Swamps tend to develop in areas that are not permanently flooded. Trees and shrubs are the most prominent plants in swamps. Coastal wetlands, such as salt marshes and tropical mangrove swamps, are exposed to a mixture of fresh water and salt water. Many kinds of animals inhabit wetlands. Many mammals, including beavers, muskrats, and otters, also live in wetlands.
Wetlands play an important role in nature.
The water stored by wetlands also serves as a source of replenishment for ground water supplies. In addition, people use wetlands for fishing, hunting, and nature study. Many wetlands throughout the world have been destroyed by human activities. Almost half the wetlands in existence at the time the United States was first settled have been destroyed. Since the early 1970's, however, awareness of the ecological and economic value of wetlands has steadily increased.