Estuaries and their surrounding wetlands are bodies of water usually found where rivers meet the sea. Estuaries are home to unique plant and animal communities that have adapted to brackish water—a mixture of fresh water draining from the land and salty seawater.
However, there are also several types of entirely freshwater ecosystems that have many similar characteristics to the traditional brackish estuaries. For example, along the Great Lakes, river water with very different chemical and physical characteristics mixes with lake water in coastal wetlands that are affected by tides and storms just like estuaries along the oceanic coasts. These freshwater estuaries also provide many of the ecosystem services and functions that brackish estuaries do, such as serving as natural filters for runoff and providing nursery grounds for many species of birds, fish, and other animals.
Estuaries are among the most productive ecosystems in the world. Many animals rely on estuaries for food, places to breed, and migration stopovers.
Estuaries are delicate ecosystems. Congress created the National Estuarine Research Reserve System to protect more than one million acres of estuarine land and water. These estuarine reserves provide essential habitat for wildlife, offer educational opportunities for students, and serve as living laboratories for scientists.
Video Transcript
Estuaries: Where the River Meets the Sea.Estuaries. Where freshwater rivers meet the salty open sea. There is a lot to love in an estuary. A popular destination for fishing, boating, birding and hiking, estuaries are a beautiful place to be. Miles of beaches, flowing grasses, marshes, creeks, and streams. This salty freshwater mix is where life begins and is the nursing grounds for 75% of the fish we catch. Estuaries are lined with marshes and sea grasses that filter water flowing to the ocean and act as a buffer protecting us from coastal storms. NOAA works closely with coastal states to manage the National Estuarine Research Reserve System of 28 protected areas along the nation’s coasts. These valuable reserves are living laboratories for scientists and exciting, hands-on classrooms for students and teachers. At the reserves, scientists study sea level rise, water pollution, erosion, and impacts of human development. These studies provide strong scientific knowledge to help us create healthy, productive estuaries. The Chesapeake Bay, the ACE Basin in South Carolina, and San Francisco Bay in California, are just a few of the 28 reserves that can be found near you . So visit an estuary and experience firsthand the beauty and wildlife where the river meets the sea.
FAQs
An estuary is a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean. Estuaries, and their surrounding lands, are places of transition from land to sea.
Is estuary a sea or river? ›
Estuaries and their surrounding wetlands are bodies of water usually found where rivers meet the sea. Estuaries are home to unique plant and animal communities that have adapted to brackish water—a mixture of fresh water draining from the land and salty seawater.
What is an estuary for kids? ›
An estuary is an area at the end of a river that is in between land and the ocean. In estuaries, fresh water from a river mixes with salt water from the ocean, creating water that we call brackish. To unlock this lesson you must be a Study.com Member.
What is the difference between a river and an estuary? ›
Rivers are bands of freshwater carried downhill by the force of gravity. They are fed by smaller tributaries and can, themselves, merge with other tributaries to form even larger rivers. Estuaries are stretches where rivers approach the ocean.
What is an estuary and why is it important? ›
Estuaries are often economic centers of coastal communities and oceanic food webs, providing habitat for more than 75 percent of the U.S. commercial fish catch at some point during their life cycles. Estuaries also support transportation and trade in the form of shipping and recreation.
What is the largest estuary in the United States? ›
The Chesapeake Bay is the largest estuary in the United States and is one of the most productive bodies of water in the world. The Chesapeake watershed spans 165,759 square kilometers, covering parts of six states — Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia, and the District of Columbia.
Is Nile river a estuary? ›
Both the Rosetta and Damietta branches discharge freshwater directly and indirectly into the Mediterranean Sea to form the Nile estuary (also known as the Nile delta coastal area).
Is Bay an estuary? ›
Estuaries are areas of transition between the land and the sea. They are often called bays, harbors, inlets or sounds.
What is an example of an estuary? ›
Other examples of coastal plain estuaries include the Hudson River in New York, Narragansett Bay in Rhode Island, the Thames River in England, the Ems River in Germany, the Seine River in France, the Si-Kiang River in Hong Kong, and the Murray River in Australia.
What is the largest estuary in the world? ›
In relation to the surface area, the largest estuary in the world is the Gulf of St. Lawrence, but in relation to shoreline length, the largest estuary is the Chesapeake Bay.
To be fair, a search for the largest estuary in North America must include a waterway on the east coast of Canada called the St. Lawrence Estuary, which many experts call the largest estuary in the world. Its actual surface area is subject to debate because its open waters adjoin the much larger Gulf of St. Lawrence.
What are the 4 types of estuaries? ›
Types. The four basic types of estuaries are (1) the salt wedge estuary, (2) the partially mixed (or slightly stratified) estuary, (3) the vertically hom*ogeneous (or vertically mixed) estuary, and (4) the fjord (or highly stratified estuary).
Is a delta an estuary? ›
The most basic difference between a delta and an estuary is that a delta is a landform while an estuary is a water body. The estuary is a water body where rivers and sea meet each other. At the same time, a delta is a landform created where rivers and sea meet each other.
How many estuaries are in the United States? ›
Since many estuaries open up into the ocean, the tides will usually have an impact on their waters, altering height and salinity. More than 100 of these water bodies are found along the coast of the United States.
Is an estuary a swamp? ›
estuary is an area where a river flows into the sea, swamp is land that is always wet and often partly covered with water and mangrove is a tropical tree that has root from its branches and that grows in swamps or shallow salt water.
Can an estuary be a river? ›
An estuary is an area where a freshwater river or stream meets the ocean. In estuaries, the salty ocean mixes with a freshwater river, resulting in brackish water. Brackish water is somewhat salty, but not as salty as the ocean. An estuary may also be called a bay, lagoon, sound, or slough.
Is an estuary a river mouth? ›
An estuary is an area where a freshwater body meets the ocean. Salty ocean water mixes with freshwater resulting in brackish water. Estuaries are dynamic ecosystems with ebb (outgoing) and flow (incoming) tides. Tides create the largest flow of saltwater, while river mouths have the largest flow of freshwater.
Do estuaries have sea life? ›
Importance of estuaries
They are often called the “nurseries of the sea” because numerous animal species rely on estuaries for nesting and breeding. Most of the fish and shellfish eaten in the United States, including salmon, herring, and oysters, complete at least part of their life cycles in estuaries.
