Editing Estuary (section)

==Definition==

[[File:New York STS058-081-038.jpg|thumb|[[Geography of New York–New Jersey Harbor Estuary|New York–New Jersey Harbor Estuary]]]]
[[File:Exe estuary from balloon.jpg|thumb|right|[[River Exe]] estuary]]
[[File:Estuary mouth.jpg|thumb|right|Estuary mouth located in [[Darwin, Northern Territory|Darwin]], [[Northern Territory]], Australia]]
[[File:Thekkumbhagam Estuary, Paravur.jpg|right|thumb|A crowded estuary mouth in [[Paravur, Kollam|Paravur]] near the city of [[Kollam]], India]]
[[File:Yachats River estuary mouth.jpg|thumb|right|Estuary mouth of the [[Yachats River]] in [[Yachats, Oregon]]]]The word "estuary" is derived from the Latin word ''aestuarium'' meaning tidal inlet of the sea, which in itself is derived from the term ''aestus'', meaning tide. There have been many definitions proposed to describe an estuary. The most widely accepted definition is: "a semi-enclosed coastal body of water, which has a free connection with the open sea, and within which seawater is measurably diluted with freshwater derived from land drainage".<ref name="james"/> However, this definition excludes a number of coastal water bodies such as coastal lagoons and [[Brackish water|brackish]] seas.

A more comprehensive definition of an estuary is "a semi-enclosed body of water connected to the sea as far as the [[tidal limit]] or the salt intrusion limit and receiving freshwater runoff; however the [[freshwater inflow]] may not be perennial, the connection to the sea may be closed for part of the year and tidal influence may be negligible".<ref name="Wolanski" /> This broad definition also includes [[fjord]]s, [[lagoon]]s, [[river mouth]]s, and [[tidal creek]]s. An estuary is a dynamic [[ecosystem]] having a connection to the open sea through which the [[sea water]] enters with the rhythm of the [[tide]]s. The effects of tides on estuaries can show [[Nonlinear tides|nonlinear]] effects on the movement of water which can have important impacts on the ecosystem and waterflow. The seawater entering the estuary is diluted by the [[fresh water]] flowing from rivers and streams. The pattern of dilution varies between different estuaries and depends on the volume of freshwater, the tidal range, and the extent of evaporation of the water in the estuary.<ref name="McLusky" />