Nutrients and Phytoplankton in Hyrum Lake

The current investigation indicates that the routine appearance of a noxious blue-green algal bloom of Aphanizomenon flos-aquae, in Hyrum Lake, a reservoir in northern Utah is a result of excess phosphorus. Data indicate that the algal growth is initiated by phosphorus liberated from the phosphorus rich bottom sediments, and at a time when nitrogen is present in excess in the lake relative to phosphorus. Results indicate that the Little Bear River is the major source of nitrogen and phosphorus contributing to the eutrophication of Hyrum Lake. Nitrogen and phosphorus fluctuations in the Little Bear River proved to be concurrent with nitrogen and phosphorus fluctuations in the reservoir