What are Non-native Aquatic Species?
A “native” species lives within its natural or historic range and zone of natural dispersal. Non-native aquatic species are initially introduced by human activities into freshwater, brackish or marine ecosystems where they could not go naturally (by swimming or floating on winds, tides or currents). Why are Non-native Aquatic Species a Problem? Non-native species also called exotic, nonindigenous or alien species can alter or degrade native habitat. They may prey on native species or outperform them in the quest for food, space and other resources, sometimes even causing the extinction of native species. Once established, exotics can rarely be eradicated. Pathways for Non-native Aquatic Species Humans have dramatically increased the scale and scope of invasions by non-native species. Each of these three species is an example of how human activities can result in the spread of non-native species. Because of their meaty legs, bullfrogs were originally introduced from the eastern US to be
