Temporal and spatial microplastic distribution in the deep North Atlantic Ocean (2000 m) in relation to environmental factors and concentrations of persistent organic pollutants (POPs)

在本项目中，我们提出了三个假设：H1)区域差异是由微塑料通量中主要运输途径和聚合物组成的差异引起的。H3)沉积物捕集器样品中持久性有机污染物和微塑料丰度呈正相关关系，证明持久性有机污染物和塑料从大气到深海的运输机制相似。我们的目标是利用来自不同采样点L1 （Kiel276）、L2、L3、BATS和NB的沉积物捕获器样本，根据季节、年度和区域模式（H1）评估沉积物捕获器样本中的微塑料丰度及其聚合物组成。这将揭示季节和年度模式，以及除了时间分辨率之外，提供北大西洋2000米深度内微塑料的空间分布。将利用暂时确定的微塑料丰度，结合有关电流和颗粒、岩石成因和生物成因通量的现有数据，评估微塑料的运输途径和潜在来源。此外，还将比较沉积物捕集器样品中微塑性丰度与环境参数和天然颗粒通量及其组分（H2）的关系。由于微塑料被强烈怀疑是有毒物质的载体，在海洋中运输高浓度持久性有机污染物，因此对大西洋深处微塑料和持久性有机污染物通量的评估为阐明深海的这一特性提供了一个宝贵的机会（H3）。由于选择了大量可能在下沉材料中检测到的潜在POP物质，这些物质仍然存在于环境样品中，如多环芳烃（PAHs）、氯化二苯（PCBs）和二氯二苯三氯乙烷（DDT）。

In the proposed project, we have formulated three hypotheses: H1) Regional differences are caused by differences in dominating transport pathways and polymer compositions within the microplastic fluxes. H2) A gradient of microplastic flux rates exist from south to the north with increasing microplastic fluxes in more northern locations because of higher biological production rates and H3) The similar transport mechanisms for POPs and plastics from the atmosphere to the deep ocean are evidenced by a positive correlation of POPs and microplastic abundances in sediment trap samples. We are aiming at evaluating microplastic abundances and its polymer composition in sediment trap samples in terms of seasonal, annual, and regional patterns (H1) using sediment trap samples from different sampling sites L1 (Kiel276), L2, L3, BATS, and NB. This will reveal seasonal and annual patterns as well as in addition to the temporal resolution, provide spatial microplastic distributions within the 2000 m depth of North Atlantic Ocean. Using temporally resolved microplastic abundances combined with available data on currents and particle, lithogenic, and biogenic fluxes, transport pathways and potential sources of microplastics will be assessed. Additionally the comparison of microplastic abundances in sediment trap samples in relation to environmental parameters and natural particle flux and its components (H2) will be carried out. As microplastic is strongly suspected of acting as a vector for toxic substances, transporting high concentrations of POPs across the oceans, the evaluation of microplastic and POP fluxes in the deep Atlantic Ocean offers a valuable opportunity to elucidate this property for the deep sea (H3). Due to the high number of potential POP substances potentially detectable in sinking material were chosen, still present in environmental samples, such as polycyclic aromatic hydrocarbons (PAHs), chlorinated diphenyl’s (PCBs), and Dichlorodiphenyltrichloroethane (DDT).