Arctic permafrost home to large mercury reserves, study finds

Feb. 5 (UPI) -- Scientists have discovered large mercury reserves trapped in Arctic permafrost.

According to a new study published in the journal Geophysical Research Letters, the mercury reserves are the largest in the world.

"This discovery is a game-changer," lead study author Paul Schuster, a hydrologist at the U.S. Geological Survey in Boulder, Colorado, said in a news release. "We've quantified a pool of mercury that had not been done previously, and the results have profound implications for better understanding the global mercury cycle."

The monumental mercury levels were revealed by permafrost cores drilled in northern Alaska. Analysis suggests the Arctic permafrost holds double the amount of Mercury found in all the rest of the planet's ocean, sediment and atmospheric systems combined.

The discovery could help scientists better understand how Earth's oceanic, geological and atmospheric systems store and recycle mercury.

The mercury trapped in the Arctic has been frozen in place since the last Ice Age. Mercury is mostly found in the atmosphere, but it can bind to particles in soil and water.

The latest findings are the results of nearly a decade of sediment core sampling in Alaska. Scientists measured 793 gigagrams, or 15 million gallons, of mercury in frozen soil samples. Researchers estimate the Arctic region is home to 1,656 gigagrams of mercury.

The logical question for scientists is: what will happen to the Arctic's mercury as the planet continues to warm? If permafrost thaws at accelerated rates, how will the planet's mercury cycle be impacted?

"There's a significant social and human health aspect to this study," said Steve Sebestyen, a research hydrologist at the USDA Forest Service in Grand Rapids, Minnesota, who wasn't involved in the research. "The consequences of this mercury being released into the environment are potentially huge because mercury has health effects on organisms and can travel up the food chain, adversely affecting native and other communities."

Many ecosystems in the Northern Hemisphere are already negatively impacted by manmade mercury pollution. One recent study in Michigan's Northern Peninsula found fish species may not be safe to eat for several decades, even under the best case scenario.

The latest research suggests mercury may further stress fragile ecosystems and the indigenous communities that rely on them.

"Rural communities in Alaska and other northern areas have a subsistence lifestyle, making them vulnerable to methylmercury contaminating their food supply," said Edda Mutter, science director for the Yukon River Inter-Tribal Watershed Council. "Food sources are important to the spiritual and cultural health of the natives, so this study has major health and economic implications for this region of the world."