Brackish marsh

Brackish marshes develop by 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.[1]

A brackish marsh section of San Elijo Lagoon in San Diego County, California

See also


  1. ^ "Field Guide to Coastal Wetland Plants of the Southeastern United States", by Ralph W. Tiner, p. 15
A Directory of Important Wetlands in Australia

A Directory of Important Wetlands in Australia (DIWA) is a list of wetlands of national importance to Australia. Intended to augment the list of wetlands of international importance under the Ramsar Convention, it was formerly published in report form, but is now essentially an online publication. Wetlands that appear in the Directory are commonly referred to as "DIWA wetlands" or "Directory wetlands".

Babbitt, North Bergen

Babbitt is a neighborhood in North Bergen Township in Hudson County, New Jersey, United States. The area, located west of Tonnelle Avenue within the New Jersey Meadowlands District, is home to light manufacturing, warehouses, transportation facilities, and part of the wetlands preservation area known as the Eastern Brackish Marsh.

Brackish water

Brackish water is water having more salinity than freshwater, but not as much as seawater. It may result from mixing seawater with fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak". Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment (see article on shrimp farms).

Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (‰), which is a specific gravity of between 1.005 and 1.010. Thus, brackish covers a range of salinity regimes and is not considered a precisely defined condition. It is characteristic of many brackish surface waters that their salinity can vary considerably over space or time.

Cedar Island National Wildlife Refuge

Cedar Island National Wildlife Refuge, located in Carteret County, North Carolina, is on the end of a peninsula marking the southern end of Pamlico Sound. The refuge lies five miles (8 km) east of the Atlantic Ocean and about 40 miles (64 km) northeast of Beaufort, North Carolina. Established in 1964, the refuge consists of approximately 11,000 acres (45 km2) of irregularly flooded, brackish marsh and 3,480 acres (14.1 km2) of pocosin and woodland habitat. The dominant marsh plants include black needlerush, saltmarsh cordgrass, saltmeadow hay, and saltgrass. The woodland areas are dominated by loblolly, longleaf and pond pine. Live oak is also abundant on some upland sites. The marsh and surrounding waters provide wintering habitat for thousands of ducks and nesting habitat for colonial waterbirds.

Mammalian species that inhabit this refuge are gray squirrel, marsh rabbit, white-tailed deer, red fox, raccoon, bobcat, gray fox, nutria, beaver, muskrat, river otter, mink and opossum.

Cedar Swamp Wildlife Area

Cedar Swamp Wildlife Area is a state wildlife area located in New Castle County, Delaware, along shore of the Delaware Bay. It is 5,515 acres (2,232 ha) in size and is managed by Delaware Department of Natural Resources and Environmental Control (DNREC), Division of Fish & Wildlife.Much of the area is a transgressive brackish marsh. It is part of the Northeastern coastal forests ecoregion.39°23′30″N 75°33′00″W

Chalan Piao

Chalan Piao is a village on the southwestern area of Saipan. Commonwealth of the Northern Mariana Islands. It is bordered on the north by Chalan Kanoa, on the east by As Perdido village and on the south by San Antonio village. To the west is the Pacific Ocean.

"Chalan Piao" translated from the Chamorro language means bamboo road. Chalan means road and piao means bamboo. The Chamorro language is spoken by the indigenous inhabitants of Saipan and the rest of the Mariana Islands, mainly Rota/Luta, Tinian and Guahan/Guam.

Farlington Marshes

Farlington Marshes is an area of reclaimed land in Langstone harbour. It was reclaimed from the harbour in 1771 and includes a larger part of what was formerly Binner's Island (the remainder of the island is now referred to as North Binness Island). Farlington Marshes is about 120 hectares in size and features both freshwater marsh and brackish marsh. It is a Local Nature Reserve and is a feeding ground for overwintering Brent geese. During World War 2 it was used as a starfish site acting as a decoy for Portsea Island. The control blockhouses remain on the marshes.

Freshwater marsh

A freshwater marsh is a marsh that contains fresh water. Freshwater marshes are usually found near the mouths of rivers and are present in areas with low drainage. It is the counterpart to the salt marsh, an upper coastal intertidal zone of bio-habitat which is regularly flushed with sea water.

Freshwater marshes are non-tidal biomes containing little or no peat (unlike bogs and fens, both a kind of mire and mires consisting heavily of moist, biologically active peat). They are most common in the Gulf Coast region, specifically in Florida. They can be one of two principal types: either fresh water mineralized marshes, which derive their water from groundwater, streams and surface runoff; or poorly mineralized fresh water marshes whose moisture comes mostly from regular direct precipitation. Freshwater marshes support an independent pH-neutral ecosystem which encourages biodiversity. Common species include ducks, geese, swans, songbirds, swallows, coots, and black ducks. Although shallow marshes do not tend to support many fish, deeper ones are home to many species, including such large fish as the northern pike and carp. Some of the most common plants in these areas are cattails, water lilies, arrowheads, and rushes.The Florida Everglades represent the largest contiguous freshwater marsh in the entire world. This immense marsh covers 4,200 square miles (11,000 km2) and is located in the southern tip of Florida. Continued human development, including drainage for development and polluted agriculture runoff, as well as alterations in the water cycle threaten the existence of the Everglades. The remaining parts of the Everglades are grasses, sedges and other emergent hydrophytes.

