The Investigator Group is an

archipelago An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands. An archipelago may be in an ocean, a sea, or a smaller body of water. Example archipelagos include the Aegean Islands (the o ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

that consists of

Flinders Island Flinders Island, the largest island in the Furneaux Group, is a island in the Bass Strait, northeast of the island of Tasmania. Today Flinders Island is part of the state of Tasmania, Australia. It is from Cape Portland, Tasmania, Cape Portl ...

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. Earlier called Eyre's Peninsula, it was named after e ...

. It is named after by her commander,

Matthew Flinders Captain (Royal Navy), Captain Matthew Flinders (16 March 1774 – 19 July 1814) was a British Royal Navy officer, navigator and cartographer who led the first littoral zone, inshore circumnavigate, circumnavigation of mainland Australia, then ...

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

Great Australian Bight The Great Australian Bight is a large oceanic bight (geography), bight, or open bay, off the central and western portions of the southern Coast, coastline of mainland Australia. There are two definitions for its extent—one by the Internation ...

. 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 rock, carbonate grains. The grains consist of sand-size grains of either cor ...

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 dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...

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 or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various sp ...

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

Flinders Island

, 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 is 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, bottlebrushes or tea-trees (although the last name is also applied to species of '' Leptospermum''). They ...

woodland A woodland () is, in the broad sense, land covered with woody plants (trees and shrubs), 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 sunli ...

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 (213 ha), the Veteran Isles (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 mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

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

Casuarina ''Casuarina'', also known as she-oak, Australian pine and native pine, is a genus of flowering plants in the family Casuarinaceae, and is native to Australia, the Indian subcontinent, Southeast Asia, islands of the western Pacific Ocean, and e ...

'' and ''Melaleuca'' woodland. The Veteran Isles support low shrubland dominated by Twiggy Daisy-bush and Marsh Saltbush. 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 Organization, international ...

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 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 i ...

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 Int ...

(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 Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, ...

, the fairy tern, as well as significant populations of Cape Barren geese,

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

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 Endemism, endem ...

. 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''), ( Māori: ''takahikare'') also known as white-faced petrel or frigate petrel is a small seabird of the austral storm petrel family Oceanitidae. It is the only member of the monotypic genus ...

s. The

biome A biome () is a distinct geographical region with specific climate, vegetation, and animal life. It consists of a biological community that has formed in response to its physical environment and regional climate. In 1935, Tansley added the ...

-restricted

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

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

Citations

References

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