Four thousand walruses are estimated to have died between summer and fall this year on the Russian side of the Bering Straits. Walruses are known to 'haulout' in large numbers on beaches. They cannot swim indefinitely and haul themselves ashore or onto sea ice to rest, a few weeks at a time.
Walrus deaths this year are twice the normal number, and have been described as "pretty sobering."
This year, however, ice on the Chukchi Sea in Russia melted away due to global warming, say scientists. As a result, more walruses came into the beach to rest and stayed longer, than ever before. Herds of 40,000 walrus were reported last week. The animals died in panic stampedes that can be caused by the appearance of a polar bear, a hunter or even a low-flying airplane. Many of the victims were young calves born in the spring.
Scientists have also said that extended shore haulouts like this ill-fated one began appearing only when sea ice started to recede. Sea ice thickness has reduced over 40% in the last 30 years.
WWF reports that local people living along the Chukchi sea say the climate has changed in their lifetime. Vladimir Petrovich Typykhkak, a 41-year-old Siberian Yupik sea hunter from the village of Sireniki, says: “The sea begins to freeze in November only, while before it did so in September.” Winters are shorter, and increasingly unpredictable, with far more blizzards than earlier.
Sea ice melt-off is a vicious cycle, WWF scientist Dr Brendan P. Kelly, explains:
... it is now known scientifically that snow and ice reflect as much as 80 percent of the incoming sunlight, while sea water absorbs over 90 percent of the sunlight. That differential reflection ... contributes strongly to the faster rate of climate change experienced today in polar regions.Sea ice is also responsible for maintaining water temperature and other factors that regulate nutrient flows in the sea. Nutrients are used by phytoplankton that live at depths where sunlight penetrates. Fish depend on phytoplankton, as do seabirds, seals, whales and walruses.
One consequence of our warming climate is the melting of sea ice. Once that melt begins, it is accelerated by the resulting change in reflectivity. As the ice changes to water, the reflectivity of the surface goes from more than 80 percent to less than ten percent – resulting in further warming, more ice melt, and yet a further decrease in reflectivity. - WWF
So, not only is sea ice melt resulting in dangerously crowded shores and longer stays, but also driving changes in food availability for a range of marine animals. The rates of melt-off are increasing every year, and with few warming curbs in sight, we will soon have the as much evidence of climate change related deaths that any skeptic could possibly want.