22 May 2012:
Rivers are Largest Source
Of Mercury in Arctic Ocean, Study Says
A new study suggests that rivers may be funneling far more toxic mercury into the Arctic Ocean than previously believed, a finding that may portend even greater mercury concentrations in the future as the effects of climate change accelerate the region’s hydrological cycle. Despite the Arctic's remoteness, scientists have long known that mercury levels in Arctic mammals are among the highest on the planet, a factor largely attributed to mercury being deposited in the Arctic Ocean from the air. But according to Harvard scientists
, circumpolar rivers — particularly three great Siberian rivers, the Lena, Ob, and Yenisei — may be contributing twice as much mercury as the atmosphere. According to the scientists, mercury levels in the Arctic tend to increase sharply during the spring and summer months. Using a sophisticated model of atmospheric and ocean conditions, they concluded that the only factor that could explain this spike was increased flow of these rivers as they melt. According to Harvard researchers, more mercury may be entering the river systems as melting permafrost increasingly releases mercury long locked in the soil. In addition, mercury is likely coming from runoff from gold, silver, and mercury mines in Siberia. The study is published in the journal Nature Geoscience
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies
Accepting entries through June 15, 2015.
Yale Environment 360
articles are now available in Spanish and Portuguese on Universia
, the online educational network. Visit the site.
Business & Innovation
Policy & Politics
Pollution & Health
Science & Technology
Antarctica and the Arctic
Central & South America
A three-part series Tainted Harvest
looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup. Read the series.
is now available for mobile devices at e360.yale.edu/mobile
The Warriors of Qiugang
, a Yale Environment 360
video, chronicles a Chinese village’s fight against a polluting chemical plant. It was nominated for a 2011 Academy Award for Best Documentary Short.
Watch the video.
Top Image: aerial view of Iceland
. © Google & TerraMetrics.
, winner of the Yale Environment 360 Video Contest, documents the work of African researchers monitoring wildlife in Uganda's remote Bwindi Impenetrable National Park. Watch the video.