Climate change According to a new study, sea ice in the Arctic is rapidly melting, causing “large-scale changes” in how polar bears can function. In Norway, scientists have found, bears are inbred while the species struggles to survive.
A study published on Wednesday found that in the Norwegian archipelago of Svalbard, polar bear populations have recorded a 10% loss in their genetic diversity from 1995 to 2016. The rapid loss of ice in the Barents Sea, as causes “harmful demographic and ecological effects” on animals, according to the study.
The Barents Sea is experiencing the “fastest loss of sea ice” in the entire Arctic, according to the World Wildlife Fund.
Polar bears rely on ice to find food, reproduction, and movement, and as sea ice continues to melt, animals are less able to perform the activities essential to their survival.
Pelagic bears (those that roam the sea ice and only occasionally move along the coast) have more difficulty finding access to land, scientists say. It has been observed that bears are “increasingly separated” from their grounds, where they will stay while pregnant.
Bears living off the coast of Svalbard face other problems caused by climate change. With less sea ice available, there are fewer opportunities to hunt seals, forcing bones to change their diet to eat more birds and bird eggs. In other areas of the Arctic, polar bears have been observed to occur increasingly cannibalistic as their food sources dwindle.
The study found that ice loss also affected the mating opportunities of polar bears and their ability to disperse to other subpopulations to other areas, causing some of the endogamous animals to keep their groups alive.
The level of inbreeding is low for now, according to the study, but as groups of polar bears become isolated due to their melting habitat, inbreeding may increase in the future, “most likely with negative effects. such as endogamous depression “.
Simo Njabulo Maduna, the study’s lead author, told CBS News that the findings could be “an early warning” about a bleak future for polar bears.
“It is worrying because the loss of genetic diversity and likely endogamous depression could lead to a reduction in the survival and productivity of this iconic species,” Maduna said.
A 2020 study found that melting sea ice is starving polar bears and that, within the last century, polar bears it could be extinct. As stated in the study, decreasing genetic diversity increases the risk of extinction.
“The magnitude and rate of loss of genetic diversity and gene flow we observed is alarming given that polar bears have historically shown relatively little genetic differentiation even on a global scale,” the study says. “The results of the simulations suggested that further loss of sea ice will lead to continued erosion of local genetic diversity in the polar bears of the Svalbard archipelago.”
The study marks the latest research showing that the changing reality of polar bears is related to climate change.
“The sum of evidence … makes it very difficult to come up with an alternative explanation,” Maduna said. “In fact, we can’t think of any mechanism other than climate-driven sea ice reduction that can reasonably explain the observed patterns.”