On the recordJuly 21, 1998
there are several causes for the increase in the clarity. The nutrients that are coming in due to erosion is probably one of the biggest parts. There is also, unfortunately, from northern California the air pollution coming over the Sierras is also causing the nitrogen to get down, which is food for the algae. So there are two problems that are really kind of almost exacerbating each other and decreasing clarity is the result. So we need to work on this. Erosion control is a very important part, but we also need it in other places.
Said by
John Ensign
Source
govinfo.gov