South San Francisco Bay National Wildlife Refuge - Greco and Bair Island Units
Map SatelliteIn addition to Greco Island this unit includes portions of Bair Island and the mainland area north of Dumbarton Bridge.
Over half the area is tidal mudflat, 1,231 hectares (3,041 acres). The other habitats are salt ponds, 325 hectares (804 acres), salt marsh, 480 hectares (1,186 acres), and open water, 320 hectares (791 acres).
See here for the general description and other comments.
The rare plant Cordylanthus maritimus ssp. palustris occurs here.
Three endangered species breed here, the salt-marsh harvest mouse, Reithrodontomys raviventris, the California clapper rail, Rallus longirostris obsoletus and the California least tern, Sterna albifrons browni. It is one of the northernmost breeding colonies of the least tern.
In the salt ponds, here and elsewhere in the Refuge, a bacterium, Halobacterium halobium, occurs which utilizes a purple pigment, bacteriorhodopsin, for photosynthesis, the second known photosynthetic substance. This and other pigments in the bacteria give the ponds their red to purple coloration.
December 1975
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman