Key Biodiversity Areas

Troubridge Island (23984)
Australia, Australasia

Site overview


KBA status: confirmed
Global KBA criteria: B1D1a
Year of last assessment: 2009
National site name: Troubridge Island
Central coordinates: Latitude: -35.1230, Longitude: 137.8272
System: marine, terrestrial
Elevation (m): 0 to 12
Area of KBA (km2): 3.17093
Protected area coverage (%): 99.83
KBA classification: Global
Legacy site: Yes

Site details


Site description: Troubridge Island lies 7 km east of Sultana Point in the south-west of Gulf St Vincent. It is a low sand island reaching about 5 m above sea level. It has a land area of approximately 3 ha at high tide but much larger areas of sand flats are exposed at low tide. All land on the island, except for an automated lighthouse and two associated cottages now used for tourist accommodation, is designated as a conservation park, and the IBA also includes the adjacent intertidal sand flats. The vegetation consists of low shrubland dominated by Nitre Bush. Grey Saltbush and introduced African Boxthorn, Tree Mallow, Sea Rocket, Marram Grass and Hairy Spinifex are also prominent. Most of the 31 plant species on the island are introduced.
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 supports breeding colonies of the Little Penguin (3000-6000 birds in 1966-1992), Caspian Tern (10-100 pairs in 1970-1990s), Crested Tern (2500 pairs in 1989; Copley 1996) and Pied Cormorant (180 pairs; Robinson et al. 1996). Additionally, two breeding pairs of the Pacific Gull frequented the island between 1966 and 1975 (Copley 1996). The IBA also provides foraging habitat for locally significant numbers of migratory shorebirds such as the Red-necked Stint (930 birds in 1981; Wilson 2000). The biome-restricted Rock Parrot has been recorded on the island (Atlas of Australian Birds database).
Other site values: South Australian Government; managed by the Department for Environment and Heritage with lighthouse cottages leased to a commercial operator. Access to Troubridge Island is only by permit or with an approved commercial tour operator.

Habitats


Land use: nature conservation and research | tourism/recreation
IUCN HabitatCoverage %Habitat detail
Introduced Vegetation25
Marine Coastal/Supratidal25
Marine Intertidal25
Shrubland25

Threats


Summary of threats to biodiversity at KBA: Maintain and enforce strict access regulations. Investigate potential impact of climate change, sea-level rise and increased storms.
Threat level 1Threat level 2Threat level 3Timing
Invasive & other problematic species, genes & diseasesInvasive non-native/alien species/diseasesUnspecified speciesOngoing
Climate change & severe weatherStorms & floodingOnly in the future
Human intrusions & disturbanceRecreational activitiesOngoing

Additional information


References: Copley, P.B. (1996) The status of seabirds in South Australia. Pp. 139-180 in G.J.B. Ross, K. Weaver and J.C. Greig, eds. The Status of Australia's Seabirds: Proceedings of the National Seabird Workshop, Canberra, 1-2 November 1993. Canberra: Biodiversity Group, Environment Australia. Department for Environment and Heritage (2009) Althorpe Islands, Goose Island and Troubridge Island Conservation Parks Management Plan 2009. Adelaide: Department for Environment and Heritage. Lashmar, A.F.C. (1987) Seabird Islands No. 177. Troubridge Island, South Australia. Corella 11: 89-92. Robinson, T., Canty, P., Mooney, T. and Ruddock, P. (1996) 'South Australia's Offshore Islands'. Canberra: Australian Government Publishing Service. Wilson, J.R. (2000) South Australia wader surveys January and February 2000. Unpublished report. Australian Wader Studies Group and South Australian Ornithologists' Association.