A likely explanation of the patches of white in Lake Mývatn in Northeast Iceland, which have puzzled scientists for weeks, appears to be a chemical reaction due to lack of oxygen, RÚV reports. An analysis of substances from the lake does not indicate that a polluting agent, such as paint, was spilled into the lake, as some had suggested at first.
White patches, such as the ones that appeared in the lake in July, had not been seen there before. According to the analysis of Árni Einarsson, director of the Mývatn Nature Research Center, the likeliest explanation is that the white color was caused by colloidal iron binding, which occurs when iron binds with organic particles called colloids. This can occur under certain circumstances, which have to do with the level of oxygen and acidity of the water.
The Mývatn Nature Research Center reacted quickly to news of the milky white color of parts of the lake and notified the Environment Agency of Iceland. Subsequently, samples were collected and analyzed. The drainage basin between Mývatn and Laxá is closely watched by the agency, not the least because it’s on the red list of threatened natural areas.