Efforts to prevent or reverse eutrophication in freshwater typically aim to decrease the amount of phosphate entering the lake or river in runoff from the watershed. But a new study by Professor Harry Hemond and Katherine Lin ’05  (who performed the research as a UROP student) suggests that phosphate control measures that simultaneously decrease nitrate inflow could, paradoxically, result in an increased release of phosphate from lake sediments that have become enriched after years of heavy phosphate inflow. Incorporating this information into engineering models of lake eutrophication could make them more accurate and useful. Read a news story.