Harmful algal blooms (HABs) are an ongoing challenge for those who manage freshwater reservoirs. The toxins produced by HABs impact a wide range of activities, including recreation, drinking water treatment, and overall ecosystem health. We’ve established a data-rich network across Pennsylvania, USA that involves state agency officials, lake managers, dam operators, drinking water utilities, and an academic institution. This public/private collaboration uses high-frequency sensors, detailed monitoring efforts across agencies, and modeling to strengthen the ability to detect HABs and toxins, establish an understanding of HAB drivers, and prepare guidance for managing this threat. Findings from this network suggest that high-frequency sensor networks are important components for supporting real-time management decision making, especially for reservoirs capable of altering hydrodynamic conditions. A combination of hypolimnetic withdrawals and surface flushing were able to temporarily relieve high temperature stress and low dissolved oxygen conditions. However, chlorophyll and phycocyanin sensors had weak correlations with algal biomass and toxin concentrations measured in bi-weekly monitoring. Largely reactionary monitoring programs based on HAB visual cues missed a substantial number of high toxin events that exceeded recreational and drinking water recommendations. Insights from this network have been key to developing water management strategies for HABs across the state, and would not be possible without close collaborations among a broad array of stakeholders.

Primary Presenter: Olivia Trombley, Dickinson College (livtrombley@gmail.com)

Authors:

Kristin Strock, Dickinson College  (strockk@dickinson.edu)