{{Short description|Islands in South Australia}} {{about|the pair of islets in South Australia|other uses|Casuarina (disambiguation)}} {{Use dmy dates|date=May 2014}} {{Use Australian English|date=May 2014}} {{Infobox islands | name = Casuarina Islets | image_name =Cape Du Couedic and the two Casuarina Islands, circa 1912 SRG-67-20-21.jpeg | image_size = | image_caption = Cape Du Couedic and the two Casuarina Islands, circa 1912 (State Library of South Australia,SRG-67-20-21) | map = South Australia | location = [[Great Australian Bight]] | area_ha = 4 | area_footnotes = <ref name=page297-298/> | elevation_m = | elevation_footnotes = | country = Australia | coordinates = {{coord|36|04|01|S|136|42|08|E|type:isle_region:AU|display=inline,title}} | population = }} The '''Casuarina Islets''' ([[French language|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 {{convert|96|km|abbr=off}} south-west of [[Kingscote, South Australia|Kingscote]]. The pair is currently part of the [[Flinders Chase National Park]].
==Location and features== Casuarina Islets are located approximately {{convert|96|km|abbr=off}} south-west of Kingscote. The North Islet and the South Islet lay respectively {{convert|370|m|abbr=off}} and {{convert|2.3|km|abbr=off}} south of [[Cape du Couedic]]. The North Islet covers an area of about {{convert|2|ha|abbr=off}} and reaches an elevation of {{convert|29|m|abbr=off}}. The South Islet covers an area of about {{convert|2|ha|abbr=off}} and reaches an elevation of {{convert|35|m|abbr=off}}.<ref name=page297-298>{{cite web|last1=Robinson|first1=A. C.|title=South Australia's offshore islands|url=http://www.environment.sa.gov.au/files/5a7dbb25-70b9-4ceb-bbfd-a25800961994/offshore-islands-gen.pdf |publisher=Australian Heritage Commission|access-date=13 December 2013 |last2=Canty |first2=P. |last3=Mooney |first3=T. |last4=Rudduck |first4=P. |pages=297–298|year=1996}}</ref>
The Casuarina Islets were formed between 7500 and 8900 years ago after sea levels rose at the start of the [[Holocene]].<ref>{{cite book|title=A Biological Survey of Kangaroo Island, South Australia, 1989 & 1990|date=1999 |publisher=Heritage and Biodiversity Section, Department for Environment, Heritage and Aboriginal Affairs, South Australia|location=Adelaide, SA|isbn=0-7308-5862-6 |page=26|url=http://www.environment.sa.gov.au/files/fb13b9bf-5c8e-445c-9c3c-a1c600c14815/ki-biological-survey-climate-geology-landuse-gen.pdf |editor1=Robinson, A. C. |editor2=Armstrong, D. M. |access-date=1 May 2014}}</ref> 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.<ref name= page297-298/> The North Islet is located in waters of {{convert|30|m|abbr=off}} depth while the South Islet located in waters of {{convert|40|m|abbr=off}} depth.<ref>{{cite journal | last = Fairclough | first = Martin C | title = KINGSCOTE Special 1:250 000 geological map | journal = MESA Journal | volume = 47 | pages = 28–31 | publisher = Government of South Australia, DMITRE | date = December 2007 | url = http://www.pir.sa.gov.au/__data/assets/pdf_file/0015/71034/MJ47_kingscote_map.pdf | issn = 1326-3544 | access-date = 18 May 2014 | archive-url = https://web.archive.org/web/20080802124157/http://www.pir.sa.gov.au/__data/assets/pdf_file/0015/71034/MJ47_kingscote_map.pdf | archive-date = 2 August 2008 | url-status = dead }}</ref>
===Economic activity===
The Casuarina Islets is one of the island sites from which [[guano]] was mined under licence from the [[Government of South Australia|South Australian Government]] prior to 1919.<ref name= page134>{{cite web|last1=Robinson|first1=A. C.|title=South Australia's offshore islands|url=http://www.environment.sa.gov.au/files/5a7dbb25-70b9-4ceb-bbfd-a25800961994/offshore-islands-gen.pdf |publisher=Australian Heritage Commission|access-date=13 December 2013 |last2=Canty |first2=P. |last3=Mooney |first3=T. |last4=Rudduck |first4=P. |page=134|year=1996}}</ref>
==Flora and fauna== [[File:Casuarina Islets - panoramio.jpg|thumb|The islets in 2009]] ===North Islet=== A survey in 1996 found nine species of plant to be present with [[Disphyma|roundleaved pigface]], [[Apium prostratum|sea celery]], [[Sarcocornia quinqueflora|beaded samphire]] and [[tetragonia implexicoma|bower spinach]] occupying the exposed areas of the islet while the more sheltered areas were occupied by [[Nitraria billardierei|nitre-bush]], [[Enchylaena tomentosa|ruby saltbush]], [[Senecio pinnatifolius|variable groundsel]] and [[Austrostipa|feather spear-grass]]. [[Vertebrate]] animals were represented by mammals, birds and reptiles. The islet supports a [[rookery|breeding colony]] of [[New Zealand fur seal]]s while serving as a [[haul out]] for [[Australian sea lion]]s. Breeding colonies of [[silver gull]]s, [[Pacific gull]]s and [[greater crested tern|crested terns]] are observed along with specimens of [[rock parrot]]s, [[welcome swallow]]s and [[Australian pipit]]. The only reptile found was a single specimen of the [[Christinus marmoratus|marbled gecko]].<ref name= page297-298/>
