EcoPedia

Estuaries

Michael Forlini | Jan 22, 2009

0 reviews |

Estuaries can be thought of as places where rivers meet the sea. They are fascinating and highly productive ecosystems distinct from all other places on Earth. However, most estuaries are at risk due to human activities. Often referred to as bays, lagoons, harbors, inlets or sounds, the defining feature of an estuary is the mixing of fresh and salt water. Some familiar examples of estuaries include San Francisco Harbor, Puget Sound, Chesapeake Bay and the NY/NJ harbor.

Estuarine environments create more organic matter each year than comparably sized areas of forest, grassland or agricultural land. The tidal, sheltered waters of estuaries also support unique communities of plants and animals, specially adapted for life at the margin of the sea. There is a variety of habitats found in and around estuaries, including shallow open waters, freshwater and salt marshes, swamps, sandy beaches, mud and sand flats, rocky shores, oyster reefs, mangrove forests, river deltas, tidal pools and sea grasses.

The productivity and variety of these habitats foster a wonderful abundance and diversity of wildlife. Shore birds, fish, crabs and lobsters, marine mammals, clams and other shellfish, marine worms, sea birds and reptiles are just some of the animals that make their homes in and around estuaries. These animals are linked to one another, and to an assortment of specialized plants and microscopic organisms, through complex food webs and other interactions. Thousands of species of birds, mammals, fish, and other wildlife depend on estuarine habitats as places to live, feed, and reproduce. And many marine organisms, including most commercially important species of fish, depend on estuaries at some point during their development. Estuaries provide ideal areas for migratory birds to rest and refuel during their long journeys. Many species of fish and wildlife rely on the sheltered waters of estuaries as protected places to spawn. Estuaries are often called the "nurseries of the sea."

See All EcoPedia Articles | Login to Comment