Etosha Pan

Description

The 4730 km² Etosha Pan is a huge, pristine oval-shaped salt pan situated in northern Namibia. It is the central feature of Namibia’s Etosha National Park. It is the terminal playa of the Cuvelai drainage system in the lowest part of the Ovambo Basin at an elevation between 1,071 to 1,086 m above sea level. Smaller pans such as the connecting Fisher’s Pan in the east and adjacent Natukanaoka, Okahakana and Adamax Pans to the west, surround the main pan.

The pan is most of the time a dry, saline desert. The vast expanse of hard, salt-encrusted, vegetationless pan floor resulted in its name “bare place” in the Ndonga language. The high temperatures during the day and moisture-sapping salt surface result in an unsuitable habitat for most animals except ‘extremophiles. During the hot dry season of the austral spring and early summer, numerous dust devils with high winds may form and move over the pan, sucking up small debris or blasting larger objects with salty sand. The only large animal to regularly inhabit the pan floor itself is ostriches that nest several kilometres into the pan where few predators will follow. In contrast, many species of large game are found around its edges as they rest on the bare pan floor. Water is found only in numerous spring-fed waterholes on the pan margin.

Etosha Pan is subject to occasional partial flooding during the rainy season. Direct rainfall accounts for only a small proportion of the pan’s water the majority of inflow during exceptionally wet years is from the Ekuma, Oshigambo, and Omuramba Ovambo rivers of the Cuvelai system. During such years floodwater transforms the pan into a shallow lake holding large sheets of water, usually not exceeding one meter in depth. The water in the pan is, however, unfit for animal consumption as the salt content is often double that of sea water. On such occasions large flocks of flamingos, pelicans, gulls and other waterbirds migrate to the pan. Both greater and lesser flamingos, and even white pelicans, may then breed at Etosha.

The pan formed in Pliocene times when the upper Cunene River and possibly the Cubango River (currently part of the Okavango system) terminated as an interior lake and swamp system, similar to the Okavango Delta in Botswana today. Continental uplift changed the course of these rivers, cutting off the lake’s water supply. The Etosha Pan is a remnant of that endorrheic lake system. Wind erosion removed most of the river-end deposits and deepened the depression. During the drying and deflation process, the soil of the pan became mineral-rich and brackish. Today the pan’s surface is a flat floor of poorly drained, saline clay. The pH is high (8.8 to 10.2), and the sodium content is in excess of 30,000 ppm. The soils surrounding the pan are shallow, brackish and alkaline, mostly cemented by calcrete.

The pan margin is fringed with halophytic vegetation consisting principally of various grasses and shrubs. Open grasslands rise gradually away from the pan and sustain a wide variety of perennial and annual grasses and shrubs. The grasslands and shrubland surrounding the pan are renowned for supporting vast herds of giraffes, zebras, blue wildebeest, oryxes, springbok, ostriches and their accompanying large predators, as well as one of the largest and healthiest populations of black rhino in the world. The area also supports a considerable diversity of smaller mammals, birds, snakes, lizards, invertebrates, etc., including the endemic white-quilled bustard and Etosha agama. The majestic scenes of elephant herds refreshing themselves at the natural springs along the margins of the pan, backdropped against the shimmering-white expanses of the pan itself and the spectacular diversity of other large mammals, makes it one of the most popular game parks in Africa.

Justification of Outstanding Universal Value

The Etosha Pan is an outstanding example of a superlatively sized salt pan that developed as a result of tectonic uplift that diverted river flow from maintaining a wetland in an endorrheic basin. Subsequent deflation by wind removed the unconsolidated sediments and exposed the saline basal clays of the basin, which is an ongoing process to this day. The 4730 km² lake bed is mostly an uninhabited, salt-encrusted extreme desert that is only rarely flooded during exceptional wet periods. It is then transformed into a shallow lake that provides refuge and breeding areas for migratory waterfowl, suggestive of the more permanent that once occupied the area. Ancient shorelines, stromatolite concentrations, fossil beds and calcrete sequences provide geomorphological evidence of the ongoing depositional and deflation processes during wet and dry periods since the Pleistocene. The pan is fringed with natural springs and halophytic grass and shrublands that support impressive numbers of large African herbivores and their associated predators, including the largest single population of black rhinoceros. The spectacular concentrations of diverse species of mammals and birds at natural springs against the vast backdrop of the salt pan create an indelible memory of the value of conservation.

Criterion (vii): The majestic scenes of a spectacular diversity of large mammals that includes some of the most charismatic African species refreshing themselves at the natural springs along the margins of the pan, backdropped against the vast expanses of Etosha Pan itself, makes it one of the most visually compelling examples of wildlife biodiversity in Africa.

Criterion (viii): Etosha Pan is one of the most outstanding global examples of a massive salt pan that formed as the result of river capture that diverted fluvial flow from an endorheic basin, with subsequent wind deflation of shallow lacustrine and swamp deposits. In addition, it is an example of recurrent flooding and formation of a large shallow lake during exceptional wet periods when fluvial discharge terminate in an endorheic basin. Lake-shore ridges, stromatolites, fossil beds and other geomorphological evidence providing testimony of such events during the Pleistocene and Holocene.

