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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #414431
Research Project: Sustaining Productivity and Ecosystem Services of Agricultural and Horticultural Systems in the Southeastern United States

Location: Soil Dynamics Research

Title: Development of a multiple linear regression (MLR) model for copper toxicity to phytoplankton

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: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/26/2024
Publication Date: 4/26/2024
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. Development of a multiple linear regression (MLR) model for copper toxicity to phytoplankton [abstract]. Society of Environmental Toxicology and Chemistry. April 26-27, Gainesville, FL.

Interpretive Summary:

Technical Abstract: Copper-based algaecides have been used extensively over the last century to control harmful algal blooms (HABs) in freshwater systems; however, their application can cause deleterious non-target effects on community structure and function due to their non-selective nature. Traditional copper dosing methods are based on the total alkalinity of a waterbody, a parameter that was shown to have no relationship with algal toxicity. 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 other organisms, such as zooplankton and beneficial green algae. 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 while using 60% less copper. In addition, it was shown that the MLR dose causes less harm to zooplankton and beneficial green algae 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.