Professor Hollibaugh recently went on a trip to sample arsenic metabolizing microbes in Mono Lake, California. Mono Lake contains large concentrations (200 mM total arsenic) as a result of geothermal activity in the watershed. Arsenic has accumulated in the lake since the end of the ice age when evaporation of water from the lake exceeded the sum of fresh water inputs. Arsenic redox reactions now play a significant role in the net ecosystem metabolism of the lake and in the microbial geochemistry of the lake, as described in a recent publication from Prof Hollibaugh’s laboratory. See the full article here.