An estuary. is a partly 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.
The features of an estuary are determined by a region's geology, and influenced by physical, chemical, and climatic conditions.For example, movements in the Earths crust elevate or lower the coastline, changing the amount of seawater that enters an estuary from the ocean.he amounts of seawater and fresh water flowing into an estuary are never constant. The quantity of seawater in an estuary changes with the changing tides, and the quantity of fresh water flowing into an estuary increases and decreases with rainfall and snowmelt.
Estuaries are partially enclosed bodies of water along coastlines where fresh water and salt water meet and mix. They act as a transition zone between oceans and continents. An estuary has a free connection with the ocean.Fresh water input from land sources (usually rivers) dilutes the estuary's salt content.stuaries are important for the health of the oceans. Estuaries can filter sediment and pollutants from the water before it flows into the oceans. Excess nutrients are removed in bordering salt marshes, resulting in cleaner water for people and marine organisms.