Atchafalaya Basin
The Atchafalaya Basin, or Atchafalaya Swamp, is the largest wetland and swamp in the United States. Located in south central Louisiana, it is a combination of wetlands and river delta area where the Atchafalaya River and the Gulf of Mexico converge; the river stretches from near Simmesport in the north through parts of eight parishes to the Morgan City southern area. The Atchafalaya is different among Louisiana basins because it has a growing delta system with wetlands that are stable; the basin contains about 30 % marsh and open water. It contains the largest contiguous block of forested wetlands remaining in the lower Mississippi River valley and the largest block of floodplain forest in the United States. Best known for its iconic cypress-tupelo swamps, at 260,000 acres, this block of forest represents the largest remaining contiguous tract of coastal cypress in the US; the Atchafalaya Basin and the surrounding plain of the Atchafalaya River is filled with bayous, bald cypress swamps, marshes, which give way to brackish estuarine conditions, end in the Spartina grass marshes where the Atchafalaya River meets the Gulf of Mexico.
It includes the Lower Atchafalaya River, Wax Lake Outlet, Atchafalaya Bay, the Atchafalaya River and bayous Chêne, Black navigation channel. See maps and photo views of the Atchafalaya Deltas centered on 29°26′30″N 91°25′00″W; the Basin, susceptible to long periods of deep flooding, is sparsely inhabited. The Basin is about 20 miles in width from east 150 miles in length; the Basin is the largest existing wetland in the United States with an area of 1,400,000 acres, including the surrounding swamps outside of the levees that were connected to the Basin. The Basin contains nationally significant expanses of bottomland hardwoods, swamplands and back-water lakes; the Basin's thousands of acres of forest and farmland are home to the Louisiana black bear, on the United States Fish and Wildlife Service threatened list since 1992. The few roads that cross the Basin follow the tops of levees. Interstate 10 crosses the basin on elevated pillars on a continuous 18.2 mile bridge from Grosse Tete, Louisiana, to Henderson, near the Whiskey River Pilot Channel at 30°21′50″N 91°38′00″W.
The Atchafalaya National Wildlife Refuge was established in 1984 to improve plant communities for endangered and declining species of wildlife, migratory birds and alligators. The Atchafalaya Basin has a long relationship with the Mississippi River throughout the Holocene epoch, the geology of the modern basin is a direct manifestation of that relationship; the Atchafalaya Basin has been part of three historic depositional lobes of the Mississippi River Delta Plain that formed south Louisiana, active delta lobe development is occurring at the mouth of the Atchafalaya River and Wax Lake Outlet. The geology of the current basin has been driven by flows of Atchafalaya River water and sediment that flowed into open water areas through relict Mississippi River distributary channels; the Atchafalaya Basin contains lacustrine and coastal delta landscapes. Natural filling of the basin with sediment was accentuated with the building of the flood control levees that were completed in the 1940s. After the levees, sediment was directed into an area about one-third the size of the original basin.
An example of the lacustrine delta development can be seen at Lake Fausse Pointe State Park, where levees severed the connection between the Grand Bayou distributary and the lake, delta development was frozen in time. Geologically, the Atchafalaya River has been a backswamp, low area between the paths of the Mississippi River through the process of delta switching, which has built the extensive delta plain of Louisiana; the natural levees of the Mississippi River and the levees along its previous course on the west define the Atchafalaya Basin. The central basin is further bordered by man-made levees designed to contain and funnel floodwaters released from the Mississippi at the Old River Control Structure and the Morganza Spillway south toward Morgan City and to the Gulf of Mexico. There were small and few channel connections to the Mississippi River; the historic lack of significant channel connection indicates that the Atchafalaya River Basin did not receive significant sediment from the Mississippi except during large floods.
