The IBA is a periodically flooded marshland that extends approximately 60 km inland from the coastal sand dunes of Eighty Mile Beach in the southern Kimberley. The IBA is defined as the maximum extent of flooded land inland of Eighty Mile Beach (which extends for 220 km between Cape Missiessy and Cape Keraudren), extrapolated from maps in Halse et al. (2005). Only a few species of shorebird move regularly between this and the intertidal Eighty Mile Beach IBA, so these are kept as separate IBAs. Most of Mandora Marsh and Anna Plains consists of grazed samphire and grassland, and includes a permanent saline creek, permanent fresh to brackish springs and a large saline basin that is bare when dry. Low-lying sections of the western marshland support introduced Buffel Grass, with a mixture of shrubs and trees present in more elevated areas. The climate is tropical with hot summers, warm winters and mean annual rainfall of 341 mm. The west end is crossed by the Great Northern Highway. Part of the IBA is included within the Eighty-mile Beach Ramsar site.
Notable sub-threshold counts from the IBA include 16,500 Grey Teal, 2650 Hoary-headed Grebe and 43,290 Eurasian Coot in August 1999, 7530 Australian Pelican in June 2000 and 19,190 Grey Teal and 160 Black-fronted Dotterel in August 2000 (Halse et al. 2005). Three near threatened species, Black-necked Stork, Letter-winged Kite and Grey Falcon, have been recorded in the IBA but not in significant numbers; the nationally threatened Australian Painted Snipe has been recorded breeding (Atlas of Australian Birds database; Hassell and Rogers 2002). The biome-restricted Black Honeyeater, Pied Honeyeater, Yellow-tinted Honeyeater, Long-tailed Finch and Grey-headed Honeyeater have rarely been recorded and are probably not present in sufficient numbers to justify inclusion as IBA trigger species (Atlas of Australian Birds database; C. Hassell in litt. 2008). Australian Yellow White-eye has rarely been recorded (Atlas of Australian Birds database) but is potentially relatively common in mangroves.
Pressure/threats to key biodiversity
Minimise grazing pressure on wetland vegetation and, where possible, exclude livestock from areas critical to waterbirds. Eradicate or otherwise prevent further spread of Buffel Grass. Monitor incidence of predation on key species of birds by foxes and instigate a control program if deemed necessary.
Crown Land including Mandora, Anna Plains and Wallal pastoral leases.
Site access / Land-owner requests
Access to the IBA must be granted by managers of the pastoral leases.
The owners of Anna Plains Station have supported the Australasian Wader Studies Group and Broome Bird Observatory to undertake bird research at the site. Thanks to Chris Hassell as compiler.
BirdLife International (2021) Important Bird Areas factsheet: Mandora Marsh and Anna Plains. Downloaded from
http://www.birdlife.org on 26/10/2021.