PDF(Pubmed)
Abstract：
To control harmful algae blooms (HABs), methods based on natural mechanisms are now required. We investigated the effects of an algicide derived from macrophyte metabolites, namely mixtures of gallic, tetradecanoic, heptanoic, and octanoic acids (1:1:1:1 mass ratio, a total concentration of 14 mg/L), on the biomass of cyanobacteria and other plankton and the production of microcystins under experimental conditions. Two types of microcosms have been created: simple (microalgae, cyanobacteria, and zooplankton) and complex (microalgae, cyanobacteria, zooplankton, and planktivorous fish). We observed the dynamics of the phytoplankton structure, the concentrations of microcystins and chlorophyll-a, hydrochemistry, and the status of zooplankton and fish in both types of microcosms with and without algicide for one month (from 19 July to 19 August 2021). The introduction of algicide caused changes in phytoplankton structure, a drop in cyanobacterial biomass, and a decrease in the total concentration of microcystins. Surprisingly, the contributions of the most toxic microcystins (LR form) were higher in both types of microcosms exposed to algicide than in microcosms without algicide. The inhibitory effect on the cyanobacterial biomass was most significant in complex ecosystems (containing fish), while it was only observed at the end of the exposure in simple ecosystems. Not only algicide but also phytoplankton consumed by fish and zooplankton, as well as nutrient excretory activity by both consumers, seem to have impact on cyanobacterial biomass. This study found that the using chemical substances similar to macrophyte metabolites can help regulate HABs and cyanotoxins. However, the results differ depending on ecosystem type.
摘要：
为了控制有害的藻类繁殖（HAB），现在需要基于自然机制的方法。我们研究了源自大型植物代谢物的杀藻剂的作用，即高卢的混合物，十四烷酸，庚酸,和辛酸(1:1:1:1质量比，总浓度为14mg/L)，在实验条件下，蓝藻和其他浮游生物的生物量以及微囊藻毒素的产生。已经创造了两种类型的缩影:简单(微藻，蓝藻,和浮游动物)和复杂(微藻，蓝藻,浮游动物,和浮游鱼类）。我们观察了浮游植物结构的动力学，微囊藻毒素和叶绿素a的浓度，水化学,以及一个月（从2021年7月19日至8月19日）在两种类型的微观世界中浮游动物和鱼类的状况。灭藻剂的引入引起浮游植物结构的变化，蓝细菌生物量的下降，和微囊藻毒素的总浓度降低。令人惊讶的是,毒性最强的微囊藻毒素（LR形式）在暴露于杀藻剂的两种微观膜中的贡献均高于不使用杀藻剂的微观膜。对蓝藻生物量的抑制作用在复杂生态系统(含鱼)中最为显著,而仅在简单的生态系统中暴露结束时观察到。不仅是杀藻剂，还有鱼类和浮游动物消耗的浮游植物，以及两个消费者的营养排泄活动，似乎对蓝藻生物量有影响。这项研究发现，使用类似于大型植物代谢产物的化学物质可以帮助调节HAB和氰基毒素。然而,结果因生态系统类型而异。
