Casuarina Islets
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 Cape Du Couedic and the two Casuarina Islands, circa 1912 (State Library of South Australia,SRG-67-20-21) | |
  Casuarina Islets | |
| Geography | |
|---|---|
| Location | Great Australian Bight |
| Coordinates | 36°04′01″S 136°42′08″E / 36.06694°S 136.70222°E |
| Area | 4 ha (9.9 acres)[1] |
| Administration | |
Australia | |
The Casuarina Islets (French: Ilots du Cassuarina), also known as The Brothers, is a pair of islands located in the Great Australian Bight immediately off the south-west coast of Kangaroo Island in South Australia approximately 96 kilometres (60 miles) south-west of Kingscote. The pair is currently part of the Flinders Chase National Park.
Economic activity
Casuarina Islets are located approximately 96 kilometres (60 miles) south-west of Kingscote. The North Islet and the South Islet lay respectively 370 metres (1,210 feet) and 2.3 kilometres (1.4 miles) south of Cape du Couedic. The North Islet covers an area of about 2 hectares (4.9 acres) and reaches an elevation of 29 metres (95 feet). The South Islet covers an area of about 2 hectares (4.9 acres) and reaches an elevation of 35 metres (115 feet).[1]
The Casuarina Islets were formed between 7500 and 8900 years ago after sea levels rose at the start of the Holocene.[2] Both islets are humps of Kanmantoo group metasandstone that have been rounded by wave action. A remnant cap of calcarenite still exists over the eastern half of the North Islet while the South Islet has lost its calcarenite cap due to wave action.[1] The North Islet is located in waters of 30 metres (98 feet) depth while the South Islet located in waters of 40 metres (130 feet) depth.[3]
The Casuarina Islets is one of the island sites from which guano was mined under licence from the South Australian Government prior to 1919.[4]
Flora and fauna
North Islet
A survey in 1996 found nine species of plant to be present with roundleaved pigface, sea celery, beaded samphire and bower spinach occupying the exposed areas of the islet while the more sheltered areas were occupied by nitre-bush, ruby saltbush, variable groundsel and feather spear-grass. Vertebrate animals were represented by mammals, birds and reptiles. The islet supports a breeding colony of New Zealand fur seals while serving as a haul out for Australian sea lions. Breeding colonies of silver gulls, Pacific gulls and crested terns are observed along with specimens of rock parrots, welcome swallows and Australian pipit. The only reptile found was a single specimen of the marbled gecko.[1]
South Islet
As of 1996, four species of plant were found to be present – round-leaved pigface which was the dominant species, sea celery, ruby saltbush and Austral seablite. Vertebrate animals were represented by mammals, birds and reptiles. A non-breeding colony of New Zealand fur seals are the main occupants of the islet while birds were represented by turnstones, sooty oystercatchers and welcome swallows. The only reptile found was a single specimen of the four-toed earless skink.[1]
