- Preprint Article
- 10.21203/rs.3.rs-8765875/v1
Large-Language-Model-Assisted Microbial Source Tracking Reveals Mechanisms of Tropical Cyclone Impacts on Microbial Water Quality in Coastal Environments
- Feb 20, 2026
- Research Square
- Chamteut Oh + 11 more +11
Abstract Extreme weather events increasingly threaten coastal water quality, yet the mechanisms by which tropical cyclones impair microbial water quality remain poorly quantified. We developed a Large-Language-Model-Assisted Microbial Source Tracking (LAMST) framework to trace the origins of microbial threats and applied it to coastal waters impacted by Hurricane Milton along Florida’s Gulf Coast. LAMST integrates 16S rRNA sequencing with species-level metadata from the NCBI BioSample database to classify taxa as marine, terrestrial, or wastewater in origin. Across 30 sites and three time points (1 week to 7 months post-storm), twelve microbial analytes, including fecal indicator bacteria (FIB), pathogens, and antimicrobial resistance genes (ARGs), were quantified. Colored dissolved organic matter as well as carbon and nitrogen stable isotopes in particulate material were characterized for the same samples and independently corroborated LAMST’s terrestrial and marine microbial classifications. Increases in terrestrial and marine bacterial counts in coastal waters indicated concurrent mobilization of land-derived inputs and marine sources following the hurricane. Site fixed-effects regressions showed terrestrial and wastewater bacteria were strongly associated with enterococci and two ARGs (i.e., sul2 and tetA ), whereas marine bacteria correlated with Vibrio parahaemolyticus . LAMST provides a quantitative, generalizable framework for source-resolved microbial tracking without reliance on regional reference sequences.
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