The Problem Of Plastic Consumption By Polar Bears
Posted on March 18th 2020
Early in 2019 52 polar bears converged up a small military settlement in Russia’s Novaya Zemlya archipelago forcing the town of Belushya Guba to declare a state of emergency. The dramatic polar bear invasion was an illustration of a widespread problem. When polar bear territory and waste intersect the bears are likely to be found muzzle deep in rubbish. That is a real threat to the safety of humans and a diet of trash is not exactly good news for the bears either.
Long running study
Rubbish dumps are often filled with plastic and according to a new survey conducted in Alaska, the polar bears are consuming a lot of it. An analysis of the contents of the stomachs of 51 polar bears killed by subsistence hunters in the Southern Beaufort Sea between 1996 and 2018 found that a quarter of the bears had stomachs containing plastic. Consuming plastic rather unsurprisingly can result in serious problems because of their physiology.
The pyloric sphincter muscle, of polar bears which controls the flow between the stomach to their small intestines is narrow and that means large plastic items can result in blockages which cause them a lot of pain. Two of the polar bears with stomachs containing more plastics than their compatriots also behaved more irritably and aggressively and failed to respond to deterrents that were meant to fend them off.
Scientists are well aware that bears in poor physical condition tend to be more aggressive. A study conducted in 2017 found that nutritionally stressed male polar bears are far more likely to attack humans. This is possibly because not only are the bears hungry they may well also be in pain. Other experts suggest it is not clear whether the aggression is down to hunger or because they have stomachs filled with plastic. This is because we do not know whether polar bears are hungry and as a result consume plastic or because polar bears visit dumps and consume plastic as a result.
Most of the plastic found in the polar bear stomachs were clear plastic shopping bags or heavy-duty black garbage bags. Some experts do not believe the polar bears are consuming plastic bags. Instead they believe that when humans toss bagged scraps away in the Arctic, the cold results in the plastic freezing the food making it impossible to eat the food without also consuming the plastic.
It is not easy to prevent polar bears from eating plastic. In contrast to the South where rubbish is managed using landfills, that is impossible in the Far North where the ground is either permafrost or the bedrock is so close to the surface it is impossible to dig deep.
Problem not easy to solve
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. The only real answer available is to reduce the amount of plastic waste from the North or to institute a program that hauls inorganic material out of the region.
More data needed
There is simply not enough data to say for sure whether plastic consumption by polar bears has increased since the study began in the 1990’s but this is information wildlife managers wish to have access to. In Canada hunters do take samples of polar bears that have been harvested but their stomachs are not always opened. In the Russian town, the polar bears did eventually leave and officials ended the state of emergency. Nevertheless, seeing polar bears feed at dumps is increasingly common.