Waves of Phosphorus: Resuspension and Release by Recreational Boating

Eutrophication, excessive growth from an overabundance of nutrients, is a pressing threat to surface waters worldwide. While significant efforts have been implemented to understand and limit phosphorus (P) loading, the release of sediment P due to boating disruption, a direct human impact, is poorly understood. Coeur d’Alene Lake, a popular recreation site, is ideal for studying release from recreational boating with many shallow bays including Kidd Island Bay. I analyzed P and turbidity from water samples collected along a transect perpendicular to shore at set times after the passing of watercraft to relate the number, size, and speed to turbidity and P resuspension. Here, as noted in elsewhere by other researchers, turbidity and P concentrations are related to boating and weather factors. This project contributes data necessary to fully understand the internal P dynamics of the lake ecosystem in the face of increasing recreational pressures caused by rising human population and affluence