MOSCOW, March 20. /TASS/. The main habitat and migration areas of walruses shift due to the changing ice cover distribution in the Bering, Chukchi and East Siberian Seas due to climate change, Deputy Director of the Fishery and Oceanography Research Institute Vyacheslav Bizikov said.
"Over recent 30 years, global climatic processes have changed significantly the ice cover distribution in the Bering, Chukchi and East Siberian Seas. Thus, in autumn, the drifting ice edge is much further north, and the new ice formation in the Bering Sea in the Arctic Ocean on the coast of Chukotka happens about a month later than usually. This changes walrus habitat and migration areas, the main feeding areas, and increases the mortality of young animals, and decreases the rate of population replenishment," the expert said at the Polar Bear Universe conference, taking place at the Skolkovo innovation center in Moscow and Chukotka.
Lately, by beginning of the walrus spring migration, the Bering Sea gets almost completely clear of ice. "On one hand, there is a reduction, and quite often a complete reduction in the use of rookeries on the Bering Sea coast of the Kamchatka, Koryakia, Chukotka. On the other hand, the functioning of previously abandoned rookeries on the shores of the Chukchi Sea is resuming - there, the number of walruses reaches several dozen thousand. We can say that we witness the walrus population shifting to its range's Arctic part," he said.
According to the scientist, since 2015, there has been a low survival rate of offspring at walrus rookeries in the Chukchi Sea. "While in the late 20th century, the annual offspring made 19% of the population, in 2018-2019 it dropped to 10%. Over recent three years, the share of first-year cubs has decreased from 11% to 7%," he added.
Risks to the population
Walruses tend to spend more time on coastal rookeries, the expert continued, where polar bears attack them. They have a significant impact on walruses by their behavior, causing mass fleering from rookeries. Most often, the predators appear from the sea on floating ice floes.
"Whenever polar bears appear, walruses rush into the water in panic, crushing each other. As of 2018, the walrus mortality rate in the panics at three key rookeries approached 1,000 animals. First-year cubs and females predominate among the dead animals," the scientist said.
At Vankarem, one of the biggest coastal rookeries in Chukotka near the village of the same name, where lives the region's indigenous population, the danger emerges from both polar bears and from the anthropogenic factors. "Vankarem is an important location during the autumn migration period. The settlement's proximity has a strong influence on the walrus rookery. In 2023, a rookery did not form up near Vankarem. There were a few hundred animals. Nevertheless, the bears did appear there as usual. There may be 10 to 20 animals at a time," he added.
As of 2013-2017, the Pacific walrus population is estimated at 256,000, and the population of polar bear is between 22,000 and 31,000, including 5,000 to 6,000 in the Russian zone.
About conference
The Polar Bear Universe 7th international conference runs on March 19-21 at the Skolkovo Innovation Center in Moscow and in Chukotka's Anadyr. Following the conference, the country plans to create a permanent international expert platform on Arctic biological diversity. TASS is the conference's general news agency.