They are subject to change by both natural processes and human action. Wetlands provide numerous products for human use and consumption, protect property and provide recreational opportunities. Beside providing habitat, wetlands provide the food base, in the form of dead plant material, that supports the food chain. Wetlands also help maintain good water quality or improve degraded water by trapping sediments and filtering pollutants. Wetlands can temporarily store flood waters, thereby protecting downstream property owners from flood damage.
Many recreational activities take place in and around wetlands.
Waterfowl hunting, fishing and crabbing are popular sports. Other recreation is largely non-consumptive, involving activities such as hiking, nature observation and photography, swimming and boating.