Journal article
Spatial and temporal variation of suspect screening derived cyanobacterial secondary metabolite mixtures during harmful algal bloom events in shallow agroecosystem lakes
Environmental science--processes & impacts
06/15/2026
DOI: 10.1039/d5em01071c
PMID: 42300830
Abstract
Freshwater harmful algal blooms (HABs) pose significant health risks to communities through drinking water sources and contact recreation. Cyanobacteria that drive HABs produce a complex array of secondary metabolites, notably cyanotoxins. The spatiotemporal variability of cyanometabolite mixtures during HAB events remains poorly understood, particularly in agroecosystems, where heavy nutrient loading can alter normal lake dynamics. Therefore, we applied high-resolution mass spectrometry-based suspect screening to characterize cyanometabolite mixture dynamics during active HAB events in two Eastern Iowa lakes as test sites, using time controlled sampling at one lake and locationally controlled sampling at the other. Using the CyanoMetDB to enable complex mixture comparisons alongside ELISA-based microcystin (MC) quantification, we tentatively identified 38 unique cyanometabolites, revealing substantial chemical diversity beyond traditional monitoring targets. Spatial analysis at one of the lakes exhibited dramatic variability across a 104-meter beach, where MC concentrations ranged from 0.65 µg L
(below advisory limits) to 36.86 µg L
(4.6-fold greater than the USEPA health advisory threshold), with metabolite mixtures exhibiting low similarity (cos(
) = 0.38) for those same sites. Temporal monitoring at the other test lake demonstrated rapid temporal changes, with MC concentrations dropping from 19.98 to 8.64 µg L
within one hour; however, the cyanometabolite mixtures over the same time were similar (cos(
) = 0.97). Collectively, these findings demonstrate that HAB chemical composition and toxicity fluctuate substantially over short distances and time scales. This first HAB metabolite suspect screening in agroecosystem lakes thus provides a useful initial framework for characterizing overlooked cyanometabolite diversity and tracking chemical dynamics, advancing efforts to better understand, monitor, and mitigate HAB-related exposure.
Details
- Title: Subtitle
- Spatial and temporal variation of suspect screening derived cyanobacterial secondary metabolite mixtures during harmful algal bloom events in shallow agroecosystem lakes
- Creators
- Stanley W Kohls - University of IowaLyndy Holdt - University of IowaNervana Metwali - University of Iowa, Occupational and Environmental HealthCorey D Markfort - University of IowaPeter S Thorne - University of IowaGregory H LeFevre - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Environmental science--processes & impacts
- DOI
- 10.1039/d5em01071c
- PMID
- 42300830
- NLM abbreviation
- Environ Sci Process Impacts
- ISSN
- 2050-7887
- eISSN
- 2050-7895
- Publisher
- Royal Society of Chemistry
- Grant note
- University of Iowa Office of Vice President of Research P3 Jumpstart Tomorrow grant (Iowa Healthy Lakes Initiative) Iowa Healthy Lakes Initiative Environmental Health Sciences Research Center: P30 ES005605 University of Iowa High Resolution Mass Spectrometry Facility
This work was funded by the University of Iowa Office of Vice President of Research P3 Jumpstart Tomorrow grant (Iowa Healthy Lakes Initiative). We thank Mary Skopec, executive director of the Iowa Lakeside Laboratory, for her inputs to the Iowa Healthy Lakes Initiative. We acknowledge the support of the Environmental Health Sciences Research Center (P30 ES005605) for providing a collaborative research environment. The authors thank Lynn Teesch and Vic Parcell of the University of Iowa High Resolution Mass Spectrometry Facility.
- Language
- English
- Electronic publication date
- 06/15/2026
- Academic Unit
- Civil and Environmental Engineering; Occupational and Environmental Health; IIHR--Hydroscience and Engineering; Center for Global & Regional Environmental Research; Mechanical Engineering
- Record Identifier
- 9985175461302771
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