Icier conditions in the past acted as an obstruction to infectious agents.
"Ice is a significant ecological barrier and it influences the way in which pathogens can be transmitted in nature and your risk of exposure," said molecular parasitologist Michael Grigg.
"What we're finding with the changes ongoing in the Arctic is that we're getting new pathogens emerging to cause diseases in the region that haven't been there before," he told BBC News.
The UBC Marine Mammal Research Unit scientist was speaking here at the annual meeting of the American Association for the Advancement of Science (AAAS).
Toxoplasma gondii is ubiquitous at lower latitudes, and many people carry it with no ill effects. But it is a danger to pregnant women and individuals with weak immune systems.
The fact that it is now prevalent in beluga is significant because Inuit will often eat the meat raw or undercooked - something they are now being strongly discouraged from doing.
Researchers already knew the parasite was present in land-mammals from the region, but the presence of the pathogen in the area's waterways and oceans is troubling. How the parasite managed to infect the whales remains a mystery, though a leading hypothesis hinges on the influx of domestic cats to the Arctic, which cats, researchers believe, may have provided the pathogen safe, reproductively favorable passage. (T. gondii can infect and transmit through basically any warm-blooded animal – but it can only sexually reproduce inside cat intestines.)
Top photo via Shutterstock