Invasive pest spreads beyond the last frontier: Corbicula clam in the Chubut River, Patagonia

Abstract

Clams belonging to the genus Corbicula are considered one of the most harmful freshwater invaders with strong economic and ecological impacts. In South America, they were first detected in 1979 in the Río de La Plata estuary and since then they have rapidly spread throughout the north of Argentina. To the south, the Corbicula clam began appearing in the Colorado (~ 38°S) and Negro River (~ 40°S) basins around 1997–1999, and in the Limay and Neuquén Rivers (~ 38°S) around 2005. Almost twenty years later, this invasive clam reached the Chubut River (Chubut Province, Argentina). Here, we report for the first time the presence of Corbicula in the Chubut River (43.29° S), which represents the southernmost record of this invasive bivalve in the world. The most likely introduction pathway for the Corbicula clam in the Chubut River is ballast water associated with an estuarine port. Special attention is now required to detect the range of the invasion along the Chubut River basin and adjacent river basins such as Chico River to evaluate the ecological effects and the potential economic impacts on the industry.