Geographic redistribution of microcystin hotspots in response to climate warming
Creators
- 1. Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA
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2.
University of Kansas
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3.
Institute of Geographic Sciences and Natural Resources Research
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4.
University of Greenwich
Abstract
High concentrations of cyanobacterial toxins such as microcystin represent a global challenge to water quality in lakes, threatening health, economies and ecosystem stability. Lakes are sentinels of climate change but how warming will affect microcystin concentrations is still unclear. Here we examine how warming impacts the probability of exceeding microcystin water quality thresholds across 2,804 lakes in the United States and show how future warming will alter these probabilities. We find that higher temperatures consistently increase the likelihood of microcystin occurrence but that the probability of microcystin concentrations above water quality thresholds is highest for water temperatures between 20 and 25 °C. Regions with temperatures that promote microcystin will shift to higher latitudes in the coming decades, leading to relative changes in exceedance probabilities of more than 50% in many basins of the United States. High nitrogen concentrations amplify the impact of rising temperatures, calling for increased awareness of a substantial hazard to ecosystems and human health under global warming.
Copyright and License
© The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Acknowledgement
The lakes 2007, 2012 and 2017 survey data were a result of the collective efforts of dedicated field crews, laboratory staff, data management and quality control staff, analysts and many others from the EPA, states, tribes, federal agencies, universities and other organizations. Please contact nars-hq@epa.gov with any questions regarding data. Funding for this work was provided by the authors’ home institutions.
Data Availability
Observations of microcystin concentrations and environmental parameters are part of the EPA NLA surveys conducted in 200731, 201270 and 201771 and are publicly available online at: https://www.epa.gov/national-aquatic-resource-surveys/data-national-aquatic-resource-surveys. CMIP6 model output was downloaded from the NASA Earth Exchange Global Daily Downscaled Projections82 and merged with NLA data. Source data are provided with this paper.
Code Availability
Data analysis was based on the R packages gamlss72 and the add-on gamlss.ggplots77. Specific functions for model selection and formulas are given in the Methods. The model can be accessed in an online tool (https://algal-risk.dge.carnegiescience.edu/) where exceedance probabilities of individually selected thresholds of toxin concentration can be calculated under any combination of environmental conditions.
Supplemental Material
Source Data Extended Data Fig. 2
Files
s44221-023-00138-w.pdf
Additional details
Dates
- Available
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2023-10-12Version of record
Caltech Custom Metadata
- Caltech groups
- Division of Geological and Planetary Sciences (GPS)
- Publication Status
- Published