| Abstract
| - Space-use was examined in 54 female polar bears (Ursusmaritimus) from Svalbard and the Barents Sea that werecollared with satellite transmitters to provide information ontheir spatial positions and annual home range sizes.Plasma samples from the same animals were analyzedfor concentrations of six relevant PCB congeners (PCB-99, -153, -156, -180, -194, and -118). Factors related to space-use strategy (such as home range size; annual, spring,and winter longitudinal position; and spring and summerlatitudinal position) were important determinants ofPCB concentrations in plasma. In addition, reproductivestatus of the polar bears and plasma lipid content affectedPCB concentrations. Among the tested variables, annualhome range size was the variable that affected ∑PCB5 (sumof PCB-99, -153, -156, -180, and -194) to the largestdegree (r2 = 0.22). We propose that the positive effect ofhome range size on ∑PCB5 in female polar bears isrelated to the higher energetic costs required to occupylarge home range sizes as compared to small home rangesizes. Polar bears with large home range sizes wouldneed to consume more prey than bears with small homerange sizes, and increased feeding without a changein elimination of persistent compounds can explain theirhigher ∑PCB5 concentrations. Polar bears with large homerange sizes were also more pelagic, inhabiting areasfurther east, closer to the ice-edge zone than animals withsmall home range sizes. Thus, prey choice associatedwith a pelagic space-use strategy may also explain thehigher ∑PCB5 in polar bears with large home range sizes.
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