Researcher at the Institute of Ecology and Evolutionof the Russian Academy of Sciences Svetlana Artemyeva told how this animal is doing and how it can be affected by the growth of transport activity on the Northern Sea Route.
Diet and exercise
— Who is a polar bear from the point of view of zoology?
— A marine mammal — physiologically similar to terrestrial predators, but most of its life is associated with the Arctic Ocean. The main prey items are members of the true seal family, Phocidae, which live in the water. In Russian seas, this primarily refers to the ringed seal, which breeds on ice.
— And secondarily?
— In the Canadian Arctic sector, Greenland seal pups are born in spring, and at this time of year they can make up to half of a polar bear’s diet. In some areas, bears hunt beluga whales. On Spitsbergen, they attack reindeer. But they mainly eat ringed seals.— What is the population size of the polar bear?
— We don’t know the exact population size — neither in Russia nor in the world. There are only expert estimates. Two dozen subpopulations are known, four of which are in our country: the Barents Sea subpopulation, which we share with Norway’s Spitsbergen; the Kara Sea subpopulation; the Laptev Sea subpopulation; and the Chukotka‑Alaska subpopulation. In the 2010s, the first and the last were counted. The results are as follows: 2.7–3 thousand and about 1.5 thousand individuals, respectively.
This unpredictable ice
— Is the polar bear’s range shrinking?
— The polar bear is found throughout the Arctic, both at the pole and along the coast. It is gradually moving south: recently, a polar bear was seen just north of Dudinka, which is effectively at the latitude of Norilsk. So, it cannot be said that the bear’s range is shrinking, but the bear is moving into new territories not because of a good situation.Negative impact factors can be divided into two large groups. The first is related to the active human development of the Arctic. Among the indigenous small‑numbered peoples of the North, the bear was considered both an object of hunting and of worship. There was even a special cooling period: after killing a bear, it was forbidden—ranging from a week to several months in different cultures—to hunt its relatives.
The second group of factors is the reduction of ice masses and changes in ice phenology. If earlier everyone knew where and when ice formed during the autumn‑winter period, now ice formation is unpredictable. Even a person cannot predict it, let alone an animal. For example, last year in Chukotka, the ice didn’t form properly at all, and now everything there is covered in ice. In the Kara Sea, it’s exactly the opposite.— How do polar bears behave when there’s a continuous polynya near the shore? Do they stay on land?
— Strong, experienced animals migrate northward beyond the ice edge in summer, when intensive melting begins. Young animals and females with cubs mostly stay along the coast. Negative consequences are possible here. The cubs that stayed on the shore with their mother essentially learn from this experience and understand that they shouldn’t go out onto the ice in summer and autumn.
The bears that stayed on the shore need something to eat. There are no seals: they’re on the ice, which is already far away. Hunting reindeer is precisely what this is all about. Some bears go to human settlements and start ransacking garbage dumps. Others destroy colonies of white gulls, feasting on chicks and eggs. And this, by the way, is also a species listed in the Red Book.
Don’t attack the bears with drones
— To sum up, how does climate change affect polar bears?
— The area where they can hunt is shrinking. It is believed that the ringed seal population is stable, but the instability of the ice cover can also have a negative impact on it. And for the polar bear, ice is also a substrate, a support for hunting, and a necessary condition for movement. He swims beautifully, but with enormous energy expenditure.
— And what about environmental pollution?
— It also has an impact. Mostly, it’s the accumulated damage from the past — heavy metals, persistent organic pollutants. We still find DDT in samples taken from animals, even though it was banned more than half a century ago. Microplastics are a major concern: they’re everywhere in the ocean, in the Arctic as well, and they’re also found in the polar bear’s body.
— How might the growth in transport activity along the Northern Sea Route affect the polar bear?
— As we’ve said, seals are the polar bear’s main food source. Therefore, the Marine Mammal Council informs the crews of Atomflot vessels: if there are females with pups on the ice, please reduce speed and avoid that area. If a pup falls into the water, it will most likely freeze and die. In addition, we need to protect and monitor polar bear den sites more thoroughly.
— Why do they need a den if they don’t hibernate?
— These are birthing dens; that’s where the cubs are born. Along the route of the Northern Sea Route, there are many such dens near Wrangel Island, Franz Josef Land, Severnaya Zemlya, and along the Taimyr coast. However, most of them are within protected areas, and outsiders are not supposed to enter them.Sometimes adult bears use temporary, shallow dens for shelter. When prey doesn’t appear for a long time and the predator senses that the weather is getting worse, it lies down to rest and wait out the bad weather.
We need a federal law that would protect the rookeries of marine mammals. Even a helicopter can land on a rookery outside national parks and reserves, scare the animals away, and the pilot won’t face any consequences for it.
Rosatom
