In microbial biofilms growing on the rock surfaces of anoxic brine pools fed by hot springs containing arsenite and sulfide at high concentrations, light-dependent oxidation of arsenite ( + 3 ) to arsenate ( + 5 ) was discovered occurring under anoxic conditions.
22.
A "'cold seep "'( sometimes called a "'cold vent "') is an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs, often in the form of a brine pool . " Cold " does not mean that the temperature of the seepage is lower than that of the surrounding sea water.
