An estuary is a partially 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 and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.
A Ramsar site is a wetland site designated to be of international importance under the Ramsar Convention, also known as "The Convention on Wetlands", an international environmental treaty signed on 2 February 1971 in Ramsar, Iran, under the auspices of UNESCO. It came into force on 21 December 1975, when it was ratified by a sufficient number of nations. It provides for national action and international cooperation regarding the conservation of wetlands, and wise sustainable use of their resources. Ramsar identifies wetlands of international importance, especially those providing waterfowl habitat.
A tidal marsh is a marsh found along rivers, coasts and estuaries which floods and drains by the tidal movement of the adjacent estuary, sea or ocean. Tidal marshes experience many overlapping persistent cycles, including diurnal and semi-diurnal tides, day-night temperature fluctuations, spring-neap tides, seasonal vegetation growth and decay, upland runoff, decadal climate variations, and centennial to millennial trends in sea level and climate.
Haverstraw Bay, located in New York, is the widest portion of the Hudson River. The width of Haverstraw Bay is approximately 3.4 miles (5.5 km), the length approximately 5 miles (8.0 km) from river kilometer 58 at Croton Point to river kilometer 66 at Stony Point. The bay is bordered by the village of Haverstraw, in Rockland County, to the west and the village of Croton-on-Hudson, in Westchester County, to the east.
The Elkhorn Slough National Estuarine Research Reserve is a nature reserve that is located at 1700 Elkhorn Road in Watsonville, California. The reserve encompasses the central shore of Monterey Bay and is approximately 100 miles (160 km) south of San Francisco, California. The Elkhorn Slough is established as a part of the National Oceanic and Atmospheric Administration and is being managed as the Elkhorn Slough Ecological Reserve through the California Department of Fish and Wildlife.
Great Bay is a tidal estuary located in Strafford and Rockingham counties in eastern New Hampshire, United States. The bay occupies over 6,000 acres (24 km2), not including its several tidal river tributaries. Its outlet is at Hilton Point in Dover, New Hampshire, where waters from the bay flow into the Piscataqua River, thence proceeding southeast to the Atlantic Ocean near Portsmouth. The northern end of the bay, near its outlet, is referred to as Little Bay.
The Jacques Cousteau National Estuarine Research Reserve, located in southeastern New Jersey, encompasses over 110,000 acres (450 km2) of terrestrial, wetland and aquatic habitats within the Mullica River-Great Bay Ecosystem.
Great Bay is located in southern New Jersey's Atlantic Coastal Plain in Ocean and Atlantic Counties, about ten miles (16 km) north of Atlantic City and is about 5.5 miles northwest of Brigantine, and 5.5 miles southwest of Beach Haven. The Mullica River flows into the bay, and together they form the Mullica River - Great Bay estuary habitat. The bay is connected to the Atlantic Ocean via the Little Egg Inlet. Great Bay is considered one of the least-disturbed marine wetlands habitats in the northeastern United States.
In 1999, the Guana Tolomato Matanzas National Estuarine Research Reserve was designated in St. Johns and Flagler counties, Florida as a part of the National Oceanic and Atmospheric Administration (NOAA) National Estuarine Research Reserve (NERR) system. The GTM Research Reserve represents the east Florida sub-region of the Carolinian bioregion. It is one of 30 NERRs in 23 states and one territory. GTM is one of three NERRs in Florida and is administered on behalf of the state by the Florida Department of Environmental Protection's Florida Coastal Office as part of a network that includes forty-one aquatic preserves, three NERRs, a National Marine Sanctuary, the Coral Reef Conservation Program and the Florida Oceans and Coastal Council. Additional interests are held in the research and management of the GTM and connected preserved or conserved lands including:
Elkhorn Slough is a 7-mile-long (11 km) tidal slough and estuary on Monterey Bay in Monterey County, California. It is California's second largest estuary and the United States' first estuarine sanctuary. The community of Moss Landing and the Moss Landing Power Plant are located at the mouth of the slough on the bay.
