Mercury bad for Arctic foxes

Mercury exposure through feeding on marine prey is reducing Arctic fox populations, research finds.

Data published in the journal PLOS ONE suggest the toxin—found more in the Arctic than any other part of the planet—has played a significant role in the long-term decline in Arctic fox numbers, according to BBC News. On the small Russian island Mednyi (where foxes prey almost exclusively on ocean birds and seal carcasses), the fox population mysteriously plummeted in the 1970s; researchers believed an infection was to blame, but were stumped as to the underlying cause. Recent analysis of hair samples from foxes and food sources on the island discovered significant levels of mercury.

When compared to Icelandic foxes, which live inland and survive on non-marine birds and rodents, the Mednyi foxes had much higher levels of mercury.