Award: OCE-1434998

The project allowed involvedment in the US GEOTRACES Program during a cruise in the Arctic Ocean aboard the Coast Guard ice breaker Healy - see image of sampling during the expedition. Samples were collected to analyze for mercury, which is a health concern as levels of its organic form, methylmercury, in Arctic fish and marine mammals are elevated. The main source of mercury to the Arctic Ocean is from the atmosphere, and gaseous forms of mercury in ocean water can also be lost to the atmosphere, and our study was focused primarily on that part of the global mercury cycle. Climate change and ice melt are likely dramatically changing this exchange and so it is necessary to document these levels. We found that concentrations of dissolved gaseous mercury under the ice near the pole were much higher than those found in open water. This suggests that further ice melt could lead to more loss of mercury from the ocean to the atmosphere. We also determined the concentrations of mercury and methylmercury in rain, snow, ice and melt water so that we could ascertain how much mercury is coming in from the atmosphere yearly compared to other sources, such as rivers. Our results have lead to a refinement of knowledge about the magnitude of these fluxes and our results are quite differen that that predicted by computer models, suggesting they need further refinement. The research allowed a PhD student to gain experience and supported his education as he will graduate in April 2017. Results from this work will be published and have been presented at scientific conferences and highlighted on the university website at: mason.mercury.uconn.edu. Last Modified: 04/03/2017 Submitted by: Robert P Mason