The Seal Beach National Wildlife Refuge is a wildlife refuge encompassing located in the California coastal community of Seal Beach. Although it is located in Orange County it is included as part of the San Diego National Wildlife Refuge Complex. It was established in 1972.
The refuge is a collaboration between the United States Fish and Wildlife Service and the Department of the Navy. It serves as a critical habitat and winter stopover for many birds along the Pacific Flyway. Among the birds found at the refuge are great blue herons and the three endangered bird species: California clapper rail, California least tern, and Belding's Savannah sparrow.
The refuge is located within Naval Weapons Station Seal Beach. Public access in the refuge is limited or restricted to once-a month tour (last Saturday of each month) as it is located within an active military base.
Habitat
Subtidal habitat
The subtidal zone is the shallow, near-shore area below the intertidal zone, the land between the high and low tide marks. Subtidal is permanently inundated, except for rare lowest low tide events. There are four tidal basins created for the restoration of wetland: Forrestal Pond, Case Road Pond, 7th Street Pond, and Perimeter Pond, which are currently supporting the subtidal habitat in the Refuge. Tidal water from Anaheim Bay supports the ponds.
Dominating plants in these subtidal habitat is eelgrass, and mudflat portions in the habitat is supporting many invertebrate species.
Intertidal channels and tidal mudflat habitats
The complex system of tidal channels delivers moisture and nourishment (oxygen and nutrients) throughout the habitat and providing food or pathway to food for fish and other organisms.
The soil of intertidal flats is a combination of clay, silt, sand, shells, and organic matter, with algae as dominant plants.
Mudflats contain organisms which are a major food source for worms and invertebrates. Fishes, sharks and rays would often come to the mudflats with the tides and feed on transient or permanent residing fish. Shorebirds also depend on preying invertebrates on the mudflats.
Coastal salt marsh habitat
Coastal salt marsh habitat, situated above mudflats, contains salt tolerant vegetation. It is the predominant habitat in the refuge with 565-acre land occupied. It is a nesting, feeding and cover area for bird and fish including the endangered light-footed clapper rails and Belding's Savannah sparrow.
A study on light-footed clapper rail was conducted since 1979. One of the study area is in the salt marsh in Anaheim Bay, the coastal salt marsh located in the Seal Beach National Wildlife Refuge. The environment of salt marsh was described: "The surrounding land lands are flat or gently sloping and provide little drainage into the bay. Consequently there are very little fresh water input other than winter rains… Most of the vegetation is characteristic of the low and middle littoral zones and is completely inundated by a 1.8 m tide (Mean Lower Low Water)." A list of major plants in the marsh was also provided: cordgrass (dominant plants at lower elevation), pickleweed and saltwort (dominant in middle elevation), seablite, saltgrass, sea lavender, arrowgrass, Jaumea carnosa, and Frankenia grandiflora. The dominating plants in the upper zone are glasswort and pickleweed. In the highest elevation (which sometimes is referred to as wetland/upland transition), there are no remaining native species.
Oil extraction beneath the bay led to the marsh subsiding. From 1957 to 1970, elevation dropped 12.5 cm and by 1984, dropped by 25 cm.
