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61-558: Swamps and marshes are specific types of wetlands that form along waterbodies containing rich, hydric soils. Marshes are wetlands, continually or frequently flooded by nearby running bodies of water, that are dominated by emergent soft-stem vegetation and herbaceous plants. Swamps are wetlands consisting of saturated soils or standing water and are dominated by water-tolerant woody vegetation such as shrubs, bushes, and trees. Swamps are characterized by their saturated soils and slow-moving waters. The water that accumulates in swamps comes from

122-577: A classic example of wetland loss from these combined factors. Europe has likely lost nearly half its wetlands. New Zealand lost 90 percent of its wetlands over a period of 150 years. Ecologists recognize that swamps provide ecological services including flood control, fish production, water purification, carbon storage, and wildlife habitats. In many parts of the world authorities protect swamps. In parts of Europe and North America, swamp restoration projects are becoming widespread. The United States government began enforcing stricter laws and management programs in

183-581: A different set of organisms. Saltwater marshes are found around the world in mid to high latitudes , wherever there are sections of protected coastline. They are located close enough to the shoreline that the motion of the tides affects them, and, sporadically, they are covered with water. They flourish where the rate of sediment buildup is greater than the rate at which the land level is sinking. Salt marshes are dominated by specially adapted rooted vegetation, primarily salt-tolerant grasses. Salt marshes are most commonly found in lagoons , estuaries , and on

244-522: A freshwater marsh, the ocean tides affect this form of marsh. However, without the stresses of salinity at work in its saltwater counterpart, the diversity of the plants and animals that live in and use freshwater tidal marshes is much higher than in salt marshes. The most severe threats to this form of marsh are the increasing size and pollution of the cities surrounding them. Ranging greatly in size and geographic location, freshwater marshes make up North America's most common form of wetland. They are also

305-576: A habitat for many species of plants, animals, and insects that have adapted to living in flooded conditions or other environments. The plants must be able to survive in wet mud with low oxygen levels. Many of these plants, therefore, have aerenchyma , channels within the stem that allow air to move from the leaves into the rooting zone. Marsh plants also tend to have rhizomes for underground storage and reproduction. Common examples include cattails , sedges , papyrus and sawgrass . Aquatic animals, from fish to salamanders , are generally able to live with

366-512: A habitat free from fish, which eat the eggs and young of amphibians. An example is the endangered gopher frog . Similar temporary ponds occur in other world ecosystems, where they may have local names. However, vernal pool can be applied to all such temporary pool ecosystems. Playa lakes are a form of shallow freshwater marsh in the southern high plains of the United States. Like vernal pools, they are only present at certain times of

427-735: A large population of mosquitoes and parasites that cause waterborne diseases . Including several diverse aquatic habitats like swamps, lakes, channels and floodplains, the Sudd is rich in fish. Some 70 species have been recorded, and this mostly involves fish that are found in much of the Nile system such as marbled lungfish , Senegal bichir , African arowana , Mormyrus caschive , Nile carp , Nile tilapia , mango tilapia , redbelly tilapia , Nile perch , Distichodus rostratus , elongate tigerfish , African tetras , African sharptooth catfish , Synodontis frontosus , S. schall and others. Among

488-457: A low amount of oxygen in the water. Some can obtain oxygen from the air instead, while others can live indefinitely in conditions of low oxygen. The pH in marshes tends to be neutral to alkaline , as opposed to bogs , where peat accumulates under more acid conditions. Marshes provide habitats for many kinds of invertebrates, fish , amphibians, waterfowl and aquatic mammals. Marshes have extremely high levels of biological production, some of

549-477: A region in the East of England , the embanked marshes are also known as Fens . Some areas have already lost 90% of their wetlands, including marshes. They have been drained to create agricultural land or filled to accommodate urban sprawl . Restoration is returning marshes to the landscape to replace those lost in the past. Restoration can be done on a large scale, such as by allowing rivers to flood naturally in

