In a new study published in PlosOne, Scientists have been examining blood samples from bears found within the Chukchi Sea, which is located between Alaska and Russia. Polar bears are known to thrive here and have always been relatively healthy despite the rising temperatures of the Earth. However, when comparing blood samples from the 80s and 90s to more recent samples taken in the 2000s and 2010s, it has become evident that these bears have recently come into contact with new pathogens that they have never come up against before and at much greater rates.
The Arctic ecosystem is changing more rapidly than any other ecosystem on the planet, ice has been melting and exposing new land where these polar bears have now been living. Melting ice has taken away the barrier between different marine species, allowing them to spread diseases to one another. In 2002 European harbour seals were infected with phocine distemper virus and thousands were killed. Just two years later in 2004, this same disease was found within sea otters in Alaska, the ideal prey for polar bears.
Researchers have identified five new pathogens in the polar bears within the Chukchi Sea: two parasites that are responsible for toxoplasmosis and neosporosis, two bacterium linked to rabbit fever and brucellosis, and a virus that causes canine distemper. These diseases are fortunately not lethal enough to kill polar bears in most cases, but they have the potential to weaken these polar bears and eventually cause them harm.
Although for now pathogens are not causing too much harm to polar bears, how long will it take until they are exposed to a deadly pathogen that will disrupt their communities and heighten their IUCN red list category from vulnerable to endangered?