During the mid-19th century, manmade channel alterations, including the removal of a large log jam and dredging, permanently connected the Atchafalaya River to the Mississippi River. From until the completion of the Old River Control Structure in 1963, the Mississippi was diverting flow into the shorter and steeper path of the Atchafalaya channel. By law, a regulated 30 percent of the latitudinal flow water from the Mississippi and Black rivers is diverted into the Atchafalaya at the Old River Control Structure; this flow diverts on average 25 percent of the Mississippi River flow down the Atchafalaya. In times of extreme flooding, the US Army Corps of Engineers may open the Morganza Spillway and other spillways to relieve pressure on levees and control structures along the Mississippi. On May 13, 2011, in the face of a rising Mississippi River that threatened to flood New Orleans and other populated parts of Louisiana, the USACE ordered the Morganza Spillway opened for the first time since 1973.
This water floods the Atchafalaya Basin between the levees along the western and eastern limits of the Morganza and Atchafalaya basin fl
Anatidae
The Anatidae are the biological family of water birds that includes ducks and swans. The family has a cosmopolitan distribution, occurring on all the world's continents; these birds are adapted for swimming, floating on the water surface, in some cases diving in at least shallow water. The family contains around 146 species in 43 genera, they are herbivorous, are monogamous breeders. A number of species undertake annual migrations. A few species have been domesticated for agriculture, many others are hunted for food and recreation. Five species have become extinct since 1600, many more are threatened with extinction; the ducks and swans are small- to large-sized birds with a broad and elongated general body plan. Diving species vary from this in being rounder. Extant species range in size from the cotton pygmy goose, at as little as 26.5 cm and 164 g, to the trumpeter swan, at as much as 183 cm and 17.2 kg. The wings are short and pointed, supported by strong wing muscles that generate rapid beats in flight.
They have long necks, although this varies in degree between species. The legs are short and set far to the back of the body, have a leathery feel with a scaly texture. Combined with their body shape, this can make some species awkward on land, but they are stronger walkers than other marine and water birds such as grebes or petrels, they have webbed feet, though a few species such as the Nene have secondarily lost their webbing. The bills are made of soft keratin with a sensitive layer of skin on top. For most species, the shape of the bill tends to be more flattened to a lesser extent; these contain serrated lamellae which are well defined in the filter-feeding species. Their feathers are excellent at shedding water due to special oils. Many of the ducks display sexual dimorphism, with the males being more brightly coloured than the females; the swans and whistling-ducks lack sexually dimorphic plumage. Anatids are vocal birds, producing a range of quacks, honks and trumpeting sounds, depending on species.
Anatids are herbivorous as adults, feeding on various water-plants, although some species eat fish, molluscs, or aquatic arthropods. One group, the mergansers, are piscivorous, have serrated bills to help them catch fish. In a number of species, the young include a high proportion of invertebrates in their diets, but become purely herbivorous as adults; the anatids are seasonal and monogamous breeders. The level of monogamy varies within the family. However, forced extrapair copulation among anatids are common, ocucurring in 55 species in 17 genera. Anatidae is a large proportion of the 3% of bird species to possess a penis, though they vary in size and surface elaboration. Most species are adapted for copulation on the water only, they construct simple nests from whatever material is close at hand lining them with a layer of down plucked from the mother's breast. In most species, only the female incubates the eggs; the young are precocial, are able to feed themselves from birth. One aberrant species, the black-headed duck, is an obligate brood parasite, laying its eggs in the nests of gulls and coots.
While this species never raises its own young, a number of other ducks lay eggs in the nests of conspecifics in addition to raising their own broods. Duck and goose feathers and down have long been popular for bedspreads, sleeping bags, coats; the members of this family have long been used for food. Humans have had a long relationship with ducks and swans. However, some anatids are damaging agricultural pests, have acted as vectors for zoonoses such as avian influenza. Since 1600, five species of ducks have become extinct due to the activities of humans, subfossil remains have shown that humans caused numerous extinctions in prehistory. Today, many more are considered threatened. Most of the historic and prehistoric extinctions were insular species, vulnerable due to small populations, island tameness. Evolving on islands that lacked predators, these species lost antipredator behaviours, as well as the ability to fly, were vulnerable to human hunting pressure and introduced species. Other extinctions and declines are attributable to overhunting, habitat loss and modification, hybridisation with introduced ducks.
