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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #412851
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 ROY, L - 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: 3/26/2024
Publication Date: 3/26/2024
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., Roy, L.A., 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]. Auburn University Research Symposium, March 26, 2024, Auburn, AL.

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 ecosystem functioning. Traditional dosing methods are based on the total alkalinity of a water body, which can be effective, however, it is not based upon experimentally derived data. This study aimed to develop a novel, science based, 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 including pH, hardness, alkalinity and dissolved organic carbon (DOC) to algal toxicity. Rigorous testing found that DOC and pH were the most important predictors of toxicity to phytoplankton as an increase of these parameters was seen to result in significant decrease in copper toxicity. To test the model, a field-based validation was carried out using a replicated, 28-day experiment in 1200L enclosures. Results from this validation show that the MLR derived dose resulted in almost identical harmful algal control to traditional dosing methods while using up to 85% less copper. In addition, preliminary results suggest that the MLR dose may cause less harm to zooplankton and beneficial green algae than traditional methods. These results hold promise in the development of more sustainable water management practices that allow for harmful algal control while also preserving ecosystem health.