珠江河口多类型海滩沉积物中微塑料的空间分布特征

Spatial Distribution Characteristics of Microplastics in Multiple Types of Beach Sediments in Pearl River Estuary

河口海滩是微塑料的重要汇聚地之一,珠江河口多种类型海滩沉积物中不同深度微塑料的分布特征仍需进一步深入研究。以珠海市不同类型的海滩为例,探究珠江河口多类型海滩中微塑料的垂向分布及其空间变化特征。选取了珠海市沙质海滩唐家湾沙滩、金沙滩以及淇澳岛红树林为例,通过分层采样的方法总共采集了57个沉积物柱样品,对多个深度的微塑料进行了详细的分析。唐家湾沙滩表层(0~5 cm)和深层(5~15 cm)沉积物中微塑料丰度分别为1107.6、821.94 n/kg,金沙滩为694.0、457.0 n/kg,淇澳岛红树林采样区为835.0、556.7 n/kg;淇澳岛红树林更深层(15~45 cm)沉积物中微塑料平均丰度为302.6 n/kg。对海滩沉积物中微塑料的颜色进行统计分析,黑色是最为常见的颜色。此外,微塑料的形状主要分为纤维状和块状,其中细长的纤维是最为常见的形状,0.315~0.500 mm是3个海滩中微塑料最常见的尺寸范围。赛璐芬和聚乙烯是3个海滩微塑料中最为常见的2种塑料类型。研究初步揭示了珠江河口海滩微塑料垂向分布特征,为进一步制定珠江河口海滩微塑料的科学防治策略提供了重要依据。

Estuarine beaches are one of the important pools of microplastics,while the distribution characteristics of microplastics at different depths in various types of beach sediments in the Pearl River estuary still need in-depth study.This study investigates the vertical distribution of microplastics and their spatial variation characteristics in different types of beaches in the Pearl River estuary.The sandy beaches of Tangjiawan Beach and Jinsha Beach and the mangrove forest of Qi'ao Island in Zhuhai are selected as examples.A total of 57 sediment column samples are collected,and microplastics in different sediment layers are analyzed in detail.The abundance of microplastics in the surface layer(0~5 cm)and deep layer(5~15 cm)of sediments is 1107.6 and 821.94 n/kg from Tangjiawan beach,694.0 and 457.0 n/kg from Jinsha Beach,and 835.0 and 556.7 n/kg from the mangrove forest of Qi'ao Island,respectively.The average abundance of microplastics in the deeper layer(15~45 cm)of the mangrove forest of Qi'ao Island is 302.6 n/kg.The color of microplastics in beach sediments is statistically analyzed,and black is the most common color.In addition,the shapes of microplastics are mainly fiber and fragment,with fibers being the most common shape,and 0.315-0.500 mm being the most common size range of microplastics in these beaches.Cellophane and polyethylene are the two most common types of microplastics in these beaches.This study preliminarily reveals the characteristics of the vertical distribution of microplastics in the beaches of the Pearl River estuary,which provides an important basis for further developing scientific control strategies for microplastics in the beaches of the Pearl River estuary.