海州湾潮间带沙蚕对沉积物微塑料的指示作用

2018年7月于海州湾潮滩设置3个断面共9个站位，通过对海州湾潮滩沉积物中以及沙蚕体内微塑料的丰度和形态特征的研究，探讨了沙蚕体内微塑料的来源，以及沙蚕对潮滩沉积物微塑料的指示作用.结果表明，潮滩沉积物中微塑料的平均丰度为（0.49±0.17） n·g^-1，处于国内近岸环境研究的较高水平.所有检测到的微塑料中，最为丰富的形态和颜色类型分别为纤维和黑灰色，材质以聚乙烯（polyethylene，PE）、聚酯纤维（polyester，PET）和聚苯乙烯（polystyrene，PS）为主.沙蚕中微塑料检出率为77.78%~86.67%，平均丰度为（6.68±2.21） n·ind^-1，其丰度与个体质量显著正相关（r=0.42，P=0.002），个体质量1.5 g以上的沙蚕中微塑料丰度显著高于<0.5 g和0.5~1 g两个组别（F₃=141.029，P=0.000），微塑料形态以黑色或蓝色小纤维为主，主要材质同样为聚乙烯和聚酯纤维.通过对0~3 mm范围内的微塑料各项特征分析发现，沉积物与沙蚕中的微塑料丰度强相关（r=0.79，P=0.01），其主要形态组成（r=0.90，P=0.035）和材质组成（r=0.73，P=0.024）同样显著相关，表明沙蚕会摄取沉积环境中的微塑料，存在与沉积物之间的微塑料交换，沙蚕作为沉积物中微塑料污染指示生物物种是可行的.

Indicator Function of Ragworm (Nereididae) on Sediment Microplastic in Haizhou Bay Intertidal Zone

Sediment samples were collected from nine sites of three sections, in the intertidal zone of Haizhou bay in July 2018. The abundance and characteristics of microplastics in the sediments (and ragworms within the sediments) were then determined to identify the source of microplastics in ragworms, and to explore the effects of ragworms on microplastics in sediment. The average abundance of microplastics in tidal flat sediments was (0.49±0.17) n·g^-1, which was at a high level in domestic offshore environmental studies. Among all the microplastics detected, the most common form and color were fiber and black-gray, respectively, and the materials were mainly polyethylene (PE), polyester (PET), and polystyrene (PS). The detection rate of microplastics in ragworm was 77.78%-86.67%, with an average abundance of (6.68±2.21) n·ind^-1; the abundance was significantly correlated with individual mass (r=0.42, P=0.002). The microplastic abundance was significantly higher in ragworms with individual mass over 1.5 g than in those with a mass of<0.5 g or 0.5-1 g (F₃=141.029, P=0.000). In ragworms, microplastics were dominated by small black or blue fibers, and the main materials were PE and PET. By analyzing the various characteristics of microplastics with a particle size of 0-3 mm, it was found that the abundance of microplastics in sediments was strongly correlated with that in ragworms (r=0.79,P=0.01); the main form (r=0.90, P=0.035) and the material composition (r=0.73, P=0.024) also showed significant correlation between sediments and ragworms. This indicates that ragworms ingest microplastics in the sedimentary environment and exchange the microplastics with the sediments. Therefore, ragworms can be used as an indicator species of microplastic pollution in sediments.