Wasur and Rawa Biru
Location:
8°03'-9°06'S, 140°30'-141°00'E; in southeastern Irian Jaya on the border with Papua New Guinea east of Merauke, Kabupaten Merauke, Irian Jaya.
Area:
431,000 ha, including the Wasur Game Reserve (308,000 ha) and Rawa Biru Strict Nature Reserve (4,000 ha within the Game Reserve).
Altitude:
Sea level to 90m.
Biogeographical Province:
5.1.13.
Wetland type:
02, 06, 07, 11, 14, 15, 16, 18 & 21.
Description of site:
An extensive complex of permanent and seasonal freshwater lakes, marshes, flooded savanna woodland and riverine floodplains, dissected by numerous rivers, including the Maro, Dalrii and Bensbach, which rise in the Star Mountains to the north. Almost the entire area floods during the wet season (December to March or April), and generally becomes inaccessible except by shallow-draft boats and canoes. The only areas above water are along ancient raised beach ridges with their attendant monsoon forest. During the dry season, the region becomes extremely dry, and water is confined to a few permanent water bodies and the deeper river channels. Some permanent lakes, such as Rawa Biru, are very deep and probably acidic. In the south, vast areas of tidal mudflats and sandy flats extend westwards along the coast almost without break from the Papua New Guinea border to Pulau Kimaam (site 134). The tidal flats are backed by large and mainly undisturbed tracts of mangrove forest, seasonally flooded paperbark swamp forest and some areas of sand dunes. The tides are extremely variable, with no clear diurnal pattern. Ebb tides frequently expose as much as 500m of mudflats, while high spring tides flood large areas inland.
Climatic conditions:
Humid tropical climate with a pronounced rainy season from December to March or April. The dry season is very hot, but with cooling onshore breezes along the coast.
Principal vegetation:
Ten main vegetation types have been described including lowland forest, Melaleuca-Eucalyptus woodland, savanna, parkland, swamp vegetation, mangrove forest and beach vegetation. The Wasur Game Reserve includes 6,180 ha of mangrove forest and 161,180 ha of savanna the Rawa Biru Nature Reserve includes 4,000 ha of seasonal freshwater swamps. The area also includes over 250,000 ha of seasonal peat swamp.
Mangrove forest occurs in a belt up to three km wide along the coast, and also far inland in the Wasur Game Reserve along ancient creek beds. The coastal mangroves are dominated by species of Avicennia, Sonneratia and Rhizophora. Bruguiera sp occurs in association with species of Acacia, Acanthus and Acrostichum at inland sites. The freshwater swamp forest is dominated by Melaleuca leucodendnon.
The lush vegetation associated with permanent open water includes Azolla imbnicata and species of Nymphaea, Lotus, Utriculania and Lemna. Creeping grasses, such as Ischaeum sp and Pseudonaphis sp, and tall herbs, such as Hanguana sp and Cyclosorus sp, grow around the margins of the lakes. Tall stands of Phragmites karka are rather scarce.
The sand dune vegetation consists of a "pescaprae" formation with Ipomoea pescaprae, Canavalia maritima, creeping herbs, grasses and sedges. Further inland, there is a shrub zone with Hibiscus tiliaceus, Barringtonia asiatica and Cocos nucifera. There are some tidal sand fiats covered with Sesuvium portulacastrum in the southeastern corner of Wasul Game Reserve.
Land tenure:
Mainly state owned, with certain areas being leased to trans-migrant settlers and a few sites leased to ranchers. Originally, all or most of the land would have comprised native hunting ranges, and had traditional boundaries. These boundaries may still exist so far as the native people are concerned, but they have little credence with the authorities. All forested land is under the jurisdiction of the Forestry Department.
Conservation measures taken:
Some 210,000 ha were designated as a Game Reserve (Suaka Margasatwa) in 1978, and this was extended by a further 94,000 ha in 1982. The permanent open-water swamps at Rawa Biru are protected in a Strict Nature Reserve (Cagar Alam) of 4,000 ha, established in 1978.
Conservation measures proposed:
There is a proposal to extend the existing protected area by a further 127,000 ha.
Land use:
Fishing, hunting, harvesting of birds' eggs, subsistence agriculture, livestock grazing and illegal logging. Most of the wetland areas are hunted by native people for meat (e.g. wallabies, deer, cassowaries and monitor lizards) and eggs of nesting birds such as Magpie Geese Anseranas semipalmata, herons, egrets, ibises and Brolga Crane Grus rubicunda. The native people also cultivate small garden plots, usually in the monsoon woodlands and typically for only one season before moving on to a new site. The principal crops are maize, taro, sweet potatoes and tapioc.
