NERC RED-ALERT CDT: Otters versus gadgets: how does passive sampling compare with sentinel species monitoring for evaluation of freshwater pollution?

This project is one of a number that are in competition for funding from the Red-ALERT CDT for entry in September 2025.

Overview of the Research:

Freshwater ecosystems are among the most threatened habitats on Earth due to numerous human pressures, including chemical contaminants. Protecting ecosystems from chemicals requires comprehensive pollution management strategies, stringent regulatory frameworks and effective monitoring programmes. However, measuring chemical contamination in freshwater systems and evaluating arising risks is extremely challenging.

Testing water to determine whether Environmental Quality Standards for contaminants are met is a key feature of monitoring, but some (e.g. hydrophobic) substances remain poorly quantifiable in water despite toxicological impacts. To tackle this, current legislation requires destructive sampling of biota (typically fish) but logistical/ethical issues impose limitations. Ad hoc collection of predator carcases is a proven alternative (e.g. H4 Indicator, Defra, 2024). Cardiff University Otter Project uses otters (mostly roadkill) for temporal and spatial modelling of chemicals and their putative sources (e.g. PFAS – O’Rourke et al 2022), but sample collection is opportunistic and thus unpredictable. Passive samplers (e.g. using membrane capture) allow targeted deployments in waterbodies, and are gaining attention as an alternative to active water sampling (e.g. Allan et al 2022). Comparisons between sampling methods are, however, scarce, largely focused on marine systems, and have yielded highly variable results. Comparative research is needed to evaluate the strengths and limitations of these methods.

Otters versus gadgets asks to what extent passive sampling can be used to gauge chemical threats to freshwater systems. Co-located active and passive sampling of water, active sampling of biota, and bio-banked otter tissues will be used to (i) evaluate differences in detection efficiency between methods and (ii) quantify vertical (food chain) transfer of chemicals at catchment (Taff-Ely living lab) scale. Landscape (Wales-wide) geospatial modelling of chemical concentrations across matrices/methods will (iii) inform risk analysis, and (iv) help identify anthropogenic drivers of variation.

The project brings together ecological theory, chemistry and modelling, within the One Health context of wildlife, ecosystem and human health. The student will receive training in analytical methods (both chemical and data). Our partnership (Cardiff University, UKCEH, NRW) provides access to cutting edge technologies, extensive environmental samples and data, and the opportunity to influence environmental policy at a critical time.

Project Keywords: Pollution, policy, chemical monitoring, freshwater ecosystems, One Health

Industrial Partner:

Natural Resources Wales is the industrial partner for this project.

Candidate Requirements:

Applicants should hold, or expect to receive, a First Class or good Upper Second-Class UK Honours degree (or the equivalent) in a relevant subject. A master’s level qualification would also be advantageous.

Relevant subjects include (but are not limited to) biological sciences, chemistry, or environmental sciences. Applicants with a chemistry background should have an interest in ecological applications, those with a biological/ecological background should have an interest in chemistry and pollution. 

*Non-UK applicants must meet the programme’s English language requirement prior to a formal offer being made. 

Equality, Diversity, and Inclusion:

We value a diverse research environment and aim to be an inclusive university, where difference is celebrated and respected. We welcome and encourage applications from under-represented groups.

If you have circumstances that you feel we should be aware of that have affected your educational attainment, then please feel free to tell us about it in your application form. The best way to do this is a short paragraph at the end of your personal statement.

Enquiries and Applications:

Formal applications should be submitted via the Red-ALERT CDT online application form prior to the closing date of this advert.