610-407: A variety of sources including precipitation, groundwater, tides and/or freshwater flooding. These hydrologic pathways all contribute to how energy and nutrients flow in and out of the ecosystem. As water flows through the swamp, nutrients, sediment and pollutants are naturally filtered out. Chemicals like phosphorus and nitrogen that end up in waterways get absorbed and used by the aquatic plants within

671-434: A very limited groundwater influence on the area's hydrology. Nuer and Dinka pastoralists use the Sudd and the surrounding areas extensively. Livestock and rain-fed agriculture are the dominant means of support for the largely rural population for which the seasonal flooded grasslands along the Sudd provides valuable grazing lands. Vegetation cover of the area can generally be classified in five categories which depend on

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732-401: A very low property value compared to fields, prairies , or woodlands . They have a reputation for being unproductive land that cannot easily be utilized for human activities, other than hunting , trapping , or fishing. Farmers, for example, typically drained swamps next to their fields so as to gain more land usable for planting crops, both historically, and to a lesser extent, presently. On

793-497: Is a good indicator of flood patterns. P. communis , E. pyramidalis and O. barthii for example dominate only in areas where the depth of flooding does not exceed 130 cm over a period of ten years or 118 cm for one month in the year. Floating vegetation of C. papyrus had caused blockages in the Sudd swamps on a number of occasions between 1879 and 1900, when the plants were torn out by increased flooding. C. papyrus needs saturated conditions and can tolerate flooding that

854-636: Is a large swamp in the western Siberia area of the Russian Federation . This is one of the largest swamps in the world, covering an area larger than Switzerland . The Atchafalaya Swamp at the lower end of the Mississippi River is the largest swamp in the United States . It is an important example of the southern cypress swamp but it has been greatly altered by logging, drainage, and levee construction. Other famous swamps in

915-465: Is not more than 150 cm deep. When the matted vegetation breaks free of its moorings, it forms floating islands of vegetation up to 30 km in length. Such islands, in varying stages of decomposition, eventually break up. Historically, the fully floating Nile cabbage ( Pistia stratiotes ) was an important plant in the Sudd, but it has largely been replaced by the invasive water hyacinth ( Eichhornia crassipes ). The sluggish waters are host to

976-696: The Bahr el Zeraf ("Sea of the Giraffes ") river branches off the Bahr al Jabal to the east, diverting part of the flow, and again joins the Bahr al Jabal just before reaching Malakal. During the course of its flow, the Bahr al Jabal passes Lake No , where the Bahr el Ghazal ("Sea of the Gazelles ") connects to the Bahr al Jabal, contributing an inflow with seasonal variation. At Malakal, the Sobat River joins into

1037-700: The southeastern United States , especially in the Gulf Coast region. A baygall is a type of swamp found in the forest of the Gulf Coast states in the USA. The world's largest wetlands include significant areas of swamp, such as in the Amazon and Congo River basins. Further north, however, the largest wetlands are bogs . Marsh In ecology , a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants . More in general,

1098-451: The white-eared kob (further away from the permanent swampland). White-eared kob, tiang and Mongalla gazelle take part in one of the largest mammal migrations on Earth, numbering about 1.2 million individuals in total. The shallow water is frequented by Nile crocodiles and hippopotamuses . In more upland areas the Sudd was known as an historic habitat for the endangered painted hunting dog , which however may have been exterminated in

1159-543: The 1970s in efforts to protect and restore these ecosystems. Often the simplest steps to restoring swamps involve plugging drainage ditches and removing levees . Conservationists work to preserve swamps such as those in northwest Indiana in the United States Midwest that were preserved as part of the Indiana Dunes . Swamps can be found on all continents except Antarctica . The largest swamp in

1220-402: The Bahr al Jabal approaching Bor and ending in the Sudd flood plain just north of Bor on the eastern bank and towards Shambe on the western bank. In the southern part, the river meanders from side to side in the restraining trough in one or more channels, but further north the swamp is not limited by higher ground and the system of river channels becomes increasingly complex. The characteristics of

