Biological invasions in inland waters: an overview

Abstract

The value of inland waters to humankind is obviously infinite and the induced changes in the goods and services they provide have a strong impact on human welfare. Lakes/rivers and wetlands currently contribute 20% to the estimated annual global value of the entire biosphere amounting to US$33 trillion per year (Costanza et al. 1997). These elevated numbers may justify the present general concern about the increasing degradation of freshwater systems, associated with the rapid extinction rate of their biodiversity - in some cases even matching that of tropical forests (Ricciardi and Rasmussen 1999).