Nutrient limitation and algal growth above and below the Maple River dam.

Abstract

In order to determine limiting nutrient of a lotic system above and below a dam, we created nitrogen, phosphorus, nitrogen and phosphorus, and control agar bioassays. Three sites were chosen, two for both stream branches above the dam and one below. After two weeks of incubation in the river, the bioassays were removed and tested for chlorophyll a amounts. We found that the nitrogen bioassays had the greatest growth in the West branch, but every other nutrient returned the greatest growth in the Main branch. The trends show that the Main and East branches are phosphorus limited, but the West branch is nitrogen limited. This study can be used as preliminary data for future studies, after the Maple River dam is removed.