1281-424: The Bahr al Jabal. Roughly 55% of water entering the area is lost to evaporation. Water levels fluctuate by up to 1.5 metres, depending on the intensity of seasonal flooding. The region receives less rainfall (typically between 55 and 65 centimetres per year) than neighbouring areas at the same latitude. Orographic lifting on the eastern and western sides of the Sudd contribute to that condition. The morphology of

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1342-486: The Nile experienced considerable difficulties, sometimes taking months to get through the Sudd. In his 1972 book The White Nile , Alan Moorehead says of the Sudd, "there is no more formidable swamp in the world". The Sudd swamp is sustained by the water from the southwestern tributaries (the Bahr el Ghazal system) and consumes a proportion of the main river through evaporation and transpiration. Sir William Garstin, Undersecretary of State of Public Works of Egypt, created

1403-420: The Sudd area consists of various meandering channels, lagoons , reed and papyrus fields and loses half of its inflowing water through evapotranspiration in the permanent and seasonal floodplains, the complex hydrology has many primary and secondary effects. A major feature of the area, is the incomplete Jonglei Canal , which was planned to bypass waters from the Sudd to avoid evaporation losses and increase

1464-651: The Sudd may be partly causing up to a third of the whole West African rise in atmospheric methane levels over the previous decade. The Sudd stretches from Mongalla to just outside the Sobat River confluence with the White Nile just upstream of Malakal as well as westwards along the Bahr el Ghazal . The shallow and flat inland delta lies between 5.5 and 9.5 degrees latitude north and covers an area of 500 kilometres (310 mi) south to north and 200 kilometres (120 mi) east to west between Mongalla in

1525-468: The Sudd. During the 1960s increase in Lake Victoria discharge, where flows at Mongalla roughly doubled, the flows at Malakal at the northern end of the swamps increased by 1.5 times the previous average flow. As a consequence of these high flows, the areas of permanent swamp and seasonal floodplains have, taken together, increased to 2.5 times their former size. The swamps have increased the most, and

1586-656: The United States are the forested portions of the Everglades , Okefenokee Swamp , Barley Barber Swamp , Great Cypress Swamp and the Great Dismal Swamp . The Okefenokee is located in extreme southeastern Georgia and extends slightly into northeastern Florida . The Great Cypress Swamp is mostly in Delaware , but extends into Maryland on the Delmarva Peninsula . Point Lookout State Park on

1647-419: The White Nile but were not able to get beyond the Sudd, which marked the limit of Roman penetration into equatorial Africa . For the same reasons in later times, the search for the source of the Nile was particularly difficult; it eventually involved overland expeditions from the central African coast, so as to avoid having to travel through the Sudd. In 2019, a study suggested that increased water flows into

1708-550: The White Nile, bypassing the swamps and carrying the White Nile's water directly to the main channel of the river. The Jonglei Canal scheme was studied by the government of Egypt in 1946, and plans were developed in 1954–59. Construction work on the canal began in 1978, but the outbreak of political instability in Sudan has held up work for many years. By 1984 when the Sudan Peoples Liberation Army brought

1769-460: The amount of water discharged at the outlet of the Sudd. From 1961 to 1963, a great increase in the flooded area occurred when the level of Lake Victoria rose, and the outflow increased. The total area of the Sudd is related to the amount of water reaching Bor from the Albert Nile and from torrents or seasonal watercourses that can add substantial amounts to the flow in the upstream end of

1830-413: The area is defined by the channel and lagoon system of the permanent Sudd swamps, the adjacent flood plains, and the surrounding flat terrain. The Bahr al Jabal runs to the north-northwest and therefore in an angle to the gradient of the floodplain , which slopes down to the north, while north of Juba the river flows in an incised trough. The banks of this trough decrease in height from south to north with

1891-598: The coasts of East Sumatra, Kalimantan (Central, East, South and West Kalimantan provinces), West Papua, Papua New Guinea, Brunei, Peninsular Malaya, Sabah, Sarawak, Southeast Thailand, and the Philippines (Riley et al. ,1996). Indonesia has the largest area of tropical peatland. Of the total 440,000 km (170,000 sq mi) tropical peat swamp, about 210,000 km (81,000 sq mi) are located in Indonesia (Page, 2001; Wahyunto, 2006). The Vasyugan Swamp

