ARCUS | Arctic Research Consortium of the United States

7th Annual ARCUS Award for Arctic Research Excellence

Honorable Mention Interdisciplinary Research
Submitted by   Nina Karnovsky
Authors   Nina J. Karnovsky, S. Kwasniewski, J. M. Weslawski, W. Walkusz, and A. Beszczyska-Moeller
Category   Interdisciplinary Research
Title   The Foraging Behavior of Little Auks in a Heterogeneous Environment
Affiliation   Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, USA

Abstract

The Atlantic sector of the Arctic is currently undergoing large-scale changes in the distribution of water masses in response to the pronounced positive values of the North Atlantic Oscillation. As a consequence the area surrounding Little Auk (Alle alle) colonies on Svalbard has experienced an increase in the inflow of Atlantic Water. In this study, the influence of water mass distribution on the foraging ecology of Little Auks was examined through simultaneous measurements made at colonies in Hornsund Fiord (77º03’N, 15º10’E) and at-sea. In the colony, we measured chick diets. While at-sea, we assessed the distribution of foraging Little Auks and the zooplankton available to them within different water masses. Our results indicate that Little Auks feed mainly on the copepod Calanus glacialis. They restrict their foraging activity to Arctic Water that contains the large copepod and avoid Atlantic Water that contains a smaller copepod (C. finmarchicus). Little Auks breeding on Svalbard may be impacted by climate change because during years when the flow of Atlantic Water increases, they may be forced to forage in areas with sub-optimal conditions. In addition, we evaluate the potential of the Little Auk as an indicator of climate change and the parameters of their breeding biology and foraging ecology that would be sensitive to shifts in oceanographic conditions.