Do OHCs affect thyroid hormone levels in glaucous gulls (Larus hyperboreus) breeding in Kongsfjorden, Svalbard? RIS ID 5267

Sampling of the birds will take place in Kongsfjorden, Svalbard, with base in Ny-Ålesund on the west coast of Spitsbergen, during June 2013, presumably five weeks. Capturing of 20-30 individuals will be carried out using trigger nest traps that will captu re the birds by its legs when it flies off. The traps are set out in the nests as the parental birds spend time away from the nest. Before placing the nest traps in the nests, we remove the eggs and put them in a heated bag to prevent them from being crus hed during the capturing and to keep the temperature stable. Blood will be drawn within three minutes. We want to locate gulls with loggers attached during the summers of 2010- 2012 that may give further information on where these birds spend the winter. Samples from 2010-2013 will be analyzed for both composition of organohalogenated contaminants, stabile isotopes and thyroid hormones. The training in catching the gulls and collecting blood will be provided by Kjetil Sagerup from the Norwegian Polarinsti tute (NP), and Geir Wing Gabrielsen, NP.