Ten‐Year Hindcast Assessment of an Improved Probabilistic Forecast System for Cyanotoxin (Microcystins) Risk Level in Lake Erie

Abstract Toxic harmful algal blooms produce public health hazards in freshwater systems around the world. There is a need for forecast systems that can mitigate risk of public exposure to toxins. We improved an approach to predict the spatially and temporally resolved probability of microcystins (MC...

Full description

Saved in:
Bibliographic Details
Main Authors: Qianqian Liu, Mark D. Rowe, Richard P. Stumpf, Reagan Errera, Casey Godwin, Justin D. Chaffin, Eric J. Anderson, Tongyao Pu
Format: Article
Language:English
Published: Wiley 2025-04-01
Series:Water Resources Research
Subjects:
Online Access:https://doi.org/10.1029/2024WR038952
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850212018847481856
author Qianqian Liu
Mark D. Rowe
Richard P. Stumpf
Reagan Errera
Casey Godwin
Justin D. Chaffin
Eric J. Anderson
Tongyao Pu
author_facet Qianqian Liu
Mark D. Rowe
Richard P. Stumpf
Reagan Errera
Casey Godwin
Justin D. Chaffin
Eric J. Anderson
Tongyao Pu
author_sort Qianqian Liu
collection DOAJ
description Abstract Toxic harmful algal blooms produce public health hazards in freshwater systems around the world. There is a need for forecast systems that can mitigate risk of public exposure to toxins. We improved an approach to predict the spatially and temporally resolved probability of microcystins (MCs) exceeding a threshold level (6 μg L−1) in western Lake Erie. This approach combines a 5‐day chlorophyll‐a forecast model, a weekly updated regression model predicting MCs from chlorophyll‐a, and an empirical relationship between predicted MCs and observed probability of MCs exceeding the threshold calibrated over a hindcast period. We included additional years in the database for calibration and assessment, applied an empirical bias adjustment to the Moderate Resolution Imaging Spectroradiometer for consistency with Sentinel‐3 satellite imagery, and applied a robust Siegel regression method. Cross‐validation showed reasonable skill over regions including surface water, public water system plant intake sites, and bottom waters. The forecast also presented useful skill when assessed against two intensive sampling events of Microcystis blooms in western Lake Erie in 2018 and 2019. Our results provide a comprehensive assessment of a novel method to forecast MC risk, which may be recalibrated and applied to other systems affected by toxic cyanobacterial blooms, where a similar relationship exists between chlorophyll and toxin concentrations at toxin levels relevant to advisory levels.
format Article
id doaj-art-ec82d65699554d61862ad0b6669f2e44
institution OA Journals
issn 0043-1397
1944-7973
language English
publishDate 2025-04-01
publisher Wiley
record_format Article
series Water Resources Research
spelling doaj-art-ec82d65699554d61862ad0b6669f2e442025-08-20T02:09:25ZengWileyWater Resources Research0043-13971944-79732025-04-01614n/an/a10.1029/2024WR038952Ten‐Year Hindcast Assessment of an Improved Probabilistic Forecast System for Cyanotoxin (Microcystins) Risk Level in Lake ErieQianqian Liu0Mark D. Rowe1Richard P. Stumpf2Reagan Errera3Casey Godwin4Justin D. Chaffin5Eric J. Anderson6Tongyao Pu7Department of Physics and Physical Oceanography University of North Carolina Wilmington Wilmington NC USAGreat Lakes Environmental Research Laboratory National Oceanic and Atmospheric Administration Ann Arbor MI USANational Centers for Coastal Ocean Science National Oceanic and Atmospheric Administration Silver Spring MD USAGreat Lakes Environmental Research Laboratory National Oceanic and Atmospheric Administration Ann Arbor MI USACooperative Institute for Great Lakes Research University of Michigan Ann Arbor MI USAStone Laboratory and Ohio Sea Grant The Ohio State University Put‐In‐Bay OH USACivil and Environmental Engineering Colorado School of Mines Golden CO USACooperative Institute for Great Lakes Research University of Michigan Ann Arbor MI USAAbstract