The role of hadal zones in the long-term fate of marine microplastics: Identification of microplastics in the deep sea of the Kuril-Kamchatka Trench, Northwest Pacific (Deep-MiPoll)

该项目的主要目的是对深海微塑料污染进行定性和定量鉴定，以更好地了解全球海洋微塑料污染的实际程度及其分布。在西北太平洋千岛-堪察加海沟，使用Multi - Corer从5146 m至9540 m的深度采集了沉积物样本。浮游生物样本的采样是由Multi网进行的，最大深度达到5900米。此外，从底拖网捕捞样本中分离出较大的人为垃圾。这些样本记录在MP研究的背景下是世界范围内独一无二的，并将首次提供关于hadal带污染的数据。样品制备将通过芬顿试剂氧化有机物的保塑法进行，随后进行密度分离，将MP从沉积物中分离出来。分析将通过最先进的微傅立叶变换红外光谱进行，这可以精确客观地确定塑料聚合物，从而确定可能的污染源。与生物和环境参数的联系将把结果置于更广泛的背景下，并审查可能的影响。塑料污染是对自然环境最紧迫的人为威胁之一。海洋受到的影响尤其严重，其次是对生态系统和单一生物的多方面负面影响。塑料一旦被引入，就会非常持久，因为没有明显的生物或化学降解。相反，塑料只是倾向于破碎，导致碎片数量稳步增加，尺寸逐渐减小，即所谓的MP（<500µm）。已经确定有相当一部分沉入海底。因此，海底必须被假定为MP积累的热点，其最深的部分，hadal带，是海洋MP的最终汇。该项目将有助于验证深海MP的丰度和组成。此外，还将研究丰度和组成随深度和沉积物的空间分异。日本周围的海域被远洋塑料严重污染，Deep-MiPoll将调查水柱和hadal沉积物中MP的出现之间可能的因果关系。在以往的深海MP研究中，采样深度在5500 m左右，因此将首次生成深海和深海的初始数据。这将是海洋微生物研究向前迈出的一大步，并有助于阐明垂直传播对海洋微生物时空分布的贡献以及深海在海洋微生物长期命运中的作用。Deep-MiPoll项目将首次使用光谱分析方法系统地调查深海样品中的MP，从而为深海生态系统的MP污染提供高度新颖和可靠的数据。

This project`s main aim is the qualitative and quantitative identification of microplastic (MP) contamination of the deep sea, to gain a better insight into the actual extent of global marine MP pollution and its distribution. In the Kuril-Kamchatka Trench, NW Pacific, sediment samples were taken from depths ranging from 5146 m to 9540 m using a Multi Corer. Sampling of plankton samples was conducted by a Multi Net and reached a maximum depth of 5900 m. Additionally, bigger items of anthropogenic litter were separated from bottom trawling samples. These sample records are worldwide unique in the context of MP research and will provide data about the contamination of hadal zones for the very first time.Sample preparation will be conducted through a plastic-preserving method using Fenton`s reagent to oxidize organic matter and a subsequent density separation to separate MP from the sediments. Analyses will be performed by state-of-the-art micro-Fourier Transform Infrared spectroscopy, which allows a precise and objective determination of the plastic polymers and thus, the identification of possible pollution sources. The connection with biological and environmental parameters will place the results in a broader context and examine possible implications.Plastic contamination is one of the most urgent manmade threats for natural environments. The oceans are affected particularly, followed by multifaceted negative effects on ecosystems and single organisms. Once introduced, plastic is very persistent, since there is no significant biological or chemical degradation. Instead, plastics merely tend to be fragmented, leading to steadily rising numbers of fragments of decreasing size, the so-called MP (<500 µm). It has been ascertained that a substantial fraction sinks to the seabed. Thus, the seabed must be presumed as a hot spot of MP accumulation and its deepest parts, the hadal zones, as a final sink for marine MP. This project will contribute to verify the abundance and composition of MP in the deep sea. Furthermore, investigations on spatial differentiation of abundance and composition with depth and through the sediments will be performed. The seas around Japan are exceedingly polluted with pelagic plastic, Deep-MiPoll will investigate a possible causal link between occurrences of MP in the water column and in hadal sediments.In previous studies on MP in the deep sea, sampling reached around 5500 m, hence initial data for deep abyssal and hadal zones will be generated for the first time. This will constitute a big step forward in MP investigations and help to clarify the contribution of vertical propagation for general spatio-temporal distribution and the role of the deep sea in the long-term fate of marine MP. The Deep-MiPoll project will investigate MP in deep-sea samples using spectroscopic analyzing methods systematically for the very first time, and thus, provide highly novel and reliable data about the MP pollution of deep-sea ecosystems.