The application of satellite technology for monitoring cyanobacterial harmful algal blooms in U.S. waters.
Citation:
Schaeffer, B. The application of satellite technology for monitoring cyanobacterial harmful algal blooms in U.S. waters. 10th Annual Center for Human Health and the Environment Research Symposium, Raleigh, NC, March 04, 2026.
Impact/Purpose:
This initiative integrates satellite imagery with field sampling and forecasting model to deliver consistent, national-scale detection, quantification, and short-term forecasts of cyanobacterial harmful algal blooms. Operational, validated products—accessible via a user-friendly web app—are already informing advisories and decisions. Standardized quantified metrics support public-health, ecological, and economic analyses. By scaling from daily 300 m coverage of thousands of lakes to ~200,000 lakes at 20 m and providing >90% accurate weekly forecasts, this work enables earlier, better-targeted management actions and strengthens evidence-based water-quality management as validation continues at higher resolution.
Description:
Cyanobacterial harmful algal blooms are widespread, dynamic, and consequential. Traditional field-based monitoring alone cannot provide the spatial and temporal coverage along, and this work examines how integrating satellite observations with in situ sampling and models enables operational, scalable water-quality assessment. Through the Cyanobacteria Assessment Network, daily 300 m Sentinel-3 imagery detects cyanobacterial biomass across thousands of U.S. lakes, exemplified by the 2017 Utah Lake event where satellite detection weeks before sampling prompted advisories that averted an estimated $370,000 in health costs. Extensive validation demonstrated decision-relevant agreement (73% with advisories, 94% with intake observations, >80% with reported toxins), supporting operational tools that translate images into quantified metrics of frequency, extent, magnitude, and occurrence rate. A Bayesian spatiotemporal forecasting system achieved >90% accuracy from 2021–2023. Looking forward, 20 m Sentinel-2 monitoring could extend coverage to ~200,000 lakes and most estuaries, underscoring both the value and the need for continued validation as scale increases and for integrating satellite data with models to guide timely management and public-health decisions.