Sudd wetland

Description

The Sudd wetland, with an estimated area of approximately 57,000 km² represents one of the largest freshwater ecosystems in the world. The extent of the Sudd wetlands is highly variable; it depends largely on the seasons and years respectively. In the wet season the size of the wetland increases up to 90,000 km² and gradually decreases to about 42,000 km² depending on high seasonal flood. It is sustained by the flow of the White Nile (or Bahr el Jebel) from Lake Victoria in Uganda, in addition to rainfall runoff from its surrounding areas. The White Nile dissipates northwards from Juba across a shallow depression to produce a network of channels, lagoons and inundated areas, which harness the nutrients of the underlying clay soils. Patterns of flood inundation heavily influence the Sudd’s vegetation, which consists primarily of permanent swamps, river and rain flooded grasslands, and floodplain woodlands. These habitats exhibit strong environmental gradients with pronounced short and long-term variations in biomass production and distribution.

The Sudd wetland falls within the “Sudd-Sahelian Flooded Grasslands and Savannas” WWF Global 200 eco-region. It is internationally recognised for its unique ecological attributes that include various endangered mammalian species, antelope migrations, millions of Palaearctic migratory birds and large fish populations. Notable wildlife species include the African elephants (Loxodonta africana), Nile lechwe (Kobus megaceros) endemic to South Sudan, tiang migration (Damaliscus lunatus tiang), white-eared kob migration (Kobus kob thomasi), buffalo (Syncerus caffer), and bird species include the shoebill (Balaeniceps rex). The Sudd is an important wintering ground for some of the migratory birds such as the Great White Pelican (Pelecanus onocrotalus), Black Crowned Crane (Balearica pavonina), White Stork (Ciconia ciconia) and Black Tern (Chlidonias niger). It forms part of the East-Asian/East African flyway of Palearctic birds, linking breeding ranges in central-Europe and Asia with winter ranges to the south. A large number of inter-African bird migrants also rely on the Sudd and surrounding habitats as a dry season refuge.

The Sudd has rich and abundant fish populations, a response to the favourable environmental conditions for recruitment and survival offered by its mosaic of habitat types. Key aquatic habitats range from open water and riverine to lacustrine and palustrine, which offer ideal spawning, rearing, growing, feeding and survival grounds for over a hundred species of fish. These habitats are largely intact and largely unaffected by industrial development and include; 31 Siluroids, 16 Characoids, 14 Cyprinoids, 11 Momyrids, 8 Cichlids, and 7 Cyprinodonotids of fish communities. There are also eight (8) endemic Nile dwarf fish species found in the Sudd wetland, which are Cromeria nilotica, Nannaethiops unitaeniatus, Barbus stigmatopygus, Chelaethiops bibie, Andersonia leptura, Aplocheilichthys loati, Epiplatys marnoi and Electris nanus.

The culture and society of the approximately 1 million people inhabiting the Sudd wetland region are closely linked to its ecological functioning. The dominant cultural affiliations in the Sudd are the tribes of Nuer (Southern Liech State), Dinka (Eastern Lakes state), Shilluk (Upper Nile State) and Anyuak (Akobo State) all of which are Nilotic and pastoralists peoples indigenous to the Nile Valley. These groups have developed traditions that have allowed them to adapt to the inundated and seasonally variable conditions across the Sudd through a combination of nomadic agro-pastoralism, non-timber forest product collection and fishing. Specific practices include the seasonal construction of settlements on small islands in flooded areas, and traditional hunting and fishing techniques. The hydrological functions and patterns of the Sudd maintain the livelihoods and cultural practices of the Sudd’s tribes.  The cultural groups living within the Sudd region also maintain beliefs and practices that serve to support and conserve the environment they live in. For example, the cultural beliefs of the Shilluk community living within the Sudd region are an important aspect in the preservation of the Nile lechwe (antelope species endemic to South Sudan) as they consider killing of the animal species as taboo, and this of course helps in their conservation and sustainable use. It is therefore valuable to support many of the cultural practices of the communities living in the Sudd as these are closely intertwined with the natural elements and preserving them also creates and maintains an awareness of past and traditional knowledge in the general public.

