Habitat fragmentation is a major source of biodiversity loss in freshwaters, with rivers around the world fragmented by dams and weirs.

These impoundments restrict connectivity, inhibit fish migrations across ecosystem boundaries, modify gene-flow and impact population sustainability. However, schemes to restore river connectivity can be achieved through either the installation of ‘fish-passes’ on the structures or through removal of the structure. There have, however, been few attempts to quantify the conservation and ecological outcomes for non-salmonid migratory fishes of this reconnection, despite these species facing unprecedented European population declines. These species include sea lamprey Petromyzon marinus, a non-homing anadromous species, and European eel Anguilla anguilla, a critically endangered catadromous species. 

There are major knowledge gaps in the movement ecology and biology of both species, despite their conservation importance, including how the distributions and movements of their juvenile lifestages in relation to both barriers and barriers that have fish passes installed. In particular, the movement ecology of yellow eels across catchments and across freshwater/estuarine boundaries, and the distribution and population demographics of sea lamprey ammocoetes are poorly understood. 

The research completed within this PhD will overcome these knowledge gaps through work completed on the Rivers Severn and Teme, western England. Telemetry infrastructure within the river can be used to track the movements and migrations of both yellow and silver eels, and the application of relevant capture methods will develop novel datasets on juvenile sea lamprey populations. For migrating silver eels, there is the possibility of tracking their emigration from freshwater and through over 300 km of the marine environment.   

Please note: the funding for this course includes waive of tuition fees for 36 months, stipend for 36 months, training costs, and research costs.

Key information

Next start date:

21 September 2026

Location:

Talbot Campus, Bournemouth University

Duration:

Expected submission: 36 months Completion: within 48 months

Entry requirements:

BU PhD Studentships are open to UK, EU and international students.

Candidates for a PhD Studentship should demonstrate outstanding qualities and be motivated to complete a PhD in 4 years. They must demonstrate:

• outstanding academic potential as measured normally by either a 1st class honours degree (or equivalent Grade Point Average (GPA) or a Master’s degree with distinction or equivalent
• an IELTS (Academic) score of 6.5 minimum (with a minimum 6.0 in each component, or equivalent) for candidates for whom English is not their first language and this must be evidenced at point of application.

In addition:

  • Strong candidates are expected to demonstrate strong knowledge and enthusiasm for fish tracking and sampling methods
  • Candidates are expected to have some experience of fish sampling in the field, with prior experience of fish telemetry methods being desirable but not essential
  • Strong quantitative skills are also essential, including proficiency in R for data analysis.

Deadline for applications: 30 June 2026

Project details

Aim and objectives

The PhD aim to is to overcome the substantial knowledge gaps in the movement ecology and biology of sea lampreys and European eels in large lowland rivers where fish passes have been installed on weirs.

Objectives:

1. Measure the in-river movements of yellow eels across the lower Severn basin, including around weirs and fish passes, to understand their movement ecology and the extent of its individual variability;
2. Assess the emigration timings and escapement rates of silver eels from the River Severn and Teme, with an emphasis on tracking their downstream movements in relation to barriers and river flows;
3. Quantify the longitudinal distributions, trophic ecology and demographics of European eel and sea lamprey in the lower River Severn and Teme, including the effects of barriers and fish passes on these.

Academic impact

This research will substantially strengthen current knowledge of how migratory, non-salmonid fishes respond to river reconnection programmes, including both juvenile and adult lifestages. Novel data should be able to be generated across these species and different lifestages that enable their responses to reconnection to be measured. This includes data generated using acoustic telemetry at relatively broad spatial scales, measuring eel and adult lamprey movements through fish passes using PIT telemetry, and identification of spawning and nursery areas. These data will be highly publishable in relevant scientific journals as well as for presenting at relevant international symposia.

Societal impact

The regulation of rivers for flood prevention is a major societal issue, especially given changing precipitation patterns through climate change. Despite best-practice and policy guidance from regulators, pressure continues to build for greater regulation of flows through hard-engineering solutions. However, these are likely to have substantial ecological and conservation consequences, with potential for extirpations of migratory species of European importance due to habitat fragmentation. The opposite approach of allowing rivers to increasingly adopt natural flows and characteristics, with less severe land-use practises in the upper catchment and greater connectivity in the lower reaches, is seen as a viable alternative, with the additional benefit of enabling more sustainability in the populations of threatened migratory species.

This PhD is ideally placed to strongly inform this debate, highlighting the potential conservation and ecological benefits that can accrue from soft-engineering solutions, and so preventing further population declines in threatened species such as European shads. 

Postgraduate research development opportunities

The PhD provides substantial training opportunities including:

- Riverine sampling and telemetry: the research is strongly reliant on the application of telemetry methods to track eels and lampreys, using acoustic and passive integrated transponder (PIT) tags in tracking their movements through the river (acoustic telemetry) and through fish passes (PIT tags). Training on all aspects of tagging, including implantation, will be provided. Sampling methods for sea lamprey ammocoetes will also be developed in the PhD, with full training provided

- Research skills: training will be provided via formal and informal approaches on research skills including literature review, writing scientific publications and presentation skills

- The student will be supported in completing the Animal Procedures Modules 1-4 and so obtain their Home Office personal license for all tagging procedures on live fish

-There will also be opportunities for discussing research results and findings with regulators and policymakers, with significant networking opportunities for the successful candidate.