Cadell and Blyth Floodplains (22522)
Australia, Australasia
Site overview
KBA status: confirmed
Global KBA criteria: A1a, A1c, D1a
Year of last assessment: 2009
National site name: Cadell and Blyth Floodplains
Central coordinates: Latitude: -12.1262, Longitude: 134.5890
System: marine, terrestrial
Elevation (m): 0 to 10
Area of KBA (km2): 414.73041
Protected area coverage (%): 98.54
KBA classification: Global
Legacy site: Yes
Site details
Site description: The boundary follows the coastal floodplains of the Cadell and Blyth rivers, and the adjacent length of Boucaut Bay. This IBA is situated between the Maningrida community to the west and the Milingimbi community to the east. The seasonal flooding comes from flows down the Blyth and Cadell Rivers and various creeks. Most of the floodplain is more than 1 m deep in wetter years.
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: Boucaut Bay has supported up to 5000 near threatened Black-tailed Godwit (Chatto 2003). The floodplains also support large numbers of other waterbirds including counts of 1000 Little Pied Cormorant, 1000 Great Egret, and total counts of waterbirds include 26,000 in 80-90% of area counted; 19,500 in 80-90% of area counted in 1992; 17,000 in 25-50% of area counted in 1999 (Chatto 2003). A waterbird nesting colony in coastal mangroves had 2000 herons, including 1000 Pied Herons in 1999; and one on the Blyth River had 1000 herons and 1000 Little Pied Cormorants in 1999 (Chatto 2000 waterbird breeding colony ref W039 and W045). More than 15,000 waders regularly recorded in the area 10 km either side of the mouth of the Blyth River; the most abundant shorebird species are Great Knot (up to 4895), Black-tailed Godwit (1099), Red-necked Stint (722) and Pied Oystercatcher (up to 311). At least 10,000 Magpie Geese and 100,000 whistling-ducks occur at times in the Maningrida-Milingimbi district; a large proportion of these birds would use the Blyth-Cadell floodplain. The near threatened Asian Dowitcher is a non-breeding visitor in small numbers, with a count of 15 in 1990 (DEWHA 2008). Chestnut Rails have been recorded on the floodplains but their local abundance is poorly known (Chatto 2006). Other species recorded at the site include the biome-restricted White-gaped Honeyeater, Bar-breasted Honeyeater and Long-tailed Finch (Atlas of Australian Birds database).
Other site values: This IBA is on traditionally owned land.
Habitats
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Wetlands(Inland) | 32 | |
| Shrubland | 5 | |
| Marine Intertidal | 32 | |
| Forest | 32 |
Threats
Summary of threats to biodiversity at KBA: Further research is needed to assess the threats to the site and the recommended management actions but these are likely to include actions to minimise the spread of alien invasive species, such as Hymenachne, and to mitigate the impacts of sea-level rises.
| 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 |
| 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 (NT022) http://www.environment.gov.au/water/publications/environmental/wetlands/database/ accessed 2008. 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.