SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, PR China; School of Environment, South China Normal University, Guangzhou 510006, PR China.
SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, PR China; Wageningen University, Aquatic Ecology and Water Quality Management Group, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
Aquat Toxicol. 2021 Nov;240:105992. doi: 10.1016/j.aquatox.2021.105992. Epub 2021 Oct 10.
Imidacloprid is one of the most used neonicotinoid insecticides all over the world and is considered as a contaminant of concern due to its high toxicity potential to aquatic organisms. However, the majority of the studies that have evaluated the effects of imidacloprid on aquatic organisms were conducted under temperate conditions. In the present study, a mesocosm experiment was conducted under sub-tropical conditions to assess the effects of imidacloprid on the structure (macroinvertebrates, zooplankton and phytoplankton) and functional endpoints of an aquatic ecosystem and to compare the results with similar temperate and (sub-)tropical mesocosm studies. Imidacloprid (0, 0.03, 0.3 and 3 µg/L) was applied to 13 mesocosms weekly over a period of 4 weeks, followed by a one month recovery period. At the community level a lowest NOEC of 0.03 µg/L was calculated for the zooplankton, phytoplankton and macroinvertebrate communities. The highest sensitivity to imidacloprid (NOEC < 0.03 µg/L) were observed for Gerris sp., Diaptomus sp. and Brachionus quadridentatus. Imidacloprid induced population declines of the larger zooplankton species (Diaptomus sp. and Ostracoda) resulted in increased rotifer abundances and shifted the phytoplankton community to a graze resistant gelatinous cyanobacteria dominated ecosystem. These cyanobacteria blooms occurred at all different concentrations and could pose an important public health and environmental concern. Although there are some differences in species and community sensitivity between the present and the other (sub-)topical mesocosm studies, it can be observed that all show a similar general community response to imidacloprid. Under (sub-)tropical conditions, the toxic effects of imidacloprid occur at lower concentrations than found for temperate ecosystems.
吡虫啉是全世界使用最广泛的新烟碱类杀虫剂之一，由于其对水生生物具有很高的毒性潜力，因此被认为是一种令人关注的污染物。然而，大多数评估吡虫啉对水生生物影响的研究都是在温带条件下进行的。在本研究中，在亚热带条件下进行了中观实验，以评估吡虫啉对水生生态系统的结构（大型无脊椎动物、浮游动物和浮游植物）和功能终点的影响，并将结果与类似的温带和（亚热带）中观实验进行比较。每周向 13 个中观实验中添加吡虫啉（0、0.03、0.3 和 3 µg/L），持续 4 周，然后进行一个月的恢复期。在群落水平上，浮游动物、浮游植物和大型无脊椎动物群落的最低无可见效应浓度（NOEC）为 0.03 µg/L。对吡虫啉（NOEC < 0.03 µg/L）最敏感的是 Gerris sp.、Diaptomus sp.和 Brachionus quadridentatus。吡虫啉诱导较大浮游动物物种（Diaptomus sp.和介形类）的种群减少，导致轮虫丰度增加，并将浮游植物群落转变为以抗食性凝胶状蓝藻为主的生态系统。所有这些蓝藻水华都发生在不同的浓度下，可能会对公共健康和环境构成重要威胁。尽管本研究与其他（亚热带）中观实验在物种和群落敏感性方面存在一些差异，但可以观察到，所有实验都对吡虫啉表现出相似的一般群落反应。在（亚热带）条件下，吡虫啉的毒性作用发生在比温带生态系统更低的浓度下。
