SOURCE: Hakai Magazine

DATE: April 5, 2019

SNIP: Dumps are often chock-full of plastic and, as a new survey from Alaska shows, polar bears are ingesting a lot of it. In an analysis of the stomach contents of 51 polar bears that had been killed by subsistence hunters in the southern Beaufort Sea between 1996 and 2018, researchers led by Raphaela Stimmelmayr, a wildlife veterinarian with Alaska’s North Slope Borough Department of Wildlife Management, found that 25 percent of the bears had plastic in their stomachs.

Ingesting plastic can cause serious problems for polar bears because of their physiology. Polar bears have a very narrow pyloric sphincter—the outlet from the stomach to the small intestine—so large items can cause painful blockages. Two of the bears whose stomachs were stuffed with more plastics than the other bears had behaved differently, too—they were more irritable and aggressive, and did not respond to deterrents meant to shoo them away.

Scientists know that bears in poor body condition are likely to be more aggressive. In a 2017 study, Geoff York, senior conservation director with the nonprofit conservation group Polar Bears International, and his colleagues showed that nutritionally stressed male polar bears are more likely to attack people. “These bears are potentially not just hungry, but in pain,” York says.

Stimmelmayr says most of the ingested plastics she found were clear plastic shopping bags and heavy-duty black garbage bags. She doesn’t think polar bears are deliberately eating plastic bags, as is the problem with leatherback turtles, which confuse the bags with jellyfish. Instead, she thinks that when people toss away bagged scraps, the cold Arctic conditions cause the plastic to freeze to the food, making it impossible for the bears to eat one but not the other.

Preventing polar bears from eating plastics isn’t easy. Unlike in the south, where garbage can be managed through landfills, that’s often not an option in the Far North, where bedrock might be too close to the surface to dig deep, or the ground is permafrost.

“Waste management is a growing issue, because of the nature of food that people are eating and the westernization of Inuit diets,” says York. “The processed nature of what we ship to the North has changed a fair bit in the last couple of decades to a very plastic-heavy [packaged] type of food.”