As much as 40% of the phosphorus reaching the lake has been reported to originate from the atmosphere. Its origins remain unknown. The Rescue Lake Simcoe Coalition and the Lake Simcoe Conservation Foundation are jointly funding research at Trent University to examine the chemical composition of the phosphorus-containing components. Knowledge of the composition is likely to lead to an understanding of the sources of the phosphorus. This research may also identify promising possibilities for intervening to keep some of the phosphorus out of the atmosphere.