According to a report in the science journal PLOS ONE, Arctic foxes could be suffering a significant population reduction because their diet is limited to marine animals containing high levels of mercury.
The science study looks at foxes on the Mednyi Island
(sometimes called Copper Island). Mednyi is located in the North Pacific Ocean, east of Kamchatka, Russia. Since 2001, the island has been completely uninhabited, containing only wildlife and plants, which are subject to scientific study.
A major type of wildlife are the Arctic foxes
(also known as the white fox, polar fox or snow fox). These are small foxes native to Arctic regions of the Northern Hemisphere. The fox has a deep thick fur which is brown in summer and white in winter.
According to Nature
, when the island was abandoned by Russians, the fox population fell from around 1000 to 100.
Concerned by the decline, scientists looked at the mercury levels in the foxes. Mercury, as a human generated pollutant, can accumulate at high levels in animals. Scientists had previously noted that the seabirds and scavenged seals that make up the foxes’ diet had high mercury levels. It was found that the Mednyi foxes had higher levels of mercury than other Arctic fox populations on the larger, neighboring Bering Island and on the coast of Iceland, neither of which has suffered a similar decline. According to the French Tribune
, the hair of foxes had 10 milligrams of mercury per kilogram on average basis.
The research paper
is titled "Correlates between Feeding Ecology and Mercury Levels in Historical and Modern Arctic Foxes (Vulpes lagopus