Werribee and Avalon (23933)
Australia, Australasia

Site overview

KBA status: confirmed

Global KBA criteria: B1, D1a

Year of last assessment: 2009

National site name: Werribee and Avalon

Central coordinates: Latitude: -38.0263, Longitude: 144.5527

System: marine, terrestrial

Elevation (m): 0 to 10

Area of KBA (km²): 36.1862

Protected area coverage (%): 77.09

KBA classification: Global

Legacy site: Yes

Site details

Site description: The Werribee & Avalon IBA consists of wetlands from the mouth of the Werribee River to Avalon saltfields, on the shores of Port Philip Bay, south-west of Melbourne. Much of the area consists of the sewage treatment ponds of the Western Treatment Works, combined with coastal mudflats past the Point Wilson Explosives Area, to include all of the Avalon saltworks and Limeburners Bay. The sewage treatment works treats 60% of Melbourne's wastes in a series of aerobic and anaerobic lagoons and Lake Borrie, with patches of reeds and other wetland vegetation, and irrigates treated effluent onto adjacent pastures. The coast includes saltmarshes, intertidal mudflats and a small area of mangroves. The site is flat, has an annual rainfall of about 750 mm and mean maximum temperatures of 24°C in January and February to a mean minimum of 7°C in July. All of this area except for the Avalon saltworks is included within the Port Phillip Bay & Bellarine Peninsula Ramsar Site which also includes extensive areas of pastoral grasslands of little ornithological value within the Western Treatment Plant.

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: Significant populations of Banded Stilt (max 1846 in 2004), Curlew Sandpiper (declining, max 5074 in 2004 but previously 13,323), Red-capped Plover (max 202 in 1996), Double-banded Plover (max 519 in 1996 but subsequent counts below 310; previous max 955 and long-term mean 508), Black-fronted Dotterel (max 303 in 1983), Pied Oystercatcher (max 159 in 1985) and Red-necked Avocet (max 1166 in 2003), Black Swan (max 6879 in 2006), Hardhead (max 9784 in 2004), Pacific Black Duck (max 2231 in 2001), Great Crested Grebe (max 633 in 2005), wetland passerines, raptors, foraging site for Fairy Tern, breeding site for Pied (700 pairs; Environment Australia 2001) and Little Pied Cormorants and regular records of Australasian Bitterns, but probably not breeding (ARI database on behalf of Melbourne Water Corporation and Australian Wader Studies Group Database). Vunerable Fairy Tern recorded in 31 of 196 (16%) and near threatened Flame Robin recorded in eight of 196 (4%) Atlas of Australian Birds surveys from 1998 to 2008 (Atlas of Australian Birds database). Striated Fieldwrens are common in suitable habitat (G. Dutson pers. obs 2007); recorded in 67 of 196 (34%) Atlas of Australian Birds surveys from 1998 to 2008 (Atlas of Australian Birds database). Non-bird biodiversity: Contains numbers of the Striped Legless Lizard and Growling Grass Frog (threatened in Australia) and Fat-tailed Dunnart (threatened in Victoria).

Other site values: A mix of State and private ownership - Melbourne Water is responsible for Sewage Treatment areas; Victorian Parks for reserves, intertidal areas and Bay waters; Cheetham Salt Company owns the salt works. Access to the Western Treatment Plant for birdwatching is available only between 06:30-21:00 by permit ($20 for a two-year permit plus a deposit for a key). Applications can be obtained by telephoning Melbourne Water on 131722 (08:00-17:30 Monday to Friday) or over the counter at 89 Millers Road, Brooklyn, 09:00-16:00 on week days; see http://www.melbournewater.com.au/content/sewerage/western_treatment_plant/bird_watching_and_fishing.asp

Habitats

Land use: military | nature conservation and research | not utilised | urban/industrial/transport

IUCN Habitat	Coverage %	Habitat detail
Artificial - Aquatic	33
Marine Coastal/Supratidal	33
Marine Intertidal	33

Threats

Summary of threats to biodiversity at KBA: Saltmarshes and weedy areas used by Orange-bellied Parrots should be managed specifically for this species. Melbourne Water has an ongoing responsibility to manage the sewage treatment systems in ways which maintain the area's ornithological importance.

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
Pollution	Industrial & military effluents	Oil spills	Only in the future
Pollution	Domestic & urban waste water	Type Unknown/Unrecorded	Ongoing
Human intrusions & disturbance	Recreational activities		Ongoing
Natural system modifications	Other ecosystem modifications		Ongoing
Climate change & severe weather	Storms & flooding		Only in the future

Additional information

References: Department of Sustainability and Environment (2003) Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar Site: Strategic Management Plan, Government of Victoria. DEWHA (2008) Directory of Important Wetlands in Australia. http://www.environment.gov.au/water/publications/environmental/wetlands/database/ accessed 2008. Hamilton, A.J. (2007) Potential microbial and chemical hazards to waterbirds at the Western Treatment Plant. Ecological Management and Restoration 8: 38-41. Lane, B.A., Schulz, M. and Wood, K.L. (1984) Birds of Port Phillip Bay, Coastal Unit Technical Report No. 1, Ministry for Planning and Environment, Victoria. Lane, B.A., Carr, G.W. and Orscheg, C. (1999) Conservation and Ramsar Management Plan, Western Treatment Plant, The Spit Conservation Reserve and Adjacent Habitats, Ecology Australia for Melbourne Water. Melbourne Water (2000) Western Treatment Plant and The Spit Nature Conservation Reserve Conservation Management Action Plan. Melbourne Water: Melbourne. Schulz, M., Beardsell, C. and Sandiford, K. (1991) Sites of Faunal Significance in the Western Wetlands of Melbourne, Wildlife Branch, Department of Conservation and Environment, Victoria. Weston, M., McMahon, A.R.G., Fearnside, P. and Starks, J. (1995) Avalon Airshow Avifauna Study: The Effects of Aircraft Activity on Waterbirds in the Point Wilson Area. Report prepared by Ecology Australia, Royal Australasian Ornithologists Union and Carr.