Salt marshes have not always been regarded as valuable resources. 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. Excessive pollutants can overburden the cleansing capabilities of marshes. Marshes also act as buffers for the mainland by slowing and absorbing storm surges, thereby reducing erosion of the coastline. In addition to all this, they provide a scenic vista in our state.

Outright destruction of salt marshes has been greatly minimized due to federal and state laws. Yet, a number of threats to salt marsh habitats still exist. Loss of quality and function of marshes is a serious problem.  Over half of the nation's people now live and work within coastal counties. The cumulative impact of these people within the watershed surrounding salt marshes can be significant. Subtle impacts which affect salt marshes include water flow modifications and pollution. Ditching to control mosquitoes has altered water flow in some marshes. This can cause water, with its vital load of nutrients, to bypass marshes. Birds that require low, wet marshes diminish along with the food supply in ditched marshes. Building canals for flood control is another modification that increases surface water levels on marshes which, in turn, stresses and kills marsh grass. Nonpoint-source pollution resulting from land runoff from diverse locations such as bridges, roads (petroleum products from cars), and air (industrial output) and from farms and lawns (pesticides and fertilizers) is difficult to control. Any one discharge may involve only small amounts of chemicals which are diluted by the receiving streams, but when combined with other chemicals from multiple other discharges, significant concentrations of pollutants may result. The precise effects of these pollutants are still largely unknown, but the potential for problems is clear. Pollution may disrupt the food web in the salt marsh by killing off some species and prompting others to greatly increase in number. Pollution also threatens the economic, aesthetic and recreational value of our marshes.

Permits regulate point-source pollution from a pipe or a single source industrial plant, but nonpoint source pollution is more difficult to monitor and control due to its multiple sources. Likely solutions include major changes in land use practices at the local level and adopting special methods to minimize runoff such as porous pavement, planting of buffer strips and construction of detention basins to contain road and agricultural runoff. Individual citizens can combat nonpoint source pollution by changing their everyday actions. There are a number of federal and state agencies and nonprofit groups that produce informational materials on regulations and conservation pertaining to salt marshes and other wetlands. It is important that citizens take a personal interest in conservation of marshes because of the benefits and values they provide for all of us now and for future generations.