Capricornia Cays (23967)
Australia, Australasia
Site overview
KBA status: confirmed
Global KBA criteria: B1, D1a, D1b
Year of last assessment: 2022
National site name: Capricornia Cays
Central coordinates: Latitude: -23.6323, Longitude: 152.1443
System: marine, terrestrial
Elevation (m): 0 to 18
Area of KBA (km2): 25.80694
Protected area coverage (%): 100.00
KBA classification: Global
Legacy site: Yes
Site details
Site description: This KBA consists of 11 small, low lying islands (~ 241 ha in total and between 2–18 metres high) comprising the Capricornia Cays of the southern, inner Great Barrier Reef south of Rockhampton and Gladstone. The KBA includes: Masthead Island, Heron Island, Tyron Island, Wilson Island, Wreck Island, North West Island, West Hoskyn, Lady Elliot Island, Lady Musgrave Island and Fairfax Islands. All of these except Lady Elliot Island are part of Capricornia Cays National Park. The three largest islands: North West (90 ha), Masthead (56 ha) and Heron (16 ha) support the largest numbers of nesting Black Noddies in the Great Barrier Reef. These islands are also home to globally significant numbers of breeding Wedge-tailed Shearwaters. North West Island is the second largest sand cay on the Great Barrier Reef. Vegetation on North West Island is dominated by Pisonia grandis low closed forest with smaller areas of Argusia argentea low woodland and Pandanus tectorius open woodland. Vegetation on Masthead and Heron Islands is similar to that of North West; however these Islands have higher proportion of their area covered by foredune vegetation communities, and Heron Island lacks Pandanus tectorius open woodland (Queensland Herbarium 2019). Heron Island, which supports a high-density population of nesting Black Noddies, is approximately half residential area and half National Park. The region is sub-tropical, receiving an average 1062 mm rain annually, average temperatures of 16-30 degrees and one tropical cyclone every two years. This KBA is entirely covered by the Great Barrier Reef Marine Park (Commonwealth) and Great Barrier Reef Coast Marine Park (QLD), however individual cays are covered by different zones within the Marine Park.
Rationale for qualifying as KBA: This KBA hosts globally significant breeding populations of Brown Booby Sula leucogaster, Wedge-tailed Shearwater Ardenna pacifica and Black Noddy Anous minutus. Brown Boobies nest on two islands within the Capricornia Cays KBA: East and West Fairfax islands. East Fairfax Island on its own regularly exceeds 1% of the global adult population, and in all years with adequate data (i.e. surveys timed with peak breeding to obtain maximum counts) adult counts of Brown Boobies exceed 1% of the global adult population, triggering a KBA under Criterion D1a. Wedge-tailed Shearwaters nest on all islands that make up Capricornia Cays KBA. It is estimated that over 7% of the of the global adult population of Wedge-tailed Shearwaters nest in this KBA, making this site likely among the to 10 largest nesting aggregations for this species in the world, and triggering a KBA under both D1a and D1b. Black Noddies have been recorded nesting on all islands that make up Capricornia Cays KBA. Of particular importance are: North West, Heron, Masthead and Lady Musgrave Islands, which all regularly exceed 1% of the global population on their own. It is estimated that 35% of the global adult population of Black Noddies nest in this KBA, triggering under criteria D1a, D1b and B1.
