Mercury pollution in marine animals may be behind a population crash.
An isolated population of Arctic foxes that dines only on marine animals seems to be slowly succumbing to mercury poisoning.
The foxes on Mednyi Island — one of Russia’s Commander Islands in the Bering Sea — are a subspecies of Arctic fox (Vulpes lagopus) that may have remained isolated for thousands of years. They were once numerous enough to support a small yet thriving group of fur hunters. After humans abandoned the settlement in the 1970s, the fox population began to crash, falling from more than 1,000 animals to fewer than 100 individuals today. Read more in Nature.