Fritchie Marsh

Fritchie Marsh is an area encompassing 6,291 acres of intermediate and brackish marsh located approximately three miles to the southeast of Slidell, Louisiana, USA. This wetland was originally documented as a freshwater marsh but has since been converted to a mixed intermediate and brackish marsh, and it threatens to become open salt water. Through the combined efforts of conservation groups and sponsors, the Fritchie Marsh Restoration Project was created and designed to restore the area to its original state. In the early years, this project showed a positive impact but soon suffered a devastating impact during Hurricane Katrina.

Hackensack RiverWalk

Hackensack RiverWalk a is partially constructed greenway along the Newark Bay and Hackensack River on the west side of the Bergen Neck peninsula in Hudson County, New Jersey. The eight-mile walkway, following (where possible) the contour of the water's edge, will run between the southern tip at Bergen Point, where it may connect to the Hudson River Waterfront Walkway, and Eastern Brackish Marsh in the north. Existing parks and promenades have been incorporated and some new sections have been built, but there remain large gaps. There is a RiverWalk in the city of Hackensack, sometimes called the Hackensack RiverWalk, but they are not part of the same project nor are they connected. A parallel walkway on the west banks of the river is known as the Meadow Path.


Jozaria is an extinct genus of stem perissodactyl from the Early to Middle Eocene of the Kuldana Formation of Kohat, Pakistan. It and other anthracobunids were formerly classified with proboscideans.

Only one specimen belonging to the species Jozaria palustris has been discovered so far. Geological evidences from the place of discovery indicate that the animal lived in a brackish marsh environment. It probably fed on soft aquatic vegetation.

Lake Borgne

Lake Borgne (French: Lac Borgne) is a lagoon of the Gulf of Mexico in southeastern Louisiana. Although early maps show it as a lake surrounded by land, coastal erosion has made it an arm of the Gulf of Mexico. Its name comes from the French word borgne, which means "one-eyed."

Mackay Island National Wildlife Refuge

Mackay Island National Wildlife Refuge was established in 1960 to provide habitat for migratory waterfowl, primarily the greater snow goose. It is located almost entirely on Knotts Island in the Currituck Sound between Back Bay in Virginia Beach, Virginia and the open sound in North Carolina. Most of the refuge lies within North Carolina but some of it is in Virginia. The refuge is primarily made up of marsh habitat. This area has long been recognized for supporting significant migratory waterfowl populations and sport fishery resources, and is part of the Charles Kuralt Trail.

The refuge is strategically located along the Atlantic Flyway, making it an important wintering area for ducks, geese, and tundra swans. At times, flocks of over 12,000 snow geese may be observed on the refuge after their arrival in November. Many other wildlife species such as wading birds, shorebirds, raptors, neotropical migrants, mammals, reptiles, and amphibians use refuge habitats for food, cover, and nesting. A pair of bald eagles also nest on the refuge.

About 74 percent of the refuge is slightly brackish marsh habitat, dominated by cattails, black needlerush, and giant cordgrass. The remaining habitat includes farmland, marsh impoundments, brush and typical upland and lowland eastern pine-hardwood forest. Vegetation in these areas includes loblolly pine, sweet gum, black gum, cypress, red maple, hickory, and oak.

The refuge has a surface area of 8,231 acres (33.31 km2). Of this, 7,357 acres (29.77 km2) is in North Carolina and 874 acres (3.54 km2) is in Virginia.

Mill Creek Marsh

Mill Creek Marsh is a nature preserve in the New Jersey Meadowlands located in Secaucus at its border with North Bergen, the Cromakill Creek, in Hudson County, New Jersey. It is fed by the Hackensack River

and is a contributing property to the Hackensack RiverWalk.

It is contiguous to the west by Mill Creek and the Schmidts Woods and Secaucus High School, to the north by Western Brackish Marsh to the east by the Eastern Brackish Marsh and Cromakill Marsh.The Eastern Spur of New Jersey Turnpike runs through the nature area, which is bordered to the south by The Plaza at Harmon Meadow, which includes the Mall at Mill Creek.

Ragged Island Wildlife Management Area

Ragged Island Wildlife Management Area, also known as Ragged Island Wildlife Refuge, is a 1,537-acre (6.22 km2) Wildlife Management Area (WMA) in Isle of Wight County, Virginia. It includes unspoiled brackish marsh and small pine islands adjacent the south bank of the James River. The area is dominated by vegetation such as marsh mallow, smartweed, saltmarsh cordgrass, and black needlerush, with loblolly pine as the most common tree species. Impenetrable areas of wax myrtle and greenbriar are also found on the property. The area is known in particular for its wide range of waterfowl.

