Peel-Harvey Estuary


Site description (2008 baseline):

Site location and context
The Peel-Harvey Estuary is in the city of Mandurah and the shires of Murray, Waroona and Harvey in Western Australia. The site comprises the Peel Inlet (south of the old Mandurah estuary bridge) and the Harvey Estuary, including all land up to the high water mark plus all islands. The Peel Inlet and Harvey Estuary form a shallow estuarine system connected to the sea via a narrow, natural channel at the Peel Inlet, and the man-made Dawesville Channel at the Harvey Estuary that was opened in 1994. The Murray and Serpentine Rivers drain into the north-eastern Inlet, and the Harvey River enters the southern estuary, in addition to several major drains from agricultural land. A large proportion of Peel Inlet and the southern end of Harvey Estuary is less than 0.5 m deep, with a maximum depth of only about 2 metres, supporting seagrass. The Dawesville Channel was created to increase the tidal range in both estuaries, and to increase tidal flushing of the waters, which were increasingly eutrophic from fertiliser run-off, drainage and clearance of natural vegetation. Parts of the IBA are fringed by samphire flats and, behind the samphire, rushes and sedges, and then Melaleuca trees. Large parts of the shoreline have been cleared, mostly for agriculture, thus altering or eliminating the tree zones. It has declined in value to waterbirds after supporting a peak of 100,000 birds in 1977 and 41,000 in 1998. Mean annual rainfall at Mandurah is 885 mm, mostly in May-August.

Key biodiversity
A high count of 150,000 waterbirds in 1976/7 included 17,000 Eurasian Coot and 8000 Black Swan (Lane et al. 2002c). Surveys in portions of the Peel Inlet in 1981-1985 averaged about 20,000 waterbirds (Jaensch et al. 1988). The IBA still supports large numbers of waterbirds with counts of 14,500 in 1989, 23,000 in 1991 and 22,000 in 1992 (Halse et al. 1990, 1994) and a total 100,000-150,000 waterbirds recorded in 1997. Several species have historically been recorded in numbers above the 1% threshold. Hoary-headed Grebe: 10,340 in 1976-77 otherwise max 967 in 1983 (DEWHA 2008; Lane et al. 2002c; Jaensch et al. 1988); Blue-billed Duck: 1200 in 1981-5 (Jaensch et al. 1988); Australian Shelduck: 5650 in 1984 (Lane et al. 2002c; Jaensch et al. 1988; DEWHA 2008) and 4527 in 1996/7 (Lane et al. 2002a); Grey Teal: 25,070 in 1976/7, otherwise max 8230 in 1982 and 12,612 in 1996/7(DEWHA 2008; Lane et al. 2002a,c; Jaensch et al. 1988); Australian Shoveler: 1500 in 1981-5, otherwise max 500 in 1984 (DEWHA 2008; Jaensch et al. 1988) and in 1996/7 (Lane et al. 2002a); and Black-winged Stilt: 2293 in 1996/7 (Lane et al. 2002a). Terrestrial species recorded from the IBA include the biome-restricted Regent Parrot, Red-capped Parrot, Rock Parrot, Western Thornbill and Western Spinebill (Atlas of Australian Birds database).

Pressure/threats to key biodiversity
The forthcoming DEC management plan for the entire Peel-Yalgorup System needs to adequately address dredging and disturbance, and any regulations need to be enforced.

Conservation responses/actions for key biodiversity
This system has been host to numerous conservation projects, involving government departments, NGOs and community groups. Listed as a Ramsar site together with Lakes McLarty, Mealup and Yakgorup.

Protected areas
Numerous - see separate section for details.

Land ownership
Nature Reserves are managed by the Western Australia DEC. Surrounding areas are mostly freehold (privately owned) land or Unallocated Crown Land.

Acknowledgements
Thanks to Michael Craig and William Rutherford as compilers and to Bill Russell for his comments.


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Peel-Harvey Estuary (Australia). Downloaded from https://datazone.birdlife.org/site/factsheet/peel-harvey-estuary-iba-australia on 23/11/2024.