阿维菌素在水产养殖生态系统中降解、毒性及其生态风险分析

Degradation, Toxicity and Ecological Risk Analysis of Avermectin in Aquaculture Ecosystem

阿维菌素是一种具有杀虫驱虫作用的十六元大环内酯类聚酮化合物,广谱、高效、低毒,广泛应用于种植业、畜牧业的寄生虫防治,对水生动物的多种寄生虫具有良好的杀虫和驱虫效果。水产养殖环境中阿维菌素主要来源于种植业灌溉排水、畜牧业废水和水产养殖用药;水环境中阿维菌素降解受光解、水解、植物降解、微生物降解和土壤吸附等多重因素影响,光解是阿维菌素降解的主要途径。阿维菌素对鱼类的毒性存在着种属差异,对不同类别水生生物的急性毒性也存在着明显的差异。对水生节肢动物中的枝角类毒性最大,而对克氏原螯虾、日本沼虾等的毒性相对较小。因此,在使用阿维菌素驱杀靶标寄生虫的同时更要关注其对非养殖动物非靶标生物的安全性。从阿维菌素理化性质、危害来源、降解途径,以及水环境生态归趋和对水产动物毒性进行分析,评价了阿维菌素在水产养殖环境中生态风险,为指导阿维菌素在水产养殖中科学使用提供理论依据。

Avermectin,which is a kind of 16-membered ring macrolide polyketone compound,has insecticidal and repellent activities.Because of its broad spectrum,high efficiency and low toxicity,avermectin is not only widely used in the control of parasites in crop farming and animal husbandry,but also has good insecticidal and anthelmintic effects on various parasites of aquatic animals.Avermectin in the water environment mainly comes from irrigation drainage of crop farming,animal husbandry wastewater and aquaculture drug input.The degradation of avermectin in the water environment is affected by multiple factors such as photodegradation,hydrolysis,phytoremediation,micro-biological degradation and soil adsorption.Photodegradation is the main way of avermectin degradation.There are species differences in the toxicity of avermectin to different fishes.And there are also obvious differences in the acute toxicity of avermectin to different types of aquatic organisms.The acute toxicity of avermectin to cladocerans was the highest among aquatic arthropods,while it is relatively less toxic to Procambarus clarkia and Macrobrachium nipponense.Therefore,when using avermectin to kill target parasites,more attention should be paid to its safety against non-farmed animals and non-target organisms.This review analyzes the physical and chemical properties,hazard sources,degradation pathways of avermectin,and its toxicity to aquatic animals and its ecological fate in the aquatic environment,evaluates the ecological risk of avermectin in aquaculture environment,which provides theoretical basis for guiding scientific use of avermectin in aquaculture.