Muir-Unicup Wetlands (26487)
Australia, Australasia
Site overview
KBA status: confirmed
Global KBA criteria: A1a
Year of last assessment: 2009
National site name: Muir-Unicup Wetlands
Central coordinates: Latitude: -34.4470, Longitude: 116.7483
System: freshwater, terrestrial
Elevation (m): 175 to 250
Area of KBA (km2): 13.76444
Protected area coverage (%): 92.57
KBA classification: Global
Legacy site: Yes
Site details
Site description: The IBA comprises a system of wetlands around Lake Muir in Western Australia, which collectively support a significant population of Australasian Bittern. It includes the following wetlands with Australasian Bittern records in the 2000s: Kulunilup Swamp, Bokarup Swamp, Cobertup Swamp, Byenup Lagoon, Tordit-Gurrup Lagoon, Geordinup Swamp and Poorginup Swamp. The wetlands captured by the IBA are shallow with extensive beds of dense sedgeland and fringing stands of shrubland and woodland. Additional wetlands in the system may be included in the IBA if they are shown to provide suitable habitat for bitterns, including swamps around Unicup Lake, where bitterns have been seen. Counts of up to two Australasian Bittern were made at Yarnup Lagoon in 1981-1985 (Jaensch et al. 1988), but Yarnup Lagoon has been excluded from the IBA because conditions are no longer considered suitable for bitterns. Lake Muir has been excluded from the IBA as it is unsuitable for bitterns but it has supported large numbers of Australian Shelduck and may prove to be globally significant for that species. .The Lake Muir region has a warm Mediterranean climate.
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: More than 40 species of waterbird have been recorded in the IBA. An estimated 12,000 Australian Shelduck were observed at Tordit-Garrup Lagoon in December 1982 when conditions at nearby Lake Muir were unsuitable for the species. Other species recorded in notable numbers are Pacific Black Duck (758 in November 1987 at Byenup Lagoon) and Hardhead (550 in March 1989 at Tordit-Garrup Lagoon). The system also supports regionally significant numbers of Australasian Darter (up to 20 at Byenup Lagoon) and Australian Little Bittern (a count of seven at Yarnup Lagoon) (Jaensch 1984; Jaensch and Vervest 1988; Jaensch et al. 1988; DEWHA 2008a). Terrestrial species recorded in the IBA include Long-billed Black-Cockatoo, Western Rosella, Red-capped Parrot, Western Corella, Elegant Parrot, Red-winged Fairy-wren, White-breasted Robin and Western Yellow Robin (Atlas of Australian Birds database). Non-bird biodiversity: The IBA supports more than 90 taxa of invertebrates and a small number of native fish species (Storey 1998; DEWHA 2008a).
Other site values: Western Australian State government with management the responsibility of Department of Environment and Conservation.
Habitats
Land use: nature conservation and research
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Wetlands(Inland) | 100 |
Threats
Summary of threats to biodiversity at KBA: Continue to undertake control of feral pigs, horses and deer. Determine the impacts of exotic species on Australasian Bitterns and their habitat and develop corrective actions where necessary.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Named species | Ongoing |
| Biological resource use | Logging & wood harvesting | Unintentional effects: subsistence/small scale (species being assessed is not the target) [harvest] | Ongoing |
| Pollution | Agricultural & forestry effluents | Type Unknown/Unrecorded | Ongoing |
| Agriculture & aquaculture | Livestock farming & ranching | Small-holder grazing, ranching or farming | Ongoing |
| Climate change & severe weather | Droughts | Ongoing |
Additional information
References: DEWHA (2008a) A Directory of Important Wetlands in Australia. Byenup Lagoon System - WA046. Downloaded from http://www.environment.gov.au/water/publications/environmental/wetlands/database/ accessed December 2008. DEWHA (2008b) Information Sheet on Ramsar Wetlands (RIS). Muir-Byenup System, Western Australia - WA056. Downloaded from http://www.environment.gov.au/water/publications/environmental/wetlands/database/ accessed December 2008. Jaensch, R.P. (1984) Breeding by Little Bitterns in nature reserves. SWANS 14: 14-17. Jaensch, R.P. and Vervest, R.M. (1988) Waterbirds in the Eastern Muir Wetlands. RAOU Report 47. Canning Bridge, Western Australia: Royal Australasian Ornithologists Union. Jaensch, R.P., Vervest, R.M. and Hewish, M.J. (1988). Waterbirds in Nature Reserves of South-western Australia 1981-1985. Reserve Accounts. RAOU Report 30. Canning Bridge, Western Australia: Royal Australasian Ornithologists Union. Storey, A.W. (1998) Assessment of the nature conservation values of the Byenup-Muir peat swamp system, south western Australia: physico-chemistry, aquatic macroinvertebrates and fishes. Unpublished report. Perth: Department of Conservation and Land Management and Canberra: Environment Australia.
Contributors: Roger Jaensch of Wetlands International and Peter Taylor provided data and comments. Roger Hearn and Ian Wheeler of DEC supported surveys of bitterns.