Emeryville Crescent State Marine Reserve is a marine reserve of California, USA, preserving marshland on the east shore of San Francisco Bay. It is managed as part of Eastshore State Park by the East Bay Regional Park District. The 103.5-acre (41.9 ha) marsh stretches from the eastern approach of the San Francisco – Oakland Bay Bridge in Oakland to the foot of Powell Street in Emeryville. The reserve encompasses the entire Emeryville Crescent Marsh and is named as such for its crescent shape.