CNRS (Délégation Paris Michel-Ange). "Arctic sea-ice controls the release of mercury."ScienceDaily 20 January 2011. 26 January 2011 <http://www.sciencedaily.com/releases/2011/01/110119084753.htm>.
Mercury in its natural gaseous form is not harmful. It is easily trapped in Arctic ice when spread from other regions through the atmosphere. When the ice begins to melt, mercury changes form into methylmercury, the toxic form. To study the amount of methylmercury in the Arctic food chain, researchers tested the amount found in murre eggs. Since murre are considered to be at the top of the arctic food chain, they are the perfect species for tracking the amount of toxins in the food chain. They studied the isotopes and found that methylmercury does not behave as predicted. Most isotopes change based on weight, but methylmercury changes between even and odd isotopes. The researchers now believe that this is because of where the murre nests were. They found that light plays a factor in breaking down methylmercury and were able to test the difference between amounts found in areas of high and low sea ice. The researchers concluded that in areas of high sea ice it is more difficult for methylmercury to go through the natural destruction process. This means that with the increase of global warming and the increase of melting sea ice, the amount of methylmercury that will be released into the atmosphere will increase significantly. With the new knowledge of the isotopes, researchers can begin to study the effects of these on the global ecosystem.
Hi Kerriann. I think some factor other than melting is required for methylation of mercury. Can you find out what it is? I know it can be done by anaerobic bacteria, but I don't know if there are other forces in play. I'm not sure I understood what the difference in isotopes is about. Did they mean that the ratios of mercury isotopes were different in the murres?
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