An estuary is an area where a freshwater river or stream meets the saltwater of the ocean. The term can also refer to the transition zone between these two habitats.
In an estuary, the salinity (saltiness) of the water varies depending on the tides and how far inland it is. Estuaries are important because they provide habitat for many different kinds of plants and animals. They are also key breeding and nursery areas for fish, shrimp, and other marine life.
Additionally, estuaries help to filter pollutants and excess nutrients from runoff before it enters the ocean. For all of these reasons, estuaries are sometimes called “the kidneys of the sea.”
There are two main types of estuaries: coastal and inland. Coastal estuaries are found where rivers empty into the ocean along a coastline. Inland estuaries are found away from the coast, where rivers or streams flow into lakes or reservoirs.
Salt marshes, mangrove swamps, and seagrass beds are all types of estuaries. These habitats are home to many different kinds of animals, including fish, crabs, shrimp, birds, and mammals.
Humans also use estuaries for many different purposes, including recreation, fishing, and transportation. In some cases, estuaries have been heavily polluted by human activity. This can cause problems for the plants and animals that live there.
