An assessment of periphyton communities in five Upper Peninsula streams, MI

Session: Mud, Macrofauna and Microbes: Benthic Organism-Abiotic Interactions at Varying Scales (1)

Aaron Christiansen, Grand Valley State University, [email protected]
M. Woller-Skar, Grand Valley State University, [email protected]

Abstract

Periphyton communities are used as bioindicators for stream conditions. This community allows for simple and quick monitoring of seasonal conditions as they can quickly change with ambient conditions within lakes and streams. I used periphytometers and nutrient concentrations to assess how five Lake Superior tributaries were changing over seasons. Total phosphorus concentrations were <1 mg/L across all streams while total nitrogen concentrations were <.75 mg/L from May-October. The nutrient concentrations show that this system can be categorized as ultra-oligotrophic, or when phosphorus concentrations are consistently below 1 mg/L. Periphyton communities were also similar within all streams but changed with seasonal environmental conditions. Periphyton included a high abundance of diatoms such as: Diatoma, Synedra, Fragillaria, Navicula, Nitzschia; Aphanacapsa was the dominant blue-green genera found and finally Ulothrix and Melosira were the dominant green algae found. High diatom composition informs us that these streams contain low nutrients and a low successional state. This study can further help with understanding community ecology within the Lake Superior Basin.