Sediment pesticide contamination and toxicity in an agricultural tailwater recovery system

Authors: Lizotte, Richard; Moore, Matthew; Russell, Juanita; Locke, Martin

Submitted to: Chemistry and Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/29/2024
Publication Date: 6/17/2024
Citation: Lizotte Jr, R.E., Moore, M.T., Russell, J.R., Locke, M.A. 2024. Sediment pesticide contamination and toxicity in an agricultural tailwater recovery system. Chemistry and Ecology. 40(6):627-642. https://doi.org/10.1080/02757540.2024.2338179.
DOI: https://doi.org/10.1080/02757540.2024.2338179

Interpretive Summary: Tailwater recovery systems are valuable agricultural water management tools, but their environmental benefits and risks need to be better understood. Invertebrates, such as crustaceans, help examine the effects of agricultural pesticides in sediments within a studied tailwater recovery system. Ditch and storage reservoir sediment from a Mississippi tailwater recovery system was examined seasonally from 2016-2019 and crustacean survival, growth, and bioavailability was used to determine potential pesticide risks. Sediments were contaminated with six herbicides, three insecticides, three legacy insecticides, and p,p’-DDE. Clomazone, bifenthrin, and SDDT concentrations were greatest in drainage ditch sediments during summer and fall. Crustacean tissues contained three current use herbicides and insecticides, as well as two legacy insecticides. Clomazone, '-cypermethrin, and SDDT concentrations were greatest in crustacean tissues from drainage ditches during fall and winter. Crustacean survival and growth varied with lowest survival during fall and winter and lowest survival in the storage reservoir relative to drainage ditch sites during winter. Less growth was seen during winter and spring with lowest growth in drainage ditches compared to the storage reservoir during spring. Study results are of interest to regulatory and other agencies and farming stakeholders by providing additional information on pesticide contamination to help improve and sustain water quality and overall environmental quality.

Technical Abstract: Tailwater recovery (TWR) systems provide a valuable best management practice in agricultural water management. However, potential environmental benefits and risks of TWR need to be assessed. TWR sediment quality in Mississippi, USA, was evaluated seasonally within the storage reservoir and drainage ditch system from 2016-2019 for pesticide contamination, effects, and bioavailability to Hyalella azteca. Sediment bioassays (28-day) were used to determine H. azteca survival and growth and tissue residue risks from sediment pesticide exposure. Sediment pesticide contamination comprised six current use herbicides, three current use insecticides, three legacy insecticides, and one metabolite (p,p’-DDE). Sediment clomazone, bifenthrin, and SDDT concentrations were greatest in drainage ditch sites during summer and fall. H. azteca tissue pesticide residues comprised three current use herbicides and insecticides, as well as two legacy insecticides. Tissue residue clomazone, '-cypermethrin, and SDDT concentrations were greatest in drainage ditch sites during fall and winter. H. azteca survival and growth varied seasonally and spatially with lowest survival during fall and winter and lowest survival in the storage reservoir relative to drainage ditch sites during winter. Growth decreased during winter and spring with lowest growth in drainage ditches relative to the storage reservoir during spring. Patterns of associated survival and growth with tissue pesticide residues indicate increased risk during fall in TWR and where system water flows mobilize sediment pesticides increasing the risk of ecological impairment.