| Research on nonindigenous species (NIS) continues to shift from being reactive to focussing more on prevention, species screening, and early detection. This dissertation examines ways to better anticipate the establishment and spread of NIS.; The interaction with NIS of globalization of commerce, building of canals and dams, pollution of aquatic ecosystems, and climate change has had devastating impacts on some freshwater ecosystems. Increased measures should therefore be taken to reduce the spread of aquatic NIS.; A review of studies comparing characteristics of failed with successful NIS, and invasive with noninvasive NIS, revealed that patterns are emerging among characteristics and association with invasion. For example, introductions were more likely to succeed with larger numbers of organisms and introductions; larger birds tended to become established more than smaller birds; and invasive plants were more likely to reproduce vegetatively than noninvasive plants.; Based on these promising results, statistical models were developed using life history characteristics of historically failed, successful, and invasive fishes in the Great Lakes. Successful fishes grew faster, had broader temperature and salinity tolerances, and more of a history of invasiveness than failed fishes. Other models developed predicted fishes likely to spread quickly and be perceived as a nuisance. These models were then used to identify fishes from the Ponto-Caspian Basin of Eurasia and potential aquaculture species posing the highest risk to the Great Lakes.; Potential interaction among species in the Great Lakes—a widely distributed NIS (zebra mussel, Dreissena polymorpha), a native fish (yellow perch, Perca flavescens), and a NIS with an expanding distribution (ruffe, Gymnocephalus cernuus) were examined in the laboratory. Ruffe consumed more amphipods among zebra mussels than did yellow perch and may mitigate the benefits to perch of increased macroinvertebrates among zebra mussel colonies.; States have enacted diverse legislation, often convoluted, to protect against nonindigenous fishes. A review of this legislation is presented. States with higher native fish biodiversity generally had weaker legal prohibitions on releases from bait buckets, aquariums, and aquaculture, and from the general importation and release of nonindigenous fishes. States with higher annual household income were more likely to be well-protected. |
