San Pablo Bay National Wildlife Refuge is a National Wildlife Refuge in

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

established in 1970. It extends along the northern shore of

San Pablo Bay San Pablo Bay is a tidal estuary that forms the northern extension of San Francisco Bay in the East Bay and North Bay regions of the San Francisco Bay Area in northern California. Most of the Bay is shallow; however, there is a deep water c ...

, from the mouth of the

Petaluma River The Petaluma River is a river in the California counties of Sonoma and Marin that becomes a tidal slough for most of its length. The headwaters are in the area southwest of Cotati. The flow is generally southward through Petaluma's old town, ...

, to

Tolay Creek Tolay Creek is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed March 10, 2011 southward-flowing stream in southern Sonoma County, California, United States, which flows through Tolay La ...

Sonoma Creek , name_etymology = , image = Beaver Dam Sonoma Creek, Sonoma Thanksgiving 2009.jpg , image_caption = Beaver dam on Sonoma Creek at Maxwell Farms Regional Park in Sonoma, California, 2009 , image_size = 300 , ma ...

, and ending at

Mare Island Mare Island ( Spanish: ''Isla de la Yegua'') is a peninsula in the United States in the city of Vallejo, California, about northeast of San Francisco. The Napa River forms its eastern side as it enters the Carquinez Strait juncture with the ...

Ecology

The refuge encompasses the largest remaining continuous patch of pickleweed-dominated

tidal marsh A tidal marsh (also known as a type of "tidal wetland") is a marsh found along rivers, coasts and estuaries which floods and drains by the tidal movement of the adjacent estuary, sea or ocean. Tidal marshes are commonly zoned into lower marshes ( ...

in the northern San Francisco Bay. Historically, the wetlands surrounding San Pablo Bay were one of the largest tidal marsh complexes on the Pacific Coast of North America. However, the area has been significantly impacted by human activities such as hydraulic mining, salt production, diking, draining, filling, agriculture, and development. All told, about 85% of San Pablo Bay's tidal marshes have been altered. In fact, damaged portions these marsh areas and along the Petaluma River were considered as sites for artificial marsh creation using dredged materials. This effort was part of a US Army Corps of Engineers, Waterways Experiment Station study conducted by a Consultant from CZRC, Wilmington, NC, Dr. John C. Nemeth in the mid-1970s. The Refuge includes a variety of habitats including open water,

mud flat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal fl ...

, tidal marsh,

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

, and seasonal and managed

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

s. The refuge hosts millions of migratory shorebirds and waterfowl, including the largest wintering population of

Canvasback The canvasback (''Aythya valisineria'') is a species of diving duck, the largest found in North America. Taxonomy Scottish-American naturalist Alexander Wilson described the canvasback in 1814. The genus name is derived from Greek ''aithuia'', ...

s on the west coast. The Refuge also provides year-round habitat for sensitive species including the

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

Ridgway's Rail and

salt marsh harvest mouse The salt marsh harvest mouse (''Reithrodontomys raviventris''), also known as the red-bellied harvest mouse, is an endangered rodent endemic to the San Francisco Bay Area salt marshes in California. The two distinct subspecies are both endangere ...

. Public access to the refuge is provided by the Tolay Creek Tubbs Island Trail.

References

Bibliography

U.S. Fish and Wildlife Service: San Pablo Bay National Wildlife RefugeFriends of the San Pablo Bay National Wildlife Refuge

External links

Highway to the Flyway:The Road to Restoration on San Pablo Bay
from Bay Nature magazine, July–September 2007 issue. Provides a brief history of the marshes of San Pablo Bay. {{authority control National Wildlife Refuges in California San Pablo Bay Parks in the San Francisco Bay Area Estuaries of California Wetlands of the San Francisco Bay Area Protected areas of Napa County, California Protected areas of Solano County, California Protected areas of Sonoma County, California Natural history of Napa County, California Natural history of Solano County, California Natural history of Sonoma County, California IUCN Category IV