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.

Estuaries form a transition zone between river environments and ocean environments and are subject to both marine influences, such as tides, waves, and the influx of saline water; and riverine influences, such as flows of fresh water and sediment. The inflow of both seawater and freshwater provide high levels of nutrients in both the water column and sediment, making estuaries among the most productive natural habitats in the world.

Most modern-day estuaries were formed during the Holocene epoch by the flooding of river-eroded or glacially scoured valleys when sea level began to rise about 10,000-12,000 years ago. Estuaries are typically classified by their geomorphological features or by water circulation patterns and can be referred to by many different names, such as bays, harbors, lagoons, inlets, or sounds, although sometimes these water bodies do not necessarily meet the above criteria of an estuary and may be fully saline.

Estuaries are amongst the most heavily populated areas throughout the world, with about 60% of the world’s population living along estuaries and the coast. As a result, estuaries are suffering degradation by many factors, including sedimentation from soil erosion from deforestation, overgrazing, and other poor farming practices; overfishing; drainage and filling of wetlands; eutrophication due to excessive nutrients from sewage and animal wastes; pollutants including heavy metals, polychlorinated biphenyls, radionuclides and hydrocarbons from sewage inputs; and diking or damming for flood control or water diversion.

Read more about EstuaryDefinition, Physiochemical Variation, Implications For Marine Life, Human Impact, Notable Examples

Other articles related to "estuary":

Broad Water
... Broadwater, is a salt water lagoon near Tywyn, Wales formed from the silted up estuary of the River Dysynni ... In the eighteenth and nineteenth centuries, the estuary was used by the shipbuilding industry, as small sailing ships were launched to carry peat from the local peat bogs ... abandoned in the nineteenth century when the estuary became too silted up, forming the lagoon ...
Severnside - Use of The Term To Cover Both Sides of The Estuary
... to coordinate planning and environmental policy across both English and Welsh sides of the estuary ... and in other matters relating to the Severn estuary as a whole ...
South Shore Estuary
... The South Shore Estuary is an estuary located along the south shore of Long Island, between the mainland and the outer barrier islands, in eastern New York state ...
Estuary, Saskatchewan - History
... By the time World War I began the growth of the new community of Estuary swelled from a few hardy pioneers to a booming 800 citizens ... From 1914–1954 Estuary had some 163 businesses, including its own power plant, a weekly newspaper, a theater, 6 blacksmith shops, 10 livery barns, 6 rooming houses, 6 hardware stores ... Throughout Estuary's short lived history there have been many mysterious fires, two of which were devastating to the town ...
Limit of Lloegyr
... and is described as roughly a line from the Humber Estuary, continuing southwestwardly and connecting to the Severn Estuary ... The line continues south across the estuary, crossing South West England such that Cornwall and Devon are excluded from Lloegyr ...

Famous quotes containing the word estuary:

    I see in you the estuary that enlarges and spreads itself grandly as it
    pours in the great sea.
    Walt Whitman (1819–1892)

    There is regret. Always, there is regret.
    But it is better that our lives unloose,
    As two tall ships, wind-mastered, wet with light,
    Break from an estuary with their courses set,
    And waving part, and waving drop from sight.
    Philip Larkin (1922–1986)