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1952-542: The dry season, when frequent fires also occur. The fluvial area is mostly overgrown with vegetation, with some main and side channels as well as lagoons of open water. The vegetation distribution is described in further detail in Sutcliffe (1974) and Petersen (2007). The main species are: The first three species are anchored so their distribution is limited to the depth of flooding. For the last species their root system needs to be permanently in water or saturated soil, which

2013-409: The elevation of the area above river flood level: the lakes and rivers, the floating plant life of the swamp, river-flooded grasslands (Toic), rain-flooded grasslands, and wooded grasslands on the fringes. Grassland and woodland areas have been cultivated by local populations. The density of the grasslands along the Sudd changes with the season, with tall grass in the rainy season and short dry grass in

2074-399: The expected damage falling on South Sudan. The complex environmental and social issues involved, including the collapse of fisheries, drying of grazing lands, a drop of groundwater levels, and a reduction of rainfall in the region, limits the practicality of the project. The draining of the Sudd is likely to have environmental effects comparable to the drying of Lake Chad or the draining of

2135-543: The few endemics of the Sudd system are Clarias engelseni , Enteromius yeiensis , Nothobranchius nubaensis , N. virgatus and two apparently undescribed species of Enteromius , and the fish fauna in significant sections still has not been properly studied. Over 400 species of bird are found in the Sudd, including shoebills (a stronghold for the species with several thousand individuals), great white pelicans , and black crowned cranes . The Sudd provides food and water to large populations of migrating birds . As

2196-465: The first detailed proposal for digging a canal east of the Sudd in 1907. By bypassing the swamps, evaporation of the Nile's water would vastly decrease, allowing an increase in the area of cultivatable land in Egypt by 8,100 km (2,000,000 acres). The Egyptian government in the 1930s proposed digging a canal east of the Sudd to divert water from the Bahr al Jabal above the Sudd to a point farther down

2257-641: The fringes of large rivers. The different types are produced by factors such as water level, nutrients, ice scour , and waves. Large tracts of tidal marsh have been embanked and artificially drained. They are usually known by the Dutch name of polders . In Northern Germany and Scandinavia they are called Marschland , Marsch or marsk ; in France marais maritime . In the Netherlands and Belgium, they are designated as marine clay districts. In East Anglia ,

2318-447: The highest in the world, and therefore are important in supporting fisheries. Marshes also improve water quality by acting as a sink to filter pollutants and sediment from the water that flows through them. Marshes partake in water purification by providing nutrient and pollution consumption. Marshes (and other wetlands) are able to absorb water during periods of heavy rainfall and slowly release it into waterways and therefore reduce

2379-469: The magnitude of flooding. Marshes also provide the services of tourism, recreation, education, and research. Marshes differ depending mainly on their location and salinity . These factors greatly influence the range and scope of animal and plant life that can survive and reproduce in these environments. The three main types of marsh are salt marshes , freshwater tidal marshes , and freshwater marshes . These three can be found worldwide, and each contains

2440-814: The marsh is sometimes called a carr . This form of vegetation is what differentiates marshes from other types of wetland such as swamps , which are dominated by trees , and mires , which are wetlands that have accumulated deposits of acidic peat . Marshes provide habitats for many kinds of invertebrates , fish , amphibians , waterfowl and aquatic mammals . This biological productivity means that marshes contain 0.1% of global sequestered terrestrial carbon . Moreover, they have an outsized influence on climate resilience of coastal areas and waterways, absorbing high tides and other water changes due to extreme weather . Though some marshes are expected to migrate upland, most natural marshlands will be threatened by sea level rise and associated erosion . Marshes provide

2501-486: The most diverse of the three types of marsh. Some examples of freshwater marsh types in North America are: Wet meadows occur in shallow lake basins, low-lying depressions, and the land between shallow marshes and upland areas. They also happen on the edges of large lakes and rivers. Wet meadows often have very high plant diversity and high densities of buried seeds. They are regularly flooded but are often dry in

