The Integration of Invasive Species into Marine Ecosystemss

This section of the book deals largely with what happens once invasive species have become established, whereas the previous two sections dealt primarily with how the arrival and establishment of these species occurs. Invader interactions can take many forms and it is expected that most species would interact with their biotic and abiotic environment in more than one way. Indeed, a truly comprehensive list of the impacts of invaders would be identical to a list of the role of any species in an ecosystem. Although the kinds of interactions may not be unique between exotics and natives, what is likely to differ is the degree to which effects occur, due to such factors as differing evolutionary histories and disruptions to habitats or species that may be concomitant with invasions. It is these ecological interactions that lie at the heart of the concern about invasive species. In a recent cover-page article in NEWSWEEK (January 15, 2007) it was estimated that globally bioinvasion toll (terrestrial and aquatic combined, including pests and pathogens) on the economy and the environment is close to US$1.4 trillion a year, and will only increase!