SG: Evaluating synchrony among ecosystem productivity, benthic cyanobacterial growth, and toxin production dynamics in rivers

Cyanobacteria growing in freshwater ecosystems, such as lakes and rivers, can produce toxins that threaten aquatic life and human health. This project advances our understanding of controls on the timing of peak cyanobacterial growth and cyanotoxin production in rivers where blooms are becoming more common. This project monitors the Eel, Russian, and Klamath rivers in northern California and uses the data to develop predictive models of cyanobacterial growth and toxin production.

This research advances the ability of managers to predict where and when toxins produced by benthic cyanobacteria reach concentrations that exceed human and animal health risk thresholds. The researchers are also broadening participation in aquatic ecosystem science by supporting a summer intern in partnership with the Klamath Basin Monitoring Program and Karuk Tribe Department of Natural Resources and by supporting a graduate student.

The investigators are also organizing two experiential field trips for K-12 students in partnership with the Mid-Klamath Watershed Council. The results of this work are critical to river managers in identifying and managing risks associated with exposure to algal toxins and transmitting that information to the public. All data and modeling approaches developed in this project are being shared publicly on web-accessible sites.

This project advances understanding of the timing and occurrence of cyanobacterial growth and cyanotoxin production in rivers by using high-frequency sensor data and new approaches in ecological modeling. To improve predictions of cyanobacterial growth and toxin production through time, the investigators are focusing on two questions: 1) To what degree do processes that shape overall productivity dynamics in rivers predict the growth of toxin-producing cyanobacteria? and 2) How do environmental conditions modify the relationship between cyanobacterial growth and cyanotoxin production over the growing season?

These questions are being addressed through the use of aquatic environmental sensors and coupled field sampling for two years at locations with previously documented occurrences of cyanobacteria that produce anatoxins, a neurotoxin produced by many species of freshwater cyanobacteria. Data on whole-ecosystem productivity rates are being used in combination with survey data to inform a series of models testing the relative importance of drivers of cyanobacterial growth and cyanotoxin production in rivers through time.

These analyses are laying the foundation for future forecasts of harmful cyanobacterial blooms and toxin production in United States rivers.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.