Justification de la Valeur Universelle Exceptionnelle

The Sudd is Africa’s largest wetland and one of the largest tropical wetlands in the world. The IUCN world heritage site gap assessment identified the Sudd-Sahelian Flooded Grasslands and Savannas eco-region, of which the Sudd is a part, as a key unrepresented ecological system globally. It is a vast social-ecological and hydrological system driven by the dynamics Nile basin’s water regime, supporting a diverse array of wildlife and various cultural traditions of its indigenous communities. Its unique assemblage of extensive freshwater and grassland habitats are characterized by extensive seasonal rain fed flooding and low substrate permeability. A wide variety of adaptive responses by humans (in particular pastoralists) and wildlife have evolved to cope with the Sudd’s resource dynamics. Under these adaptive strategies, carrying capacity for herbivores (both domestic and wild) has been maximized, albeit in harsh conditions, and current herbivore numbers rival population numbers across other African countries. Fundamental to facilitating this carrying capacity has been unconstrained foraging movement across an intact and functioning landscape in order to access widely spread resources. As a result, the Sudd and the Saharan flooded grassland ecosystem it supports, support two of the largest ungulate migrations in the world, those of the tiang and white-eared kob.

Criterion (v): Within the islands of the Sudd there are various traditional human settlements which represent the culture of the inhabitants. The specific practices such as seasonal construction of human settlements on small islands in flooded areas within the Sudd, and traditional hunting and fishing techniques by itself represents human interaction with the natural environment. The hydrological functions and patterns of the Sudd maintain the livelihoods and cultural practices of the Sudd’s tribes.

Criterion (vii): The Sudd’s vast flooded expanse with lagoons, channels and floating vegetation transform the entire Sudd habitats into a scenic landscape of exceptional natural beauty, and sustain the ecosystem of remarkable habitat features and species diversity, enhancing the maintenance of the ecological process and incredible natural phenomena. The annual seasonal floods’ discharge across the wetland systems throughout the year modifies the entire ecosystems in terms of nutrient cycle and other ecological processes and this of itself is a critical source of live-force especially during the dry season.

Criterion (ix): The complexity of the Sudd ecosystems, inter-dependence of climatic, geo-morphological, hydrological and biological processes of its own represents outstanding and significant on-going ecological and biological processes in the evolution and development of wetland ecosystems and communities of plants and animals. The continuous transformation of geomorphic feature such as islands, channels, river banks, flood plains, lagoons and lakes in turns influences the biotic and a biotic dynamics of the Sudd ecosystems. The sudd wetland contains a number of ecological processes related to the floods, channals, inundation, nutrient cycle associated with biological processes such as breeding, growth, animal migration, colonization (alien species) and plants succession. These ecological processes of the Sudd swamps are important for the basis of scientific research and of human development systems and long-term evolution process. 

Criterion (x): The Sudd wetlands contain rich biodiversity with unique wildlife assemblage and habitats, and as such it is a home to some of the world’s most endangered or threathened large mammalian and bird species. These include the African elephants, Nile lechwe (endemic to South Sudan), tiang migration, white-eared kob, buffalo, sitatunga, Nile crocodile, hippopotamus (Vulnerable Species) and the shoebill (Balaeniceps rex), all of which are well adapted to survival in this wetland ecosystem systems. The white-eared kob and tiang migration is an example of a superlative natural phenomena of the largest antelope migration in the world, similar to that of wildebeests migration in Serengeti, in Tanzania ecosystem. The habitats of the Sudd swamps are diverse and represented by the permanent and seasonal rivers, lagoons, permanent swamps, seasonal and rain flooded grasslands, and floodplain woodlands and highland communities. These habitat types comprise of unique species diversity and are composed of all the major classes of aquatic organism, reptiles, birds and mammalian species. These include; some 350 plants species (belonging to different genera), 470 bird species, over 100 fish species, 100 mammalian species and over 120 insect species and unknown number of reptilian and amphibian species.

Déclarations d’authenticité et/ou d’intégrité

Systematic aerial surveys and reconnaissance of the Sudd wetland region conducted between 2007 and 2013 demonstrated that the Sudd wetland has large tracts of largely undisturbed and intact habitats. These habitats support significant viable wildlife populations, including the world’s largest concentrations of shoebill (~7,000) and Nile lechwe (~11,000), in addition to substantial populations of tiang, elephant, buffalo, hippopotamus and sitatunga. There is no significant industrial infrastructure, such as oil wells or pipelines, water abstraction points, dams, roads or bridges, within the permanent extent of the Sudd. Agricultural and other community-based natural resource use activities within its extent are mostly subsistence and small-scale and present limited threat to its ecological or cultural integrity.

