[1][2][3] Busby Islet covers an area of about 10 hectares (25 acres) and as of 1996 had a maximum elevation of one metre (3.3 ft).

[1][2] The islet is part of a drying spit at low water which falls to a depth of 5 m (16 ft) within about 0.25 km (0.16 mi) to the south.

[3] As of 1996, Busby Islet was reported as supporting a ‘low shrubland of highly salt-tolerant succulents such as grey samphire, glassworts and Austral seablite’ while the summit of the island supports ‘marginally less salt tolerant nitre bush and African boxthorn.’[2] Sources dated 1987 and 1996 suggest that bird species are the dominant fauna.

[1][2] As of 1980 and 1981, the following bird species were observed on Busby Islet: Australian pelican, black-faced shag, little pied cormorant, little black cormorant, pied cormorant, white-faced heron, sacred ibis, chestnut teal, black swan, brown falcon, grey plover, pied oystercatcher, sooty oystercatcher, ruddy turnstone, silver gull, pacific gull, caspian tern, fairy tern, crested tern, sharp-tailed sandpiper, red-necked stint, curlew sandpiper, eastern curlew, whimbrel, greenshank, rock parrot, raven and little grassbird.

[8][9][10] Busby Islet is one of the island sites from which guano was mined under licence from the South Australian Government prior to 1919.