This Marine IBA is identified using both tracking data and seaward extensions around breeding colonies. It falls within the French Southern Territories Exclusive Economic Zone (EEZ) and the Indian Ocean, Antarctic and Southern FAO ocean region. The site covers an area of 5074 km2 and borders the coastline. The depth ranges from 0 to 2673 m, with a mean annual wind speed of 3.19 m/s, mean annual sea surface temperature falls between 3.99 and 4.59 °C and mean annual chlorophyll-a concentrations found to range between 0.22 and 0.86 mg/m3.
15 species trigger IBA criteria at this Marine IBA. BirdLife analyses of tracking data estimates that 251-4252 individuals of Wandering Albatross (VU) from Iles Crozet are present at the site during the Brood-guard (Mar-Apr), Immature (Feb-Oct), Incubation (Dec-Mar), Juvenile (Dec-Jun) and Post-guard (Apr-Dec) life-history stages. 223-1541 individuals of Sooty Albatross (EN) from are present at the site during the Juvenile (Apr-May) life-history stage. 540-5400 individuals of Sooty Albatross (EN) from Iles Crozet are present at the site during the Incubation (Oct-Dec) and Post-guard (Jan-May) life-history stages. 4425-35400 individuals of White-chinned Petrel (VU) from Iles Crozet are present at the site during the Post-guard (Jan-Apr) life-history stage. Seaward extensions around breeding colonies; Île de la Possession, Île de l'Est include key near-colony areas for breeding populations of White-chinned Petrel (VU) 60000-270000 individuals, Grey Petrel (NT) 6000-27000 individuals, Great-winged Petrel (LC) 60000-270000 individuals, Imperial Shag (LC) 609-811 individuals, Soft-plumaged Petrel (LC) 66000-297000 individuals and Kerguelen Tern (NT) 444-444 individuals.
BirdLife International (2021) Important Bird Areas factsheet: Île de la Possession / Île de l'Est - Marine. Downloaded from http://www.birdlife.org on 16/04/2021.