Limmen Bight (23447)
Australia, Australasia
Site overview
KBA status: confirmed
Global KBA criteria: A1a, A1c, D1a
Year of last assessment: 2009
National site name: Limmen Bight
Central coordinates: Latitude: -14.8130, Longitude: 135.3392
System: marine, terrestrial
Elevation (m): 0 to 10
Area of KBA (km2): 2189.33811
Protected area coverage (%): 58.78
KBA classification: Global
Legacy site: Yes
Site details
Site description: The IBA comprises the coastline from the Roper River to the Limmen Bight (for the shorebirds on intertidal flats) and the inland swamps south of the Roper River (which have large numbers of Black-winged Stilts) to the National Park boundary. The wetlands north of the Roper River are also important for birds but do not qualify for IBA status on current data. The main habitats are wide intertidal mudflats, scattered low samphire shrubland on otherwise bare coastal flats, and small areas (fringing channels) of low closed mangroves.
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: The IBA has supported up to 3038 near threatened Black-tailed Godwit (DEWHA 2008). A waterbird nesting colony near the mouth of the Roper River had about 2500 waterbirds including egrets, Pied Heron and cormorants (Chatto 2000 ref W055). At least ten other waterbird/seabird breeding rookeries also exist within the site, including the largest Pied Cormorant rookery (more than 2000 adults) and largest Little Tern (up to 100 nests) breeding colony in the Northern Territory. Other breeding colonies support large numbers of birds, including 10,000 Crested Tern and 5000 Roseate Tern. The highest number of shorebirds recorded over the site was 29,106 in April 1990; 24,938 were on mudflats north of Spillen Creek (i.e. mainly near Port Roper), the remainder were south of Spillen Creek. A total of 27,742 shorebirds for most of the site was recorded in February 1983; other counts have been below 5000 (DEWHA 2008; Chatto 2000; Chatto 2003; Chatto 2006). Sightings recorded in the Atlas of Australian Birds for 1998 to 2008 suggest the IBA supports small populations of the near threatened Australian Bustard and four tropical savanna biome-restricted species. Non-bird biodiversity: High densities (> 5/km2) of dugong occur offshore between Limmen Bight River and Rosie Creek (seagrass beds), both in the Wet and the Dry. Medium densities of Saltwater Crocodile Crocodylus porosus occur in the Roper River estuary. Marine turtles (mix of species not yet described) use nest sites on offshore islands associated with the site (DEWHA 2008).
Other site values: Arnhemland and Marra ALT; may also include some of Saint Vidgeon, Nathan River and Lorella pastoral leases. This IBA is on Traditionally Owned land and private grazing properties.
Habitats
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Marine Intertidal | 95 | |
| Shrubland | 5 |
Threats
Summary of threats to biodiversity at KBA: More research is needed to identify threats and management actions but the area is likely to be susceptible to the impacts of sea-level rise and the impact of invasive alien plants e.g. Hymenachne.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Agriculture & aquaculture | Marine & freshwater aquaculture | Industrial aquaculture | Only in the future |
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Named species | Ongoing |
| Climate change & severe weather | Storms & flooding | Only in the future |
Additional information
References: Chatto, R. (2000) Waterbird breeding colonies in the Top End of the Northern Territory. Technical Report 69, Parks and Wildlife Commission of the Northern Territory, Palmerston. Chatto, R. (2003) The distribution and status of shorebirds around the coast and coastal wetlands of the Northern Territory. Technical Report 73, Parks and Wildlife Commission of the Northern Territory, Palmerston. Chatto, R. (2006) The distribution and status of waterbirds around the coast and coastal wetlands of the Northern Territory. Technical Report 76, Parks and Wildlife Commission of the Northern Territory, Palmerston. DEWHA (2008) Directory of Important Wetlands in Australia (Tidal Wetlands System - NT007). http://www.environment.gov.au/water/publications/environmental/wetlands/database/ accessed 2008. Garnett, S. (1983) Report on the fifth aerial survey of migratory wading birds between Weipa and Millingimbi. The Stilt 4: 15-17. Garnett, S. (1987) Aerial surveys of waders (Aves: Charadriiformes) along the coast of north-eastern Australia. Australian Wildlife Research 14: 521-528. Harrison, L., McGuire, L., Ward, S. Fisher, A., Pavey, C., Fegan, M. and Lynch, B. (2009) An inventory of sites of international and national significance for biodiversity values in the Northern Territory. Department of Natural Resources, Environment, the Arts & Sport, Darwin, NT. Ward, S. and Harrison, L. (2009) Recognising sites of conservation significance for biodiversity values in the Northern Territory. Department of Natural Resources, Environment, the Arts & Sport, Darwin, NT.