Little auk and thick-billed murre in the NOW Polynya

• Main Authors: Mosbech, Anders, Johansen, Kasper Lambert, Cuyler, Christine, Frederiksen, Morten, Linnebjerg, Jannie Fries, Lyngs, Peter, Merkel, Flemming Ravn
• Format: Conference Object
• Language: English
• Published: 2017
• Subjects: Arctic; Greenland; Svalbard; Climate change; East Greenland; little auk; thick-billed murre; Zooplankton; Copepods
• Online Access: https://pure.au.dk/portal/en/publications/cb00fbbc-b4ae-4180-97a8-368245fc2cf5; http://conferences.au.dk/fileadmin/conferences/2017/NOW/NOW_Conference_web_14nov_Final.pdf

We describe ecological linkages for the little auk and thick-billed murre population in the North Water region and discuss potential future trends based on a comparison with little auk and thick-billed murre colonies elsewhere in the Arctic with different ice conditions and prey availability. The NOW Polynya marine ecosystem is host to the largest seabird populations in Greenland and the area has a diverse seabird assemblage with 14 regular breeders. The little auk and the thick-billed murre are the most abundant of all the seabird species in NOW, and the two species have the largest biomass. While the thick-billed murre has a widespread distribution across the Arctic, the large little auk colonies occur only in the High Arctic near a polynya or other productive marine areas. Although the abundance estimate is uncertain, the little auk population in the NOW region is estimated at 33 mill. pairs, which amounts to more than 80 % of the world population. These huge numbers cause a significant fertilizing impact in the terrestrial environment near the large colonies. The little auks feed their chicks in the colony on High arctic copepods, which are especially large and lipid-rich, and also to some extend rely on the copepods for their own foraging, supplemented with other zooplankton. The high abundance of the large Calanus copepods in NOW during summer is most likely the main cause for the high abundance of little auks in the NOW area. Climate change could change the copepod availability and potentially cause declines in the little auk population. However, some flexibility in little auk prey items has been documented from colonies in East Greenland and Svalbard. With its ecological linkages to the NOW, we argue that the little auk may serve as an important monitoring organism of changes in the NOW ecosystem in the future, and propose parameters which could potentially form part of such a monitoring program. The thick-billed murre colonies in the Greenland part of the NOW region hold about 362,000 birds (count ...