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, such as in European shads Alosa spp.
The River Severn and Teme is the population stronghold of European shads in western Britain, especially for Twaite shad Alosa fallax but potentially also for Allis shad Alosa alosa. Up to 2021, the lower basin was highly impounded but has now been reconnected through fish passes and weir modifications. However, understanding how reconnection has benefitted the shad populations requires further work to understand the behaviour of spawning adults in and around weirs fitted with passes, the influence of reconnection on spawning distributions and the implication of these on egg, larval and juvenile ecology.
The PhD builds on work completed on the river and shad population since 2017, with access to historical adult movement data (pre/ post reconnection) as well as the opportunity to collect novel data within the research period using a range of methods, including acoustic telemetry.
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 work
- 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
Aim and objectives
The PhD aim to is to overcome the substantial knowledge gaps in the autecology of Alosa spp. in the River Severn, especially the relationship between adult spawning migrations and the ecology and distribution of their progeny.
Objectives:
1. Measure the in-river movements of adult shad around weirs and fish passes to understand their behaviours around these structures, including the extent of pass attraction and passage;
2. Assess the temporal and spatial upstream extents of Alosa spp. in the river in relation to reconnection and spawning hotspots
3. Apply novel telemetry methods (e.g. predation tags) to assess in-river mortality of adult spawners
4. Assess the spawning distribution, egg deposition, larval drift and juvenile Alosa spp. distribution in the river, including assessment of timing and the drift dynamics.
