Predicting relative risk of cyanobacteria harmful algal blooms at the national scale

Cyanobacterial harmful algal blooms (CHABs) can produce toxins that impair freshwater ecosystems used for drinking water, recreation, and habitat for aquatic biota. With CHABs increasing in extent and intensity globally, water managers need information about how to prioritize lake monitoring. We present an overview of the Cyanobacterial Assessment Network (CyAN) web application that make remote sensing data on lake CHABs available to the user. In addition, we present an analysis of lake CHABs risk that combines CyAN data with the U.S. EPA National Lakes Assessments completed in 2007 and 2012. We find that the interannual mean bloom magnitude from CyAN is positively correlated with the likelihood of lakes having detectable microcystin levels. Such information can help inform setting priorities for lake water monitoring in regional contexts.

Impact/Purpose

Cyanobacterial harmful algal blooms (HABs) can produce toxins which impair freshwater ecosystems used for drinking water, recreation, and habitat for aquatic biota. With CHABs increasing in extent and intensity globally, water managers need information about how to prioritize lake monitoring. This presentation to the contacts at the Southern California Coastal Water Research Project (SCCWRP) highlights an analysis from Pacific Ecological System Division scientists that combines data from the remote sensing Cyanobacteria Assessment Network (CyAN) and the National Lakes Assessments completed in 2007 and 2012 to predict the likelihood of CHABs. By developing models based on the subset of lakes that are captured in the CyAN data and those that are sampled in the NLA, the likelihood of exceeding health thresholds associated with HABs can be extrapolated to all lakes monitored via CyAN. The Cyanobacteria Assessment Network Co-PIs are the interagency leaders of the project to collect cyanobacteria data in water via remote sensing and are an important source of feedback on this methodological approach.

Citation

Handler, A., J. Compton, Ryan A Hill, S. Leibowitz, AND B. Schaeffer. Predicting relative risk of cyanobacteria harmful algal blooms at the national scale. CyAN Co-PI Meeting, NA, OR, July 08, 2021.