An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.
In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material, and rises from the bed of a body of water close to the surface or above it, which poses a danger to navigation. Shoals are also known as sandbanks, sandbars, or gravelbars. Two or more shoals that are either separated by shared troughs or interconnected by past or present sedimentary and hydrographic processes are referred to as a shoal complex.
Barrier islands are a coastal landform, a type of dune system and sand island, where an area of sand has been formed by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend for hundreds of kilometers, with islands periodically separated by tidal inlets. The largest barrier island in the world is Padre Island of Texas, United States, at 113 miles (182 km) long. Sometimes an important inlet may close permanently, transforming an island into a peninsula, thus creating a barrier peninsula, often including a beach, barrier beach. Though many are long and narrow, the length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends, and basement controls. The amount of vegetation on the barrier has a large impact on the height and evolution of the island.
The Greenough River is a river in the Mid West region of Western Australia.
The Peel-Harvey Estuarine System is a natural estuarine system that lies roughly parallel to the coast of Western Australia and south of the town of Mandurah.
The Barker Inlet is a tidal inlet of the Gulf St Vincent in Adelaide, South Australia, named after Captain Collet Barker who first sighted it in 1831. It contains one of the southernmost mangrove forests in the world, a dolphin sanctuary, seagrass meadows and is an important fish and shellfish breeding ground. The inlet separates Torrens Island and Garden Island from the mainland to the east, and is characterised by a network of tidal creeks, artificially deepened channels, and wide mudflats. The extensive belt of mangroves are bordered by samphire saltmarsh flats and low-lying sand dunes.
Leschenault Estuary is an estuarine lagoon that lies to the north of Bunbury, Western Australia. It had in the past met the Indian Ocean at the Leschenault Inlet, but that has been altered by harbour works for Bunbury, and the creation of The Cut north of the historical inlet location.
The Fitzgerald River is a river in the Great Southern region of Western Australia.
Pallinup River is a river located in the Great Southern region of Western Australia. It was previously known as Salt River.
Wilson Inlet is a shallow, seasonally open estuary located on the coast of the Great Southern region of Western Australia.
Broke Inlet, originally named Broke's Inlet, is an inlet in the South West region of Western Australia located 19 kilometres (12 mi) west of Walpole.
Irwin Inlet is an inlet in the located on the Great Southern region of Western Australia.
Hardy Inlet is an inlet that is located in the South West region of Western Australia.
The Phillips River is an ephemeral river in the Goldfields-Esperance region of Western Australia.
The Steere River is a river in the Goldfields-Esperance region of Western Australia.
Wellstead Estuary is an estuarine inlet in the Great Southern region of Western Australia.
The Hamersley River is an ephemeral river in the Great Southern region of Western Australia.
The Adyar River, which originates near the Chembarambakkam Lake in the Kanchipuram district, is one of the three rivers that winds through Chennai, Tamil Nadu, India, and joins the Bay of Bengal at the Adyar estuary. The 42.5-kilometre (26.4 mi) long river contributes to the estuarine ecosystem of Chennai. Despite the high pollution levels, boating and fishing take place in this river. The river collects surplus water from about 200 tanks and lakes, small streams and the rainwater drains in the city, with a combined catchment area of 860 square kilometres (331 sq mi). Most of the waste from the city is drained into this river and the Cooum.
Taylor Inlet is an inlet located in the Great Southern region of Western Australia. The inlet is located on the coast near Nanarup Beach approximately 23 kilometres (14 mi) east of Albany and is contained within the Taylor Inlet nature reserve.
St Georges Basin is an open intermediate estuary, or inland sea, located in the South Coast region of New South Wales, adjacent to the Jervis Bay Territory.
