Wetlands in Rann of Kachchh

GREAT RANN OF KACHCHH - Gujarat

Location: 200 km WNW of Ahmedabad, Gujarat
Area: 700,000 ha
Altitude: 0-10 m
Biogeographical province: 4.15.7
Wetland type: 02, 06, 07, 08, 16

Description of site: The Great Rann is a vast saline plain stretching eastwards from the eastern edge of the Indus delta, 340 km to longitude 71 -15’E. Isolated hill ranges within the salt waste rise to over 500 m elevation. India’s frontier with Pakistan passes through the northern edge of the Rann; its western boundary is the Arabian Sea; to the south lies the peninsula of Kachchh, and to the north and east the great Thar Desert. It is linked by a narrow channel to the Little Rann (site 50) which, in turn, is linked to the Gulf of Khambhat through the marshy depression in which Nalsarovar (site 57) survives as a freshwater remnant of the sea that once covered all three sites. The Arabian Sea formerly isolated present-day Saurashtra and Kachchh into islands; a combination of tectonic uplift, silt deposition by the southerly watercourses of the Indus, and aeolian input has caused the marine recession. The modern Great Rann is now flooded only between May and October when sea water, driven by high winds and tides from the Arabian Sea and monsoon run-off from the hills of Gujarat and Rajasthan, mix together over the plains. For the remainder of, year, the Rann is a vast expanse of sun-baked mud and sand with halite and gypsum scences. During years with low rainfall or drought no freshwater, or very little, enters the Great Rann and the tidal sea water has high salinity. In such years water starts evaporating and seeping underground quite fast, leaving the surface dry sooner than in other years. Vegetation is more or less confined to the “bets”, areas of relatively salt-free land a few metres higher than the plains and several hundred hectares in extent. These become true islands during the monsoon and support grasses and a few shrubby bushes. At its western extremity, the Rann merges into the southern part of the Indus Delta, a region of numerous low-lying muddy islands, tidal creeks, mangrove swamps, and extensive inter tidal mudflats

Climatic conditions: Dry, tropical monsoon climate with an average annual rainfall of less than 300 mm concentrated in July, August, and September. Tempera- tures range from about 7° C in winter to well 40° C in summer Principal vegetation: Areas with low salinity support grassland with many grass species, notably Dichanthium annulatum, Sehima nervosum, Cenchrus ciliaris, C. setigerus and Panicum antidotale, and the occasional Acacia nilotica, and Capparis sp. In the more saline areas, Salvadora persica and Tamarix dioica are widespread. The mangroves in the coastal zone are mostly poor and disturbed; the dominant species is Avicennia albs. Peripheral to the Rann, the climax vegetation was probably a low xerophytic scrub dominated by stunted Acacia spp., and Euphorbia spp., together with the introduced Prosopis juliflora Land tenure: State-owned Conservation measures taken: None

Conservation measures proposed: A proposal was made for the establishment of a Flamingo Sanctuary to protect the breeding colony of flamingos at Pachham Island (Flamingo City), but the site has been abandoned by the birds Land use: The grasslands are extensively grazed by domestic livestock. There is a permanent military presence on both sides of the international frontier

Disturbance and threats: There is excessive grazing by camels in the salt marshes and mangrove swamps. The pressure of military personnel and equipment on the northern edge of the Great Rann is having an adverse effect on several wildlife species, and hunting of the larger species has become a major problem. Prosopis julifora, an introduction from Mexico, has been planted extensively and may well pose a serious threat to the indigenous flora. Wild asses (Equus hemionus khur) occasionally graze in peripheral croplands

Economic and social values: No information

Fauna: The Great Rann is a critically important refuge for the Indian wild ass (Equus hemionus khur); a threatened subspecies of the Asiatic wild ass. Other mammals include the chinkara gazelle (Gazella dorcas) and wolf (Canis lupus). The Asian population of the lesser flamingo (Phoenicopterus minor) is centred on the Great Rann of Kachchh. Very little information is available on the numbers, movements, and breeding of the population. One estimate suggests that a few tens of thousands of birds are involved. Large numbers of young immature birds are frequently reported, and it is assumed that the breeding colony of the greater flamingo (Phoenicopterus ruber) in Indian territory was at Pachham Island in the centre of the Great Rann. Numbers have declined drastically this century; the population was estimted at some 200,000 adults in 1945 and 400,000 in 1960, but only 18,000 breeding pairs were located in 1970, and the Pachham site has since been abandoned. It is likely that the birds still breed somewhere in the Rann, but the precise location of the colony is unknown. Pelecanus onocrotalus and Recurvirostra avosetta have also been found breeding in the past, and may still do so. The Rann is an important staging area for migratory waterfowl, particularly Anatidae and shorebirds, during their southward passage into the peninula of India in autumn. Large numbers of birds remain throughout the winter when conditions permit, e.g. during a brief visit to the Rann in late February 1980, de Block recorded:

1200 Pelecanus onocrotalus 600 Phalacrocorax carbo
10 Ciconia nigra 6000 Phoenicopterus ruber
300 Anas acuta 8000 Fulica atra

The coastal mudflats and mangroves swamps in the west support breeding colonies of Ardeola grayii, Egretta gularis, E. albs, and Ardea cinerea, and are known to be of great importance for shorebirds, gulls, and terns, but no census data are available. In years of low rainfall or drought, no birds visit the area due to high water salinity The small fish Cyprinodon dispar is very common in the Rann Special floral values: None known