As sea ice levels continue to decline in the northern hemisphere, scientists are observing an unsettling trend in harp seal young mortalities regardless of juvenile fitness. While a recent study found that in harp seal breeding regions ice cover decreased by up to 6% a decade from 1979 on, a follow-up study in PLoS ONE compared the rate of harp seal strandings to total ice cover from 1992 to 2010. The data showed a direct relationship between the two, with seal pup strandings rising sharply as ice cover was reduced.
In the first years of a harp seal’s (Pagophilus groenlandicus) life stable ice platforms are critical to their survival. Mother’s their birth young on se ice and raise them until they are capable of surviving on their own. The rapidly diminishing sea ice along the east coasts of Canada and the United States, however, interrupts this process at a critical state of development preventing pups from reaching maturity. As the ice melt increases, scientists have observed a rising rate of occurrences of "strandings", in which vulnerable pup’s are left stranded on small blocks of ice isolated from their parents and eventually succumbing to starvation or the elements.
As a part of the study, researchers compared the DNA of 106 stranded harp seals with those that had been accidentally captured by fishing boats. The conclusion of this study was that the odds of survival for the young pups were completely independent from their durability, strength, or adaptive capabilities.
The world is warming due to rising greenhouse gas levels in the atmosphere primarily from burning fossil fuels, but also connected to deforestation and industrialized agriculture.
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