About the Project
Introduction/Background
Persistent organic pollutants (POPs) are chemical substances that are resistant to environmental degradation through chemical, biological, geological and physical processes. POPs enter coastal waters from various diffuse and point sources, located near the coast or originating from further inland.
There are many classes of POPs which have been produced for multiple purposes, including pesticides in agriculture, coolants and insulators in industry, flame retardants, pharmaceuticals, consumer and personal products from households. They can be produced by combustion processes, and are found in waste and seepage and leakages from dump sites and landfills.
POPs persist in the environment – they often have half-lives of tens of years in water and sediment, can undergo long-range transport, bioaccumulate in human and animal tissue, biomagnify in food chains, and have potentially significant impacts on human health and the environment. For example, Desforges et al. (2018) found that polychlorinted biphenyl (PCB, a class of POP used in industry) concentrations found in killer whales can be 100 times safe levels, resulting in severely damaged reproductive organs, cancer and damage to the immune system. The study predicts the collapse of the global killer whale population from PCB pollution. The Northwest European Shelf has been identified as a region of higher trophic level (animal) exposure to PCBs (e.g. Handoh & Kawai, 2014).
POPs tend to be either hydrophobic (lipophilic) or hydrophilic (lipophobic), that is they tend to either be water hating or water soluble (see O’Driscoll et al. 2013 for examples of hydrophobic v. hydroplhilic POPs). Hydrophobic POPs sorb to organic matter in the ocean: they can settle with detritus (dead-matter) in sediment and can be recycled with nutrients before entering the food chain, or they can sorb directly to plankton. So they enter the food chain either directly or indirectly, where they bioaccumulate and biomagnify up the food chain, thus are a threat to the ecosystem and its services.
Project
The major objective of this work is to study POP exchange processes at lower trophic levels (LTLs phyto- and zoo-plankton) in the Northwest European Shelf ocean ecosystem as part of an integrated and holistic investigation into the cycling, pathways and fate of POPs within the shelf and coastal system. To accomplish this, the student will further develop the state-of-the-art model described by O’Driscoll et al. (2013) to simulate these processes, thereby quantifying the spatio-temporal variability of the processes acting within each of the major ocean sub-systems (water, sediment and ecosystem).
The proposed modelling approach will extend the model of O’Driscoll et al. (2013) to include POP exchange processes in phytoplankton (uptake, depuration, growth, and metabolism rates) and zooplankton (same as phytoplankton and egestion in faeces and eggs). Rate constants depend on a number of variables and will be calculated/chosen for key plankton species.
Hydrodynamic, biogeochemical and ecosystem model results are used from existing NERC National Oceanographic Centre model runs (e.g. NEMO-ERSEM, https://noc.ac.uk/science/research-areas/marine-systems-modelling).
The project is not only science driven but will contribute to national and international efforts to mitigate against ocean pollution, especially ecosystems under pressure from stressors.
References
Desforges, J-P. al. Science, 2018, Vol. 361, iss. 6409, 1373-1376,
DOI: 10.1126/science.aat1953
Handoh, I.C. & Kawai, T. 2014. Modelling exposure of oceanic higher trophic-level consumers to polychlorinated biphenyls: Pollution ‘hotspots’ in relation to mass mortality events of marine mammals. Marine Pollution Bulletin, 85, 824–830.
O’Driscoll, K., B. Mayer, T. Ilyina, T. Pohlmann, 2013. Modelling the cycling of persistent organic pollutants (POPs) in the North Sea system: fluxes, loading, seasonality, trends. J. Mar. Syst., 111-112, 69-82."
ADDITIONAL CASE STUDENTSHIP PROPOSAL DETAILS
Company/Non-Academic Partner Name - The Agri-Food & Biosciences Institute (AFBI)
Website - www.afbini.gov.uk
Name of Supervisor at Partner - Dr Matthew Service ([Email Address Removed])
Monitoring and research conducted at AFBI is undertaken in support of fish and shellfish stock assessments and the implementation of the ecosystem approach to managing the fisheries and other resources of the Irish Sea.
The ecosystem approach has been increasingly promoted as an effective framework for fisheries management to meet societal needs, while reducing the direct and indirect impacts of fishing activities on the environment.
Understanding the transport and fate of organic contaminants is a key component to developing an understanding on functioning of the ecosystem and how it relates to sustainable fisheries management.
Continue with Facebook
