Isotopic Composition of Blood of Polar Bears ( Ursus maritimus) of the Kara—Barents Sea Population

摘要

The data on the content of carbon and nitrogen isotopes in the blood samples of polar bears obtained in the present study confirm that polar bears in the Taimyr region (and the Kara—Barents sea population in general) are partly dependent on the resources of terrestrial origin. However the "terrestrial carbon" evidently reaches bears' tissues indirectly, via marine food webs utilizing organic carbon brought into the polar basin by Siberian rivers.