Effects of a stream lab on carbon levels in macroinvertebrates in the Maple River.

Abstract

To test the hypothesis that discharge from the stream lab affects the amounts of organic material found in organisms within the secondary production level of the Maple River, I set up an experiment with four sampling sites according to location relative to the UMBS Stream Lab in Pellston, Michigan. An upstream site was located before the intake pipes, a midstream site was in the Maple River adjacent to the stream lab, a downstream site was placed after the stream lab water is expelled, and a site was placed within the stream lab. After sampling over a period of 17 days and using ash-free dry mass, I found that the upstream site had a significantly higher average ash-free dry mass, as well as higher average weight of organisms, while the other sites showed weights that were considerably less. There was more of a change in carbon levels between the upstream and midstream sites, than levels between the midstream and downstream sites. This suggests that the effect of reduced macroinvertebrate growth on the Maple River was caused by material being removed from the stream by the stream lab, rather than by material from the lab being added into the water downstream of the lab.