What are Wetlands?

As the name implies, wetlands are lands saturated by or covered with salt and/or fresh water for all or part of the year which produces a unique ecosystem characterized by specific types of hydrology, soils, wildlife, and vegetation. Some of the more familiar names for different kinds of wetlands are swamps, marshes, mudflats, lagoons, and estuaries. Along the coast, they are frequently the transition zone between dry land (upland) and bodies of water. Wetlands can also be habitat inundated by surface or groundwater such as freshwater marsh, ponds or pannes. The water saturated soils of wetlands determines the type of plant and animal communities that can live in these specialized environments.

The wetlands that would be restored by the South Bay Salt Pond Restoration project are coastal wetlands. Coastal wetlands are typically salt or brackish depending on the quantity of freshwater inflow from a stream or rainfall. Some of these wetlands are seasonal wetlands because they are only inundated for part of the year. Plants that are specially adapted to the variation in the salinity and water level (due to tidal action and/or seasonal rains) will be found in coastal wetlands. These plants include pickleweed, cordgrass, gum-plant and salt grass.

Coastal wetlands are home to a variety of animals that either live year round or during some part of their life in the wetland. Numerous fish species, including topsmelt, arrow goby, staghorn sculpin, and starry flounder are residents of wetlands for all or part of the year feeding on the abundant invertebrate species that inhabit the wetland. Several of these fish depend upon the wetland for reproduction and rearing of juvenile fish. Endangered California clapper rails build platform nests in the marsh, whereas the threatened Western snowy plover nest and forage on tidal flats, sandy beaches, and salt ponds south of the San Mateo Bridge. Heron, snowy egret, salt marsh song sparrow nest near pickleweed and other marsh plants. Coastal salt marsh mammals include shrews, the endangered salt marsh harvest mouse, and other rodents live in the marshes. Harbor seals haul out (rest out of the water) in tidal areas in south San Francisco Bay. Coastal salt marshes are also home to insects such as the salt marsh water boatman, wandering skipper, and numerous species of beetles and flies, which graze on leaves and seeds, help pollinate the wetland flowers, and prey upon a variety of small animals.

 References Used:

Baylands Ecosystem Habitat Goals, SF Bay Area Wetlands Ecosystem Goals Project
Feasibility Analysis: South Bay Salt Pond Restoration, Siegel and Bachand
Turning Salt into Environmental Gold, Save the Bay
Wetland Restoration, EPA fact sheet 843-F-01-002e
Wetland Overview, EPA fact sheet 843-F-01-002a
The Ecology of San Francisco Bay Tidal Marshes: A Community Profile, FWS/OBS-83/23