ABSTRACT
Tijuana River in Southern California was designated as a National Estuarine Research Reserve (NERR) site in 1982. The 1025-ha site, located in San Diego County at the U.S./Mexico border, encompasses a wide array of habitats, including uplands, coastal sage, upland–wetland transition, salt marshes, tidal creeks and channels, and mudßats and sandßats, as well as dunes and beaches. A signiÞcant fraction of the reserve area consists of salt marsh and riparian wetland habitats (Table 7.1). The intertidal salt marsh habitat is particularly well developed. The Tijuana River watershed is extensive, covering 1731 km
and bisecting the estuary into northern and southern regions. More than 75% of the watershed area lies within Mexico (Figure 7.1) (Nordby and Zedler, 1991; Zedler et al., 1992; Zedler, 2001).
