Estuary
- A semi-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 are thus 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. As a result they may contain many biological niches within a small area and so are associated with high biological diversity. [source: Wikipedia: http://en.wikipedia.org/wiki/Estuary]
