Armstrong Reef (29483)
Antarctica, Antarctica
Site overview
KBA status: confirmed
Year of last assessment: 2015
National site name: Armstrong Reef
Central coordinates: Latitude: -65.8931, Longitude: -66.2334
System: marine, terrestrial
Elevation (m): 0 to 250
Area of KBA (km2): 13.84591
KBA classification: Regional
Legacy site: Yes
Site details
Site description: Armstrong Reef is a small island group situated ~2 km southwest of Renaud Island, part of the Biscoe Islands, lying off the Graham Coast of the central Antarctic Peninsula. Armstrong Reef extends over 4.3 km in a southwest-northeast orientation and consists of a number of small ice-free islands each with areas of < 100 ha. The IBA qualifies on the basis of the Imperial Shag (Phalacrocorax [atriceps] bransfieldensis) colony present and comprises the islands of the reef and the intervening marine area. Plutonic rocks dominate the geology of the island group (Smellie et al. 1985). The nearest scientific station is Vernadsky (UKR), which is located ~121 km to the northeast. The area is remote from the most popular tour ship routes and thus receives few visitors.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that was identified using previously established criteria and thresholds for the identification of Important Bird and Biodiversity Areas (IBAs) and for which available data indicate that it does not meet global KBA criteria and thresholds set out in the Global Standard.
Additional biodiversity: Poncet & Poncet (1987) reported a large Adélie Penguin ( Pygoscelis adeliae ) colony on Armstrong Reef, with approximately 12 800 breeding pairs recorded in 1984, which originally qualified the site as an IBA. However, a recent ground nest count made in January 2013 (Casanovas et al . in press) indicated a decrease in the colony to ~2813 breeding pairs and the site therefore no longer qualifies as an IBA on account of the penguin colony. However, a large colony of 633 pairs of Imperial Shag was also recorded breeding amongst the Adélies and on three islets within the island group (unpublished data S. Poncet pers. comm. 2005). More recently, Casanovas et al . (in press) reported 114 pairs at the site based on an accurate nest count. A sizeable colony of 126 pairs of Southern Giant Petrel ( Macronectes giganteus ) was documented breeding on Armstrong Reef in 1983 (Patterson et al. 2008). In view of the interseasonal variability in breeding numbers, the IBA has been retained based on the criteria for Imperial Shags. Non-bird biodiversity: None known.
Delineation rationale: Shortest perimeter around islands and/or ice-free areas >5km2.
Threats
Summary of threats to biodiversity at KBA: None known.
Additional information
References: Casanovas, P., Naveen, R., Forrest, S., Poncet, J. & Lynch, H.J. in press. A comprehensive coastal seabird survey maps out the front lines of ecological change on the western Antarctic Peninsula. Polar Biology. Patterson, D.L., Woehler, E.J., Croxall, J.P., Cooper, J., Poncet, S., Peter, H.-U., Hunter, S. & Fraser, W.R. 2008. Breeding distribution and population status of the Northern Giant Petrel Macronectes halli and the Southern Giant Petrel M. giganteus. Marine Ornithology 36: 115-24. Poncet, S. & Poncet, J. 1987. Censuses of penguin populations of the Antarctic Peninsula, 1983-87. British Antarctic Survey Bulletin 77: 109-29. Smellie, J.L., Moyes, A.B., Marsh, P.D. & Thomson, J.W. 1985. Geology of Hugo Island, Quintana Island, Sooty Rock, Betbeder Islands and parts of Biscoe and outcast islands. British Antarctic Survey Bulletin 68: 91-100.