Effects of nitrogen and phosphorus on populations of Mougeotia, Gomphosphaeria, and Cymbella.

Abstract

Phosphates and nitrates are considered important factors in the distribution of algae as well as to their productivity (Prescott 1968). This is evidenced by limnological studies which have related high nitrogen and phosphorous readings to luxuriant algal floras (Prescott 1982). The direct addition of these two nutrients to unproductive lakes often helps to bring the desired productivity, however this also creates the opposite extreme of unwanted dense mats of filamentous algae. Phosphorous and nitrogen are typically the limiting factors of algal growth, therefore with the addition of these two nutrients, an increase, relative to the concentrations of the added nutrients, should be seen. In this experiment, various concentrations of nitrogen (urine) and phosphorous (liquid laundry detergent) were added to Douglas Lake periphyton to determine the change in algal growth.