The Clean Water Act defines wetlands as "[…] those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs and similar areas." [Taken from the EPA regulations listed at 40 CFR 230.3(t)]

There are many types of wetlands.

There are Marshes

There are Swamps.

Marshes are defined as wetlands that are frequently or continually inundated with water. They support emergent soft-stemmed vegetation that like saturated soil types. There are many different kinds of marshes-:

1. Tidal Marshes. - Tidal marshes can be found along protected coastlines in middle and high latitudes worldwide. They are most prevalent in the United States on the eastern coast from Maine to Florida and continuing on to Louisiana and Texas along the Gulf of Mexico. Some are freshwater marshes, others are brackish (somewhat salty), and still others are saline (salty), but they are all influenced by the motion of ocean tides. Tidal marshes are normally categorized into two distinct zones, the lower or intertidal marsh and the upper or high marsh.
2. Non-Tidal Marshes. - These are the most common in North America. They are most often fresh water and frequently occur along streams and in poorly drained depressions, in the shallow boundaries of rivers, ponds and lakes. Some marshes may dry out completely while others have water varying from a few inches to a few feet deep all year round. The soil in this type of marsh is high in organic matter and support many species of lily, cattails, bulrushes waterfowl and other small mammals.

Freshwater marshes are one of the most productive ecosystems on earth due to their high nutrient levels. They sustain a wide and varied assortment of wildlife that is way out of proportion to there size. Non-tidal marshes serve to offset flood damage and filter excess nutrients from surface runoff.

Swamps are said to be wetlands that are dominated by woody trees or plants. Some are dominated by Cedars and cypress and some by bushes and shrubs such as buttonbush and smooth alder. Swamps provide habitats for many birds, small mammals and crustacean such as shrimp crayfish and clams. Swamps also provide havens for many rare or endangered species as well such as the American Crocodile.

In the 1600s, over 220 million acres of wetlands are thought to have existed in the lower 48 states. Since then, extensive losses have occurred, and over half of our original wetlands have been drained and converted to other uses. The years from the mid-1950s to the mid- 1970s were a time of major wetland loss, but since then the rate of loss has decreased.

The lower 48 states contained an estimated 105.5 million acres of wetlands in 1997. This is an area about the size of California. In the 1980s, an estimated 170-200 million acres of wetland existed in Alaska-- covering slightly more than half of the state-- while Hawaii had 52,000 acres. Next to Alaska, Florida (11 million), Louisiana (8.8 million), Minnesota (8.7 million), and Texas (7.6 million) have the largest wetland acreage.

1. Drainage
2. Dredging and stream channelization
3. Deposition of fill material
4. Diking and damming
5. Tilling for crop production                                     
6. Levees
7. Logging
8. Mining
9. Construction
10. Runoff
11. Air and water pollutants
12. Changing nutrient levels
13. Releasing toxic chemicals
14. Introducing nonnative species
15. Grazing by domestic animals

1. Erosion
2. Subsidence
3. Sea level rise
4. Droughts
5. Hurricanes and other storms

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