This map shows the distribution of wetlands in the United States in the 1900s. Wetlands are a very important habitat for many plants and animals. They are home to many different types of animals that make up the food chain. They prevent flooding in a unique way. When rivers and streams overflow their banks, wetlands provide storage for water and prevent soil erosion.
Wetlands can help clean water by trapping sediment and pollutants in the plant roots.
Their existence helps reduce the number and scope of flood control projects needed. The quantity and quality of wetlands are limited. Many things can harm them including run off from oil, pesticides, and industrial waste. Chemical drainage from farmlands also harm them. All of these things damage wetlands where birds and animals find food.