Melting Arctic ice caused by climate change is fueling the spread of a deadly virus that destroys seals, otters and sea lions, new research has revealed.
Phocine distemper virus (PDV) has been teasing marine mammals for decades and killing thousands of European seals in the North Atlantic Ocean in 2002.
Two years later, it was discovered that North Sea otters had contracted the virus in Alaska.
Researchers were confused about how it could have spread between the species because they had no contact, because Arctic sea ice blocked routes between them.
The focine distemper virus appeared to have spread from European seals in the North Atlantic to sea lions and other marine mammals in the North Pacific. Researchers say that this was probably due to the melting of arctic sea ice that opened passages between the two oceans
Now, a UC Davis School of Veterinary Medicine research team has discovered that infected seals from Europe were traveling through passages along Northern Russia and Northern California opened by lower sea ice levels.
This & # 39; historical & # 39; change in sea ice may have brought the Arctic and subarctic seals in a way that would not have been possible before.
The team behind the study discovered that this was the likely cause of the introduction of PDV in the North Pacific.
Researchers spent 15 years studying the spread of PDV between marine mammals in the North Atlantic and marine mammals in the North Pacific. They discovered that there was an increase in the number of cases in North Pacific species when the ice at the North Pole was particularly thin
Dr. Tracey Goldstein, from UC Davis and the author of a virus spread study, said: “The loss of sea ice causes marine wildlife to search and forage in new habitats and remove that physical barrier, creating new paths are possible for them to move.
& # 39; As animals move and come into contact with other species, they offer opportunities to introduce and transmit new infectious diseases, with potentially devastating consequences. & # 39;
Dr. Goldstein and colleagues examined the timing of the introduction of PDV in the North Pacific, the risk factors associated with the rise and the transmission patterns.
Researchers from UC Davis School of Veterinary Medicine, who provided the data used in this image, used satellite data to link animal movement and risk factors. They used this information to show that exposed animals could carry PDV long distances
The team used data on exposure to PDV and infection in a number of marine mammals, including ice seals, firmer sea lions, northern fur seals and sea otters in the production of the study. They also used data on movements of animals collected between 2001 and 2016.
They discovered that there were widespread infections and exposure to the virus in the North Pacific in 2003. This peaked again in 2009 and coincided with a reduction in polar ice at sea.
A study by researchers from the University of Cincinnati earlier in 2019 showed that the Arctic could soon be completely free of sea ice during its transition from summer to winter due to climate change.
Ice in the Arctic fluctuates strongly according to a seasonal cycle, but rising global temperatures have caused dramatic changes in the area.
"The goal is the sensitivity of sea ice to temperature," says Won Chang, co-author and UC assistant professor of mathematics.
"What is the minimum global temperature change that will eliminate all the Arctic ice in September? What is the turning point? "
According to the Cincinnati team, that turning point can only heat up 2 degrees.
Dr. Goldstein and her team used satellite data to link data about animal movements and risk factors. They used this information to show that exposed animals might be able to carry PDV long distances.
Elizabeth VanWormer, an author on the research paper said that the problem of virus spread between the North Atlantic and the North Pacific, as well as changes in marine mammal behavior only get worse as the ice continues to melt.
"While sea ice continues its melting trend, the opportunities for this virus and other pathogens to move between North Atlantic and North Pacific marine mammals may occur more frequently," she said
& # 39; This study emphasizes the need to understand PDV transmission and the potential for outbreaks in sensitive species in this rapidly changing environment. & # 39;
The outbreak of PDV in 2002 was not the first time it caused fatalities in the European marine mammal population.
More than 18,000 animals were killed in 1988 as a result of a PDV outbreak, including 60% of the British seal population.
In 2003, marine mammals in the North Pacific were first infected with PDV. This was the reason for the 15-year research led by Dr. Goldstein at the UC Davis School of Veterinary Medicine.
WHAT ARE THE EFFECTS OF LOWER SEA ICE LEVELS?
The amount of Arctic sea ice peaks around March as the winter comes to an end.
NASA recently announced that the maximum amount of sea ice this year was low, following three other record-low measurements in 2015, 2016 and 2017.
This can lead to a number of negative effects that affect the climate, weather patterns, plant and animal life and indigenous human communities.
The amount of sea ice in the Arctic is decreasing, and this has dangerous consequences, says NASA
Moreover, the disappearing ice can change shipping routes and affect coastal erosion and ocean circulation.
NASA researcher Claire Parkinson said: & # 39; The ice cover in the North Pole continues to show a downward trend and this is related to the continuing warming of the North Pole.
& # 39; It is a two-way street: global warming means that less ice will form and more ice will melt, but because there is less ice, less incident solar radiation from the sun will be reflected, and this contributes to warming up. & # 39;
. (tagsToTranslate) dailymail (t) sciencetech (t) Climate change and global warming