[2] It consists of one land mass with two relatively smaller peaks rising out of the sea in an arc extending to the south east via a spit of rock connected to its most southerly point.

An unnamed rock which is permanently dry is located immediately west of the "south section" of Pearson Island.

[10] Firstly, landforms associated with the formation of the inselberg and with its constituent material respectively are sheet structures and orthogonal jointing.

[12] Secondly, the action of the sea has resulted in the erosion of the “lower inclined sheet structures” on the west side of the island at sea level resulting in the formation of a steep cliff face when compared to the relatively flat profile of the east side of the island.

[15] Firstly, the parts of the island above the height of 100 metres (330 feet) above sea level support a woodland of sheoak where both shelter and soil is present.

The woodland’s density increases with altitude with the result that individual sheoaks will reach a height of 3 metres (9.8 feet) and support an understorey of species such as dryland tea tree, ruby saltbush and rock fern.

Fourthly, where the soil is granitic in origin, the heath is dominated by twiggy daisy-bush with sub-ordinate species such as common correa and shore westringia.

Sixthly, a herbfield featuring both karkalla and Austral stork's bill and fringed with round-leaved pigface is found on “the thinnest, most exposed soils on top of granite outcrops fronting the sea”.

An account from 1911 mentioned seals, Cape Barren geese, and a raptor's nest at the island's summit made from a ton of sticks.

As of 1996, the following mammals have been observed - Pearson Island rock-wallaby, bush rat and a breeding colony of Australian sea lion.

[18][19] As of 2006, the following birds have been observed - Richard's pipit, wedge tailed eagle, white-faced heron, eastern reef egret, ruddy turnstone, masked woodswallow, galah, red-necked stint, Cape Barren geese, Horsfield's rufous tailed, Australian raven, white-fronted chat, crimson chat, rockhopper penguin, Nankeen kestrel, white bellied sea eagle, welcome swallow, silver gull, Pacific gull, singing honeyeater, budgerigah, rock parrot, golden whistler, osprey, house sparrow, red-capped robin, red-tailed tropicbird, great cormorant, white-browed scrubwren, crested tern, common starling, hooded dotterel, barn owl, masked plover, silver eye and breeding colonies of fairy tern, little penguin and sooty oystercatcher.

[31] A little penguin survey was scheduled to be conducted on Pearson Island by the South Australian Research and Development Institute (SARDI) in 2013.

[37] Pearson Island has been the subject of scientific interest since the early twentieth century in respect to its geology, its ecology and its terrestrial and marine flora and fauna.

[34] Pearson Island was first visited by Edgar Waite, the then director of the South Australian Museum in 1914 followed by F Woods Jones, the then chair of anatomy at the University of Adelaide in 1920.

The 1923 expedition was funded by Sir George Murray, the then chief justice of Supreme Court of South Australia and led by F Woods Jones.

The 1969 expedition was a joint project conducted in conjunction with the then Department of Fisheries and Fauna Conservation and was led by scientists Scoresby Shepherd and I.M.