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 bodies of water along our coasts that are formed when fresh water from rivers flows into and mixes with salt water from the ocean. In estuaries, the fresh river water is blocked from streaming into the open ocean by either surrounding mainland, peninsulas, barrier islands, or fringing salt marshes.ypes of Estuaries. Every estuary is different. Some are deep and some are shallow. Some have big areas and some are quite small. Some have large openings to the sea and others have small openings. Some have rivers that input lots of fresh water while others have rivers with only trickles of fresh water.