Microplastics in the Southern Ocean: sources, fate and impacts.

Rationale: 

Alongside rapid climate change, plastic contamination of the ocean is a high-profile issue of growing global concern. Initial observations of plastic litter in the surface water and sediments of the Southern Ocean indicate the wide spread of these contaminants throughout the world’s ocean. The knowledge of abundance, distribution, and characteristics of the sub-millimetre plastic particles (microplastics) in the ocean interior and sediment remain scarce, while the transport pathways and processes controlling their supply to and fate therein are poorly understood. Addressing these fundamental questions is critical for understanding the risks from exposure to plastics, especially in such unique environments as Southern Ocean, where different water masses form and mix, shaping global circulation and climate.  This project offers a unique opportunity to explore microplastic loads in the Southern Ocean, how they change in relation to local physical and biogeochemical forcing, and how these contaminants are distributed by the large-scale circulation.  This research will provide new insight into processes and pathways governing the supply, distribution and fate of microplastics on regional and global scales. It will improve our understanding of the interactions, impacts and potential threats of these contaminants in the marine environment, so that adequate mitigation actions can be taken. 

Methodology: 

The student will work primarily with water samples collected in the Southern Ocean (Pacific and Atlantic sectors) and sediment cores from around South Georgia, NE Scotia Sea and northern Antarctic Peninsula. They will have opportunities to participate in research expeditions and to collect additional samples from similar/contrasting ocean regions. The samples from different locations and ocean compartments will allow the student to investigate the extent to which the Antarctic Circumpolar Current is a barrier to microplastics in the Southern Ocean. The student will explore how microplastics are supplied to the study region, how they disperse into the ocean interior and accumulate at the seabed in relation to local physics (e.g. water-masses properties and movement), biogeochemistry (e.g. surface productivity, downward particle flux), and sediment characteristics. For their research, the student will use the cutting-edge laboratory and analytical techniques, including infrared spectral imaging, elemental and isotope analyses. Building on the existing methods for sampling and analyses will be encouraged. Through CASE partnership with Perkin Elmer, the student will have an opportunity to use novel techniques for identifying and characterising plastics. They will have access to ancillary data from different observation platforms (e.g. satellites, sensors) to interpret their findings and give them regional and global contexts. 

Location: 
NOC/UoS
Training: 

The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at National Oceanography Centre.

The student will learn to read and critically evaluate published research in a field and identify gaps and problems. They will learn to identify the approaches in which these issues/gaps can be addressed and how to  implement them in a blend of observations, sample collection and laboratory work. The student will learn to analyse the data, interpret the results and present their finding through scientific writing (thesis, peer-reviewed publications) and presentations to fellow researchers and wider community.   

Specific training will include:

  • infrared spectroscopic imaging for plastic detection and characterisation;
  • infrared spectral data processing and interpretation; image processing and analysis;
  • elemental analyses for biogeochemical and isotope characterisation of particulate matter;
  • field sampling and experimental design;
  • method development and/or optimisation;
  • statistical analysis, data acquisition and evaluation techniques;

 

Eligibility & Funding Details: 

Please see https://inspire-dtp.ac.uk/how-apply for details.

 

Background Reading: 
  1. Pabortsava, K., Lampitt, R.S. High concentrations of plastic hidden beneath the surface of the Atlantic Ocean. Nat Commun 11, 4073 (2020). https://doi.org/10.1038/s41467-020-17932-9
  2. Cunningham, E., et al.  High Abundances of Microplastic Pollution in Deep-Sea Sediments: Evidence from Antarctica and the Southern Ocean. Environmental Science & Technology 2020 54 (21), 13661-13671, DOI: 10.1021/acs.est.0c03441
  3. Pardo, P. C., et al., Water masses distribution in the Southern Ocean: Improvement of an extended OMP (eOMP) analysis, Prog. Oceanogr., 103, 92–105, https://doi.org/10.1016/j.pocean.2012.06.002, 2012.