Ragged Island WMA is managed by the Virginia Department of Game and Inland Fisheries. The area is open to the public for hunting, trapping, fishing, and hiking. A boardwalk allows access for viewing the marsh and its wildlife. The WMA may accessed from two parking areas on U.S. Highway 17 just south of the James River Bridge. Access for persons 17 years of age or older requires a valid hunting or fishing permit, or a WMA access permit.

Salt pannes and pools

Salt pannes and pools are water retaining depressions located within salt and brackish marshes. Pools tend to retain water during the summer months between high tides, whereas pannes generally do not. Salt pannes generally start when a mat of organic debris (known as wrack) is deposited upon existing vegetation, killing it. This creates a slight depression in the surrounding vegetation which retains water for varying periods of time. Upon successive cycles of inundation and evaporation the panne develops an increased salinity greater than that of the larger body of water. This increased salinity dictates the type of flora and fauna able to grow within the panne. Salt pools are also secondary formations, though the exact mechanism(s) of formation are not well understood; some have predicted they will increase in size and abundance in the future due to rising sea levels.

Salt pannes and pools are unique microhabitats dominated by various species of halophytes, benthic plants and varying estuarine marine life that vary considerably in composition due to a variety of factors:

Substrate type: affects the ability of the depression to hold water.

depth and diameter: affect water temperature and evaporation rate in the depression. A shallow and wide pool will evaporate at a greater rate than a pool of the same volume of water which is deeper and has a smaller surface area. Evaporation rate also affects salinity, the higher the evaporation rate the higher the salinity, with rates as high as a third greater than ocean water.

location within the intertidal zone, whether high marsh or low marsh and distance from the mean low tide mark which affects the length and duration of inundation until the depression is subject to evaporation as well as length of time until the rising tide replenishes the water volume.These factors affect the types of species which can survive within the various types of salt pannes and pools.

Variants of salt pannes and pools:

Low salt marsh

Low salt marsh panneUsually devoid of vegetation, that may be present include smooth cordgrass (Spartina alterniflora), marine algae such as knotted wrack (Ascophyllum nodosum) and rockweeds (Fucus spp.). The substrate is typically soft, silty mud.

High salt marsh

Arrow-grass (forb) panneBriefly flooded, very shallow with a moderate amount of vegetation usually dominated by Arrow grass (Triglochin maritimum), with the deeper sections possibly remaining unvegetated.

Smooth cord-grass (short form) panneShallow anaerobic depressions with poor drainage, poor water quality due to low nutrient levels and high concentrations of sulfides and similar compounds which inhibit plant growth. Short form (6-12" tall)smooth cord-grass (Spartina alterniflora) is the dominant plant species. Typically found on the high salt marsh, but can occasionally be found on the upper margins of low salt marsh.

Salt marsh mosquito panne

Minimal vegetation often found on the upper half of the high salt marsh. It is typically deeper than forb and smooth cord-grass pannes. Usually flooded by the higher of the two spring tides, retains water for 2–3 weeks later until drying out. The female eastern salt marsh mosquito (Aedes sollicitans) lays eggs on the exposed surface. The eggs lay dormant until the next time the panne floods.

Widgeon grass (Ruppia maritima) - marsh minnow deepwater pool

Pools on the high salt marsh that are semi-permanently and permanently flooded. They are able to sustain populations of Sheephead minnow (Cyprinodon variegatus variegatus), Mummichogs, (Fundulus heteroclitus), and other species of small fish which may become trapped in the pools and benthic species of vegetation. Occasioanally can be found at the upper edge of the low salt marsh.

Surf zone

As ocean surface waves come closer to shore they break, forming the foamy, bubbly surface called surf. The region of breaking waves defines the surf zone. After breaking in the surf zone, the waves (now reduced in height) continue to move in, and they run up onto the sloping front of the beach, forming an uprush of water called swash. The water then runs back again as backswash. The nearshore zone where wave water comes onto the beach is the surf zone. The water in the surf zone, or breaker zone, is shallow, usually between 5 and 10 m (16 and 33 ft) deep; this causes the waves to be unstable.

Tidal marsh

A tidal marsh (also known as a "tidal wetland") 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. They are also impacted by transient disturbances such as hurricanes, floods, storms, and upland fires.

Woodland Beach Wildlife Area

Woodland Beach Wildlife Area is a state wildlife area located in Kent County, Delaware, along shore of the Delaware Bay. It is 6,320 acres (2,558 ha) in size and is managed by Delaware Department of Natural Resources and Environmental Control (DNREC), Division of Fish & Wildlife.Much of the area is a transgressive brackish marsh.

The Thomas Sutton House serves as a residence and office for the personnel of the Woodland Beach Wildlife Area. It was listed on the National Register of Historic Places in 1973.

Aquatic ecosystems
Classification systems

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