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Award details

Improving ecotoxicological risk assessment by understanding how freshwater chemistry influences chemical bioavailability, uptake and toxicity in fish, PhD (funded) studentship in Biosciences Ref: 4144

About the award


Lead supervisor: Prof Rod Wilson, College of Life and Environmetal Sciences, University of Exeter

ECORISC Partner organisation: Astrazeneca


Project Overview

Freshwater chemistry varies greatly, e.g. H+ and calcium vary by >1,000-fold depending on location, which majorly influences chemical speciation and the physiological properties of fish gills that affect chemical uptake. This mechanistic project will fill this knowledge gap to tailor ecological risk assessment to regional conditions. Our multidisciplinary supervisory team provides world-class expertise in physiology, ecotoxicology, and analytical chemistry to support the student in this truly novel project.

Novelty of the Project

The electrical gradient across fish gills, i.e. between the blood and external water, is known as the trans-epithelial electrical potential (TEP). This TEP influences the uptake of any charged molecules, including inorganic ions required by fish (e.g. Na+, Cl-) and toxic metal ions but also any ionisable organic molecules (from pesticides to pharmaceuticals). However, the TEP itself is not constant and is dramatically influenced by natural variability in freshwater chemistry (e.g. changing from as negative as -35 mV to as positive as +10 mV in response to changes in variables such as pH, calcium, salinity, and dissolved organic carbon – see review by Pinheiro et al., 2021 – Biological Reviews; DOI: 10.1111/brv.12711). But how TEP affects the uptake of toxic chemicals represents a major knowledge gap in ecotoxicology. Furthermore the influence of fundamental freshwater water chemistry on gill TEP may explain large inconsistencies in chemical uptake observed between individual fish and different studies.
Expertise that you would develop: The student will develop expertise in physiology experimentation with fish in vivo and using in vitro cell cultures, including measuring TEP across gills and chemical uptake in a range of fish species. We will also provide training in skills relevant to analytical chemistry and understanding chemical speciation, and statistical and modelling methods.


This project is one of 12 projects being advertised by the NERC-funded ECORISC (Ecotoxicological Risk Assessment Towards Sustainable Chemical Use) Centre for Doctoral Training programme. More information on the CDT can be found at: Funding will be provided for 3 years and 10 months. During this time you will work on your research project but will also receive a unique and outstanding training in pollution science and transferrable skills.

Over the first two years of their PhD programme, you will receive subject-specific training, in: i) ecotoxicology; ii) environmental chemistry; iii) ecology; and iv) risk assessment; and v) core skills required for an environmental specialist. Successful completion of this training will result in the award of phase 1 of the Certified Environmental Risk Assessor qualification from the Society of Environmental Toxicology and Chemistry. The formal training programme will be complemented by yearly residential challenge events, ECORISC annual conferences and tailored specialist skills training conducted as group and individual exercises.

ECORISC students will also be required to undertake two workplace experiences based with our business, policy and regulation, third sector and research organisation partners.

An inclusive CDT programme

Inclusivity is at the heart of the ECORISC programme. We strongly encourage applications from under-represented groups and are employing a number of mechanisms, such as the possibility of part-time working, to ensure the programme is open to all. We will ensure that individuals with disabilities are provided reasonable accommodation to participate in the application process. If you have any questions, then please don’t hesitate to contact us at

Entry requirements

The studentship is open to highly motivated UK applicants with at least an upper second class Honours degree (or equivalent) in a relevant subject. Successful applicants will be passionate about environmental pollution science and want their science to make a difference.

How to apply

To be considered for this and other PhD’s offered under the ECORISC CDT, you should initially complete a short online application form available at: Applications should be submitted before 1700 (British Summer Time) on 16th May. Your will be notified of the outcome of the process by 25th May.

Successful applicants, will be provided with an opportunity to meet with supervisory teams and then be invited to submit a project-specific application form which will be used to shortlist candidates for an interview.

If you have any questions on the ECORISC CDT or the application process, please contact us at


Application deadline:16th May 2021
Value:Funding will be provided for 3 years and 10 months.
Duration of award:per year
Contact: PGR Admissions