Eighty Mile Beach


Site description (2008 baseline):

Site location and context
Eighty Mile Beach is in the southern Kimberley, south of Broome. The IBA is defined as the intertidal flats and sandy beach between Cape Missiessy, 142 km south of Broome, to Cape Keraudren, 220 km further south. It lies immediately adjacent to the Mandora Marsh & Anna Plains IBA, but as only a few species of shorebird move regularly between the beach and plains, these are kept as separate IBAs (Oriental Plover and Little Curlew feed on the plains and sometimes use the beach as a hot-weather refuge). The climate is semi-arid monsoonal with a hot wet summer and a warm dry winter. Eighty Mile Beach is a long and relatively featureless beach with intertidal mudflats rich in benthic organisms. The beach is approximately 100 m wide and includes several irregular, muddy, microscale embayments, while the adjoining tidal mudflats vary from an estimated 1 to 5 km in width. Shorebirds are found along this entire stretch of coastline but are most concentrated where the mud-flats are widest. The IBA is included within the Eighty-mile Beach Ramsar site.

Key biodiversity
A count in 2001 indicated the wader population at Eighty Mile Beach numbered approximately 470,000 individuals (Minton et al 2003b) while another 150-200,000 use the site as a migration stop-over (DEWHA 2008). The beach regularly supports a few individuals of the near threatened Asian Dowitcher. The near threatened Black-tailed Godwit has been recorded in large numbers but not in recent years: counts include 205 in 1993, 450 in 1994, max 15 1995-2000, 268 in 2001, 1 in 2002, 1 in 2003, 0 in 2004, 2 in 2005, 18 in 2006 and 24 in 2007 (Australian Shorebird Count Database). It also supports nationally important and occasionally globally important numbers of Broad-billed Sandpiper (max 205 in 2001); and Curlew Sandpiper: counts include 5199 in 2007, 1608 in 2006, 4332 in 2005, 495 in 2004, 693 in 2003, 1430 in 2002, 11,867 in 2001 and max 4115 in 1993-2000 but not all counts were complete or at optimal times (Australian Shorebird Count Database) and a historical max count of 60,000 (Lane 1987); Little Curlew (max 3261 in 2005, 1280 in 2006 and 1155 in 2004); Sharp-tailed Sandpiper (max thousands on the beach in 1982 and 25,000 in mid-September 1984) (Australian Shorebird Count Database). It has occasionally supported high numbers of terns but the regularity of such numbers is uncertain: max 30,000 White-winged Tern in 2004, with previous highest count of 6000 in 1989 (Minton et al. 2004); max 6046 Roseate Tern in 2004 but only 405 in 2005 (Rogers et al. 2006) and max 1994 Gull-billed Tern in 2003 (Minton et al. 2003c).

Non-bird biodiversity: The nationally Vulnerable Flatback Turtle Natator depressus regularly nests at scattered locations along Eighty Mile Beach. The primary dunes of Eighty Mile Beach are stabilised by Spinifex longifolius and Crotalaria cunninghamii. Secondary parallel, calcareous dune ridges and swales commonly feature scattered Dune Wattle Acacia bivenosa. Important grasses include Whiteochloa airoides and the local endemic Triodia epactia, a resinous hummock-forming species. There are two minor mangrove stands within the IBA, each of which occupy about 50 ha around small tidal creeks near Mandora Station. The mangrove stands are dominated by Avicennia marina 4-6 m in height with a few Ceriops tagal. Samphire communities also occur in the vicinity. Many of the 114 species of benthic fauna found in the IBA are present in high densities.



Pressure/threats to key biodiversity
Minimise disturbance along the roosting and feeding areas used by shorebirds. Ensure that exploration licences and shipping procedures minimise the impact on the beach and inshore waters.

Conservation responses/actions for key biodiversity
30 km of fencing has been erected on Anna Plains pastoral lease to exclude cattle from part of Eighty Mile Beach and the dune systems (funded by the Commonwealth Coastcare program in 2001). The Department of Conservation and Land Management is currently undertaking negotiations with surrounding pastoral leaseholders to add significant terrestrial areas adjacent to the site to the conservation estate. The 1994 DEC report, A Representative Marine Reserve System for Western Australia, recommended that a section of Eighty Mile Beach and adjoining marine waters, including tidal flats and a 40 metre strip of land above high tide, should be reserved for the protection of marine flora and fauna, including migratory shorebirds. Eighty Mile Beach has been intensively surveyed for shorebirds by the Australasian Wader Studies Group since 1981, mainly through an ongoing program of shorebird banding expeditions.

Land ownership
Crown Land with four adjoining pastoral leases (Mandora, Anna Plains, Wallal, Pardoo).

Site access / Land-owner requests
Permission for access needs to be acquired from stations.

Acknowledgements
The owners of Anna Plains Station have supported the Australasian Wader Studies Group and Broome Bird Observatory to undertake bird research at the site.


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Eighty Mile Beach (Australia). Downloaded from https://datazone.birdlife.org/site/factsheet/eighty-mile-beach-iba-australia on 23/12/2024.