The Investigator Group is an

archipelago An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands, or sometimes a sea containing a small number of scattered islands. Examples of archipelagos include: the Indonesian Arch ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest o ...

that consists of Flinders Island and five island groups located off the western coast of the

Eyre Peninsula The Eyre Peninsula is a triangular peninsula in South Australia. It is bounded by the Spencer Gulf on the east, the Great Australian Bight on the west, and the Gawler Ranges to the north. Originally called Eyre’s Peninsula, it was named af ...

. It is named after by her commander,

Matthew Flinders Captain Matthew Flinders (16 March 1774 – 19 July 1814) was a British navigator and cartographer who led the first inshore circumnavigation of mainland Australia, then called New Holland. He is also credited as being the first person to ut ...

when he explored the area in 1802. The Group lies within the

Great Australian Bight The Great Australian Bight is a large oceanic bight, or open bay, off the central and western portions of the southern coastline of mainland Australia. Extent Two definitions of the extent are in use – one used by the International Hydrog ...

. All the islands except Flinders Island, and a part of Pearson Island, are within the Investigator Group Wilderness Protection Area and the Waldegrave Islands Conservation Park.

Description

Generally

The Investigator Group is a group of islands and associated landforms that are located within an area extending for a distance of about south west from Cape Finniss on the west coast of Eyre Peninsula in South Australia. The group consists of the following islands and island groups placed in order of increasing distance from Cape Finniss: the Waldegrave Islands, The Watchers, Flinders Island, Topgallant Islands, the Ward Islands and the Pearson Isles.

Waldgrave Islands

The northernmost group lies 3 km offshore near the small town of Elliston. It consists of Waldegrave (292 ha) and Little Waldegrave (32 ha) Islands. They have

calcarenite Calcarenite is a type of limestone that is composed predominantly, more than 50 percent, of detrital (transported) sand-size (0.0625 to 2 mm in diameter), carbonate grains. The grains consist of sand-size grains of either corals, shells, oo ...

soils and were grazed by sheep until 1967. The vegetation is mainly regenerating pasture, with patches of native

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It ...

dominated by Native Juniper and Coast Daisy-bush.

The Watchers

The Watchers are a pair of rocks that are spaced about apart and which are located about west of Little Waldegrave Island. The western rock has a charted height of and is reported in another source as being . The eastern rock is charted as an

intertidal The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species ...

reef.RAN, 1979DMH, 1985, chart 38Robinson et al., 1996, page 188

Flinders Island

Flinders Island Flinders Island, the largest island in the Furneaux Group, is a island in the Bass Strait, northeast of the island of Tasmania. Flinders Island was the place where the last remnants of aboriginal Tasmanian population were exiled by the colo ...

, which is 28 km offshore and at 36 km² is the largest island in the Investigator Group. Flinders Island is leasehold land used for grazing. It has sandy, calcarenite soils, is mainly vegetated with pasture grasses, and has some remnant patches of

heathland A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a coole ...

and ''

Melaleuca ''Melaleuca'' () is a genus of nearly 300 species of plants in the myrtle family, Myrtaceae, commonly known as paperbarks, honey-myrtles or tea-trees (although the last name is also applied to species of ''Leptospermum''). They range in size f ...

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the '' plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

Topgallant Islands

Topgallant Islands are located 6 km to the east of Flinders Islands and is a small island with steep cliffs and some stunted shrubland.

Ward Islands

Ward Islands are located 16 km to the west of Flinders Island and is covered with shrubland and heathland.

Pearson Isles

The southernmost group consists of

Pearson Island Pearson Island is an island located in the Australian state of South Australia within the Pearson Isles an island group located in the larger group known as the Investigator Group about southwest by west of Cape Finniss on the west coast o ...

(213 ha), the

Veteran Isles Veteran Isles (french: Ile du Veteran; also known as the Veteran Islands) is a pair of islands in the Australian state of South Australia which is part of the Pearson Isles which itself is part of the larger island group known as the Investiga ...

(14 ha) and Dorothee Island (56 ha). Pearson Island, the second largest of the whole Investigator Group, and containing its highest point at 231 m above

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardis ...

, is vegetated with shrub and heathland with patches of ''

Casuarina ''Casuarina'' is a genus of 17 tree species in the family Casuarinaceae, native to Australia, the Indian subcontinent, southeast Asia, islands of the western Pacific Ocean, and eastern Africa. It was once treated as the sole genus in th ...

