Back in 2002, researchers discovered a deadly virus among European harbor seals located in the North Atlantic Ocean. This eventually spread to sea lions, seals, and otters living in the North Pacific Ocean. Scientists eventually found that this was phocine distemper virus, which specifically targets marine mammals’ nervous and respiratory systems. Tens of thousands of harbor seals were killed, but what was even more baffling was how this disease traveled across literal oceans.
As Associate Director of the One Health Institute at UC Davis’ School of Veterinary Medicine, Tracey Goldstein and her colleagues studied 15 years of collected data that measured Arctic sea ice and tagged animals, courtesy of the National Oceanic and Atmospheric Administration. They found that melting ice as a result of a steadily warming climate created a pathway for this virus to travel along, hence the spread to Pacific marine mammals.
The decline of sea ice has led to a spike in numerous diseases — not just that of phocine distemper virus. This is likely due to new waterways opening up for animals carrying these diseases to travel through, eventually coming in contact with newer species and families. This affects human beings as well. Outbreaks of toxic algal blooms affect all marine wildlife, which increases the rate of ticks that carry these diseases. While no evidence has been found supporting phocine distemper virus being transmittable to humans, this disease is in the same family as the measles virus.
The distemper virus is not the only detrimental result of climate change on animals. Ocean temperatures along the west coast of the United States have been increasing, which promotes the growth of toxic algae. Plankton is affected by this as well, which is the root of the marine food chain, starting from corals all the way up to polar bears, whales, and walruses.
There are countless other detrimental effects climate change has brought onto the marine world, but what we are seeing here in this outbreak amongst marine mammals is a direct physical reaction to climate change itself; a disturbing look into what could be the future of the human race if we do not take action right now. Our ecosystem is on thin ice; pun intended. Studying these diseases among marine animals could provide us the framework that shows how to prepare and prevent an increase in diseases among ourselves.