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Location Australia, Western Australia
Central coordinates 115o 24.83' East  33o 37.44' South
IBA criteria A4i
Area 2,038 ha
Altitude 0 - 5m
Year of IBA assessment 2008

BirdLife Australia

Summary The Busselton Wetlands IBA regularly holds large numbers of waterbirds, including more than 1% of the global populations of Banded Stilt and Red-necked Avocet, occasionally more than 1% of the global populations of Australian Shelduck and Sharp-tailed Sandpiper, and regularly more than 1% of the Australian population of Black-winged Stilt (=White-headed Stilt).

Site description The Busselton Wetlands are a chain of coastal wetlands that stretch approximately 25 kilometres east and west of Busselton along Geographe Bay. The IBA consists of the Vasse and Wonnerup lagoons and the Broadwater. These are part of an extensively modified wetland system, now comprising an extensive, shallow (less than 1 m deep), nutrient-enriched wetland system with widely varying salinities, comprised of primarily open water fringed by samphire, rushes, flooded pastures and paperbark trees. Water levels in its two principal components, the Vasse and Wonnerup estuaries (now functioning as lagoons), are managed through the use of flood gates, with the aim of minimising flooding of adjoining lands and largely excluding seawater. Large portions of these lagoons often dry out in summer, and water quality decreases as higher temperatures and eutrophic inflows allow large phytoplankton blooms, and salinity increases as water levels drop. The Broadwater is a low-lying lagoon which fills with water over the wet winter months, and has fringing freshwater swamps. New River and associated waterways between the Broadwater and Vasse-Wonnerup have not been included in the IBA as they support low numbers of waterbirds, but they may be important for the hydrological intregrity of the system. Busselton is one of Australia's fastest developing urban areas and the IBA’s proximity to residential, farming and tourism areas presents a range of threats, management issues and opportunities. The IBA overlaps with the Vasse-Wonnerup Ramsar site but also includes the Broadwater.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Australian Shelduck Tadorna tadornoides non-breeding  1986-2008  1,548-6,108 individuals  medium  A4i  Least Concern 
Himantopus leucocephalus non-breeding  1986-2008  3,290-5,000 individuals  medium  A4i  Not Recognised 
Banded Stilt Cladorhynchus leucocephalus non-breeding  1986-2008  4,000 individuals  medium  A4i  Least Concern 
Red-necked Avocet Recurvirostra novaehollandiae non-breeding  1986-2008  1,915-4,000 individuals  medium  A4i  Least Concern 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Broadwater Nature Reserve 80 protected area contained by site 80  
Sabina Nature Reserve 102 protected area contained by site 46  
Tuart Forest National Park 2,049 protected area overlaps with site 9  
Un-named (No. 41568) Nature Reserve 21 protected area contained by site 21  
Un-named (No. 44838) Nature Reserve 32 protected area contained by site 32  


IUCN habitat Habitat detail Extent (% of site)
Artificial - terrestrial Improved grassland & pasture  minor
Coastline Lagoons  major

Land ownership Parts of five protected areas (managed by DEC), freehold land and unallocated Crown Land (managed by the Shire of Busselton).

Land use

Land-use Extent (% of site)
nature conservation and research major
rangeland/pastureland minor
Notes: Some grazing on freehold land.
water management major
Notes: An important area for flood protection for Busselton.

Other biodiversity Other native species include Water Rat, Brown Bandicoot, Western Ringtail Possum, Western Grey Kangaroo, Tiger Snake, Long-necked Tortoise, Squelching Froglet, Lea’s Froglet, Motorbike Frog, Banjo Frog and Moaning Frog. No nationally rare, threatened or endemic wetland plants have been recorded at the site. Problematic exotic plants such as Bulrush (Typha orientalis) and Arum Lily (Zantedeschia aethiopica) have become established in and around Sabina and Abba Rivers, which feed into the wetland.

Protection status Several - see separate section.

Access/Land-Owner requests Access to the IBA is variable. Estuarine marshland and tidal floodplain are largely on private land. Information regarding public access is available through the Department of Environment and Conservation for the Vasse and Wonnerup Lagoons, and the Shire of Busselton for the Broadwater. A number of access points for walkers and cyclists are provided on the Busselton Wetlands Trails.

Acknowledgements Comments and bird counts have been contributed by Birds Australia WA volunteer observers; Bernie Masters and the Busselton Naturalists' Club volunteers; Peter Taylor and Sue Abbotts; Bruce and Anne Buchanan; and Kim Onton and colleagues at the Department of Environment and Conservation.

References Bamford, A.R. and Bamford, M.J. (1994) Study of the use by waterbirds of the floodplains of the Vasse and Wonnerup Estuaries: Phase 1 Report. Como, Western Australia: Department of Conservation and Land Management.

Bamford, M.J. and Bamford, A.R. (1995) Waterbirds of the floodplains of the Vasse and Wonnerup Estuaries: patterns of usage and the effects of disturbance. Final report to Department of Conservation and Land Management.

DEWHA (2008) A Directory of Important Wetlands in Australia. Information Sheet on Ramsar Wetlands (RIS) for Vasse - Wonnerup System Western Australia and The Broadwater - NSW036. Downloaded from on November 2007.

Gole, C., Taylor, P. and Abbotts, S. (2008) Bird surveys of the Busselton Wetlands. Western Australian Bird Notes 125: 1-3.

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 No. 30. Melbourne: RAOU.

Lane, J.A.K., Clarke A.G., Pearson G.B. and Winchcombe, Y.C. (2007) Waterbirds of the Vasse Wonnerup wetlands in 1998-2000, including Ramsar status and comparisons with earlier data. Busselton, Western Australia: Department of Environment and Conservation.

Western Australian Planning Commission (2005) Busselton Wetlands Conservation Strategy. Perth: Western Australian Planning Commission.

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Busselton Wetlands. Downloaded from on 16/09/2014

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