Criterion (x): Only the hardiest organisms can survive the hypersaline and extreme dry environment of the very large salt pan. However, a permanent supply of water in natural springs along the margin of the pan and a succession of halophytic grass and shrub communities surrounding the pan support vast herds of grazing ungulates and associated predators that migrate in a clockwise direction around the pan. The natural springs support the largest and healthiest black rhino population in the world, with 113 additional species of mammals and 340 resident and migratory bird species occurring on and around the pan. Etosha has been a conservation area for more than a century that resulted in the spectacular recovery of previously extirpated species such as lions and elephants. It thus represents an exemplary global example of the value of conservation.

Statements of authenticity and/or integrity

The vast expanses of Etosha Pan are almost wholly encompassed within the boundaries of the Etosha National Park and are virtually pristine. Strict regulations forbid vehicular traffic on the pan surface. The fringes of the pan are undisturbed with only the occasional tourist road giving access to viewpoints and waterholes at the edge of the pan. Only one tented camp and the historic Namutoni Fort is located on the pan margin. No dams or other development restrict the infrequent discharges from the Cuvelai drainage into the pan. Etosha Pan is surrounded by one of the most spectacular assemblages of large game that includes healthy populations of elephants, rhinoceros, giraffes, many different species of large ungulates as well as associated large predators such as lions, leopards, cheetahs and hyenas. Many of these species spend their entire natural life within reach of the numerous waterholes on the margins of the pan, within the proposed boundaries, though are free to range over the vast area that is included in the national park.

Etosha Pan is within the boundaries of the Etosha National Park, a conservation area protected by legislation since 1907. There is no mining, exploration or any other non-tourism based economic activities in the proposed area.

Comparison with other similar properties

Etosha Pan at 4,730 km² is one of the larger salt pans in the world, comparable in size to Salar de Uyuni (Bolivia) of 10,582 km², Lake Eyre (Australia) of 8,430 km², Sua Pan of ca. 4,921 km² and Ntwetwe Pan of ca 4,700 km² in the Makgadikgadi system (Botswana), and Great Salt Lake (USA) of 4,662 km². Only Lake Eyre, Sua Pan and Ntwetwe Pan have broadly similar geological histories.

Etosha Pan is most similar to the Makgadikgadi system in Botswana. The Makgadikgadi Pans in the eastern Kalahari basin was included in the Tentative List of Botswana on similar criteria and values as Etosha Pan, though Criterium (v) is currently not deemed applicable to Etosha. As the two sites may be complementary, harmonization of the tentative lists and a transboundary serial nomination shall therefore be investigated.

Both Etosha Pan and the Makgadikgadi Pans systems support large herds of plains ungulates such as zebra and wildebeest, with breeding populations of flamingos and other aquatic birds when the pans are flooded. Both pan systems furthermore originated from ancient inland lake or swamp systems that dried out after tectonic changes diverted or cut off inflow from major rivers that terminated in the two respective endorheic basins. Presently the Makgadigadi pan system consists of multiple pans, separated by relict dune ridges, with a combined extent of ca. 16,058 km². Individual pans are, however, considerably smaller with Sua Pan being the largest.

Makgadigadi is suggested to be the largest salt pan system in the world based on reconstructions that its ancient lake extent reached ca. 30,000 km². Geomorphological reconstructions propose that the Etosha system may have been of a similar size (ca. 22,700 km²) some 32,000 years Before Present, while other studies suggest linkage with the Omadhiya lakes some 60 km north of Etosha that may have resulted in a lake or wetland of ca. 82,000 km². However, speculations regarding the size of the Plio-Pleistocene system are not considered as an important argument for a possible nomination of Etosha Pan. In terms of Criterium (viii) the geological processes are most important, in which regard Etosha and Makgadikgadi is very similar. In the case of the Etosha Pan system, which is more tropical, individual pans are isolated by extensive hardpan calcrete, suggesting overall wetter environmental conditions. Etosha also has other types of evidence that suggests less overall aridity, e.g. stromatolites and spring tufa sequences. There is little to choose between the two sites apart from integrity and configuration. Though much smaller in extent than the combined area of the Makgadikgadi Pans, Etosha Pan stands out as it is virtually pristine and without any modern human impact.

In regards Criterium (x), a number of existing sites on the World Heritage List were inscribed for the biodiversity values of large African savannah ungulates and other fauna. Despite that reality, which will be explored in detail in a nomination dossier, the megafauna of Etosha is a distinctive feature of the site and is under considerable threat or has been extirpated at other World Heritage properties, thus Criterium (x) cannot be disregarded in a future evaluation of the site. Etosha is also one of the oldest protected areas in the world and an example of the value of conservation efforts worldwide in terms of many species that have recovered from the brink of extinction to form large and healthy populations today.