MANAGING CYANOBACTERIA IN THE SUBTROPICS: CAUSAL ANALYSIS OF TEMPORAL SHIFTS IN CYANOBACTERIA DRIVER IMPORTANCE (S)
Several commonly-observed cyanobacteria genera possess physiological adaptations that enable their resilience across wide-ranging disturbance regimes. These adaptations can mask short- and long-term changes in the underlying environmental variables driving cyanobacteria proliferation, which complicates the development of cyanobacteria bloom mitigation actions. In the present work, we analyzed monthly observations of cyanobacteria abundance (genus-level), water quality constituents, and hydrology over 17.5 years (1993-2010) in Lake George, a subtropical flow-through lake located along the St. Johns River (Florida, USA). This unique dataset captured a multitude of relevant system dynamics, including the near disappearance of once-abundant Microcystis. Time-varying Granger causality, a time series analysis method adopted from the fields of economics and neuroscience, revealed how cyanobacteria succession and environmental variability specifically contributed to blooms in this dynamic waterbody, and demonstrated how environmental drivers of cyanobacteria shifted in relative importance over time. The results quantify the roles and feedbacks of hydrologic variability (seasonal and long-term) and inter-genus (Microcystis, Oscillatoria, Cylindrospermopsis, Anabaena) relationships on driving cyanobacteria abundance and community structure.
Nelson, N. G., University of Florida, USA, firstname.lastname@example.org
Muñoz-Carpena, R., University of Florida, USA, email@example.com
Kaplan, D., University of Florida, USA, firstname.lastname@example.org
Phlips, E. J., University of Florida, USA, email@example.com
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