual growth rate of C. fluminea would increase with temperature, chlorophyll- a , and dissolved oxygen. We sampled C. fluminea at two sites in the lower Columbia River (CR), USA. Modal progression analyses indicated a life span of 2–3 years. A generalized linear mixed model (GLMM) predicting the abundance of C. fluminea indicated a significant negative association with chlorophyll- a concentration, whereas a GLMM predicting the population growth rate of C. fluminea indicated a significant positive association with dissolved oxygen. The GLMM predicting the individual growth rate of C. fluminea indicated the individual growth rate was not significantly related to any individual environmental variable. Overall, these results emphasize that the biology of C. fluminea in the CR is similar in many regards to other populations studied in temperate regions globally, but that important spatial differences can occur between sites separated by 60 km within the same river system.