Researchers from the University of Toronto have been studying algae inanother lake, in the Arctic, but with a very different goal in mind. They were trying to see if the lake could clean itself up after years of having raw sewage dumped into it.For nearly 50 years, until 1998, sewage from a Canadian government base on Meretta Lake in the territory of Nunavut flowed directly into the lake. The researchers first analyzed lake water samples for levels of phosphorus, which is found in sewage and acts as a nutrient for algae.