Levels of POPs and Hg and potential effects on progesterone levels in breeding glaucous gulls (Larus hyperboreus) at Kongsfjorden, Svalbard

Breeding glaucous gulls, between 20-30 individuals, will be captured during a four week period of field work (May-June, 2015) in Kongsfjorden on the west coast of Spitsbergen, with a base in Ny-Ålesund, Svalbard. The birds will be captured using an automatic trigger nest trap that will capture the parental bird on the nest by its legs when the trap is triggered. Before placing the trap in the nests, we remove the eggs and put them in a heated bag to prevent them from being crushed during the capturing and to keep the temperature stable. The eggs from the nests will be replaced by wooden eggs. After capturing the birds, blood sampling, weighing, and biometrical measurements will be performed. All birds will be ringed with numbered steel rings from the Norwegian Ringing Centre, Stavanger museum and a white three letter code plastic ring to simplify identification with binoculars. The fieldwork will be supervised by Kjetil Sagerup (Akvaplan-NIVA), who will be present throughout the duration of the fieldwork. Samples from 2011-2015 will be analyzed for both chemical composition of POPs, mercury and progesterone hormones. The sampling will be in collaboration with Kjetil Sagerup from Akvaplan-NIVA under the supervision of Geir Wing Gabrielsen, Norwegian Polar institute (NP).