Modelling the surface transport and spatio-temporal extent of microplastic pollution in the Southern Ocean and Antarctic waters

项目背景：南大洋和南极海洋环境通常被认为是原始的，在很大程度上超出了人类的影响。然而，越来越令人担忧的是在南极和亚南极沃茨和沉积物中发现的微小漂浮塑料碎片（微塑料）的存在[Waller等人，2017年]。微塑料可以被南极磷虾等关键滤食性物种摄入，其毒理学效应反过来可以通过食物链积累并影响海鸟、海豹和鲸鱼等大型捕食者[科尔等人，2013; Kaposi等人，2014; Lusher et al. 2015.]。微塑料在海底的沉积也可能影响海底生物群落。然而，至关重要的是，南极洲海洋塑料的范围，数量，来源和影响在很大程度上是未知的。最近的研究表明，航运和科学研究站等当地来源并不能解释记录的微塑料浓度，这表明塑料从更偏远的地区涌入[Waller等人，2017年]。该项目将利用模型和实地观察，更好地了解到达南极沃茨的微塑料的来源、传播路线和时间尺度。最终，该项目将有助于为极地海洋污染的未来治理提供信息。项目目的和方法：该项目的主要目的是更好地量化南极洲和周边南大洋海洋微塑料的来源、路径和分布。南大洋是来自地球仪的水团的汇合和上涌区，因此可能会从遥远的来源收集微塑料。然而，与南大洋相关的强大绕极流也可以作为向南流入南极沃茨的颗粒的屏障。在整个南大洋收集足够的时间和空间分布的微塑料浓度的困难意味着海洋模型是“填补空白”的重要工具。该项目将使用拉格朗日（即粒子跟踪）模型来绘制从本地和远程来源到达南极沃茨的微塑料路径[例如，货车Sebille等人，2015年]。特别是，模型数据将有助于评估风暴和漩涡等较小尺度过程在促进微塑料穿过环绕南极大陆的锋面屏障向南转移方面的作用[Tamzitt等人，2017; Fraser et al. 2018]。模型数据将通过英国南极调查局（BAS）收集的海洋微塑料分布和浓度的观测进行初始化和验证。虽然主要是理论上的，学生可能有机会参加到南大洋的BAS研究巡航，以获得实地考察和微塑料数据收集的经验。学生将从与新成立的南极研究科学委员会（SCAR）的互动和合作中受益行动组塑料在极地环境。将有一些灵活性，以调整这个博士项目，让成功的申请人直接自己的研究，并满足任何特定的利益-它将不得不大致保持在目前的职权范围内，与现有数据保持一致，并保持在项目主管的专门知识范围内。

Project Background: The Southern Ocean and Antarctic marine environment are often considered pristine and largely beyond the reach of human impact. However, of increasing concern is the presence of tiny floating plastic fragments (microplastics) found in Antarctic and sub-Antarctic waters and sediments [Waller et al., 2017]. Microplastics can be ingested by keystone filter feeder species such as Antarctic krill, with toxicological effects that can in turn accumulate through the food chain and impact larger predators such as seabirds, seals and whales [Cole et al., 2013; Kaposi et al., 2014; Lusher et al. 2015.]. The deposition of microplastics on the seabed will also likely impact benthic communities. Crucially, however, the extent, quantity, sources and impacts of marine plastics in Antarctica are largely unknown. Recent studies indicate that local sources such as shipping and scientific research stations do not account for recorded concentrations of microplastics indicating an influx of plastic from more remote regions [Waller et al., 2017]. This project will use models and field observations to better understand the sources, dispersal routes and timescales of microplastics that have reached Antarctic waters. Ultimately, this project will help to inform the future governance of polar marine pollution.Project Aims and Methods: The primary aim of this project is to better quantify the sources, pathways and distribution of marine microplastics in Antarctica and the surrounding Southern Ocean. The Southern Ocean acts as a confluence and upwelling zone for water masses from across the globe, and hence likely collects microplastics from far reaching sources. However, the strong circumpolar currents associated with the Southern Ocean can also act as barriers to the southward flux of particles into the Antarctic waters. The difficulty of collecting sufficient temporal and spatially distributed concentrations of microplastics across the Southern Ocean means that ocean models are an essential tool to 'fill in the gaps'. This project will use Lagrangian (i.e. particle tracking) models to map the pathways of microplastics that have reached Antarctic waters from both local and remote sources [e.g. Van Sebille et al. 2015]. In particular, model data will help to assess the role of smaller scale processes such as storms and eddies in facilitating the southward transfer of microplastic across the frontal barriers that encircle the Antarctic continent [Tamzitt et al., 2017; Fraser et al. 2018]. Model data will be initialised and validated by observations of marine microplastic distribution and concentrations collected by the British Antarctic Survey (BAS). Although largely theoretically based, there may be the opportunity for the student to participate in a BAS research cruise to the Southern Ocean to gain experience of fieldwork and microplastic data collection.The student will benefit from interaction and collaboration with the newly-formed Scientific Committee on Antarctic Research (SCAR) action group Plastics in Polar Environment.There will be some flexibility to adjust this PhD project to allow the successful applicant to direct their own research and cater for any specific interests - it will have to stay broadly within the current remit, be aligned with available data and remain within the expertise of project supervisors.