Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, c/ Catedrático José Beltrán 2, Paterna, Valencia 46980, Spain.
IMDEA Water Institute, Science and Technology Campus of the University of Alcalá, Av. Punto Com 2, Alcalá de Henares, Madrid 28805, Spain.
Aquat Toxicol. 2024 Feb;267:106828. doi: 10.1016/j.aquatox.2023.106828. Epub 2023 Dec 28.
This paper investigates the effects of the fungicide azoxystrobin, a compound widely used in rice farming, on aquatic communities representative of two habitats characteristic of Mediterranean wetland ecosystems: water springs and eutrophic lake waters. The long-term effects of azoxystrobin were evaluated on several structural (phytoplankton, zooplankton, macroinvertebrate populations and communities) and functional (microbial decomposition, macrophyte and periphyton growth) parameters making use of freshwater mesocosms. Azoxystrobin was applied in two pulses of 2, 20, 200 µg/L separated by 14 d using the commercial product ORTIVA (23 % azoxystrobin w/w). The results show that these two habitats responded differently to the fungicide application due to their distinct physico-chemical, functional, and structural characteristics. Although overall sensitivity was found to be similar between the two (lowest NOEC < 2 µg/L), the taxa and processes that were affected differed substantially. In general, the most sensitive species to the fungicide were found in the water spring mesocosms, with some species of phytoplankton (Nitzschia sp.) or macrocrustaceans (Echinogammarus sp. and Dugastella valentina) being significantly affected at 2 µg/L. In the eutrophic lake mesocosms, effects were found on phytoplankton taxa (Desmodesmus sp. and Coelastrum sp.), on numerous zooplankton taxa, on chironomids and on the beetle Colymbetes fuscus, although at higher concentrations. The hemipteran Micronecta scholtzi was affected in both treatments. In addition, functional parameters such as organic matter decomposition or macrophyte growth were also affected at relatively low concentrations (NOEC 2 µg/L). Structural Equation Modelling was used to shed light on the indirect effects caused by azoxystrobin on the ecosystem. These results show that azoxystrobin is likely to pose structural and functional effects on Mediterranean wetland ecosystems at environmentally relevant concentrations. Moreover, it highlights the need to consider habitat-specific features when conducting ecotoxicological research at the population and community levels.
本研究考察了杀菌剂唑菌酯（azoxystrobin）对两种具有地中海湿地生态系统特征的生境（泉水和富营养化湖）水生群落的影响。唑菌酯是一种广泛应用于水稻种植的化合物。研究利用淡水中型生物群系，评估了唑菌酯的长期影响，包括几个结构（浮游植物、浮游动物、大型无脊椎动物种群和群落）和功能（微生物分解、大型植物和周丛生物生长）参数。唑菌酯以 ORTIVA（23%唑菌酯 w/w）的商业产品形式，通过 14 天的时间间隔施加两次，每次 2、20 和 200µg/L。结果表明，由于这两种生境具有不同的物理化学、功能和结构特征，因此它们对杀菌剂的应用有不同的反应。尽管两种生境的总体敏感性相似（最低无可见效应浓度<2µg/L），但受影响的类群和过程却有很大差异。一般来说，最敏感的物种是泉水中型生物群系中的浮游植物（菱形藻属）或大型甲壳动物（Echinogammarus sp.和Dugastella valentina），在 2µg/L 时受到显著影响。在富营养化湖中型生物群系中，在浮游植物（Desmodesmus sp.和 Coelastrum sp.）、许多浮游动物、摇蚊和甲虫 Colymbetes fuscus 以及半翅目昆虫 Micronecta scholtzi 等类群中发现了影响，尽管在更高浓度下。此外，有机物质分解或大型植物生长等功能参数也在相对较低的浓度（无可见效应浓度 2µg/L）下受到影响。结构方程模型用于揭示唑菌酯对生态系统的间接影响。这些结果表明，唑菌酯在环境相关浓度下可能对地中海湿地生态系统造成结构和功能影响。此外，它还强调了在种群和群落水平进行生态毒理学研究时需要考虑生境特异性特征。
