It is estimated that at least nine non-native species of marine plants and 83 species of marine animals have been introduced into Puget Sound. Some of these were intentionally introduced, such as the Pacific oyster and Manila clam, to substitute for the loss of native shellfish species. Other animals have arrived through ship ballast water and other accidental introductions.
Sources:
Addition resources:
Encyclopedia of Puget Sound list of invasive species; Washington Invasive Species Council; USGS non-indigenous aquatic species; WA Noxious Weeds Control Board; WDFW prohibited aquatic animals species list
Overview
Non-native species are those that do not naturally occur in an ecosystem. A non-native species is considered invasive when it is capable of aggressively establishing itself and causing environmental damage to an ecosystem. Plants, animals, and pathogens all can be invasive.