Numerous governments and conservation and hunting organisations have made considerable progress in protecting ducks and duck populations through habitat protection and creation and protection, captive-breeding programmes. The family Anatidae was introduced by the English zoologist William Elford Leach in a guide to the contents of the British Museum published in 1820. While the status of the Anatidae as a family is straightforward, which species properly belong to it is little debated, the relationships of the di
Ciénega
A ciénega is a wetland system unique to the American Southwest. Ciénagas are alkaline, spongy, wet meadows with shallow-gradient, permanently saturated soils in otherwise arid landscapes that occupied nearly the entire widths of valley bottoms; that description satisfies historic, pre-damaged ciénagas, although few can be described that way now. Incised ciénagas are common today. Ciénagas are associated with seeps or springs, found in canyon headwaters or along margins of streams. Ciénagas occur because the geomorphology forces water to the surface, over large areas, not through a single pool or channel. In a healthy ciénaga, water migrates through long, wide-scale mats of thick, sponge-like wetland sod. Ciénaga soils are squishy, permanently saturated organic, black in color or anaerobic. Adapted sedges and reeds are the dominant plants, with succession plants — Goodding's willow, Fremont cottonwoods and scattered Arizona walnuts — found on drier margins, down-valley in healthy ciénagas where water goes underground or along the banks of incised ciénagas.
Ciénagas are not considered true swamps due to their lack of trees, which will drown in historic ciénagas. However, trees do grow in many drained ciénagas, making the distinction less clear. Undamaged ciénagas nonexistent today, were characterized by a slow-moving, broad flow through extensive emergent vegetation as just described, but today, the ongoing region-wide erosion that followed the arrival of Europeans in the American Southwest and the subsequent misuse of the land by settlers entrenched water flow between vertical walls, resulting in an ever-worsening incision process, a drawdown of local water tables and the drying up of most marshland environments, leaving behind scarcely few undamaged ciénagas. Many that remain today look and function like a creek: narrow and continuing to degrade. "Since the late 1800s, natural wetlands in arid and semi-arid desert grasslands of the American Southwest and Northern Mexico have disappeared."Ciénagas in Progressive States from Healthy to Dead Ciénaga is a Spanish term meaning desert marsh, bog or shallow, slow-moving flow of water through dense surface vegetation — mistakenly thought of as originating from cién-aguas "100 waters" — derived from ciéno, meaning silt.
There are ciénaga and ciénega. Spelling it with an a, would seem best because the Spanish word for water, agua, is spelled with an a, although spelling with an e is far more common and used by most in the scientific community. There are an inordinate variety of pronunciations, spellings — corruptions and variants — definition and confusion about the etymology of the word ciénaga. · Spellings: ciénega ciénaga cieneguilla cienequita sienaga sinigie senigie seneca chenegays · Pronunciations, in descending order of usage: see-en-ă-ga see-en-ā-ga sen-ă-key · Etymology: cieno – The Real Academia Espanola, 2009, states that the root for ciénaga is “silt,”, the meaning of cieno. The linguist says that the term has nothing to do with “hundred.” Cien agua – Meaning “100 waters” Although under recognized, ciénagas have been important for a long time. “In general, most prehistoric agricultural settlements were located near ciénagas or on the floodplains of the major perennial streams where irrigated agriculture could be practiced.”
