When introduced into regions where they are not native, plants and animals can be a real threat to native species.  Often the new environment may have few or no natural predators and the non-native species can thrive and overtake ecosystems. The non-native species can also prey disproportionately on a native species, spread disease and other pathogens.  

Threats from invasive species are often made worse by the effects of climate change.  Warming temperatures with changes in the amount and timing of precipitation can help increase the abundance of invasive species whose population growth was limited by existing climate conditions. 

In the Columbia River Basin, several species of animals and plants have been identified as a threat to ESA-listed fish.  Invasive plants can crowd out existing native plants and reduce suitable habitat for native fish.  Scientists estimate that juvenile salmon encounter at least eight separate non-native species (all of them predators) on their way to the Pacific Ocean.

The federal caucus agencies are helping reduce invasive species through restoring spawning and rearing habitat to its natural state - eliminating non-native plants - and controlling non-native predators in the hydrosystem.