Sentinels Of Arctic Ecosystem Health: Polar Bear And Arctic Fox

Abstract

Climate change is impacting human, wildlife, and ecosystem health in the Arctic. Currently, we lack sufficient information to fully appreciate the ramifications of these changes and are thus ill equipped for predicting, mitigating or adapting to the outcome of such impacts. Warming in the Arctic has generated a need for baseline information on biodiversity and ecosystem health such that change over time may be assessed. Sentinel species can be used to monitor and therefore, intervene to prevent adverse health outcomes before they manifest at the population level. This dissertation examines the use of polar bears (Ursus maritimus) and arctic foxes ( Alopex lagopus) as sentinels for climate change in the Arctic. To this end we: develop hematological biomarkers in polar bears which can be used to model change over time in health; demonstrate relationships between this biomarker and infectious agent exposure (e.g serology); and establish prevalence and risk factors for infectious agents that can serve as indicators of change in disease occurrence at the Arctic marine-terrestrial interface. We found that den emergent female polar bears with dependent young were the most immunologically vulnerable cohort and suggest therefore, that they be targeted in future monitoring efforts. We also detected evidence suggesting serologic exposure of polar bears to morbillivirus and Toxoplasma gondii may be associated with immunological status and age (morbillivirus only). Furthermore, we used molecular epidemiologic techniques to identify the strain of the highly lethal morbillivirus in arctic fox as "arctic" canine distemper virus and the species of Echinococcus in arctic fox on the Alaska North Slope as Echinococcus multilocularis. The results of this study illustrate the utility of the "One Health" approach in addressing the impacts of climate change. Understanding Arctic ecosystem health will require the collaborative efforts of experts in diverse fields as well as input from local, traditional ecological knowledge over the proper spatial and temporal scales.