Spatially extensive standardized surveys reveal widespread, multi-decadal increase in east antarctic Adélie penguin populations

• Published in: PLOS ONE
• Main Authors: Southwell, Colin, Emmerson, Louise, Mckinlay, John, Newbery, Kym, Takahashi, Akinori, Kato, Akiko, Barbraud, Christophe, Delord, Karine, Weimerskirch, Henri
• Other Authors: Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, National Insitute of Polar Research, National Institute of Polar Research Tokyo (NiPR), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: [SDE]Environmental Sciences; Antarctic; Antarctic Peninsula; East Antarctica; Ross Sea; Antarc*; Antarctica; Sea ice
• Online Access: https://hal.science/hal-01304814; https://doi.org/10.1371/journal.pone.0139877

International audience Seabirds are considered to be useful and practical indicators of the state of marine ecosystemsbecause they integrate across changes in the lower trophic levels and the physicalenvironment. Signals from this key group of species can indicate broad scale impacts orresponse to environmental change. Recent studies of penguin populations, the most commonlyabundant Antarctic seabirds in the west Antarctic Peninsula and western Ross Sea,have demonstrated that physical changes in Antarctic marine environments have profoundeffects on biota at high trophic levels. Large populations of the circumpolar-breeding Adéliepenguin occur in East Antarctica, but direct, standardized population data across much ofthis vast coastline have been more limited than in other Antarctic regions. We combineextensive new population survey data, new population estimation methods, and re-interpretedhistorical survey data to assess decadal-scale change in East Antarctic Adélie penguinbreeding populations. We show that, in contrast to the west Antarctic Peninsula andwestern Ross Sea where breeding populations have decreased or shown variable trendsover the last 30 years, East Antarctic regional populations have almost doubled in abundancesince the 1980’s and have been increasing since the earliest counts in the 1960’s.The population changes are associated with five-year lagged changes in the physical environment,suggesting that the changing environment impacts primarily on the pre-breedingage classes. East Antarctic marine ecosystems have been subject to a number of changesover the last 50 years which may have influenced Adélie penguin population growth, includingdecadal-scale climate variation, an inferred mid-20th century sea-ice contraction, andearly-to-mid 20th century exploitation of fish and whale populations.