Mercury is a highly toxic heavy metal that persists in the environment for a very long time after its release. In the Arctic, its concentrations are alarming and threaten wildlife, ecosystems and human populations that are highly dependent on marine resources. Despite decades of international efforts, levels in Arctic predators continue to rise. A recent study reveals the active role of ocean currents in transporting enormous quantities of mercury accumulated over decades to the coasts of Greenland.
by Laurie Henry
Cover photo: polar bear in the Arctic © Rune Dietz / Aarhus University
Despite the decline in industrial emissions worldwide, mercury has continued to pollute many ecosystems for decades. Although emitted far from the poles, it travels long distances carried by atmospheric and oceanic circulation. It reaches remote polar regions such as the Arctic, where numerous complex cycles make it particularly persistent.
Mercury contamination levels in Arctic predators continue to rise despite numerous international efforts to reduce emissions. In a recent study published in Nature Communications, researchers from Aarhus University and the University of Copenhagen have discovered that ocean currents act as vehicles for transporting huge quantities of mercury to the Greenland coast.
Persistent mercury in the Arctic
The signing of the Minamata Convention in 2013 raised high hopes for a reduction in industrial emissions, particularly those linked to coal and mining. While projections predicted a measurable improvement within a few decades, readings taken at the North Pole do not confirm this improvement. In several regions of Greenland, mercury levels observed in recent years remain high and are sometimes even rising.