Chesapeake Bay, North America's second largest estuary, once had a flourishing oyster population that has been almost wiped out by overfishing.
The term estuary can be traced to the Latin word aestuarium, derived from aestus, which means "tide" or "boiling (of the sea).
The time it takes an estuary to go through a complete cycle is called its flushing time.
Where an enormous volume of river water enters the sea (as, for example, from the Amazon into the South Atlantic), its estuary could be thought of as extending well beyond the coast.
An estuary retains many nutrients derived from both land and sea, and it protects water quality.
An estuary is a semi-enclosed coastal body of water where freshwater from one or more rivers or streams mixes with saltwater from the sea.
An estuary is typically the tidal mouth of a river and is made up of brackish water.
Historically, the oysters filtered the estuary's entire water volume of excess nutrients every three or four days.