Project highlights

  • You will have the opportunity to conduct innovative experiments in a state of the art mesocosm facility.
  • With Wessex Water involved in the project, there will be a placement opportunity so you can experience research in an industry environment.
  • Research outputs with real-world application that can inform policy


River ecosystem are threatened by a cocktail of chemicals produced by human activities. Whilst the ecological impact of some chemicals is understood, the action of new emerging contaminants remains unknown. Poly and perfluoroalkyl substances (PFAS) are a group of highly persistent, synthetic organofluorine compounds that are widely used in commercial products/applications. They are considered “forever” chemicals and are highly mobile and readily transported from the terrestrial environment to groundwater and surface water. Despite growing concern regarding their impact on health, ecotoxicology studies are limited for PFAS and implications of environmentally relevant concentrations for riverine populations, communities and ecosystem function are largely unknown. Furthermore, many river ecosystems are already degraded by excessive water use associated with growing populations, and these be affected further, by widespread shifts in rainfall and temperature patterns under climate change. Hence, it is important that we understand both how PFAS is currently impacting river ecosystems and under plausible future scenarios of environmental change. To do this requires realistic experimental systems (mesocosms – flumes) that can recreate important properties of natural rivers but thermal and flow regimes can be accurately controlled and replicated.

You will join a vibrant research team addressing the research gaps highlighted above, and conduct experiments in a new state of the art mesocosm facility at the University of Birmingham (EcoLaboratory – Outdoor Environmental Change Laboratory; see Fig. 1 below). You will undertake experiments informed by a combination of environmental surveys and historical data from streams monitored by project partner Wessex Water. Specifically, the project will test the effect of PFAS on river ecosystem structure, functioning and food webs. The main objectives will be to: (1) undertake analysis of novel PFAS concentration data collected by Wessex Water, and other water companies, as part of the Chemical Investigation Programme (phase 3 – CIP3); (2) use artificial streams in the Birmingham EcoLaboratory facility to determine the impact of PFAS on invertebrate populations and communities, via factorial manipulation (PFAS concentration, flow and thermal regimes); and (3) assess the impact of environmentally relevant PFAS concentrations (informed by CIP3 data) on food webs and ecosystem function under current and future climate scenarios. The results of the research will reveal how riverine ecosystems are affected by synthetic chemicals and identify how these may change under future climate scenarios, thus providing a basis to inform mitigation strategies. In addition, quantifying ecological impacts of PFAS could have significant long-term financial benefits for the water industry by allowing for more targeted investment.

CENTA Flagship

This is a CENTA Flagship Project

Case funding

This project is suitable for CASE funding


University of Birmingham


  • Climate and Environmental Sustainability
  • Organisms and Ecosystems


Project investigator


  • Dr Mark Ledger ([email protected])
  • Mr Richard Standerwick, Wessex Water PLC (CASE Partner)
  • Dr Thomas Aspin, Wessex Water PLC (CASE Partner)
  • Dr Francois Edwards, CEH

How to apply


This project will determine the effect of synthetic chemicals on populations and communities under current and future climate scenarios. Experiments will be conducted in replicate freshwater mesocosms in our new facility at the University of Birmingham (see Fig. 1 above). There will be opportunities to work at different scales (i.e. micro – meso) to assess impacts on 1: key aquatic invertebrate species, 2: community structure and feeding interactions, and; 3: ecosystem functioning.  The experiments will be informed by environmental surveys and data collected by Wessex Water (the project partner). This project also benefits from being closely linked with chemists and ecologists at Wessex Water, who seek to better understand chemical impacts on river life in their catchments in southern England. The successful candidate will also gain from being part of a large, interdisciplinary, research team based at the University of Birmingham

Training and skills

You will be trained in the use of mesocosms (artificial streams and ponds) for research in hydroecology. A detailed understanding of the taxonomy of freshwater invertebrates and algae will be gained.  A good understanding of experimental design, data science and statistical analysis will also be achieved.  In addition there will be scope to develop expertise in environmental sensing using the sensor network at the EcoLaboratory facility on the campus at Birmingham. In particular you will use a range of data logging and communication protocols and have scope to develop open source hardware for environmental monitoring.

Partners and collaboration

The project will benefit from a collaboration with our partners Wessex Water and the UK Centre for Ecology & Hydrology. You will have access to extensive datasets enabling comparative analysis of chemical impacts on river organisms. Placement opportunities with the CASE partners are also an option.

Further details

For more information or to arrange an informal chat please contact Dr Kieran Khamis ([email protected]) or Dr Mark Ledger ([email protected]).

Possible timeline

Year 1

Review literature, analyse historical data, plan and undertake fieldwork to identify PFAS concentrations in water, sediment and biota. Plan experiments. Opportunity for placement #1 with project partners.

Year 2

Undertake experiments exploring impacts on populations. Establish experiments exploring impact on food webs and ecosystem function. Opportunity for placement #2 with project partners.

Year 3

Complete experiments, all laboratory analysis and data analysis. Thesis write-up with view to publish findings in international peer-reviewed journals

Further reading

Coggan TL, Moodie D, Kolobaric A, Szabo D, Shimeta J, Crosbie ND, Lee E, Fernandes M, Clarke BO. 2019. An investigation into per- and polyfluoroalkyl substances (PFAS) in nineteen Australian wastewater treatment plants (WWTPs). Heliyon 5 (8): e02316 DOI: 10.1016/j.heliyon.2019.e02316

Li F, Duan J, Tian S, Ji H, Zhu Y, Wei Z, Zhao D. 2020. Short-chain per- and polyfluoroalkyl substances in aquatic systems: Occurrence, impacts and treatment. Chemical Engineering Journal 380: 122506 DOI: 10.1016/j.cej.2019.122506

Phong Vo HN, Ngo HH, Guo W, Hong Nguyen TM, Li J, Liang H, Deng L, Chen Z, Hang Nguyen TA. 2020. Poly‐and perfluoroalkyl substances in water and wastewater: A comprehensive review from sources to remediation. Journal of Water Process Engineering 36: 101393 DOI: 10.1016/j.jwpe.2020.101393

Stewart RIA, Dossena M, Bohan DA, Jeppesen E, Kordas RL, Ledger ME, Meerhoff M, Moss B, Mulder C, Shurin JB, et al. 2013. Mesocosm experiments as a tool for ecological climate-change research. Advances in Ecological Research 48, 71– 181.


The project is resilient to the impacts of COVID-19; experiments are conducted in an open air mesocosm facility which operated without interruption during 2020-21. Data driven aspects of the project are manageable and unlikely to be problematic.