Wetland Functions and Values
Wetlands provide a variety of important functions and values to society. A function is generally defined as how a wetland works, while a value is an interpretation of the relative worth of a wetland function.
1. Water Quality Improvement - Weltands are natural filters for waters flowing in and through them. Meanders in a stream or tidal channels and/or presence of wetland vegetation slows the flow of water, and suspended sediments settle to the bottom. If the sediments contain toxins, these toxins are deposited in the wetlands and buried by additional sediments. This action effectively removes potentially harmful particles from the system. Some plants and animals may take up pollutants and transform them into harmless forms, thus improving water and sediment quality. These pollutants include heavy metals, pesticides, and excess nutrients. Stormwater runoff from various land uses or municipal drainage may contain elevated amounts of pollutants. To a certain extent, wetlands will remove or transform these pollutants prior to water flowing into other aquatic systems.

2. Erosion Reduction - Erosion occurs naturally from rivers, currents, tidal currents, storms, and wind-generated waves. Erosion forces can increase as a result of seawalls, river diversions, dams and reservoirs, channels, canals, ship and boat traffic, jetties, groings, and improper coastal development. Vegetated wetlands absorb and dissipate waver energy, and their extensive root structure helps stabilize shoreline sediments. In addition, sediment retained by the vegetation often increases substrate elevation, providing additional protection to adjacent uplands.

3. Flood Control - Wetlands are located in depressions in the landscape, often occurring along drainage areas or bay shorelines. Therefore, they function to slow down or dissipate floodwaters during rainfall events or storm surges. Even wetlands that do not normally retain water are critical during these periods, as they function as temporary storage areas until floodwaters recede. In this way, they protect upland areas as well as areas downstream. Their location in the landscape functions as a buffer between powerful floodwaters and other areas.

4. Food Chain Support - Wetlands support very complex and extended food chains. Wetland plants (producers) produce food for other organisms (consumers). Consumers can be eaten by other consumers (primary to secondary consumers), thus increasing the complexity of the food chain. Other organisms (decomposers) function to break down dead material in the wetland and assist in decomposing materials to useful nutrients. The nutrients are then used by plants to produce more plant material for consumers to eat. This cycle is often explained in terms of a food web. Many organisms important to commercial fisheries also utilize the wetland at some time in their life, thus linking wetlands to other aquatic systems.

5. Fish and Wildlife Habitat - Weltands are often described as one of the most productive ecosystems in the world. They often support several species and large populations of fish and wildlife at different times of the year. Wetlands are important to fish, amphibians, reptiles, birds, and mammals. Wetlands that are flooded seasonally are just as important as those that retain water for long periods. Many species have eveolved to utilize wetlands at certain times of the year for reproduction, feeding, and resting. Typically abundant invertebrate populations are present in wetlands when they are flooded. Although humans may perceive some of these insects as a nuisance, many insect species are essential food for wetland-dependent animals.
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