Abstract
The combination of the effects of pollutants and climate change has been hypothesized to be a worst-case scenario for arctic wildlife. The Barents Sea subpopulation of polar bears (Ursus maritimus) is subject to pronounced loss of sea ice habitat due to c hanging climate. In addition, this subpopulation is defined as a "hotspot" population in terms of contaminant exposure in Arctic wildlife. Prolongation of sea ice-free summer seasons is expected to challenge polar bears energetically. Since recent knowled ge suggests that contaminants may interfere with energy metabolism, we hypothesize that exposure to contaminants may lead to suboptimal energy metabolism during sea ice-free periods in polar bears. In order to explore the hypothesis, we will compare aspec ts related to fasting and health status, energy metabolism and contaminant exposure in 60 female polar bear sampled from Svalbard first in spring (April) and re-sampled the following autumn (September). First, we will investigate the influence of local se a ice cover on fasting and health status of polar bears measured as body condition, serum biochemistry and oxidative stress status. Second, we will investigate fasting processes at the physiological, molecular and biochemical level. Third, we will look at effect of fasting on toxicokinetics and biotransformation of a wide range contaminants including legacy and emerging organochlorinated, -brominated and -fluorinated compounds. Finally, we will combine the information of fasting status and processes, heal th parameters and contaminants to investigate whether energy metabolism differs between individuals that at exposed to different levels of contaminants. The proposed study will bring new information about both the effects of climate change and contaminant exposure in an apex arctic predator. This information is highly relevant both for scientific community and management agencies.
Norway