Thinning sea ice is killing off harp seal pups in record numbers, reports the first-ever study examining all the species’ breeding grounds.
Harp seal breeding grounds—Newfoundland, the Greenland Sea and the White Sea—have all seen six-percent decreases in sea ice per decade since 1979, the year satellite records of sea ice began, the study said. And it’s interfering with the survival of harp seal pups.
“The kind of mortality we’re seeing in eastern Canada is dramatic,” David Johnston, research scientist at the Duke University Marine Lab, told CBC News and other media. “Entire year classes may be disappearing from the population in low ice years. Essentially all of the pups die. It calls into question the resilience of the population.”
Every February and March, female harp seals plant themselves on the thickest and oldest ice packs in sub-Arctic waters, CBC News explained. There they bear and nurse their young until the pups can sustain themselves by swimming and hunting. Although the nursing period has adapted to a mere 12 days to accommodate the spring ice melt, the overall lack of ice has gotten severe enough that the pups are not getting the time they need.
To get their numbers, scientists studied winter ice from satellite images between 1992 and 2010 in the Gulf of St. Lawrence in Canada, one of the major breeding grounds, and compared them with seal pup mortality reports in the same area. The study was reported in the scientific journal PLoS One.
The harp seal, also known as saddleback seals, are infamous for protests over the seal hunt. Currently the European Union only allows Inuit harp seal products. New calls went out for a reduction or elimination of commercial seal hunting after the study came out on January 5. It was conducted by researchers from Duke University and the International Fund for Animal Welfare.