Study Shows Mercury Levels in Arctic Wildlife Could Rise for Centuries

Levels of mercury in Arctic wildlife could continue to rise significantly even as countries curb their emissions, a new study suggests.

- Sachi Kitajima Mulkey

Researchers analyzed more than 700 samples of fish, mammals, and peat collected across Greenland over the past 40 years and found evidence that the mercury in them was distributed by ocean currents.

The finding, published this past week in the journal Nature Communications, helps explain why levels of mercury contamination have continued increasing in the Arctic even as global emissions have begun to plateau.

"We got a lot of surprises when we analyzed the data," said Dr. Jens Sondergaard, a senior ecological science researcher at Aarhus University in Denmark and lead author of the study. "It's a really striking trend."

Exposure to high concentrations of mercury, a potent neurotoxin, can lead to neurological and other health-related effects, and the study confirms that mercury emitted today could continue posing a large threat to humans and wildlife in the region for centuries.

By analyzing mercury isotopes, a unique kind of chemical signature that can be matched like a fingerprint, the researchers traced the spread of mercury contamination to the patterns of ocean currents around Greenland. Previous research has shown that mercury can persist in oceans for more than 300 years.