There are three (3) main government departments with jurisdiction relevant to the management of the Sudd wetland; these include the Ministry of Environment and Forestry, the Ministry of Wildlife Conservation and Tourism, and the Ministry of Water Resources and Irrigation. There is also a growing mandate for the sustainable management of wetlands in South Sudan, through the development of new environmental laws. This alone would facilitate the integration of this internationally recognized biodiversity hotspot area, which forms a mosaic habitat of the Sudd wetlands. It would have added advantage of not only supporting the existing management structures but prioritizing the available resources. However, a lack of an integrated conservation and development approach is a major barrier to wildlife and ecosystem services protection across the Sudd wetland.

The Sudd area covering about 57,000 Km² was designated as Africa’s second largest RAMSAR site in 2006 and therefore falls under an internationally recognised framework that mandates its conservation and wise use. Currently, there are four protected areas in the Sudd: Shambe National Park (1,750 km²), and Zeraf (10,961 km²), Meshra (4,432 km²) and Fanyikang (504km²) Game Reserves, all of which are home to some globally endangered or threathened wildlife and bird species such as the elephants, Nile lechwe, white eared kob, tiang, buffalo, sitatunga and shoebill stork. Ecological research including aerial wildlife surveys, aerial surveillance and animal movement studies have been conducted across the Sudd from 2007 to present. These have assisted in understanding how effectively the existing four protected areas can protect the Sudd’s ecosystems. Most of the protected areas (which were designated between 31 and 75 years ago) have never had their boundaries demarcated. Additional and more up to date information is needed to guide development activities and conservation area planning. With the improvements in political stability across the Sudd wetland region, efforts are currently underway by the Government of South Sudan and its partners to initiate and scale-up improved natural resource management in key areas.

Across the Sudd region, overexploitation of wildlife and habitat fragmentation are notable threats, including commercial poaching linked to small-arms availability, inadequate planning for returning displaced peoples, competition for scarce natural resources (e.g. pasture and water), road building without sufficient environmental planning, and the expansion of the oil industry into ecologically sensitive areas (the Sudd contains South Sudan's largest oil reserves), which result in habitat degradation from infrastructure and pollution, as well as increased hunting and trafficking activity. The Jonglei Canal Project that began in 1978 presented a significant threat to the social, ecological and hydrological functioning of the Sudd. A large channel was cut between Malakal southwest towards Bor, with the onset of the 1983 Sudan civil war construction of the canal was cancelled. Today a partially inundated channel remains, however, it had no documented negative impact on the Sudd wetland ecosystem.

Comparaison avec d’autres biens similaires

There are two other tropical wetland systems of similar global significance, both of which are properties on the World Heritage List; these are the Okavango Delta in Botswana and the Pantanal Conservation Area (210,000 km²) in Brazil, Bolivia and Paraguay. Both of these are characterised by natural elements of similarity to the Sudd, these include an extensive system of lagoons, seasonally flooded grasslands and rivers supporting diverse wildlife populations and human livelihoods. The Sudd wetland however is distinct from both of these since it falls within the northern hemisphere and different eco-regional context. It therefore has an entirely different ecological assemblage that includes significant populations of African megafauna, some of which are endemic and globally threatened. Of most significance is the role that the Sudd performs in providing dry season feeding grounds for the tiang migration, one of only two long-distance movements of Alcelaphinae antelope species on Earth, the other being the wildebeest migration in the Masai-Mara and Serengeti, in addition the Sudd flooded plain hosts the largest population of globally threatened shoebill stork (Balaeniceps rex) in Africa, with an estimated population of between 5000 to 8000 birds. The Sudd being the largest wetlands in Africa and second largest in the world serves as a giant filter that controls and normalizes the water quality. It also regulates flooding by acting as a giant sponge that absorbs excess water during periods of high water yield. Furthermore, neither the Okavango nor the Pantanal support a unique cultural heritage such as those of the Nuer, Dinka and Shilluk and Anyuak, which is finely adapted to its natural patterns and cycles within minimal environmental impact.