Polar bears in Alaska face increasing pathogen threats due to climate change

Polar bears in Alaska are facing increasing numbers of pathogens due to the warming climate, as revealed in a study published in PLOS One on October 23. Research indicates that pathogens previously unable to survive in Arctic conditions now persist in these environments. This is believed to be a result of rapid changes caused by climate change. The findings highlight a significant increase in exposure to viruses, bacteria and parasites among polar bears, posing new threats to their already vulnerable populations.

Pathogen exposure in the Chukchi Sea region

According to the study, blood samples collected from 232 polar bears in the Chukchi Sea between 2008 and 2017 were compared with samples from 115 bears surveyed between 1987 and 1994. Brucellosis and tularemia. Exposure to the parasite Toxoplasma gondii, associated with cats, increased from 2 percent to 14 percent, while antibodies to canine distemper virus were also found more frequently.

Dr. Karin Rohde, a wildlife biologist with the U.S. Geological Survey who contributed to the study, told science.org in a statement that warmer temperatures are enabling pathogens to infiltrate areas that were previously inaccessible to them. This phenomenon was particularly evident in the Chukchi Sea, where polar bears have been forced to adapt to less sea ice due to longer periods of time on land, often exposed to human activities and waste.

Implications for the Arctic food chain

The study also examined chemical markers in the polar bears’ hair to assess their diet, revealing a link between prey consumption and pathogen exposure. The findings showed that the entire Arctic food chain, including species such as ringed seals, could be affected.
According to sources, concerns were raised about potential risks to humans, who depend on the subsistence diet associated with polar bears. Dr. Rohde said in another statement that further research is necessary to understand how these pathogens may affect other species and human communities in the region.

Dr. Andy Dobson, a wildlife disease ecologist at Princeton University, also commented that although the research offers interesting insights, conclusive results will require additional data from across the population range.