The journal Proceedings of the Royal Society B. has published a study by Norwegian zoologists who have studied the populations of polar bears in the Svalbard archipelago, according to the Daily Mail. It turned out that from 1995 to 2016, due to the melting of sea ice, isolating the bears from each other, they lost 10% of their genetic diversity. The situation is most serious on the western coast of Svalbard - here, in the Barents Sea region, the loss of sea ice is greatest, and here genetic diversity is disappearing at the fastest pace.
Computer simulations show that the melt will only worsen in the future, leading to the isolation of even more polar bears. As a result, the so-called "inbred depression" can occur - a decrease in the viability of individuals arising from inbreeding. “The extent and rate of loss of genetic diversity that we have observed is alarming. Polar bears have historically shown relatively little genetic differentiation even on a global scale, but now they are facing increasing climate pressures”, - the researchers write.
Increasingly, polar bears that go inland in search of food are mating with grizzly bears that reach Alaska. Their offspring is a completely new species, the pisley bear. According to the observations of experts, peasles are not so affected by climate change and can live at higher temperatures.
Along with inbreeding, climate change is forcing polar bears into cannibalism. In February 2020, Ilya Mordvintsev, a senior researcher at the Severtsov Moscow Institute of Ecology and Evolution, spoke about this: animals in the Arctic eat their congeners, since melting ice and mining displaces them from their usual habitat and breaks their usual way of life. “Cases of cannibalism among polar bears is a long established fact, but we are concerned that such cases were rare in the past, and now they are registered quite often”, - Mordvintsev told Interfax.