The differences in biomass and relative abundance of periphytic algal types between light and shaded sites in the Maple River, Pellston, Michigan.

Abstract

Many abiotic factors affect the growth of periphytic algae in lentic environments, one of the most important being light intensity. Though experiments and studies have been done the effects of light intensity on algae, the results have varied widely depending on the species and environment studied. This report focuses mainly on the light preferences of periphytic algae in the east branch of the Maple River (Lat. 84 46'N, Long. 45 30.5' W, sec. 14 T36N, R4W, Cheboygan County, Michigan). The study includes differences in biomass between shaded and open sites, as well as the relative abundance of species between sites. The biomass results show that all algae are present in greater quantities in open environment with high light intensity compared to shaded environments. 89% of cells noted in this study were diatoms, which occurred with no statistical difference between the open and shaded area. Of the remaining 11% of cells counted, Chlorophyta and Cyanophyta tended to be more abundant in the open area. The Chlorophyte, Oscillatoria, seemed dominate in the open areas, but the sample sizes were too small to merit statistical testing. Small numbers of Rhodophyta were also counted, and were found only in shaded areas, but, again, the samples were too small to determine significance.