Salt Water Wetlands
Saltwater wetlands, or marshes, are ecosystems dominated by shrubs and grasses influenced by saltwater tidal inundations and fluctuations. Daily tidal flooding brings in nutrients to the wetland to feed a number of salt -adapted species of plants and animals. A saltwater wetland acts as a buffer shielding land from severe weather, and detoxifies wastes brought in by the tides on a daily basis. Microorganisms in saltwater marshes neutralize pollutants found in water.
Saltwater wetlands are one of the most biologically productive habitats on earth, rivaling tropical rainforests, and are accorded a high level of protection by the Clean Water Act. Although eighty percent of this type of habitat has been lost to development in the San Francisco Bay Area over the past 200 years, new efforts are being made to restore these marshes.
None of San Francisco’s original salt marshes – once quite extensive -- remain. But due to benign neglect and nature’s own healing power, wetland habitats have developed on several areas of bay fill. One example is at Heron’s Head Park (looks like a Heron’s head when viewed from the air) in the Bayview. Formerly known as Pier 98, this 25-acre parcel of non-permitted fill was slated for removal before the discovery of the developing ecosystem led to the expansion and enhancement of the wetlands and uplands habitats instead. Hundreds of volunteers participated. A field guide to 100 Birds of Heron’s Head documents bird species that can be found in this saltwater wetland. In the summer of 2011, for the first time in San Francisco in many decades, a pair of endangered Clapper Rails raised two young - at Heron’s Head Park.
One of most successful examples of saltwater wetland restoration in San Francisco is Crissy Field in the Presidio. An 18-acre tidal marsh was restored between 1998 and 2000, alongside the rehabilitation of 16 acres of dune habitat, which collectively support 105 different species of shrubs, wildflowers and marsh plants. Crissy Field has a long human history – first as a 130-acre salt marsh which served as a gathering site for the Ohlone, then as a landing site for Spanish, Russian, and English traders, then as a U.S. airfield, and now as a restored wetland. More than 135 bird species can now be found at Crissy Field, along with 25 fish species, and over 100 invertebrate species.
Other saltwater wetlands in San Francisco include a 1.5-acre wetland at Pier 94, the 34-acre Yosemite Slough at Candlestick Point State Park (scheduled to be fully restored by the spring of 2013) and the edges of Mission Creek and Islais Creek channels.
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