Mercury profiles in the Arctic Ocean near the Lomonosov Ridge

Samples were collected in the Arctic Ocean north of Greenland along transects across the Lomonosov Ridge. The Swedish icebreaker Oden with support from the Russian nuclear icebreaker 50 Let Pobedy was used to collect water samples in 2007 at multiple depths from sixteen stations in this virtually unexplored area of the Arctic. Stations depths ranged from around 1000 m to over 4000 m with most of the samples collected in the upper few hundred meters. In this work, we present mercury and methylmercury concentrations in depth profiles from multiple sites. Methylmercury concentrations peaked at 100 to 200 m in 14 of the 16 sites with peak concentrations ranging from 40 to 110 pg/L. The peaks in methylmercury generally corresponded with minima in dissolved oxygen. Total mercury concentrations were more variable and general trends were not observed.