Upper Left Photo Credit: Jessica Weinberg, NPS
Upper Right and Bottom Photo Credits: Mason Cummings, NPS

Crabs are benthic invertebrates (creatures without a backbone that live on the ocean floor) and compose a significant portion of the San Francisco Bay Area national parks’ estuarine species. The state protected Dungeness crab (Cancer magister) is an important commercial species harvested from Alaska to California. The European green crab (Carcinus maenus) is one of the most successful and economically damaging invasive predators in coastal marine systems, having established populations on five continents. The native red rock crab (Cancer productus) acts as a steward to the estuary by preying on invasive species such as the green crab.