Legacy Mercury Threatens Arctic Wildlife Health

Recent research shows that despite a global decline in mercury emissions since the 1970s, mercury concentrations in Arctic wildlife—specifically polar bears and toothed whales—are now 20 to 30 times higher than pre-industrial levels. Scientists analyzed over 700 samples from Greenland collected over 40 years, using mercury isotope signatures to determine that legacy mercury pollution, originating from historic coal combustion and gold mining, persists in the Arctic for centuries and is transported via ocean currents. These isotope patterns indicate that oceanic transport is the primary driver of regional contamination, rather than recent atmospheric deposition. The findings explain the ongoing rise in mercury levels in Arctic wildlife, which poses significant health risks to both animals and Indigenous communities relying on marine mammals for food. The persistence of legacy mercury highlights the limitations of current international efforts such as the UN's Minamata Convention to fully protect Arctic ecosystems. The results emphasize the need for continued monitoring and innovative strategies to address long-lived pollutants in marine environments.