珠三角河网鱼类微塑料污染特征研究

Characteristics of Microplastic Pollution in Fish in the Pearl River Delta

近年来,微塑料作为一种新型污染物在水环境中的污染受到越来越多的关注,已经成为一个新兴的全球性环境问题。为了解珠三角河网水域常见野生鱼类中微塑料的污染特征,选取8种野生淡水鱼为研究对象,分析其鳃部和肠道中微塑料的丰度、粒径、形态、颜色和组成成分。结果表明,在所有鱼体中共检测出60个微塑料,平均每条鱼摄入了1.6个微塑料,鳃部的平均丰度为(0.638±1.276)items·g^(−1),肠道的平均丰度为(0.256±0.326)items·g^(−1),鳃部的平均丰度大于肠道的平均丰度。通过对鱼类微塑料的丰度与鱼的体长、体质量的相关性分析表明,鱼类微塑料的丰度与鱼的体长、体质量相关性较弱。本次实验检测出的微塑料粒径多大于100μm,主要为碎片状,颜色主要为黑色和灰色,检测的聚合物类型主要为聚乙烯和聚丙烯。中上层鱼类摄入的微塑料大多为颗粒状,分析其来源可能为个人护理及化妆品内添加的塑料微珠,通过生活污水排入到环境中,从而被摄食。底层鱼类摄入的多为碎片状,分析其来源可能是固体废物,经过风化和光解沉入水底,从而被底层鱼类所摄食。泥鳅(Misgurnus anguillicaudatus)的平均微塑料摄入量最高,鳃和肠道中微塑料含量最高的鱼类均来自左滩采样点。上述研究结果有助于了解珠三角河网野生淡水鱼类群体的微塑料污染现状,可为水生态风险评估提供参考。

In recent years,as a new type of pollutant,microplastic pollution in the water environment has received more and more attention and has become an emerging global environmental problem.In order to understand the pollution characteristics of microplastics in common wild fish in the Pearl River Delta,we selected eight kinds of wild freshwater fish as research objects and analyzed the abundance,particle size,shape,color,and composition of microplastics in their gills and intestines.A total of 60 microplastics were detected in all of the fish,with an average intake of 1.6 microplastics per fish.The average abundance of gills was(0.638±1.276)items·g^(−1),and the average abundance of gut was(0.256±0.326)items·g^(−1),and the average abundance in the gills was greater than that of guts.The correlation analysis between the abundance of microplastics in fish and fish body length and body weight showed that the abundance of microplastics in fish was weakly related to body length or body weight of fish.The microplastic particles detected in this experiment were mostly greater than 100μm in size,mainly in fragments,and mostly black or gray in color.The types of polymers detected were mainly polyethylene and polypropylene.Most of the microplastics ingested by pelagic fish were in a granular form,and its source may be plastic microbeads added to personal care and cosmetic products,which were discharged into the environment through domestic sewage and then ingested.Most of the microplastics ingested by bottom fish were in the form of fragments,and the source might be solid waste,which sank to the bottom after weathering and photolysis and was then ingested by bottom fish.Misgurnus anguillicaudatus had the highest average microplastic intake,and the fish with the highest microplastic content in their gills and guts were all from the Zuotan sampling site.These research results may help us to understand the status of microplastic pollution in wild freshwater fish populations in the Pearl River Delta and may provide reference for water ecological risk assessment.