San Francisco Estuary tidal marsh habitat has been dramatically altered in the past one hundred and sixty years. Approximately 85% of the original tidal marsh habitat in the region has been lost due to creation of salt ponds, conversion to agricultural and industrial/urban use, and water diversion and management. The reduction in area, fragmentation of remaining habitat, degradation in habitat quality, and spread of invasive species have all contributed to reductions in the population size and viability of tidal marsh obligate species.
Nur, N., and J. Kelly. 2011. San Francisco Estuary watershed indicators: avian indicators. Report on selected indicators for a Watershed Assessment Framework, California Department of Water Resources, Sacramento CA.