Frost Flowers Capturing Mercury from the Atmosphere
14.06.2010 - Water & Oceans, Ice & Snow, Arctic
Frost flowers – the structures that form on the surface of fresh sea ice – also cause a drop in atmospheric mercury levels at the poles in springtime. Researchers are now trying to find out how the flowers take up mercury, as explained by Jody Demming of the University of Washington at the IPY Oslo Science Conference.
When they discovered the presence of bacteria in the frost flowers, the scientists were surprised given the extreme conditions frost flowers find themselves in (freezing temperatures, high salinity, high UV levels). These bacteria secrete protective exopolymers which protect them from freezing and heavy metals. Since the levels of mercury found in the frost flowers were 26 times higher than in sea ice, the scientists think that it is this polymer and its reaction with the metal that are causing frost flowers to adsorb mercury during depletion events.
