San Francisco Bay Estuary (USA)

Abstract

The San Francisco Bay Estuary (SFBE) is the second largest estuary in the United States, encompassing approximately 4,145 km 2 (1600 mi2) and draining about 40% (155,400 km 2; 60,000 mi 2) of the State of California through the Sacramento and San Joaquin Rivers, which pass through the San Francisco Bay-Delta to the Pacific Ocean. The SFBE has perhaps suffered the most extensive degradation of any estuary in the United States. Many years of diking, draining, filling, pollution, and introduction of alien species have taken a great toll on the ecosystem. Although 80% of the tidal salt marshes have been lost, many of the remaining marshes are now protected, and there are large-scale restoration efforts under way to return salt evaporation ponds, agricultural areas, and some urban areas back to tidal wetlands. The SFBE was designated as a Wetland of International Importance under the Ramsar Convention on Wetlands in 2013.