Ardley Island is located in Maxwell Bay, ~500 m from Fildes Peninsula, King George Island. The island is ice-free, about 2 km by 1 km in size, and is connected to Fildes Peninsula by an isthmus that becomes submerged at high water (ASPA No. 150 Management Plan, 2009). Ardley Island is designated ASPA No. 150 for the diverse range of seabirds that breed within the area. The IBA qualifies on the basis of the Gentoo Penguin (Pygoscelis papua) colony present and is defined by the boundary of ASPA No. 150, which includes all of Ardley Island.
Ardley Island is largely snow-free in summer and has relatlively low relief rising to ~65 m (ASPA No. 150 Management Plan, 2009). The island supports some of the best developed plant communities in the South Shetland Islands with ~250 lichen species and numerous mosses and liverworts. Antarctic Hairgrass (Deschampsia antarctica) is well-established and increasingly abundant on the island.
Ripamonti Station (CHL) is a small summer-only research facility with capacity for ~4 personnel located on the northern coast of the island (COMNAP, Antarctic Facilities, accessed 24/08/2010). Six major scientific stations with a combined capacity of more than 200 personnel are located within Maxwell Bay and nearby to the IBA: Great Wall (CHN, 850 m), Eduardo Frei and Teniente Marsh (CHL, 1 km), Bellingshausen (RUS, 1.5 km), Artigas (URY, 2.9 km), King Sejong (KOR, 6.5 km) and Jubany (ARG, 13 km).
Approximately 4635 breeding pairs of Gentoo Penguin were present on Ardley Island in 2005/06 (ASPA No. 150 Management Plan, 2009, data from J. Valencia). Adélie Penguins (Pygoscelis adeliae) and Chinstrap Penguins (P. antarctica) also breed at the site, with 334 pairs and 9 pairs respectively in 2005/06, and 260 pairs and 15 pairs respectively counted on 11 Dec 2014 (H. Lynch pers. comm. 2015). A small number of Southern Giant Petrel (Macronectes giganteus) breed on Ardley Island, estimated at 5 breeding pairs in 1998 (Patterson et al. 2008).
Other confirmed breeding species include the Brown Skua (Catharacta antarctica), South Polar Skua (Catharacta maccormicki), Wilson's Storm-petrel (Oceanites oceanicus), Black-bellied Storm-petrel (Fregetta tropica), Cape Petrel (Daption capense) and Antarctic Tern (Sterna vittata).
Non-bird biodiversity: Weddell Seals (Leptonychotes weddellii) frequent Ardley Island and are known to breed on beaches and sea ice in Maxwell Bay between September and November (ASPA No. 150 Management Plan, 2009). Crabeater Seals (Lobodon carcinophagus), Antarctic Fur Seals (Arctocephalus gazella) and Leopard Seals (Hydrurga leptonyx) are regularly observed in the Ardley Island area and occasionally haul out on the island.
BirdLife International (2019) Important Bird Areas factsheet: Ardley Island, King George Island. Downloaded from http://www.birdlife.org on 21/01/2019.