Lake Argyle (24820)
Australia, Australasia
Site overview
KBA status: confirmed
Global KBA criteria: B1, D1a
Year of last assessment: 2009
National site name: Lake Argyle
Central coordinates: Latitude: -16.3120, Longitude: 128.7603
System: freshwater, terrestrial
Elevation (m): 100 to 110
Area of KBA (km2): 933.99814
Protected area coverage (%): 98.56
KBA classification: Global
Legacy site: Yes
Site details
Site description: Lake Argyle varies in size from less than 750 km² to over 2000 km². The maximum depth is about 50 m over the original channel of the Ord River but the southern and eastern slopes are very shallow with gradients less than 1 in 500. Water levels fluctuate about 4 m every year, preventing the growth of extensive fringing vegetation, but allowing floating weeds to develop extensive mats up to hundreds of metres wide. The IBA includes the maximum extent of the lake, which includes large areas of mud flats and flat grasslands when the lake is not in full flood.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Additional biodiversity: Lake Argyle supported around 181,400 waterbirds in 1986 (Jaensch and Vervest 1990), 150,000 in 2005 (Hassell et al. 2006), which could be extrapolated to 200,000, and 245,000 in 2007 (Bennelongia 2007). Other waterbirds with high numbers estimated in these surveys (note that the 2005 survey was better timed for shorebirds) include: 50,800, 54,327 and 9659 Eurasian Coot (in 1986, 2005 and 2007 respectively), 17,200, 11,602 and 4300 Grey Teal, 972, 4558 and 4082 Glossy Ibis, 60, 5091 and 99 Marsh Sandpiper, 150, 3732 and 119 Australasian Grebe, 3362, 510 and 1725 Plumed Whistling-Duck, 90, 2308 and 30 Wood Sandpiper, 657, 369 and 1133 Radjah Shelduck, 460, 646 and 517 Australasian Darter, 398, 52 and 4 Brolga and, in 2005, 6264 Pink-eared Duck, 1687 Little Curlew and 159 Freckled Duck. Few waterbirds breed, max 245 pairs of Pied Cormorant in 1986. A flock of 3000 Flock Bronzewings was seen in December 2005. Yellow Chats breed, and more than 100 were counted in 1986. Six Australian Painted Snipe were seen in August 2007 (G. Dutson pers. obs.; http://www.birdswa.com.au/sightings/sightings_124.htm). Terrestrial restricted-range or biome-restricted species which have been recorded in small numbers around the margin of the IBA include Banded Honeyeater, Bar-breasted Honeyeater, Bush Stone-curlew, Long-tailed Finch, Masked Finch, Northern Rosella, Purple-crowned Fairy-wren (probably now extirpated; G. Dutson pers. obs.), Sandstone Shrike-thrush, Silver-crowned Friarbird, Star Finch, White-gaped Honeyeater, White-quilled Rock-Pigeon and Yellow-tinted Honeyeater (Atlas of Australian Birds database).
Other site values: Western Australian State Government.
Habitats
Land use: rangeland/pastureland | water management (100%)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Wetlands(Inland) | 95 | |
| Grassland | 5 |
Threats
Summary of threats to biodiversity at KBA: Cattle and other ungulates should be fenced off important shallows in the south and east. Cooperative management plans with land-holders, indigenous owners and graziers should be developed to agree and ensure grazing policies. Weeds must be monitored and controlled.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Unspecified species | Ongoing |
| Agriculture & aquaculture | Livestock farming & ranching | Agro-industry grazing, ranching or farming | Ongoing |
| Pollution | Agricultural & forestry effluents | Soil erosion, sedimentation | Only in the future |
Additional information
References: Bennelongia Pty Ltd (2007) Waterbird Monitoring at the Lake Argyle and Lake Kununurra Ramsar Sites, North-Eastern Kimberley region. Unpublished report: Bennelongia Pty Ltd, Jolimont, Western Australia. DEWHA (2008) Directory of Important Wetlands in Australia. Lake Argyle-WA097. Downloaded from http://www.environment.gov.au/water/publications/environmental/wetlands/database/ in January 2009. Jaensch, R.P. and Vervest, R.M. (1990) Waterbirds at remote wetlands in Western Australia 1986-88. Part one: Lake Argyle and Lake Gregory. Royal Australasian Ornithologists Union Report 32:1-26.