New regional-scale surveys of the Adélie penguin breeding population in Prydz Bay: a step towards improved estimation of krill consumption in East Antarctica

Understanding circumpolar penguin abundance is critical for developing realistic ecosystem models that might be used to inform the management of impacts due to climate change or fisheries. A review of historical Adélie penguin survey data in east Antarctica revealed Prydz Bay as a priority region for new survey work to improve population estimates. Prydz Bay is considered to have the largest breeding population of Adélie penguins in east Antarctica but the most recent abundance survey was conducted 30 years ago. To understand current levels of prey consumption in east Antarctica it is therefore critical to understand if population numbers in Prydz Bay have changed in the past three decades. Accordingly, an aerial photography survey was undertaken in 2009/10. The survey used sample counts to estimate abundance for two sub-regions, comparative air and ground counts to assess detectability of penguins from the air, and data obtained from cameras to adjust counts to a point in the breeding chronology consistent with CEMP Standard Method A3. Recent abundance estimates are approximately double those obtained in the early 1980s. The new abundance estimates will significantly improve estimates of prey consumption by Adélie penguins in this region.