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2562-486: The other hand, swamps can (and do) play a beneficial ecological role in the overall functions of the natural environment and provide a variety of resources that many species depend on. Swamps and other wetlands have shown to be a natural form of flood management and defense against flooding. In such circumstances where flooding does occur, swamps absorb and use the excess water within the wetland, preventing it from traveling and flooding surrounding areas. Dense vegetation within

2623-671: The project. However, on 21 February 2008, the Sudanese government said the revival of the project was not a priority. Nevertheless, in 2008, Sudan and Egypt agreed to restart the project and finish the canal in 24 years. South Sudan gained independence in 2011. It is estimated that the Jonglei canal project would produce 3.5–4.8 x 10 m of water per year (equal to a mean annual discharge of 110–152 m /s (3 883–5 368 ft /s), an increase of around 5–7% of Egypt's current water supply. The canal's benefits would be shared by Egypt and Sudan, with

2684-533: The region. The long-running civil war in Southern Sudan seriously disrupted conservation efforts in the Sudd, especially as the widespread availability of weapons has encouraged wildlife poaching, including of elephants. There are three game reserves: Zeraf Island between the Zeraf River and the Nile, Shambe Reserve, and Mongalla Game Reserve . The early explorers searching for the source of

2745-432: The river with its network of channels and lagoons are distinguishable in satellite imagery and digital elevation models. The geology of the area is defined by heavy clay soils, highly impermeable with a top layer of "black cotton" vertisol of approximately 500 mm on average. Sandy soils are found only at depths of approximately 30 metres (98 ft) and below, as determined by well drilling profiles. This indicates

2806-495: The seasonal floodplain is 1.5 times its previous size. From the southern inflow of the Bahr al Jabal ("Sea of the Mountain") at Mongalla, the defined riverbed successively widens into a floodplain, where the waters flow in meandering river stretches and various channels and lagoons throughout the dry season. With rising water levels it expands over the semi-flooded grasslands during the flood season. Slightly downstream of Bor,

2867-463: The sheltered side of a shingle or sandspit . The currents there carry the fine particles around to the quiet side of the spit, and sediment begins to build up. These locations allow the marshes to absorb the excess nutrients from the water running through them before they reach the oceans and estuaries. These marshes are slowly declining. Coastal development and urban sprawl have caused significant loss of these essential habitats. Although considered

2928-408: The south and Malakal in the north. Its size is highly variable, averaging over 30,000 square kilometres (12,000 sq mi). During the wet season it may extend to over 130,000 square kilometres (50,000 sq mi) comprising 21% of the country, depending on the inflowing waters, with the discharge from Lake Victoria being the main control factor of flood levels and area inundation. Since

2989-532: The southern tip of Maryland contains many swamps and marshes. The Great Dismal Swamp lies in extreme southeastern Virginia and extreme northeastern North Carolina . Both are National Wildlife Refuges . Another swamp area, Reelfoot Lake of extreme western Tennessee and Kentucky , was created by the 1811–12 New Madrid earthquakes . Caddo Lake , the Great Dismal and Reelfoot are swamps centered at large lakes. Swamps are often associated with bayous in

3050-596: The spring, or on a small scale by returning wetlands to urban landscapes. Sudd The Sudd ( Arabic : السد , romanized :  as-Sudd , Dinka : Toc) is a vast swamp in South Sudan , formed by the White Nile 's Baḥr al-Jabal section. The Arabic word sudd is derived from sadd ( سد ), meaning "barrier" or "obstruction". The term "the sudd" has come to refer to any large solid floating vegetation island or mat. The area which

3111-492: The summer. Vernal pools are a type of marsh found only seasonally in shallow depressions in the land. They can be covered in shallow water, but in the summer and fall, they can be completely dry. In western North America, vernal pools tend to form in open grasslands, whereas in the east, they often occur in forested landscapes. Further south, vernal pools form in pine savannas and flatwoods . Many amphibian species depend upon vernal pools for spring breeding; these ponds provide

