ABSTRACT
Tidal wetlands are an essential ecological resource but have been reduced dramatically during the past century. In California, the area of coastal wetlands has been reduced from over 120,000 ha at the turn of the century to less than 25,000 ha in 1992 [12]. In some specific regions the loss of coastal wetlands has been more dramatic, for example, over 80% of the coastal wetlands in Southern California and 95% of historic wetlands in San Francisco Bay have been lost due to development, changes in the watershed hydrology or accelerated sedimentation. These tidal marshes and lagoons are not isolated ecosystems but can influence regional biological diversity and complex biological chains; for example, migratory bird flyways or salmon runs along rivers tributary to the tidal wetland.
