You have been assigned to conduct a site assessment for a lake in Montana. There is a new biofuels plant operating and discharging into the stream that feeds the lake and provides water for agricultural production of cattle and switchgrass. You observed high levels of algae floating on the surface of the lake, and the water was highly turbid. You also measured the DO at 1 m to be 5 mg/L,and at a depth of 20 m the DO was 1.0 mg/L.

a How would you describe the productivity level of the lake? Explain your reasoning.

b. Similar lakes have had threatened Yellowstone Cutthroat Trout populations. But this lake does not. What changes would you suggest be made in managing the lake's water quality prior to reintroducing trout to the lake?