INTRODUCTION

Globalization, in the context of biological invasions, is the increased movement of species around the world. In this chapter, non-indigenous species (NIS) are defined as taxa moved from one geographic location of the world to another from which they were historically absent. The largest geographic barriers to species dispersal, the world's oceans, have been circumvented by the development of a global economy. Increased demand for and transport of goods has resulted in the transfer – both intentional and unintentional – of NIS on unprecedented scales. For example, colonization rates of European crustaceans in North America are estimated to be 50 000 times background levels associated with natural dispersal (Hebert and Cristescu 2002). A number of dispersal vectors are responsible for transport of aquatic NIS, though transoceanic shipping has played a particularly important role as the global economy has expanded.

Establishment of NIS represents one of the most significant threats to the world's indigenous biota (Mooney and Drake 1989; Mack et al. 2000), in addition to adverse ecological and economic effects that they impart on lakes throughout the world (e.g., Hall and Mills 2000). For example, establishment of Nile perch (Lates niloticus) in Lake Victoria and peacock bass (Cichla ocellaris) in Gatun Lake resulted in extirpation or decline of native fish species (Zaret and Paine 1973; Ogutu-Ohwaya 1990; Witte et al. 1992).