【作者】 毛居东； 范德江； 郑世雯；

【Author】 Mao Judong;Fan Dejiang;Zheng Shiwen;College of Marine Geosciences, Ocean University of China;Key Lab of Submarine Geosciences and Prospecting Techniques, MOE, Ocean University of China;College of Environmental Science and Engineering, Ocean University of China;

【机构】 中国海洋大学海洋地球科学学院； 中国海洋大学海底科学与探测技术教育部重点实验室； 中国海洋大学环境科学与工程学院；

【摘要】 微塑料(MPs)作为全球性新污染物,在海洋中分布广泛,其粒径微小且吸附性能强,毒害效应显著,严重威胁了海洋生态环境。东海内陆架沉积环境稳定,接受了大量来自长江入海的物质,是微塑料等污染物汇聚的重要场所。为了更好地了解微塑料在海洋沉积物中的赋存状态和空间分异特征,我们采集了东海内陆架29个站位的表层沉积物样品,使用激光红外成像系统识别、鉴定微塑料聚合物类型和粒径大小,并分析微塑料在东海内陆架的丰度及空间分布特征。按照20-30、30-50、50-100、>100μm四个粒径级别和ρ<1、1<ρ<1.2、ρ>1.2g/cm3(轻、中、重)三个密度级别对微塑料的空间分异特征进行综合研究。结果表明,29个样品的微塑料平均丰度为1363.97个/千克干重(items/kg d.w.),范围为68.68-6742.83items/kg d.w.,表现出由近岸向远岸递减、中间呈现斑状分布的特点。鉴定出的微塑料聚合物类型主要以聚酰胺(47.02%)和聚氨酯(20.38%)为主,尺寸以20-30μm(48.23%)和30-50μm(30.30%)级别为主。微塑料按照不同粒径级别和密度级别的空间分布呈现出南北向的趋势变化,尤其是存在一个"重密度微塑料通道"。我们的研究结果认为东海内陆架表层沉积物微塑料的丰度可能被严重低估,特别是20-50μm区间内的微塑料可能未被完全检出,此外不同粒径、密度的微塑料受到不同来源、河流输运、水动力条件等因素影响,可能在沉积过程及结果上会呈现出一定的空间分异特征。更多还原

【Abstract】 As a new global pollutant, microplastics(MPs) are widely distributed in the ocean. Due to the small size and strong adsorption, the toxic effect is significant, which seriously threatens the marine ecological environment. The inner shelf of the East China Sea has a stable sedimentary environment and receives a large number of materials from the Yangtze River, which is an important area for the sink of microplastics. To achieve a better understanding of the occurrence state and spatial heterogeneity of microplastics in marine sediments, we collected surface sediment samples from 29 stations in the East China Sea, used laser direct infrared(LDIR) to identify polymer types, particle size, and analyze their abundance and spatial distribution characteristics of the inner shelf of the East China Sea. The spatial heterogeneity of microplastics were conducted comprehensively according to the four particle size levels of 20-30, 30-50,50-100, >100μm, and the three density levels of ρ<1, 1<ρ<1.2, ρ>1.2g/cm3(light, medium, heavy).The results indicated that the average abundance of microplastics in the 29 samples was 1363.97items per kg of dry weight sediment(items/kg d.w.), ranging from 68.68 to 6742.83 items/kg d.w.,showing a decreasing trend from the near shore to far, with a patchy distribution in the middle.The types of microplastic polymers were mainly polyamide(47.02%) and polyurethane(20.38%),and the sizes were mainly 20-30μm(48.23%) and 30-50μm(30.30%). According to different size and density levels, the spatial heterogeneity of microplastics showed a trend change from south to north, especially there was a "heavy density microplastics channel". Our results suggest that the abundance of microplastics in the surface sediments of the inner shelf of the East China Sea may be seriously underestimated, especially the microplastic particles in the range of 20-50μm may not be completely detected. In addition, microplastics with different particle size and density are affected by different source, river transport, hydrodynamic conditions and other factors, which may show certain spatial heterogeneity characteristics in deposition process and results.更多还原