Abstract
This study examined vertically-resolved patterns in microbial community structure across a freshwater trophic gradient extending 1600 km from the oligotrophic waters of Lake Superior to the eutrophic waters of Lake Erie, the most anthropogenically influenced of the Laurentian Great Lakes system. Planktonic bacterial communities clustered by Principal Coordinates Analysis (PCoA) on UniFrac distance matrices into four groups representing the epilimnion and hypolimnion of the upper Great Lakes (Lakes Superior and Huron), Lake Superior's northern bays (Nipigon and Black bays), and Lake Erie. The microbes within the upper Great Lakes hypolimnion were the most divergent of these groups with elevated abundance of Planctomycetes and Chloroflexi compared to the surface mixed layer. Statistical tests of the correlation between distance matrices identified temperature and sample depth as the most influential community structuring parameters, reflecting the strong UniFrac clustering separating mixed-layer and hypolimnetic samples. Analyzing mixed-layer samples alone showed clustering patterns were correlated with nutrient concentrations. Operational taxonomic units (OTU) which were differentially distributed among these conditions often accounted for a large portion of the reads returned. While limited in coverage of temporal variability, this study contributes a detailed description of community variability that can be related to other large freshwater systems characterized by changing trophic state.
Original language | English (US) |
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Pages (from-to) | 263-276 |
Number of pages | 14 |
Journal | Journal of Great Lakes Research |
Volume | 45 |
Issue number | 2 |
DOIs | |
State | Published - Apr 2019 |
Bibliographical note
Funding Information:We thank the captains and crews of R/V Blue Heron, CCGS Limnos and R/V Lake Guardian along with Technical Operations personnel from Environment and Climate Change Canada and EPA-GLNPO who ably assisted with the sampling program. Jacques Finlay (University of Minnesota) and Anton Post (Florida Atlantic University) also provided shipboard assistance with sample collection and processing and Emily Davenport (BGSU) assisted with data analysis. This work was supported by the National Science Foundation (grant numbers OCE-0927277 , OCE-0927512 ). The work conducted by the US Department of Energy Joint Genome Institute was supported by the Office of Science of the US Department of Energy (contract number DE-AC02-05CH11231) and Community Sequencing Project 723.
Funding Information:
We thank the captains and crews of R/V Blue Heron, CCGS Limnos and R/V Lake Guardian along with Technical Operations personnel from Environment and Climate Change Canada and EPA-GLNPO who ably assisted with the sampling program. Jacques Finlay (University of Minnesota) and Anton Post (Florida Atlantic University) also provided shipboard assistance with sample collection and processing and Emily Davenport (BGSU) assisted with data analysis. This work was supported by the National Science Foundation (grant numbers OCE-0927277, OCE-0927512). The work conducted by the US Department of Energy Joint Genome Institute was supported by the Office of Science of the US Department of Energy (contract number DE-AC02-05CH11231) and Community Sequencing Project 723.
Publisher Copyright:
© 2019
Keywords
- Amplicon sequencing
- Bacteria
- Flow cytometry
- Laurentian Great Lakes
- Trophic state