The South Shore Estuary is an estuary

Estuary

An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

 located along the south shore of Long Island

Long Island

Long Island is an island located in the southeast part of the U.S. state of New York, just east of Manhattan. Stretching northeast into the Atlantic Ocean, Long Island contains four counties, two of which are boroughs of New York City , and two of which are mainly suburban...

, between the mainland and the outer barrier islands, in eastern New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 state. It stretches for over 70 miles (112.7 km) from West Bay in Nassau County

Nassau County, New York

Nassau County is a suburban county on Long Island, east of New York City in the U.S. state of New York, within the New York Metropolitan Area. As of the 2010 census, the population was 1,339,532...

 to the Shinnecock Bay in Suffolk County

Suffolk County, New York

Suffolk County is a county located in the U.S. state of New York on the eastern portion of Long Island. As of the 2010 census, the population was 1,493,350. It was named for the county of Suffolk in England, from which its earliest settlers came...

.

Geography

The South Shore Estuary includes a series of interconnected bays, rivers, streams, wetland

Wetland

A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....

s and small islands located along Long Island's south shore between the mainland and the barrier islands. Reynolds Channel, West Bay, Middle Bay, East Bay, South Oyster Bay

South Oyster Bay

South Oyster Bay is a natural harbor along the western portion of the south shore of Long Island in New York in the United States. The harbor is formed by Jones Beach Island, a barrier island on the southern side of Long Island. It is approximately 3 mi wide between the two islands, and...

, Great South Bay

Great South Bay

Great South Bay is a lagoon situated between Long Island and Fire Island, in the State of New York. It is approximately long. It's protected from the Atlantic Ocean by Fire Island, a barrier island, as well as the eastern end of Jones Beach Island and Captree Island.Robert Moses Causeway adjoins...

, Patchogue Bay

Patchogue Bay

Patchogue Bay is a bay on the south-central shores of Long Island in the U.S. state of New York.Part of the Great South Bay, Patchogue Bay is a cove between the points of land known as Blue Point and Howells Point, and across which ferries run south to Fire Island.The Patchogue Bay bay bottom up to...

, Moriches Bay

Moriches Bay

Moriches Bay a lagoon system on the south shore of Long Island. The name Moriches comes from Meritces, a Native American who owned land on Moriches Neck.Two Townships both Brookhaven and the Southampton share Its shoreline in Suffolk New York....

 and Shinnecock Bay are part of this natural system, and familiar places to many.

Ecology

Estuaries are transition zones between the world's freshwater and marine ecosystem

Marine ecosystem

Marine ecosystems are among the largest of Earth's aquatic ecosystems. They include oceans, salt marsh and intertidal ecology, estuaries and lagoons, mangroves and coral reefs, the deep sea and the sea floor. They can be contrasted with freshwater ecosystems, which have a lower salt content. Marine...

s where fresh water mixes with salt water.

Long Island's South Shore estuary is a dynamic ecosystem

Ecosystem

An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

, formed during the past 5,000 years by the interaction of a rising sea level with the glacially-deposited material that makes up Long Island. ‎In this estuarine environment, tidal marshes, mud and sand flats, underwater plant beds and broad shallows support microscopic plants and animals which, in turn, support the finfish, shellfish

Shellfish

Shellfish is a culinary and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environments, some kinds are found only in freshwater...

, waterfowl and other wildlife that typify the South Shore estuary.

The entire natural system, including the New York barrier islands and the 173 square miles (448.1 km²) of shallow bays behind them,
is still changing and evolving in response to wave action, tides, coastal storms, and the continuing rise of sea level.