It was not until 1984 that Dean A. Hendrickson and W. L. Minckley alerted academics in the Southwest to the importance of its overlooked ciénagas. So-called progress and development led to the unfortunate thinking that, "the only good wetland was a drained wetland." Since their rather inauspicious invitation for further study, the effort to understand and restore ciénagas has gained prominence. Although not the exclusive view, but suggestive of how ciénagas were thought of is this exchange, a 1940s-era conversation between Richard Bradford's narrator, Joshua Arnold, his school chum in the New Mexico novel, Red Sky at Morning"I didn't know there was this much water around Sagrado," I said. "The Sagrado River's been dry since I got here.""This is a cienega," Parker said. "It's some kind of underground spring. Costs a fortune to drain it or pump it off, Cloyd isn't about to spend money for things like that." The importance of ciénagas is staggering. They are critical for other animals. Wetlands in the Southwest occupy under two percent of the land area and have an exorbitant impact on the region.
“There are over 1,900 species listed under the Endangered Species Act as either threatened or endangered. Although their numerical count is less dramatic, ninety-five percent of ciénaga habitat is dry today. Abundant archeology surrounds ciénagas.
Raised bog
Raised bogs called ombrotrophic bogs, are acidic, wet habitats that are poor in mineral salts and are home to flora and fauna that can cope with such extreme conditions. Raised bogs, unlike fens are fed by precipitation and from mineral salts introduced from the air, they thus represent a special type of bog, ecologically and in terms of their development history, in which the growth of peat mosses over centuries or millennia plays a decisive role. They differ in character from blanket bogs which are much thinner and occur in wetter, cloudier climatic zones. Raised bogs are threatened by peat cutting and pollution by mineral salts from the surrounding land. There are hardly any raised bogs today that are still growing; the last great raised bog regions are found in western Canada. The term raised bog derives from the fact that this type of bog rises in height over time as a result of peat formation, they are like sponges of peat moss, full of water, that form a more or less dome shape in the landscape.
In Germany, the term Hochmoor refers only to the classical, lens-shaped bogs of northwest Germany. The bogs are not influenced by mineral-rich groundwater or surface water, but are fed by precipitation — rainwater, hence their alternative German designation of Regenmoor or "rain-fed bog", thus the latter refers to all bogs, not just those that are arched or only arched, but which are characterized by an extreme mineral salt deficiency and other resulting ecological properties. A living raised bog needs a balanced climate in which to grow; the quantity of precipitation has to be greater than the water losses through discharge and evaporation. In addition, the precipitation must be evenly spread through the year. Raised bogs in Europe have been developing for about 11,000 years, since the beginning of the Holocene and after the retreat of the last ice sheet; as far as their origins are concerned, a distinction is made between lake mires or'siltation-formed raised bogs' and'mire-formed raised bogs'.
The former emerged in a secondary process after the silting up of oxbows. At first, fens emerged under the influence of groundwater. Oxygen deficiencies and high acidity in the moist substrate inhibited the decomposition of dead plant parts and led to peat formation, thus the raised bog rises slowly above the groundwater level, hence its name. As the resulting peat rises above the influence of mineral salts in the groundwater, it reaches a point where the development of the raised bog begins to change in nature. By contrast, mire-formed raised bogs are created directly on the mineral substrate of low-salt areas without having been formed as fens, they are formed either as a primary bog due to the erosion of dry mineral soils, for example due to clearing, climate change or infiltration, or as a secondary process as a result of the growth of a raised bog on neighbouring mineral soil. The formation of a typical raised bog is a slow process, which lasts from centuries to a thousand years in favourable, undisturbed conditions.
Furthermore, there are a number of transitional and intermediate bogs, which in different ways combine characteristics of both raised bogs and fens. The main constituents of the peat are rootless peat mosses that grow in height whilst at the same time the lower layer becomes peat as the air is excluded. Depending on the geographical location, various species of peat moss are involved in making a raised bog; the growth rate of the peat layer is only about a millimetre per year. Growing bogs can be divided into two layers. The'acrotelm' is the upper part and includes the vegetation layer and the bog'floor'. Here fresh organic substances are created by the growth and dying of plant elements; the "catotelm" is the underlying water-saturated part with less biological activity. This layer is counted as a geological subsoil due to the small earth-forming processes that are still going on and is known as the peat preservation horizon. In raised bogs, the upper peat layer is called white peat, since it consists of undecomposed light brown peat mosses.