Currituck Banks North Carolina National Estuarine Research Reserve is a component site of the North Carolina National Estuarine Research Reserve on the Currituck Banks, north of Corolla, North Carolina. Currituck Banks is one of three original National Estuarine Research Reserve sites dedicated by NOAA in 1985. The reserve encompasses 965 acres of varied habitat and is bordered by the Currituck Sound. The Currituck banks are part of a 70-mile long barrier spit that extends from Virginia Beach to Oregon Inlet.
Brackish marshes develop from salt marshes where a significant freshwater influx dilutes the seawater to brackish levels of salinity. This commonly happens upstream from salt marshes by estuaries of coastal rivers or near the mouths of coastal rivers with heavy freshwater discharges in the conditions of low tidal ranges.
The San Francisco Bay National Estuarine Research Reserve is one of 27 reserves established as part of the United States National Estuarine Research Reserve System. The reserve is used to promote San Francisco Bay wetlands and estuary research, education, and stewardship.
The North Inlet-Winyah Bay National Estuarine Research Reserve, in the U.S. State of South Carolina, features the salt marshes and ocean dominated tidal creeks of the North Inlet Estuary plus the brackish waters and marshes of the adjacent Winyah Bay Estuary. North Inlet is a relatively pristine system in which water and habitat quality are much higher than those in Winyah Bay. As the estuary with the third largest watershed on the east coast, Winyah Bay has been greatly influenced by agriculture, industry and other human activities. More than 90 percent of North Inlet's watershed is in its natural forested state
The Delaware National Estuarine Research Reserve consists of two unique components, one on Blackbird Creek and the other on the St. Jones River. Freshwater wetlands, ponds and forest lands dominate the Blackbird Creek component. The St. Jones component is dominated by salt marsh and open water habitats of the Delaware Bay.
The Great Bay National Estuarine Research Reserve encompasses a diversity of land and water areas around Great Bay, an estuary in southeastern New Hampshire. Protected lands cover 10,235 acres (4,142 ha), including approximately 7,300 acres (3,000 ha) of open water and wetlands that include salt marshes, rocky shores, bluffs, woodlands, open fields, and riverine systems and tidal waters.
The Mission-Aransas National Estuarine Research Reserve is a large contiguous complex of wetland, terrestrial, and marine environments on the Texas Coastal Bend in the United States. Named for the two major rivers that flow into the area, the reserve contains public and private lands and waters. The land is primarily coastal prairie with unique oak motte habitats. The wetlands include riparian habitat, freshwater marshes, and saltwater marshes. Within the water areas, the bays are large, open, and include extensive tidal flats, seagrass meadows, mangroves, and oyster reefs. These unique and diverse estuarine habitats in the western Gulf of Mexico support a host of endangered and threatened species including the endangered whooping crane.
The Weeks Bay National Estuarine Research Reserve is a field laboratory and research facility along Weeks Bay estuary, about 6,000 acres (2,400 ha) in size. It receives freshwater from the Magnolia and Fish Rivers, and drains a 198 square miles (510 km2) watershed into the portion of Mobile Bay via a narrow opening. This sub-estuary of Mobile Bay averages just 4.8 ft deep and is fringed with marsh and swamp. The reserve lands also include upland and bottomland hardwood forests, freshwater marsh, submerged aquatic vegetation and unique bog habitats. Weeks Bay is a critical nursery for shrimp, bay anchovy, blue crab and multitudes of other fish, crustaceans and shellfish that support robust commercial fisheries providing $450 million/year for Alabama.
Designated in 1991, the Chesapeake Bay National Estuarine Research Reserve - Virginia (CBNERR-VA) is one of 29 protected areas that make up the National Estuarine Research Reserve System (NERRS). Established to promote informed management of the nation's estuaries and coastal habitats.
The Lake Superior National Estuarine Research Reserve includes land and water areas along the St. Louis River and Lake Superior in Douglas County, in the northwest corner of Wisconsin, United States. It is one of 29 National Estuarine Research Reserves. The Reserve is operated as a program of the Natural Resources Institute of the University of Wisconsin-Madison Division of Extension. It has an area of 16,697 acres (6,757 ha), and was designated in 2010.