Additional biodiversity: This site supports approximately 80% of Australia’s Pisonia grandis forests, a low woody tree species restricted to small tropical islands. Pisonia grandis is threatened globally by clearing for guano mining and plantation agriculture, therefore the intact Capricornia Cays P. grandis forest is of regional, national and international value. This KBA provides important nesting habitat to conservation significant populations of IUCN Endangered green turtles Chelonia mydas and IUCN Vulnerable loggerhead turtles Caretta caretta (Endangered Nationally*). The Capricornia Cays and adjacent mainland coast support almost the entire breeding population of loggerhead turtles in the South Pacific Ocean basin, and a large proportion of the total global population. This site is among the largest remaining green turtle rookeries in the world. These species will likely be added as KBA Triggers in the future. Capricornia Cays KBA also supports breeding populations of silver gull Chroicocephalus novaehollandiae, lesser crested tern Thalasseus bengalensis and regionally significant colonies of roseate terns Sterna dougallii, black-naped terns Sterna sumatrana and bridled tern Onychoprion anaethetus. White-bellied sea-eagles Haliaeetus leucogaster breed on the islands during winter months. Non-breeding populations of threatened birds feeding and/or roosting in this KBA include: Far Eastern Curlew Numenius madagascariensis (IUCN Red List Endangered, Critically Endangered Nationally*); beach stone-curlew Esacus magnirostris (IUCN Red List Near Threatened, Vulnerable in Queensland**) and little tern Sternula albifrons (IUCN Red List Least Concern, Endangered in Queensland**). Additionally, a subspecies of silvereye Zosterops lateralis chlorocephala is endemic to Capricornia Cays (Garnett 1992). *status under Australian Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) List of Threatened Fauna **status under Queensland Nature Conservation Act 1992 threatened species list ref: Queensland Department of National Parks, Recreation, Sport and Racing (2014). Management Plan - Capricornia Cays National Park and adjoining State waters. Available at: https://parks.des.qld.gov.au/__data/assets/pdf_file/0023/168305/capricorn-cays-management-plan-final-140820.pdf [accessed 27 April 2021]
Manageability of the site: All cays that make up this KBA are managed by Great Barrier Reef Marine Park Authority and Queensland Parks and Wildlife Service and come under a single Management Plan: Queensland Department of National Parks, Recreation, Sport and Racing (2014). Managem
Other site values: The Gurang Gurang, Gooreng Gooreng, Gurang, Bailai and Tarebilang Bunda peoples are the Traditional Owners of Capricornia Cays KBA. A Native Title Claim and Traditional Use of Marine Resources Agreement (TUMRA) exist over the area, administered by the Port Curtis Coral Coast Trust (PCCC) Prescribed Body Corporate (PBC). This area is an important part of Gooreng Gooreng, Gurang and Tarebilang Bunda sea country and the agreement ensures Traditional Owners will maintain access to resources and have input into the management and protection of cultural heritage places of significance (Queensland Department of National Parks, Recreation, Sport and Racing 2014).
Delineation rationale: The KBA boundary consists of 1km radius circles centred over each island/cay, with the exception of the two Fairfax Islands which are bounded by a single ellipse. This ellipse has a minor axis length of 700m and a major axis length of 1429m and is of approximately equal area to a 1km radius circle.
Habitats
Land use: The KBA is currently managed by the Great Barrier Reef Marine Park Authority and Queensland Parks and Wildlife Service for a variety of uses, but primarily conservation and preservation of this World Heritage Area. Uses include: tourism, education, scientific research and cultural heritage / traditional use. The following Great Barrier Reef Marine Park use Zones cover Capricornia Cays KBA: Commonwealth Island (GBRMPA) (IUCN II), Conservation Park (IUCN IV), Habitat Protection (IUCN VI), Marine National Park (IUCN II), Preservation (IUCN IA) Scientific Research (IUCN IA)
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Marine Coastal/Supratidal | 15 | |
| Forest | 5 | |
| Forest | 25 | |
| Marine Intertidal | 25 | |
| Marine Neritic | 75 |
Threats
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Climate change & severe weather | Habitat shifting & alteration | Ongoing | |
| Climate change & severe weather | Storms & flooding | Ongoing | |
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Only in the future | |
| Invasive & other problematic species, genes & diseases | Problematic native species/diseases | In the past but now suspended and likely to return | |
| Pollution | Garbage & solid waste | Ongoing | |
| Pollution | Industrial & military effluents | Oil spills | Only in the future |
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Named species | Ongoing |
| Human intrusions & disturbance | Recreational activities | Ongoing | |
| Climate change & severe weather | Storms & flooding | Only in the future |