Olympia oysters (Ostrea lurida) are native to San Francisco Bay but their populations have been declining since the time of the Gold Rush (mid 1800’s). Due to increased human activities, the oysters had to contend with overharvesting, invasive species, and pollution caused by gold mining.
Scientists from SERC and several other institutions have been working to restore Olympia oyster populations in San Francisco Bay for over a decade. At some sites, however, these efforts have been hampered by intense predation by an invasive snail, the Atlantic oyster drill (Urosalpinx cinerea). These snails eat oysters, mussels, barnacles, and other hard-shelled organisms. The oyster drill is an example of a negative impact of a non-native species on a native species. Another native species, the brown rockweed Fucus distichus, on the other hand, may benefit native oysters by forming a canopy that provides shade and retains humidity, keeping the oysters cool and moist during low tide.