The top of both peaks each “retains some pockets of soil, predominantly coarse and granitic but with small patches of calcareous sandy loam”.

[1][2] Dorothee Island was formed along with the rest of the Pearson Isles about 10,500 years ago following the rise of sea levels at the start of the Holocene.

[3] Geologically, Dorothee Island and the other parts of the Pearson Isles are the summits of an inselberg partially concealed by sea level rise.

A “calcareous sandy loam” associated with the central crevasse on the northern half of the island supports a grey saltbush heath.

[1][7][8][9][10] As of 2006, birds were represented by the following species: Nankeen kestrel, Australian raven, barn owl, black cormorant, Cape Barren geese, common starling, crested tern, fork-tailed swift, house sparrow, masked lapwing, Pacific gull, rock parrot, ruddy turnstone, short-tailed shearwater, silvereye, silver gull, welcome swallow, white-faced heron, white-faced storm petrel and breeding populations of the following species: little penguin, sooty oystercatcher, white-faced storm petrel and short-tailed shearwater.

It is with some reservations that the Committee makes this recommendation as these names were first used on the chart of Captain Baudin's voyage prepared by F Peron and L de Freycinet and difficulty is experienced in relating islands shown in this chart to present day Admiralty Charts but as these names do not appear on modern charts this recommendation is a means of perpetuating them in the general area of the first use'.Dorothee Island is first mentioned as specifically receiving protected area status in 1972 as part of the Investigator Group Conservation Park proclaimed under the National Parks and Wildlife Act 1972 for the purpose of protecting “delicate island ecology and Australian sea lion and New Zealand fur seal haul-out areas”.