===South Islet=== As of 1996, four species of plant were found to be present{{snd}}round-leaved pigface which was the dominant species, sea celery, ruby saltbush and [[Suaeda australis|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 [[turnstone]]s, [[sooty oystercatcher]]s and welcome swallows. The only reptile found was a single specimen of the [[four-toed earless skink]].<ref name= page297-298/>
==History== The Casuarina Islets (Ilots du Cassuarina) were named by [[Nicolas Baudin]] on 3 January 1803 after one of the ships in his expedition, {{ship||Casuarina|schooner|2}} which was under the command of [[Louis de Freycinet]] at the time.<ref name= page297-298/><ref name= page118>{{cite web|last1=Robinson|first1=A. C.|title=South Australia's offshore islands|url=http://www.environment.sa.gov.au/files/5a7dbb25-70b9-4ceb-bbfd-a25800961994/offshore-islands-gen.pdf |publisher=Australian Heritage Commission|access-date=13 December 2013 |last2=Canty |first2=P. |last3=Mooney |first3=T. |last4=Rudduck |first4=P. |page=118|year=1996}}</ref> The islets are also known as The Brothers.<ref>{{Citation | title =Ornithological Association | newspaper =The Advertiser (Adelaide, SA) | page =8 | date =10 May 1909 | url =http://nla.gov.au/nla.news-article5725106 | access-date = 18 May 2014}}</ref>
==Protected area status== The South Islet was declared a closed area in 1909 in respect to birds and animals under the ''Birds Protection Act 1900'' following lobbying by the [[South Australian Ornithological Association]] which was concerned about the ongoing survival of one of the few remaining colonies of New Zealand fur seals on Kangaroo Island.<ref>{{cite journal| title =Bird Protection District | journal =South Australian Government Gazette | volume = year 1909 | issue =23 | pages =847 | publisher =Government of South Australia | location =Adelaide | date =6 May 1909 | url = http://www.austlii.edu.au/au/other/sa_gazette/1909/23.pdf | access-date = 22 January 2016}}</ref> North Islet was declared a sanctuary in September 1955 to protect the fur seal population ‘from shooting parties from the mainland’.<ref name= page138>{{cite web|last1=Robinson|first1=A. C.|title=South Australia's offshore islands|url=http://www.environment.sa.gov.au/files/5a7dbb25-70b9-4ceb-bbfd-a25800961994/offshore-islands-gen.pdf |publisher=Australian Heritage Commission|access-date=13 December 2013 |last2=Canty |first2=P. |last3=Mooney |first3=T. |last4=Rudduck |first4=P. |page=138|year=1996}}</ref> Both islets were declared as fauna reserves under the ''Fauna Conservation Act 1964'' and as a fauna conservation reserve under the ''Crown Lands Act 1929-1966'' on 16 March 1967.<ref name= page140>{{cite web|last1=Robinson|first1=A. C.|title=South Australia's offshore islands|url=http://www.environment.sa.gov.au/files/5a7dbb25-70b9-4ceb-bbfd-a25800961994/offshore-islands-gen.pdf |publisher=Australian Heritage Commission|access-date=13 December 2013 |last2=Canty |first2=P. |last3=Mooney |first3=T. |last4=Rudduck |first4=P. |page=140|year=1996}}</ref><ref name=FCR-1967>{{cite web|title=CROWN LANDS ACT, 1929-1966: FAUNA CONSERVATION RESERVES DEDICATED.|url=http://www8.austlii.edu.au/au/other/sa_gazette/1967/11.pdf |website=THE SOUTH AUSTRALIAN GOVERNMENT GAZETTE |publisher=Government of South Australia|access-date=5 February 2018|pages=961–962|date=16 March 1967}}</ref> Both Islets were proclaimed as part of the Flinders Chase National Park in 1972 and have since been specifically proclaimed as prohibited areas in order to protect breeding fur seals and seabirds.<ref name= page297-298/><ref name= page147>{{cite web|last1=Robinson|first1=A. C.|title=South Australia's offshore islands|url=http://www.environment.sa.gov.au/files/5a7dbb25-70b9-4ceb-bbfd-a25800961994/offshore-islands-gen.pdf |publisher=Australian Heritage Commission|access-date=13 December 2013 |last2=Canty |first2=P. |last3=Mooney |first3=T. |last4=Rudduck |first4=P. |page=147|year=1996}}</ref><ref name=NPWact>{{cite journal |title= No. 56 of 1972 (National Parks and Wildlife Act, 1972) |date= 27 April 1972 |pages= 660 & 699 |url= http://www.austlii.edu.au/au/legis/sa/num_act/npawa56o1972293/ |access-date= 20 January 2017 |publisher= Government of South Australia}}</ref> As of December 2012, the waters around both islets are part of a restricted access zone located within the boundaries of the [[Western Kangaroo Island Marine Park]].<ref>{{cite web|title= Western Kangaroo Island Marine Park Management Plan 2012|url= http://www.environment.sa.gov.au/files/5531fc53-c6cf-4f8c-b518-a11700a1d969/mp-gen-16westernkangarooisland-managementplan.pdf |publisher=Department of Environment Water and Natural Resources|access-date=15 May 2014|pages=27–28|year=2012}}</ref>
==References== {{reflist|30em}} {{Kangaroo Island}} {{AusplacesnamedbyFrench |state=collapsed}} {{Islands of South Australia |state=collapsed}}
{{DEFAULTSORT:Casuarina Islets}} [[Category:Islands of South Australia]] [[Category:Uninhabited islands of Australia]] [[Category:Kangaroo Island]]