School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
Water Res. 2022 Oct 1;224:119040. doi: 10.1016/j.watres.2022.119040. Epub 2022 Aug 30.
The contamination of pesticides has been recognized as a major stressor in fresh water ecosystems in terms of the losses of services and population declines and extinctions. However, information on the adverse effects of pesticides on zooplankton communities under natural field conditions are still lacking, although zooplankton is quite sensitive to most of pesticides in laboratory studies. In this study, a natural lake ecosystem (Liangzi Lake) was used to determine the relationship between pesticide contamination and abundance decline of metazoan zooplankton. In August 2020, the comprehensive trophic level indexes and the abundance of phytoplankton in the 14 sampling sites of Liangzi Lake were comparable, but the abundance of metazoan zooplankton showed significant variations across two orders of magnitude. These results suggested that other factors, such as pesticide contamination, might be responsible for the variations of metazoan zooplankton community. Furthermore, the responsible pesticides were screened, and totally 29 pesticides were obtained. Finally, five pesticides were identified to provide more than 99.4% toxic contributions and chlorpyrifos and cypermethrin were two main causal agents. These results were further supported by laboratory exposure experiments using D. magna and field study in November 2020, where the concentrations of the 29 pesticides were strongly decreased and the abundance of metazoan zooplankton was comparable across the 14 sites of Liangzi Lake. Taken together, this work provided an evidence that the contamination of pesticides might be responsible for the abundance decline of metazoan zooplankton in a natural freshwater ecosystem.
农药污染被认为是淡水生态系统的主要胁迫因素，会导致服务功能丧失、种群减少和灭绝。然而，尽管浮游动物在实验室研究中对大多数农药相当敏感，但关于农药对浮游动物群落的不利影响的信息在自然野外条件下仍然缺乏。在这项研究中，利用自然湖泊生态系统（梁子湖）来确定农药污染与后生浮游动物丰度下降之间的关系。2020 年 8 月，在梁子湖的 14 个采样点中，综合营养层指数和浮游植物的丰度相当，但后生浮游动物的丰度在两个数量级上表现出显著变化。这些结果表明，其他因素，如农药污染，可能是后生浮游动物群落变化的原因。此外，还筛选了责任农药，并获得了 29 种农药。最后，确定了 5 种农药提供了超过 99.4%的毒性贡献，毒死蜱和氯氰菊酯是两个主要的原因。这些结果得到了使用 D. magna 的实验室暴露实验和 2020 年 11 月的野外研究的进一步支持，在这两项研究中，29 种农药的浓度强烈下降，梁子湖 14 个采样点的后生浮游动物丰度相当。总之，这项工作提供了证据表明，农药污染可能是自然淡水生态系统中后生浮游动物丰度下降的原因。
