Date of Award

Spring 1981

Document Type



Life & Environmental Sciences

First Advisor

John Christenson

Second Advisor

Jean Smith

Third Advisor

Arthur Westwell


Man's activities, which introduce excess nutrients into bodies of water, can adversely affect the aquatic environment. The Yellowstone River is one such system in which pollution has been a problem. Recent abatement programs have focused upon improving the river's condition. By observing the daily curve of oxygen change in a segment of the river in the vicinity of Billings, Montana, the component rates of production and respiration were calculated along with chemical analysis of the phosphate and nitrate levels present. The present trophic status of this segment of the Yellowstone River was assessed.