Do Changes in Stratification, Caused by the Application of Road Salt Deicers, Impact The Vertical Profiles of Lake Microbial Communities?
Date of Award
4-2018
Degree Name
Master of Science
Department
Biological Sciences
First Advisor
Dr. Kathryn M. Docherty
Second Advisor
Carla M. Koretsky, Ph.D
Third Advisor
Steve Kohler, Ph.D
Keywords
Road salt, microbial ecology, lakes, geochemistry, greenhouse gases
Access Setting
Masters Thesis-Abstract Only
Restricted to Campus until
4-15-2028
Abstract
The use of road salt deicers is increasing in northern regions that experience icy winters. Saline runoff can enter bodies of freshwater such as lakes and change the geochemistry within the water column by interfering with seasonal turnover and extending periods of hypolimnetic anoxia. This extended anoxia can cause shifts in the location of various taxa. In this study, we examined the vertical microbial community profiles of three lakes with different mixing regimes in southwest Michigan. We took samples during all four seasons, and compared community composition with geochemical and physical parameters related to stratification. The communities of all three lakes differed from each other, and within each lake the oxic zone, anoxic zone, and sediment communities were also significantly different. Differences between the lakes increased with depth; sediment communities were the most endemic to each lake, while oxic zone communities were the most similar across lakes. Seasonal changes in lake oxygen stratification resulted in seasonal differences in microbial community structure, including several functional groups of taxa related to carbon and nitrogen cycling, within each lake. Sediment methanogen relative abundances and methane production were highest in the meromictic lake and lowest in the dimictic lake, suggesting that road salt inputs which impact stratification can result in increases in greenhouse gas production through microbially-mediated processes.
Recommended Citation
Sprague, Emily I., "Do Changes in Stratification, Caused by the Application of Road Salt Deicers, Impact The Vertical Profiles of Lake Microbial Communities?" (2018). Masters Theses. 3398.
https://scholarworks.wmich.edu/masters_theses/3398