Coastal wetlands provide a vital link between land and open sea, exporting nutrients and organic material to ocean waters, and harboring juveniles of numerous aquatic species including many fish.   Water flow in these highly productive communities circulates food, nutrients, and waste products throughout the system.   Wetlands buffer the effects of storms, reducing shoreline erosion, and improve water quality by filtering and assimilating many pollutants from sewage outfalls and agricultural runoff.   In addition, wetlands provide a unique opportunity for nature study.

Wetlands that are less common along the California coast are freshwater marshes, riparian wetlands, bogs, and vernal pools.   Freshwater marshes occur in ponds and slow moving streams.   Like salt-water marshes, they are vegetated mostly with herbaceous plants, predominantly cattails, and species of sedges, and rushes.   Freshwater marshes have mineral soils that are less fertile than those of salt marshes, and exhibit a greater variety of plant species than do salt marshes.   Riparian wetlands, which occur on the banks of steams, rivers, and lakes, commonly feature woody vegetation such as red alder, wax myrtle, and willow.   Bogs, unlike marshes and streams, have detrital soils composed of peat, and are vegetated mostly with mosses.   Vernal pools occur in small depressions underlain by dense, impenetrable clay pan soils that allow water to accumulate in winter and spring.   The pools support small, usually annual plants, which flower as the water in the pools begins to evaporate.

Coastal California is part of the Pacific Flyway, one of the four principal bird migration routes in North America.   During the spring and fall months, coastal wetlands support flocks of waterfowl such as great blur herons, brant, pintails, mallard, and canvasbacks, and shorebirds such as sandpipers, curlews, willets, and godwits, which stop here to rest, feed, and in some cases over winter.

Since the 1850's 90 per cent of California's original coastal wetland acreage has disappeared, and many of the remaining wetlands are in danger of being further degraded or destroyed due to landfill, diking, dredging, pollution, flood control, residential development and other effects of urban sprawl.

Much of the text materials are excerpts and adaptations from the California Coastal Commission's California Coastal Resource Guide , which can be ordered from University of California Press by calling 1-800-822-6657.