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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #415460
Research Project: Sustaining Productivity and Ecosystem Services of Agricultural and Horticultural Systems in the Southeastern United States

Location: Soil Dynamics Research

Title: Optimizing copper sulfate pentahydrate dosages for controlling of harmful algal blooms using multiple linear regression (MLR)

Author
item MCDONALD, M - Auburn University
item HENNESSEY, A - Auburn University
item JOHNSON, P - Auburn University
item GLADFELTER, M - Auburn University
item MERRILL, K - Auburn University
item TENISON, S - Auburn University
item GANEGODA, J - Auburn University
item HOANG, T - Auburn University
item Torbert, Henry - Allen
item Beck, Benjamin
item WILSON, A - Auburn University

Submitted to: Society of Environmental Toxicology and Chemistry (SETAC)
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2024
Publication Date: 10/20/2024
Citation: Mcdonald, M.B., Hennessey, A.V., Johnson, P.P., Gladfelter, M.F., Merrill, K.L., Tenison, S.E., Ganegoda, J.S., Hoang, T.C., Torbert III, H.A., Beck, B.H., Wilson, A.E. 2024. Optimizing copper sulfate pentahydrate dosages for controlling of harmful algal blooms using multiple linear regression (MLR) [abstract]. National Society of Environmental Toxicology and Chemistry, October 20-24, 2024, Fort Worth, TX.

Interpretive Summary:

Technical Abstract: Copper sulfate pentahydrate has been used extensively over the last century to control harmful algal blooms (HABs) in freshwater systems; however, its application can cause negative effects on community structure and function due to its non-selective nature. Traditional copper dosing methods are based on the total alkalinity of a water body; however, this method was based off of first-hand experience, not empirical data. This study aimed to develop a novel, predictive multiple linear regression (MLR) model that can be used to determine an optimal algicidal dose that minimizes non-target effects on the overall aquatic ecosystem. This model was developed from a series of comprehensive bioassays relating key water quality parameters such as pH, hardness, alkalinity and dissolved organic carbon (DOC) to algal toxicity. Rigorous testing found that DOC and pH were the only significant predictors of toxicity to phytoplankton. A field-based validation of the model was conducted using a replicated, 28-day experiment in an active catfish aquaculture pond located at the E.W. Shell Fisheries Station at Auburn University. Results from this experiment show that the MLR derived dose resulted in identical harmful algal control to traditional dosing methods (95% reduction) while using 60% less copper. In addition, the MLR dose caused less harm to the overall plankton community than the alkalinity-based dose. These results hold promise in the development of more sustainable water management practices that allow for harmful algal control while also preserving natural ecosystem function.