A new study shows the concentrations of the toxic element mercury in rivers and fjords connected to the Greenland Ice Sheet are comparable to rivers in industrial China. This is an unexpected finding that is raising questions about the effects of glacial melting in an area that is a major exporter of seafood. This study was published in Nature Geoscience.
Jon Hawkings, a postdoctoral researcher at Florida State University and the German Research Centre for Geosciences said that there are high levels of mercury in the glacial meltwaters we sampled in southwest Greenland. This is leading to a look at the whole host of other questions such as how that mercury could potentially get into the food chain.
The international study began as a collaboration between Hawkings and glaciologist Jemma Wadham, a professor at the University of Bristol’s Cabot Institute for the Environment. Researchers sampled waters from three different rivers and two fjords next to the ice sheet to gain a better understanding of meltwater water quality from the glacier and how nutrients in these meltwaters may sustain coastal ecosystems. One of the elements they measured for was the potentially toxic element mercury, but they did not expect that they would find such high concentrations in the water there.
Researchers are sure if the mercury levels will spread distant away from the ice sheet and whether this glacier derived mercury is making its way into the aquatic food web, where it can often concentrate. Fishing is Greenland primary industry with the country being a major exporter of cold-water shrimp, halibut and cod.The finding underscores the complicated reality of rapidly melting ice sheets across the globe. About 10% of the Earth’s land surface is covered by glaciers, and these environments are undergoing rapid change as a result of rising temperatures. Scientists are working to understand how warming temperatures and thus more melting glaciers will affect geochemical processes critical to life on Earth.