Disturbances and threats:
The area is under great pressure from many sources, and it is estimated that within the next three years, a considerable portion of the reserve will have been destroyed. There are two major road systems in the reserve; a south coastal road from Merauke to the Papua New Guinea border, and the Trans-Irian highway which bisects the reserve into two almost equal parts. In addition, there are many smaller dirt roads and trails. This accessibility has resulted in a considerable amount of illegal hunting, logging, cutting and burning. At the height of the dry season, large areas are intentionally burned, presumably as a means of driving game for the hunt and killing snakes. Much of the marsh vegetation has been badly damaged by the large numbers of introduced Rusa Deer Cervus timonensis and Wild Boar Sus scrofa, and also by hunters in motor vehicles. Some coastal savanna woodland and grasslands, particularly within the Wasur Game Reserve, are illegally used by recent settlers for grazing cattle.
Economic and social values:
The wetlands support a considerable amount of subsistence hunting and fishing. The proximity of Wasur to the large township of Merauke, its relatively easy access and its numerous natural attractions make it a valuable recreation resource with great potential for tourism.
Fauna:
Over 390 species of birds have been recorded in the area. The site is particularly important for waterbirds, many species occurring in very large numbers. The wetlands are especially rich in herons, egrets, storks and ibises. A recent survey recorded:
2,500 Egnetta picata 350 E. garzetta
5,000 E. intenmedia 250 E. alba
over 30,000 Threskiornis molucca over 350 Ephippionhynchus asiaticus
350 Canphibis spinicollis
and over 4,000 Plegadis falcinellus (both P. f. falcinellus and P. f. peregrinus). Other resident waterfowl and dry season visitors from northern Australia include Tachybaptus novaehollandiae, Pelecanus conspicillatus, Phalacroconax melanoleucos, P. sulcirostnis, Anhinga novaehollandiae, Ixobrychus minutus, I. sinensis, I. flavicollis. Zonerodius heliosylus, Nycticorax caledonicus, Butonides striatus. Egretta sacra, Ardea novaehollandiae, A. sumatrana, Platalea regia. Ansenanas semipalmata (10,000 in December 1983), Dendrocygna guttata, D. arcuata. Tadorna radjah, Nettapus pulchellus, Anas superciliosa, A. gibberifnons, Aythya austnalis. Gnu rubicunda, Rallus philippensis. Rallina tricolor, Poliolimnas cinereus, Gymnocrex plumbeiventris. Porphyrio porphyrio, Irediparra gallinacea, Himantopus leucocephalus, Esacus magnirostris and Vanellus miles. The rare New Guinea Flightless Rail Megacrex inepta may still occur in the area.
The coastal wetlands are an extremely important staging and wintering area for migratory shorebirds. Twenty-five species of Palearctic shorebirds and three Australian species (Haemasopus longirostnis. Stiltia isabella, Charadrius cinctus) have been recorded. The most numerous species (with recent counts in brackets) are as follows:
Pluvialis dominica (112) Charadrius mongolus (3,130)
Limosa limosa (432) Numenius minutus (4,000)
N. phaeopus (96) N. madagascaniensis (45)
Tringa nebulania (35) T. glareola (large numbers)
Xenus cineneus (278) Calidnis tenuirostis (180)
C. ruficollis (520) C. acuminata (655)
Gulls and terns include Larus novaehollandiae (a scarce winter visitor from Australia), Chlidonias hybnida, Gelochelidon nilotica, Hydroprogne caspia, Stenna hinundo and S. albifrons.
Other wetland birds include the raptors Pandion haliaetus, Haliastur sphenurus, H. indus and Haliaeetus leucogaster, and thirteen species of kingfishers: Alcedo azurea, A. pusilla, Ceyx lepidus, Dacelo gaudichaud, D. tyro, D. leachii, Clytoceyx rex, Melidora macrorrhina, Halcyon nigrocyanea, H. macleayii, H. chloris, H. sancta and H. torotoro.
Some 81 species of mammals have been recorded, including the introduced Rusa Deer Cervus timorensis (abundant), Sus scrofa, Hydromys chrysogaster, Syconyctenis australis, Tachyglossus aculeatus, Phalanger macullatus, Petaurus bnevipes, Doncopsis veterum and Macropus agilis. Many of the mammals are endemic to New Guinea. The Dugong Dugong dugon still occurs along the coast.
Reptiles include the endemic monitor lizard Varanus salvadorii as well as V. timoriensis, Chiamydosaunus kingi and the endangered endemic Carettochelys insulpta. The Estuarine Crocodile Crocodylus porosus probably still occurs in very small numbers. Fishes include Scleropages sp.
Special floral values:
The wetland ecosystems are unique in Indonesia, and quite different from any other wetland areas protected within reserves.
Research and facilities:
In September-December 1983, Bishop (1984) conducted a survey of the area to determine appropriate boundaries for the reserve, to examine the impact of egg-collecting on the waterbird populations, and to investigate the hunting of Rusa Deer as it related to conserving the reserve. Nash and Nash have carried out a survey of the Estuarine Crocodile population. There are no research facilities in the reserve, but the land-use agency Euroconsult maintains an office in Merauke with excellent mapping facilities.
References:
Bishop (1984); IUCN (in prep); Karpowicz (1985); MacKinnon & Artha (1981b); Petocz (1984).
Criteria for Inclusion:
123.
Source:
Marcel J. Silvius and K. David Bishop.