Phosphorus in Riverine and Lake Bottom Sediments: Role in the formation of Cyanobacterial Blooms in Lake Superior

Abstract

In recent years a pattern of major storms followed by major blooms has occurred in Lake Superior. Cyanobacterial blooms negatively affect water quality and are a growing public health concern. This study investigates the impact of storm-derived sediment on the formation of cyanobacterial blooms in Lake Superior. Sediment samples were analyzed for total phosphorus, resin-exchangeable phosphorus, and bioavailable phosphorus. The analyses revealed a strong correlation between fine-grain size and high phosphorus concentration. The analysis of bioavailable P also suggested algae accessed sedimentary phosphorus. I conclude storm-derived sediment supply bioavailable phosphorus to algae. This increases the growth of algae and results in the formation of cyanobacterial blooms in Lake Superior.