Invasive Species
Species of Concern in the Pacific Northwest
Marine Algae
Marine Animals
Freshwater Plants
Freshwater Animals
Riprarian Plants
National Invasive Species Information
Invasive species are generally defined as species that are non-native to an ecosystem and cause harm to the economy, environment, or human health. The United Nations has stated invasive species are second only to direct habitat destruction as the greatest threat to decreasing global biodiversity.
Laws excluding and controlling terrestrial weed species have been around for over 100 years, but only recently have aquatic species begun to receive the same attention. In 1998, Executive Order 13112 on Invasive Species 
directed federal agencies to have broad involvement in invasive species.
Over 20 EPA program areas are concerned with invasive species in some manner. The Region 10 invasive species program focuses primarily on aquatic invasive species, both freshwater and marine.
Washington, Oregon and Idaho have established statewide invasive species councils, and formation of an Alaska council is underway. The three coastal states have ballast water regulations, and all four states are members of a variety of regional partnerships, including the Western Regional Panel and the Columbia River Basin 100th Meridian Initiative, which focuses on preventing the infestation of zebra mussels.
Additional Resources and Information
The links provided may be outside the EPA.gov domain.