Washington’s diverse and productive salt marshes and pocket estuaries, already threatened by shoreline development and pollution, now face a new invader. The European green crab (Carcinus maenas), considered one of the world’s worst invasive species, recently entered inland waters of Washington. If a population establishes, it could threaten native habitats and species.

WSG, the Washington Department of Fish & Wildlife, and partners have teamed up to lead a volunteer-based early detection and monitoring program to improve our understanding of native salt marsh and pocket estuary organisms, and how they could be affected by green crabs.