Over half of our original salt marshes in the United States have been destroyed, many of them between 1950 and the mid-1970s. Most of that destruction was due to filling of marshes to create more land area for homes, industry and agriculture. Other losses were caused by ditching for mosquito control and diking to create impoundments. Fortunately, people are beginning to realize the importance of these habitats. Federal and state laws and regulations now reflect an appreciation by the general public for the function and value of marshes.
Salt marshes perform many functions valuable to human beings.
As previously mentioned, they are a major producer of detritus and provide nursery grounds for numerous commercially and recreationally important species. In addition, salt marshes serve as filters to remove sediments and toxins from the water. Marsh plants break down many pollutants into less harmful forms. Uptake by sediments and burial in the marsh minimize the toxic effects of pollutants. There is a limit to this capacity to serve as a waste treatment center.