Impacts of subchronic exposure to a commercial 2, 4-D herbicide on developmental stages of multiple freshwater fish species. (January 2021)

• Record Type: Journal Article
• Authors: Dehnert, Gavin K.; Freitas, Mariella B.; Sharma, Prashant P.; Barry, Terence P.; Karasov, William H.
• Is Part Of: Chemosphere. Volume 263(2021)
• Publication Date: 2021-01
• Subjects: Larval fish -- Herbicides -- 2, 4-D -- Developmental toxicology -- Phylogeny -- Ecotoxicology; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.127638
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Invasive, nuisance aquatic species such as Eurasian watermilfoil ( Myriophyllum spicatum ) are rapidly spreading across the United States. One common active ingredient used to control this invasive species is 2, 4-Dichlorophenoxyacetic acid (2, 4-D). Application of 2, 4-D to aquatic environments typically occurs while many freshwater fish are spawning and due to 2, 4-D stability in aquatic environments, many non-target species experience prolonged exposure throughout embryogenesis and larval development. The impacts of 2, 4-D exposure on phylogenetically distant fish species is poorly understood. Herein, we investigated the impacts of the 2, 4-D commercial herbicide DMA4®IVM on nine freshwater fish species from six different families (four orders) at different points during ontogeny. Each species was exposed to ecologically relevant concentrations of a commercial 2, 4-D herbicide (0.05, 0.50, and 2.00 ppm or mg/L 2, 4-D a. e.), and effects on morphology, survival, and growth were evaluated. Our results demonstrate that exposure of embryonic and larval fish to ecologically relevant concentrations of a commercial 2, 4-D herbicide reduced survival in early developmental stages of six freshwater species that spanned five phylogenetic families and three phylogenetic orders; however, sensitivity to 2, 4-D exposure did not show correlation with phylogenetic proximity. Altogether, our results indicate that the use of 2, 4-D herbicides in aquatic ecosystems at current recommended concentrations (≤2 ppm whole-lake treatment) could present risk to multiple freshwater fish species survival during early development. Graphical abstract: Image 1 Highlights: Ecologically relevant concentrations of 2, 4-D reduced survival in six fish species. 2, 4-D reduced survival in species from 5 families and 3 orders. Sensitivity to 2, 4-D exposure did not show correlation with phylogenetic proximity. Early developmental stages are more at risk to 2, 4-D exposure than juvenile fish.