A recent assessment by the International Union for Conservation of Nature (IUCN) forecasts a 30-percent decrease in current polar bear population in the next 35 years due to global warming. Currently a 26,000 populace, polar bears made it into the 2015 Red List of Threatened Species.
Dena Cartor from IUCN's species survival commission stressed the graveness of the threat and the high risk of polar bear extinction. The bears depend on sea ice when they hunt for food. Receding ice sheets and the emerging ice-free landscape will drive them to fast for a longer period. This could lead to starvation and damaging health consequences, which could affect their reproductive abilities.
How Climate Change Could Influence Polar Bear Encounters
Researchers found that the continuous shrinkage of sea ice in the Chukchi Sea during the summer forces polar bears to spend more time on land. The change could pave ways to numerous problems arising from increased polar bears and human encounters. The study was published in the Public Library Of Science (PLOS) One journal on Nov. 18.
The research team analyzed tagged polar bears movements in two periods during summer months. Only female polar bears were studied since male bears have wider necks than heads which enabled them to slip loose from the collars. In the 1986 to 1995 study period, 20 percent of the 103 tagged polar bears spent over seven days on land. In the 2008 to 2013 study period, 38.9 percent of the 47 tagged polar bears spent 30 days on land. The female bears, which include nursing ones, spent summers between Herald Island and Wrangel Island. Several spent summers in the Alaskan or Russian coasts.
Findings showed that sea ice changes affect bears' behavior. Researchers also found that northern areas' sea ice shrunk 20 to 40 days faster in the 2008 to 2013 period compared to the 1986 to 1995 period. In the southern areas, ice land melted 15 days earlier.
"Increases in terrestrial habitat use can lead to increased interactions with humans that may result in safety concerns for humans or in disturbance or death for polar bears," wrote the researchers. By tracking the polar bears' land usage, scientists could then arrive an efficient management protocol for polar bears.
The Chukchi Sea, which is located between Alaska and Russia, experienced the most substantial sea ice reduction in the Arctic in recent years. The dangers of declining sea ice is not just the polar bears's problems. Early in 2015, the international community was shocked when nearly 6,000 walruses rushed to the Alaskan shore when their ice habitat melted.
Photo: Christopher Michel | Flickr