'' and ''Melaleuca'' woodland. The Veteran Isles support low shrubland dominated by Twiggy Daisy-bush and

Marsh Saltbush ''Atriplex paludosa'', commonly known as marsh saltbush, is a species of saltbush endemic to Australia. Description It grows as an erect shrub up to a metre high. Leaves are oval in shape, one to four centimetres long, and 2 to 15 millimetres wi ...

. Lying 3 km south-south-west of the Veteran Isles is Dorothee Island, the most southerly of the Investigator Group.

History

European discovery

On Saturday, 13 February 1802, Flinders gave the name Investigator Group to the group of islands consisting of Flinders Island, the Pearson Islands, the Topgallant Islands, the Waldegrave Islands and Ward Islands.

Protected area status and other designations

Reserves declared by the South Australian government

Protected area status has been conferred to all islands within the group with exception of the majority of Flinders Island and part of Pearson Island.WAC, 2013, pages 16-17DEH, 2006, page 5 The Investigator Group Wilderness Protection Area comprises Ward Islands, Top Gallant Isles, Pearson Isles with exception of a portion of land on Pearson Island which is held by the

Australian Maritime Safety Authority Australian Maritime Safety Authority (AMSA) is an Australian statutory authority responsible for the regulation and safety oversight of Australia's shipping fleet and management of Australia's international maritime obligations. The authority ...

for "lighthouse purposes". The Waldegrave Islands Conservation Park occupies the Waldegrave Island, Little Waldegrave Island and the Watchers. A heritage agreement has been in force on Flinders Island since 1995 in respect to a strip of land along the north coast of the island extending west from the island’s most northerly headland, Point Malcolm.DEH, 2006, page 12 As of 2012, the

Investigator Marine Park __NOTOC__ Investigator Marine Park is a marine protected area in the Australian state of South Australia located in the state's coastal waters in its west adjoining the west coast of Eyre Peninsula and islands in the Investigator Group respective ...

includes the waters adjoining Flinders Island, Topgallant Isles, the Ward Islands and the Pearson Isles.DEWNR, 2012, pages 23 & 26

Non-statutory arrangements

Investigator Islands Important Bird Area

The group was identified by

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

as an

Important Bird Area An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations. IBA was developed and sites are identified by BirdLife Inte ...

(IBA) known as the Investigator Islands (sic) Important Bird Area in 2009, because of its population of the

vulnerable species A vulnerable species is a species which has been categorized by the International Union for Conservation of Nature as being threatened with extinction unless the circumstances that are threatening its survival and reproduction improve. Vulnera ...

, the

fairy tern The fairy tern (''Sternula nereis'') is a small tern which is native to the southwestern Pacific. It is listed as " Vulnerable" by the IUCN and the New Zealand subspecies is " Critically Endangered". There are three subspecies: * Australian fai ...

, as well as significant populations of

Cape Barren geese The Cape Barren goose (''Cereopsis novaehollandiae'') is a large goose resident in southern Australia. Etymology The species' common name is derived from Cape Barren Island, where specimens were first sighted by European explorers. It is known ...

Pacific gull The Pacific gull (''Larus pacificus'') is a very large gull, native to the coasts of Australia. It is moderately common between Carnarvon in the west, and Sydney in the east, although it has become scarce in some parts of the south-east, as a re ...

and

black-faced cormorant The black-faced cormorant (''Phalacrocorax fuscescens''), also known as the black-faced shag, is a medium-sized member of the cormorant family. Upperparts, including facial skin and bill, are black, with white underparts. It is endemic to coa ...

. Other birds for which the IBA is significant include large numbers of breeding

short-tailed shearwater The short-tailed shearwater or slender-billed shearwater (''Ardenna tenuirostris''; formerly ''Puffinus tenuirostris''), also called yolla or moonbird, and commonly known as the muttonbird in Australia, is the most abundant seabird species in A ...

s and

white-faced storm-petrel The white-faced storm petrel (''Pelagodroma marina''), also known as white-faced petrel is a small seabird of the austral storm petrel family Oceanitidae. It is the only member of the monotypic genus ''Pelagodroma''. Description The white-faced ...

s. The

biome A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...

-restricted

rock parrot The rock parrot (''Neophema petrophila'') is a species of grass parrot native to Australia. Described by John Gould in 1841, it is a small parrot long and weighing with predominantly olive-brown upperparts and more yellowish underparts. Its h ...

has been recorded from most islands in the group. The islands met the IBA criteria in 2009.

Citations and references

Citations

References

* * * * * * * * {{DEFAULTSORT:Investigator Group Islands of South Australia Great Australian Bight Penguin colonies