Geographic signatures of North American West Coast estuaries

West Coast estuaries are geologically young and composed of a variety of ge omorphological types. These estuaries range from large fjords to shallow la goons; from large to low freshwater flows. Natural hazards include El Ninos , strong Pacific storms, and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable shellfish, waterfowl and marine birds, marine mammals, and a variety of al gae and plants. Although populations of many of these living resources have declined (salmonids), others have increased (marine mammals). West Coast e stuaries are also centers of commerce and increasingly large shipping traff ic. The West Coast human population is rising faster than most other areas of the U.S. and Canada, and is distributed heavily in southern California, the San Francisco Bay area, around Puget Sound, and the Fraser River estuar y. While water pollution is a problem in many of the urbanized estuaries, m ost estuaries do not suffer from poor water quality. Primary estuarine prob lems include habitat alterations, degradation, and loss; diverted freshwate r flows; marine sediment contamination; and exotic species introductions. T he growing West Coast economy and population are in part related to the qua lity of life, which is dependent on the use and enjoyment of abundant coast al natural resources.