The combination of natural and human disturbances to estuaries can greatly impact these delicate ecosystems.
When a natural disturbance is followed by a human disturbance, or vice versa, a habitat may become so damaged that it never recovers. One disturbance caused by humans that has greatly compromised many estuaries is invasion of nonnative, or invasive species.
Congress created the National Estuarine Research Reserve System (NERRS) to protect more than one million acres of estuarine land and water. These estuarine reserves provide essential habitat for wildlife, offer educational opportunities for students, and serve as living laboratories for scientists.
Examples of natural disturbance to estuaries include wind, tidal currents, and the continual pounding of waves, and ice.
Human disturbances to estuaries include pollution, coastal development, and the introduction of nonnative species.
Invasive species are animals and plants that have found their way into areas outside their normal range. They often cause ecological damage and economic losses, compete with native species can drastically reduce native populations and can even cause extinction.
During the last century, millions of acres of estuarine habitats have been destroyed; many more are in poor health and in danger of being lost. As a response to the value and importance of estuaries, NERRS was created. Its mission is to protect one million acres of estuarine land and water in 17 states and Puerto Rico. NERRS also works to restore estuaries.