Diatoms as bioindicators: does the stream lab have an effect downstream?

Abstract

Diatom communities developed on tiles in four different locations on the Maple River were subjected to short term growth in order to test the hypothesis that the Michigan Biological Stream Lab will have an effect at the effluent location. Gutters with ceramic tiles attached to them were placed in four specific locations, three in the Maple River (located in Pellston, Michigan) and one in the stream lab. Tiles were collected and then sampled. Once processed, diatoms were counted and then analyzed. Using the Shannon -Weiner Diversity Index, it showed that the downstream location was the least diverse (H=1.3910) and the stream lab was the most diverse (H=1.6616). Since the downstream site was the least diverse, one can assume that the stream lab did have an effect on the downstream habitat. The upstream site was the most diverse which can be correlated with the least amount of macroinvertebrates grazing on the tiles. Future studies should take into account the phsycial measurements (flow, sediment, depth, temperature, and light) and how they play a role in the downstream habitat.