Introduced species are species that are not historically native to an ecosystem.

    Ecosystems are functional units whose physical, chemical, and biological components interact and function through the transfer of energy. Because they are dynamic and evolving, new species occasionally may naturally immigrate into and become a part of an ecosystem. Rapid technological advancement and increased human mobility has artificially accelerated the process of species introductions. These introductions occur on purpose and accidentally. Many introduced species cannot thrive in the new environment and do not survive long enough to breed and become established. Occasionally introduced species do well. They reproduce, become established, and can dramatically alter complex ecosystem processes that have evolved over thousands of years. These invasive introduced species can harm marine ecosystems and are the ones that most concern scientists.

   Some of the numerous species that have been introduced into the Inland Waters of Washington and British Columbia include:

ALGAE
	Japanese Seaweed (Sargassum muticum)
FLOWERING PLANTS
	Japanese Eelgrass (Zostera japonica) Spartina Cordgrasses (Spartina alterniflora, S. anglica, and S. patens)
INVERTEBRATES
Porifera, Demospongiae	Boring Sponge (Cliona spp.)
Cnidaria, Anthozoa	Orange-striped Green Anemone (Diadumene lineata formerly known as Haliplanella luciae)
Mollusca, Gastropoda	Atlantic Oyster Drill (Urosalpinx cinerea) Japanese Oyster Drill (Ceratostoma inornatum)
Mollusca, Bivalvia	Eastern Oyster (Crassostrea virginica) Pacific Oyster (Crassostrea gigas) Japanese littleneck or Manila clam (Venerupis philippinarum) Mediterranean mussel (Mytilus galloprovincialis) Soft shell clam (Mya arenaria) Varnish Clam or purple mahogany clam (Nuttallia obscurata) Naval Shipworm (Teredo navalis)
Although they have not been documented in the Inland Waters, these invasive invertebrate species are of concern:
Arthropoda, Crustacea	Chinese mitten crab (Eriocheir sinensis) Green crab (Carcinus maenas)
VERTEBRATES
Chordata, vertebrata	Atlantic Salmon (Salmo salar)

  Scientists have identified the introduction of non-indigenous animals and plants as a major threat to biodiversity in marine ecosystems. The science of controlling or preventing the introduction of alien species is in its infancy. The SeaDoc Society is funding research that is advancing scientific knowledge about the invasion and impacts of some introduced marine species and is sharing research findings to ensure that pertinent scientific data are available to managers, policymakers, and concerned citizens. Abstracts from introduced species research projects funded by the SeaDoc Society are listed below:

Wootton, J. Timothy Spread and impact of the introduced Japanese seaweed, Sargassum muticum, in native kelp forests of the San Juan Archipelago

Strathmann, Richard R. Do marine reserves safeguard native species from impacts of non-native invasive species?

Marine Invasive Species Team of the Pacific Northwest

National Invasive Species Council Web site

Puget Sound Water Quality Action Team's Web site on aquatic nuisance species

Washington Sea Grant's Non-indigenous Species Page

WDFW Web site on aquatic nuisance species