New research shows that the decline in Arctic sea ice is linked to the emergence of a deadly virus that threatens marine mammals in the North Pacific.
PDV, a pathogen that is responsible for the death of thousands of European harbour seals in the North Atlantic in 2002. The disease was also identified in the northern sea otters of Alaska in 2004. The interspecies crossover of this disease raises questions about how the virus spreads.
Spanning over 15 years, the study highlights how the radical reshaping of historic sea ice may have opened pathways for contact between Arctic and sub-Arctic seals. The previously impossible pathways allowed for the virus’ introduction into the Northern Pacific Ocean.
“The loss of sea ice is leading marine wildlife to seek and forage in new habitats and removing that physical barrier, allowing for new pathways for them to move,” said corresponding author Tracey Goldstein, associate director of the One Health Institute at the UC Davis School of Veterinary Medicine. “As animals move and come in contact with other species, they carry opportunities to introduce and transmit new infectious disease, with potentially devastating impacts.”
Researchers conducted sampling of marine mammals for phocine distemper virus exposure and infection from 2001 and 2016. The animals sampled include; ice-associated seals, northern fur seals, Steller sea lions and northern sea otters from southeast Alaska to Russia, along the Aleutian Island and the Bering, Chukchi and Beaufort seas.
Arctic ocean sea ice and open water routes were assessed by the group of scientists from the North Atlantic to North Pacific oceans. Researchers used satellite telemetry data to link animal movement and risk factor data to demonstrate that exposed animals have the potential to carry the virus long distances.