When did Asian striped shore crabs come to America?

Asian striped shore crabs (Hemigrapsus sanguineus) are believed to have arrived in North America in the late 1980s or early 1990s.

While the exact date of their introduction is unknown, it's believed they were brought over as stowaways on ships or in ballast water.

They were first discovered in San Francisco Bay in 1992, and since then, they've spread along the Pacific Coast of North America.