Looking again at phosphorus, this is a figure of historical bottom total phosphorus at site 1. Total phosphorus concentration in ppb is on the y-axis and time is along the x-axis from 1976 to 2006. In recent years, the averages have not exceeded 15 ppb. This is a good sign because in other nearby lakes that go anoxic, bottom total phosphorus levels can become greater than 100 ppb. However we do see a trend, as represented by the red line, in increasing bottom total phosphorus levels. Anoxia is a cause for concern not only because it harms cold water fish, but also because it results in increased phosphorus levels.