Abstract
Harmful algal blooms (HABs), in particular those consisting of the cyanobacteria Microcystis, are becoming increasingly more common across the globe. Despite the growing body of evidence that suggests vertical heterogeneity of Microcystis can be a precursor to HAB formation, the abiotic drivers of vertical distribution of Microcystis are poorly understood in the field environment. The prediction of subsurface cyanobacteria is also pertinent because subsurface concentrations are not easily recognizable to the public or lake system managers, creating a risk of exposure to harmful algal toxins. High-frequency temporal and vertical data were collected from a research station anchored in a stratified and eutrophic lake for five months. Using a combination of dimensional analysis and machine learning approaches, data show that the magnitude of the subsurface Microcystis concentration peak and the center of gravity of the deep cyanobacteria layer are statistically significantly mediated by the thermal structure of the lake. The peak subsurface cyanobacteria biovolume is related to the thermocline depth and temperature, whereas the center of gravity of the subsurface cyanobacteria biovolume is related to the mixed layer depth and temperature. Furthermore, our data suggest there is a seasonal evolution of the subsurface cyanobacteria center of gravity that could potentially indicate timing of HAB onset. Based on easily measured parameters associated with the vertical lake temperature profile and meteorological conditions, we provide evidence of predictable trends in subsurface cyanobacteria variables.
| Original language | English (US) |
|---|---|
| Article number | e2020WR027987 |
| Journal | Water Resources Research |
| Volume | 57 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2021 |
Bibliographical note
Funding Information:Funding was provided by the Legislative‐Citizen Commission on Minnesota Resources and the National Science Foundation Graduate Research Funding Program. The authors wish to thank the reviewers for their insightful comments and the Minnesota Pollution Control Agency for their supplemental data provided that was used to validate research station and grab sample measurements. A special thank you goes out to Dr. Jiaqi You, for providing guidance and conducting lab analyses of grab samples; Dr. Shahram Missaghi, for help with outreach and coordination; and Dr. Anne Ahlvers‐Wilkinson, for jump‐starting the entire project. Lastly, this manuscript was written in Minneapolis, Minnesota. Both George Floyd and Daunte Wright were alive upon the original submission date; George Floyd was dead by the first round of revisions, and Daunte Wright by the second. Let this manuscript serve as a testament to the power of a million tiny things building together through quiescent conditions and reacting collectively to turbulence. May George Floyd, Daunte Wright, and all victims of police violence rest in peace.
Funding Information:
Funding was provided by the Legislative-Citizen Commission on Minnesota Resources and the National Science Foundation Graduate Research Funding Program. The authors wish to thank the reviewers for their insightful comments and the Minnesota Pollution Control Agency for their supplemental data provided that was used to validate research station and grab sample measurements. A special thank you goes out to Dr. Jiaqi You, for providing guidance and conducting lab analyses of grab samples; Dr. Shahram Missaghi, for help with outreach and coordination; and Dr. Anne Ahlvers-Wilkinson, for jump-starting the entire project. Lastly, this manuscript was written in Minneapolis, Minnesota. Both George Floyd and Daunte Wright were alive upon the original submission date; George Floyd was dead by the first round of revisions, and Daunte Wright by the second. Let this manuscript serve as a testament to the power of a million tiny things building together through quiescent conditions and reacting collectively to turbulence. May George Floyd, Daunte Wright, and all victims of police violence rest in peace.
Publisher Copyright:
© 2021. American Geophysical Union. All Rights Reserved.
Keywords
- cyanobacteria vertical distribution
- eutrophic lake
- harmful algal bloom
- microcystis
- stratified lake
