Climate change increases polar bears’ pathogen exposure
The Artctic is warming almost four times as quickly as the global average.
Warming temperatures in the Arctic are increasing the risk of polar bears being exposed to certain pathogens, a new study has found.
The researchers, led by Karyn Rode and Caroline Van Hemert of the U.S. Geological Survey, examined blood samples from polar bears in the Chukchi Sea for antibodies to six pathogens.
Comparing samples from 1987-1994 with samples taken between 2008-2017, the scientists found that exposure to five of the pathogens had increased. These pathogens were: Toxoplasma gondii, Neospora caninum, Francisella tularensis, Brucella abortus/suis, and canine distemper virus.
Looking at factors that increases polar bears’ risk of exposure to the pathogens, the research team discovered that the level of exposure was higher in females than males. This was potentially due to pregnant females denning on land to raise cubs. They also found links between diet and increased exposure.
Climate change is having a significant impact on polar bears, with the Arctic warming almost four times more quickly than the global average.
Some of the pathogens studied can be transmitted to humans. As some people living in the Arctic hunt polars bears for food, the increase in pathogens could cause health risks for them. The researchers argue that more work is needed to screen for signs of disease.
The authors said: “For some pathogens, the number of polar bears testing positive for serum antibodies, an indicator of pathogen exposure, more than doubled and were among the highest levels identified in a population.
“These results suggest that pathogen transmission pathways have changed in this Arctic ecosystem.”
The study has been published in the journal PLOS ONE.
Image © Shutterstock
BSAVA is to partner with BVA Live (11-12 June 2026) to champion clinical research.
