Department of Integrative Biology, University of Wisconsin - Madison, Madison, WI, USA.
Department of Animal Biology, Federal University of Vicosa - Vicosa, MG, Brazil.
Chemosphere. 2021 Jan;263:127638. doi: 10.1016/j.chemosphere.2020.127638. Epub 2020 Aug 1.
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.
入侵性、滋扰性水生物种，如欧亚水蕹菜（Myriophyllum spicatum），正在迅速蔓延至美国各地。一种常用于控制这种入侵物种的常用活性成分是 2,4-二氯苯氧乙酸（2,4-D）。在许多淡水鱼类产卵期间，通常会将 2,4-D 应用于水生环境中，并且由于 2,4-D 在水生环境中的稳定性，许多非目标物种在胚胎发生和幼虫发育过程中会经历长时间的暴露。2,4-D 暴露对进化上相距较远的鱼类物种的影响知之甚少。在此，我们在个体发生的不同阶段，研究了商业 2,4-D 除草剂 DMA4®IVM 对来自六个不同科（四个目）的 9 种淡水鱼类的影响。每个物种都暴露于生态相关浓度的商业 2,4-D 除草剂（0.05、0.50 和 2.00 ppm 或 mg/L 2,4-D a. e.），并评估了对形态、存活和生长的影响。我们的结果表明，暴露于胚胎和幼虫期的鱼类接触生态相关浓度的商业 2,4-D 除草剂会降低 6 种淡水物种在早期发育阶段的存活率，这些物种跨越五个进化科和三个进化目；然而，对 2,4-D 暴露的敏感性与进化亲缘关系没有相关性。总之，我们的研究结果表明，在当前推荐的浓度（≤2 ppm 全湖处理）下，在水生生态系统中使用 2,4-D 除草剂可能会对多个淡水鱼类物种在早期发育期间的生存构成风险。
