Polar bears face higher risk of disease in a warming Arctic

As the Arctic warms, polar bears are at increased risk of being infected with viruses, bacteria and parasites that they were unlikely to encounter just 30 years ago, a study has found.

In a study that provides clues about how polar bear disease and ice loss are related, scientists examined blood samples from bears in the Chukchi Sea, between Alaska and Russia.

They analyzed samples collected between 1987 and 1994, then collected and studied samples 30 years later between 2008 and 2017.

Researchers found that a significant number of recent blood samples contained chemical signals that indicated the bear was infected with one of five viruses, bacteria, or parasites.

It’s difficult to tell from blood samples how a bear’s health has been affected, but Dr. Karin Rohde, a wildlife biologist with the U.S. Geological Survey, believes something has changed throughout the Arctic ecosystem. He said it shows that there is.

The researchers tested for a total of six different pathogens. Viruses, bacteria, and parasites are primarily associated with land animals, but they have also been previously documented in marine animals, including species that polar bears hunt.

Dr. Lord said the study covered a 30-year period. [this population of polar bears]”.

“So we wanted to see if exposure had changed, especially for some of the pathogens that we think occur primarily on land.”

The five pathogens that are becoming more common in polar bears are collectively called pathogens: two types of parasites that cause toxoplasmosis and neosporosis, two types of bacteria that cause rabbit fever and brucellosis, and This is the virus that causes canine distemper.

“Bears are generally quite resistant to disease,” Dr. Lord explains. “We don’t usually know that this impacts bear populations, but I think what this highlights is that [in the Arctic] It’s changing. ”

• There are approximately 26,000 polar bears in the world, the majority of which live in Canada. It is also found in the United States, Russia, Greenland, and Norway.
• Polar bears are listed as endangered by the International Union for Conservation of Nature, with climate change a major factor in their decline.
• Adult males can grow to about 3 meters long and weigh up to 600 kilograms.
• Polar bears can eat up to 45 kg of fat at one time
• These bears have a powerful sense of smell and can smell prey from up to 10 miles away.
• They are good swimmers and have been found up to 100km offshore. Their feet may be slightly webbed, allowing them to swim at speeds of about 10km/h.

In the United States, polar bears are classified as an endangered species. Scientists say the biggest threat to their future is the continued loss of sea ice habitat they rely on as a base for raiding marine prey.

Previous studies using collar cameras on bears have found that bears spend much of the year on land, so there is no sea ice available for hunting. Bears can’t find enough calories.

Dr. Lord explained that polar bears are top predators. “Our study suggests that polar bears are exposed to several pathogens primarily through prey species.

“So what we observed as changes in pathogen exposure in polar bears is indicative of changes that other species are also experiencing.”

Here are the findings: Published in a scientific magazineNarupuroswan.