First avian influenza death of Alaska polar bear reflects growing spread of virus

ANCHORAGE, Alaska (KTUU) – The first known avian influenza death of an Alaska polar bear is causing grave concerns from scientists, who are pushing for answers while they continue to monitor the largest land carnivore in the world today.

The bear was found in October by a North Slope wildlife team in Utqiagvik, the northernmost city in the US. It was first reported by the Alaska Department of Environmental Conservation after they received tissue samples of the bear from the North Slope Borough Department of Wildlife Management.

Due to the polar bear being listed under the Endangered Species Act, more tests were run on the sample from the animal. Polar bears were initially listed in 2008 as threatened due to the decline of sea ice in their habitat, an environmental change that will likely continue contributing to the species’ decline.

“Anytime you find a new species that’s affected, [there] is more information and more data that we need to try to understand what this virus is capable of doing,” said Dr. Bob Gerlach with the DEC’s Division of Environmental Health.

Gerlach, the state veterinarian, maintains the state has been doing surveillance, while also investigating mortality events, in this case, looking for avian influenza.

In Alaska, there have been five confirmed avian influenza cases among foxes (3), brown bears (1) and black bears (1). Gerlach thinks the polar bear could have either eaten a bird or been around a dead bird, which caused exposure to the virus.

From studies conducted by the U.S. Geological Survey and U.S. Fish and Wildlife Service, using samples from previous outbreaks, scientists know the virus can stay active for long periods.

“They’ve actually collected samples from water and sediment in the fall and found the avian influenza, and in the spring when they thawed out, they were able to recover the virus again,” Gerlach said. “So it can — because it’s frozen in those environments — stay infective for a long time period. That’s why we see it more in the rainier, wet and cold seasons than you do in the dry, warm seasons like during the summer.”

Alaska is a central location for migratory waterfowl, with birds passing through the state from elsewhere in North America or across the Pacific Ocean. It’s a cause for concern as the USGS has discovered three different introductions that are impacting birds and causing the virus to spread in the state.

“We’re seeing it from 2022 and 2023 being very impactful and having a big impact on both domestic poultry and wild birds and now terrestrial mammals,” Gerlach said.

Gerlach believes there’s an adaptation with avian influenza that makes it unique and different from others, allowing it to linger in a species and come back over time. Especially since in South America, there have been some large mortality events of seals and sea lions even though there have been no detections of the virus in marine mammals in Alaska.

With the adaptation being a possible threat to other species, it begs the question of if it will also threaten people. So far, scientists know the risk to people is extremely low, but it’s why researchers with domestic animals are working with public health to better understand how the virus is changing and if there will be continued threats to other animals.

There have also been concerns for those in rural and Native villages in Alaska which rely on a subsistence lifestyle. Gerlach says if you are following standard procedures and cleaning poultry with sanitation and cooking all produce, there will not be a risk from consumption. If you see a bird that does not look healthy, he says, do not harvest it.

According to Gerlach, the types of animals most at risk of avian influenza will be those that are young, old or immunocompromised.

With Alaska being a vast state, the DEC relies on the public to inform local wildlife biologists and health authorities to investigate any problems.

“It’s only through the collaboration that we have with our other fellow agencies and our office is only providing one small part to this,” Gerlach said. “The wildlife biologists that are out there in the public that are reporting these morbidity mortalities are really important with respect to how we understand what’s going on and how this is going to impact us up here in Alaska.”

Gerlach encourages the public to ask questions and if they see something unusual, report it. He asks the public to not handle sick or dead animals but instead, call attention to them by calling the proper authorities.

If you come across a dead or sick animal, you may report it by reaching out through the U.S. Fish and Wildlife’s dead bird hotline or contacting a local fish and game office.

Copyright 2024 KTUU. All rights reserved.