Arafura Swamp


Site description (2008 baseline):

Site location and context
This IBA includes the Arafura swamp, 450 km east of Darwin, and the coastal saline flats of Castlereagh Bay west to Milingimbi, but not the tropical savanna in the surrounding catchment. The north-west boundary opposite the island of Milingimbi and the north-east boundary at the mouth of the swamp are based on the shorebird surveys of Chatto (2003). The site is in the wet tropics with an average of 1600 mm of rain along the coast during December to March. The swamp is fed by the Goyder and Gulbuwangay Rivers which terminate at the southern end of the swamp where the water disperses across a broad floodplain which narrows at the coast where it is constricted by bedrock. The swamp receives and retains water throughout the year and the Goyder River has the second-highest dry-season flow of any river in the Northern Territory. During the wet season there are extensive floods across the coastal plain where the swamp empties into the sea.

Key biodiversity
Brennan et al. (2003) estimated 300,000 waterbirds in Arafura Swamp on both of two aerial surveys, including about 130,000 unidentified egrets in both 1998 and 2000. Chatto (2000) identified six small waterbird colonies supporting eight species, with maximum counts of 150 and 300+ Royal Spoonbills. Brennan et al. (2003) recorded a colony of 500-1000 Australian White Ibis and estimated a minimum of 1200 Magpie Goose nests. The following records of threatened species are from outside the IBA boundary and may not constitute resident populations: one Gouldian Finch was recorded in 1980, one Northern (Crested) Shrike-tit was seen in 1990, there were two records of Partridge Pigeon in 1990 and six records of Hooded Parrot in the last 20 years (Brennan et al. 2003). Chatto (2003) recorded significant numbers of waders on the coastal salt flats in the north-west of the IBA but numbers are unknown. Other high counts include 500 Great Egrets and 7500 Cattle Egrets (Chatto 2006). White-gaped Honeyeaters and Long-tailed Finches have also been recorded at the swamp (Atlas of Australian Birds database).

Non-bird biodiversity: Brennan et al. (2002) recorded five native fish, 220 bird, 39 mammal, 72 reptile, 23 frog and 1,324 plant species in the wider Arafura catchment. These include the Vulnerable False Water Rat Xeromys myoides and a form of the Banded Rainbowfish Melanotaenia trifasciata which is endemic to the Goyder River. The IBA also holds numerous sites of high cultural value.



Pressure/threats to key biodiversity
The cattle at the north of the swamp must be fenced away from the fragile banks and waterways separating the tidal and freshwater sections. Community ranger weed management programs should be supported to continue and strengthen their quarantine, awareness and surveillance activities whilst maintaining their control of Mimosa pigra and other weeds.

Conservation responses/actions for key biodiversity
Arafura Swamp is listed as an Australian wetland of national importance (DEWHA 2008) and is classified as a site of conservation significance by the Northern Territory Government (Harrison et al. 2009; Ward & Harrison 2009). Brennan et al. (2002) have completed a detailed assessment of the site's biological value, based on 8,000 vertebrate records and 30,000 plant records collected in 13 field trips between 1998-2001.

Land ownership
Arnhemland ALT

Site access / Land-owner requests
This IBA is on Traditionally Owned land.

Acknowledgements
The Yolngu people supported the research and publication of Brennan et al.(2003).


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Arafura Swamp (Australia). Downloaded from https://datazone.birdlife.org/site/factsheet/arafura-swamp-iba-australia on 22/11/2024.