Toxic harmful algal blooms produce public health hazards in freshwater systems around the world. There is a need for forecast systems that can mitigate risk of public exposure to toxins. We improved an approach to predict the spatially and temporally resolved probability of microcystins (MCs) exceeding a threshold level (6 μg L−1) in western Lake Erie. This approach combines a 5‐day chlorophyll‐a forecast model, a weekly updated regression model predicting MCs from chlorophyll‐a, and an empirical relationship between predicted MCs and observed probability of MCs exceeding the threshold calibrated over a hindcast period. We included additional years in the database for calibration and assessment, applied an empirical bias adjustment to the Moderate Resolution Imaging Spectroradiometer for consistency with Sentinel‐3 satellite imagery, and applied a robust Siegel regression method. Cross‐validation showed reasonable skill over regions including surface water, public water system plant intake sites, and bottom waters. The forecast also presented useful skill when assessed against two intensive sampling events of Microcystis blooms in western Lake Erie in 2018 and 2019. Our results provide a comprehensive assessment of a novel method to forecast MC risk, which may be recalibrated and applied to other systems affected by toxic cyanobacterial blooms, where a similar relationship exists between chlorophyll and toxin concentrations at toxin levels relevant to advisory levels.https://doi.org/10.1029/2024WR038952Lake Eriecyanobacterial harmful algal bloommicrocystinsprobabilistic forecastcross‐validationskill assessment
spellingShingle Qianqian Liu
Mark D. Rowe
Richard P. Stumpf
Reagan Errera
Casey Godwin
Justin D. Chaffin
Eric J. Anderson
Tongyao Pu
Ten‐Year Hindcast Assessment of an Improved Probabilistic Forecast System for Cyanotoxin (Microcystins) Risk Level in Lake Erie
Water Resources Research
Lake Erie
cyanobacterial harmful algal bloom
microcystins
probabilistic forecast
cross‐validation
skill assessment
title Ten‐Year Hindcast Assessment of an Improved Probabilistic Forecast System for Cyanotoxin (Microcystins) Risk Level in Lake Erie
title_full Ten‐Year Hindcast Assessment of an Improved Probabilistic Forecast System for Cyanotoxin (Microcystins) Risk Level in Lake Erie
title_fullStr Ten‐Year Hindcast Assessment of an Improved Probabilistic Forecast System for Cyanotoxin (Microcystins) Risk Level in Lake Erie
title_full_unstemmed Ten‐Year Hindcast Assessment of an Improved Probabilistic Forecast System for Cyanotoxin (Microcystins) Risk Level in Lake Erie
title_short Ten‐Year Hindcast Assessment of an Improved Probabilistic Forecast System for Cyanotoxin (Microcystins) Risk Level in Lake Erie
title_sort ten year hindcast assessment of an improved probabilistic forecast system for cyanotoxin microcystins risk level in lake erie
topic Lake Erie
cyanobacterial harmful algal bloom
microcystins
probabilistic forecast
cross‐validation
skill assessment
url https://doi.org/10.1029/2024WR038952
work_keys_str_mv AT qianqianliu tenyearhindcastassessmentofanimprovedprobabilisticforecastsystemforcyanotoxinmicrocystinsrisklevelinlakeerie
AT markdrowe tenyearhindcastassessmentofanimprovedprobabilisticforecastsystemforcyanotoxinmicrocystinsrisklevelinlakeerie
AT richardpstumpf tenyearhindcastassessmentofanimprovedprobabilisticforecastsystemforcyanotoxinmicrocystinsrisklevelinlakeerie
AT reaganerrera tenyearhindcastassessmentofanimprovedprobabilisticforecastsystemforcyanotoxinmicrocystinsrisklevelinlakeerie
AT caseygodwin tenyearhindcastassessmentofanimprovedprobabilisticforecastsystemforcyanotoxinmicrocystinsrisklevelinlakeerie
AT justindchaffin tenyearhindcastassessmentofanimprovedprobabilisticforecastsystemforcyanotoxinmicrocystinsrisklevelinlakeerie
AT ericjanderson tenyearhindcastassessmentofanimprovedprobabilisticforecastsystemforcyanotoxinmicrocystinsrisklevelinlakeerie
AT tongyaopu tenyearhindcastassessmentofanimprovedprobabilisticforecastsystemforcyanotoxinmicrocystinsrisklevelinlakeerie