Seasonal Variation in Microbial Populations in Lake Macatawa Watershed

The levels of fecal indicator bacteria (FIB), specifically Escherichia coli, are used by the mDEQ and other organizations to monitor water quality and safety. Transient large spikes in the numbers of E. coli have plagued the Lake Macatawa Watershed over the last decade, along with high sediment levels and nutrient imbalances. Project Clarity, a $12M restoration project initiated in 2013, is working to restore the 179 mi2 watershed by creating remediation sites and educating the community. Our goal is to assess Project Clarity’s impact on water quality by collecting weekly samples from 12 representative sites to gather information about biological, chemical, and physical parameters. Total DNA samples are isolated each week using membrane filtration and the V4 region of the 16S rRNA gene is amplified for 16S community sequencing. Physical and chemical parameters including total suspended solids, nutrients (phosphate and nitrate), temperature, stream discharge, dissolved oxygen, and biological oxygen demand are measured and correlated to the composition of the watershed’s microbiome. Microbial community composition varies seasonally and with location in the watershed. In particular, stream sites are distinct from sites in Lake Macatawa. Large populations of cyanobacteria with the potential to cause toxic algal blooms are present in some lake sites at certain times of the year. In addition to using the 16S community sequencing as a monitoring technique, it may also allow us to identify other organisms that can be used to monitor water quality and safety through non-culture based techniques