The lower layer is black peat, well humified and has a black-brown colour with still recognizable plant remains. The formation of raised bogs is dependent on the climate, to say the amount of precipitation and rate of evaporation, which in turn are decisively determined by the temperature. In addition, the relief of the terrain has an influence on the water discharge behaviour and thus the shape of a raised bog; this results in geographical limitations to the formation of raised bogs. Favourable conditions for the development of raised bogs are found in North America, Northern Europe and Western Siberia, South America, Southeast Asia and in the Amazon Basin. In these regions, bogs of all kinds and peat deposits of four million square kilometres have been formed, covering three percent of the earth's surface. In the southern hemisphere low-mineral-rich bogs are formed from peat mosses. Only in the Tierra del Fuego do; the most peaty countries in the tropics are found in Southeast Asia. In many cases it is not yet clear how these bogs have emerged as mosses are absent here.
Coastal bogs or Atlantic bogs, as th
WWT Slimbridge
WWT Slimbridge is a wetland wildlife reserve near Slimbridge in Gloucestershire, England. It is midway between Gloucester on the eastern side of the estuary of the River Severn; the reserve, set up by the artist and naturalist Sir Peter Scott, opened in November 1946. Scott subsequently founded the Wildfowl & Wetlands Trust, which has since opened eight reserves around the country. Slimbridge comprises some 800 hectares of pasture, reed bed and salt marsh. Many water birds live there all year round, others are migrants on their ways to and from their summer breeding grounds. Other birds overwinter, including large numbers of white-fronted geese and increasing numbers of Bewick's swans. Besides having the world's largest collection of captive wildfowl, Slimbridge takes part in research and is involved in projects and internationally run captive breeding programmes, it was there that Peter Scott developed a method of recognising individual birds through their characteristics, after realising that the coloured patterns on the beaks of Bewick's swans were unique.
The public can visit the reserve throughout the year. Besides examining the collections, they can view birds from hides and observatories and take part in educational activities; the Wildlife and Wetland Trust at Slimbridge was set up by Peter Scott and opened on 10 November 1946, as a centre for research and conservation. In a move unusual at the time, he opened the site to the public so that everyone could enjoy access to nature; this modest beginning developed in time into the formation of the Wildfowl & Wetlands Trust, the only United Kingdom charity to promote the protection of wetland birds and their habitats, both in Britain and internationally. Although starting out at Slimbridge, the Wildfowl & Wetlands Trust now owns or manages eight other reserves in Britain, advocates for wetlands and conservation issues world-wide. WWT Consulting is based at Slimbridge, it provides ecological surveys and assessments, offers consultancy services in wetland habitat design, wetland management, biological waste-water treatment systems and the management of reserves and their visitor centres.
The Queen in years became Patron to the WWT, Prince Charles became the President. A bust of founder Sir Peter Scott by Jacqueline Shackleton was completed in 1986 and is on display in the grounds, his wife Philippa, Lady Scott, sat for Jon Edgar as part of his Environmental Series of heads, a bronze was unveiled in the visitor centre in December 2011. A sculpture by Peter Scott's mother, Kathleen Scott, entitled: Here Am I, Send Me! commissioned for West Downs Preparatory School, is on display in the grounds. The site consists of 800 hectares of reserve, of which part is landscaped and can be visited by the public. At Slimbridge is the largest collection of wildfowl species in the world, wild birds mingle with these in the enclosures; some of the captive birds form part of international breeding programmes. The reserve includes a mixture of pastureland, much of which gets flooded in winter, reed beds and salt marshes besides the Severn Estuary. Many wildfowl visit the site including greater white-fronted geese, spoonbills and common cranes, the latter being birds that were bred here and released on the Somerset Levels.
