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The Crustacean Invasion: European green crabs are native to western Europe and northwest Africa, but have invaded ecosystems in every continent but Antarctica. Because they disperse over long distances during their larval stage and aren't exactly picky eaters (these crabs will eat clams, shrimp, and other invertebrates!), European green crabs are quite successful at invading new territories. Where they establish new populations, these crabs threaten shellfish fisheries and ecosystem health. For reasons not yet well known, European green crabs have been particularly successful in Seadrift Lagoon, a manmade lagoon near San Francisco that is tidally linked to Bolinas Lagoon. There, they've established the largest West Coast concentration in a closed marine ecosystem! But folks at Greater Farallones National Marine Sanctuary are hard at work removing these invasive crabs. Since 2009, teams have worked to remove tens of thousands of crabs from the lagoon, and their work continues.