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3172-404: The surrounding landscape is a large swath of dry Sahel across Africa, the swamp is also a haven for migrating mammals, especially antelopes , such as the bohor reedbuck , sitatunga (the most aquatic antelope of the Sudd, mostly inhabiting permanent swampland), the endangered Nile lechwe (not in permanent swampland, but generally near the water's edge and often walking in shallow water), and

3233-616: The swamp also provides soil stability to the land, holding soils and sediment in place whilst preventing erosion and land loss. Swamps are an abundant and valuable source of fresh water and oxygen for all life, and they are often breeding grounds for a wide variety of species. Floodplain swamps are an important resource in the production and distribution of fish. Two thirds of global fish and shellfish are commercially harvested and dependent on wetlands. Historically, humans have been known to drain and/or fill swamps and other wetlands in order to create more space for human development and to reduce

3294-528: The swamp covers is one of the world's largest wetlands and the largest freshwater wetland in the Nile Basin . For many years the swamp, and especially its thicket of vegetation, proved an impenetrable barrier to navigation along the Nile. The ancient Egyptians failed to penetrate the Sudd and reach the areas south of it. In AD 61, a party of Roman soldiers sent by the Emperor Nero proceeded up

3355-445: The swamp, purifying the water. Any remaining or excess chemicals present will accumulate at the bottom of the swamp, being removed from the water and buried within the sediment. The biogeochemical environment of a swamp is dependent on its hydrology, affecting the levels and availability of resources like oxygen, nutrients, water pH and toxicity, which will influence the whole ecosystem. Swamps and other wetlands have traditionally held

3416-478: The system. The combined flows then stream to the north as the White Nile in a defined bed, joining with the Blue Nile waters at Khartoum to form the main Nile. Sudd was designated as a Ramsar Wetland of International Importance in 2006. An area of 57,000 square kilometres (22,000 sq mi) was designated. Hydrologically the Sudd plays an important role in storing floodwaters and trapping sediments from

3477-524: The threat of diseases borne by swamp insects. Wetlands are removed and replaced with land that is then used for things like agriculture, real estate, and recreational uses. Many swamps have also undergone intensive logging and farming, requiring the construction of drainage ditches and canals. These ditches and canals contributed to drainage and, along the coast, allowed salt water to intrude, converting swamps to marsh or even to open water. Large areas of swamp were therefore lost or degraded. Louisiana provides

3538-500: The word can be used for any low-lying and seasonally waterlogged terrain. In Europe and in agricultural literature low-lying meadows that require draining and embanked polderlands are also referred to as marshes or marshland. Marshes can often be found at the edges of lakes and streams, where they form a transition between the aquatic and terrestrial ecosystems . They are often dominated by grasses , rushes or reeds. If woody plants are present they tend to be low-growing shrubs, and

3599-404: The works to a halt, 240 km of the canal of a total of 360 km had been excavated. The rusting remains of the giant German-built excavation machine—variously nicknamed either "Sarah" or "Lucy" —are visible on a Google Earth image at the south end of the canal, where it has been located since it was destroyed by a missile. When peace was restored in 2000, speculation grew about a restart of

3660-901: The world is the Amazon River floodplain, which is particularly significant for its large number of fish and tree species. The Sudd and the Okavango Delta are Africa's best known marshland areas. The Bangweulu Floodplains make up Africa's largest swamp. The Mesopotamian Marshes is a large swamp and river system in southern Iraq , traditionally inhabited in part by the Marsh Arabs . In Asia, tropical peat swamps are located in mainland East Asia and Southeast Asia. In Southeast Asia, peatlands are mainly found in low altitude coastal and sub-coastal areas and extend inland for distance more than 100 km (62 mi) along river valleys and across watersheds. They are mostly to be found on

3721-664: The year and generally have a circular shape. As the playa dries during the summer, conspicuous plant zonation develops along the shoreline. Prairie potholes are found in northern North America, such as the Prairie Pothole Region . Glaciers once covered these landscapes, and as a result, shallow depressions were formed in great numbers. These depressions fill with water in the spring. They provide important breeding habitats for many species of waterfowl. Some pools only occur seasonally, while others retain enough water to be present all year. Many kinds of marsh occur along

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