There are some rare species of plant on the reserve including the grass-poly and the wasp orchid, a variant of the bee orchid. The number of ducks and swans is greatest in winter, with large flocks of greater white-fronted geese, sometimes with a rare lesser white-fronted goose amongst them. Bewick's swans are a feature of Slimbridge in winter, arriving from northern Russia to enjoy the milder climate of southern England, their behaviour has been studied intensively at Slimbridge. Birds of prey such as peregrine and merlin visit the centre in the winter, as well as wading birds and some woodland birds, it is a good place to see the elusive water rail. Species present all year round include little and great crested grebes, redshank, tufted duck, kingfisher, reed bunting, great spotted woodpecker and little owl. In the spring, passage waders visit the pools alongside the estuary. Swans and geese start to arrive in late October. Passage waders in the autumn include red knot, dunlin and grey plovers, common greenshank, spotted redshank, curlew sandpiper and common and green sandpipers.
Besides Bewick's swan and flocks of white-fronted geese, large waterfowl present in the reserve in winter include the Brant goose, pink-footed goose, barnacle goose and Taiga bean goose. The swans tend to fly off in the day and return to feed in the late afternoon, another spectacular sight at the end of winter afternoons is the arrival of large flocks of starlings. Smaller wildfowl present in winter include wigeon, Eurasian teal, common pochard, northern pintail, water rail, redshank, golden plover and ruff. Before the establishment of the WWT reserve at Slimbridge, no Bewick's swans were wintering on the Severn Estuary. In 1948, one arrived at Slimbridge attracted by a captive whistling swan. A mate for this bird was acquired from the Netherlands and the pair successfully bred. More wild Bewick's swans joined the group. So that the birds could be better studied, the tame resident swans were relocat
Bayou
In usage in the United States, a bayou is a body of water found in a flat, low-lying area, can be either an slow-moving stream or river, or a marshy lake or wetland. The term bayou can refer to a creek whose current reverses daily due to tides and which contains brackish water conducive to fish life and plankton. Bayous are sometimes paved to help prevent flooding. Bayous are found in the Gulf Coast region of the southern United States, notably the Mississippi River Delta, with the states of Louisiana and Texas being famous for them. A bayou is an anabranch or minor braid of a braided channel, moving much more than the mainstem becoming boggy and stagnant. Though fauna varies by region, many bayous are home to crawfish, certain species of shrimp, other shellfish, frogs, American alligators, American crocodiles, turtles, snakes and many other species; the word entered American English via Louisiana French in Louisiana and is thought to originate from the Choctaw word "bayuk", which means "small stream".
The first settlements of Bayou Teche, other bayous, were by the Cajuns, and, why bayous are associated with Cajun culture. An alternative spelling, "buyou", has been used, as in "Pine Buyou", used in a description by Congress in 1833 of Arkansas Territory; the term Bayou Country is most associated with Cajun and Creole cultural groups derived from French settlers and stretching along the Gulf Coast from Houston, Texas to Mobile and picking back up in South Florida around the Everglades with its center in New Orleans, Louisiana. Houston has the nickname "Bayou City"; as of 2016 "bye-you" is the most common pronunciation, while a few use "bye-oh", although that pronunciation is declining. Bayou Bartholomew Bayou Lafourche Bayou Teche Cypress Bayou Bayou St. John Big Bayou Canot Buffalo Bayou Bayou La Batre Bayou Corne Backswamp Billabong Hurricane on the Bayou Oxbow lake Yazoo stream Bayeux
WWT Llanelli Wetlands Centre
WWT Llanelli Wetlands Centre at Llanelli, Wales is one of nine wetland nature reserves in the UK managed by the Wildfowl and Wetlands Trust, a nature conservation charity. The 500 acres reserve is situated 1 mile east of Llanelli and 5 miles north of Swansea in south Wales, on the eastern side of Carmarthen Bay, it is part of the Burry Inlet estuary, an SSSI, an SPA, a Ramsar site. In winter, more than 60,000 birds return here to overwinter. One of the species protected at the centre is the little egret. WWT Llanelli Wetlands Centre website
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