Habitat foraging niche of a High Arctic zooplanktivorous seabird in a changing environment

Abstract Here, we model current and future distribution of a foraging Arctic endemic species, the little auk (Alle alle), a small zooplanktivorous Arctic seabird. We characterized environmental conditions [sea depth, sea surface temperature (SST), marginal sea ice zone (MIZ)] at foraging positions of GPS-tracked individuals from three breeding colonies in Svalbard: one located at the southern rim of the Arctic zone (hereafter ‘boreo-Arctic’) and two in the high-Arctic zone on Spitsbergen (‘high-Arctic’). The birds from one ‘high-Arctic’ colony, influenced by cold Arctic water, foraged in the shallow shelf zone near the colony. The birds from remaining colonies foraged in a wider range of depths, in a higher SST zone (‘boreo-Arctic’) or in the productive but distant MIZ (second ‘high-Arctic’ colony). Given this flexible foraging behaviour, little auks may be temporarily resilient to moderate climate changes. However, our fuzzy logic models of future distribution under scenarios of 1 °C and 2 °C SST increase predict losses of suitable foraging habitat for the majority of little auk colonies studied. Over longer time scales negative consequences of global warming are inevitable. The actual response of little auks to future environmental conditions will depend on the range of their plasticity and pace of ecosystem changes

Sea ice drift tracks from the Distributed Network of autonomous buoys deployed during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition 2019 - 2021

The largest ever network of autonomous ice-tethered buoys was deployed as a Distributed Network (DN) surrounding the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Central Observatory (CO). This extensive network of 112 Global Positioning System (GPS) buoys and 12 multi-instrumented ice stations captured the annual cycle of Arctic sea ice drift and deformation for the first time as the DN traversed the Transpolar Drift Stream. GPS position data from buoys deployed during the year-long MOSAiC experiment capture sea ice drift and deformation at spatial scales ranging from 100s of meters to 200 kilometers (km) from late September 2019 into 2021. This dataset contains 216 quality-controlled drift tracks from buoys deployed at sites within a 45 km radius of the MOSAiC CO. Initial deployments began 26 September 2019 (Leg 1) with new deployments of buoys in mid-March-April 2020 (Leg 3), and August-September 2020 (leg 5). This dataset has been fully reprocessed to update drift tracks with the last of the data collected by buoys that were still operational after the initial download and processing. Complete temporal coverage of this data set is now 26 September 2019 through 23 May 2021. CC BY 4.