In a recent study investigating the impact of climate change on polar bears, researchers have uncovered troubling data indicating that as the Arctic warms, these majestic creatures are increasingly at risk of encountering viruses, bacteria, and parasites. This includes environmental threats they were less likely to face just 30 years ago.

The study focused on blood samples from polar bears living in the Chukchi Sea, an area situated between Alaska and Russia. Researchers meticulously analyzed samples collected between 1987 and 1994 and then compared them to those gathered three decades later, from 2008 to 2017.

The findings revealed that a significantly higher proportion of the more recent blood samples showed signs of infection from one of five pathogens—including viruses and parasites. Dr. Karyn Rode, a wildlife biologist at the US Geological Survey, emphasized the challenges of determining the precise effects on the bears’ physical health based solely on blood samples. However, she noted, “These results indicate that something is changing throughout the entire Arctic ecosystem.”

The research team tested for a total of six different pathogens, primarily linked to land-based animals but also previously recorded in marine species that polar bears hunt. Dr. Rode highlighted the context of the study, saying, “We covered three decades during which there was significant sea ice loss and increased land use in this polar bear population. We wanted to know if exposure to these pathogens had changed, particularly for those known to be more associated with land-based animals.”

Among the pathogens that have become more prevalent in polar bears are two parasites responsible for toxoplasmosis and neosporosis, alongside two types of bacteria leading to rabbit fever and brucellosis, and the canine distemper virus.

Dr. Rode reassured that “bears are generally pretty robust to disease,” stating that these pathogens have not typically impacted polar bear populations. However, she remarked, “What this highlights is that conditions in the Arctic are indeed changing.”