PhD Blue mussel conservation and restoration in a multi-stressor world

This project is part of the NERC-funded Centre for Doctoral Training, ECOWILD.

For more details, and for a full list of projects offered under this programme, please visit: https://ecowild.site.hw.ac.uk/

Project Description

This project aims to fill knowledge gaps around the factors which have led to the decline of blue mussels in the NE Atlantic area and more specifically in Scotland and the UK. The role of simultaneous multiple stressors will be assessed from historical data and tested by using in situ (field) and laboratory analyses of wild and reseeded mussels. This addresses questions around the persistence, resilience and dynamism of natural mussel populations and habitats (sedimentary beds versus rocky shores), as well as informing best practice for prediction of optimal locations for restoration efforts, which are increasingly being undertaken to enhance ecosystem services (water filtration, prey provision), biodiversity and human food security.

The student would be involved in mussel surveys (including coordination with community group partners), mapping, historical data collation and analysis, mussel health evaluation (e.g. bacteria; parasites), tissue analyses and exposure to selected multistressors. Ground-truthing of field sites would also be done in order to predict conditions for use in the lab and also to select sites best suited to restoration efforts. GIS will be use to map locations where this work will take place and to evaluate proposed approaches.

The student would be part of a wide group of wetland and marine students at Heriot-Watt (across the Institute of Life & Earth Sciences and The Lyell Centre) and UHI (SAMS). Opportunities for academic career development such as demonstrating to undergraduate and postgraduate classes and attendance at meetings and conferences would be strongly encouraged.

What do you need to know

Blue mussels are declining globally despite previously being ubiquitous and abundant in marine shore habitats. Reasons for decline are likely multi-factorial, hence the focus here on multi-stressors, including physical disturbance, harvesting, predation, disease, contaminants and climate change. Populations in close proximity can vary in health, but larval production often remains good, enabling juvenile collection and planting out in threatened areas. This will allow testing of reasons for observed impacts and effective restoration. The supervisory team draws together key skills giving a new perspective on this topic, combining unique expertise in mussel distribution patterns, population trends and community engagement (HWU; SAMS UHI), population survey, conservation and restoration licencing (NS), stressor impact measurement (HWU), analytical chemical analysis (HWU Lyell) and in-vivo toxicity testing (Astra-Zeneca).

What expertise and skills will the student develop?

Work involved will include testing of different approaches for spat capture and redeployment, analysis of source and receiving environmental variables (chemicals, physical variables, habitat features), analysis of body condition and disease status and coordination with community groups in relation to surveying, collection and redeployment of mussels. Skills to be developed will include mussel collection and husbandry, field measurements of biotic and abiotic stressors, chemical analytical techniques, statistical analyses, GIS mapping, networking and communication with agency and stakeholder groups.

Why is the project novel?

There is much data on individual contaminant levels in blue mussels, this species having been a standard biomonitoring species for several decades. Paradoxically, this information hasn’t been applied to mussel population health assessment. This project will use existing information to provide baselines for focussed studies on relevant stressor combinations. Other novel aspects include using historical archive and community records to identify mussel restoration areas, coordination of community groups to oversee survey and restoration and integration new restoration techniques with time-series health monitoring and chemical status of reseeded mussels. The combination of expertise in mussel population assessment, distribution mapping (HWU, SAMS), community survey coordination and engagement (HWU, NS), ecotoxicology (HWU, SAMS, Astra-Zeneca) and restoration (HWU, NS) provides a unique blend of relevant experience.

What real-life challenge does it address?

Blue mussels have shown a dramatic recent decline in abundance across their range for which reasons are unknown. Mussels provide key ecological roles as water filters and sediment depositors, linking the water column with the seabed. They are also a key prey species for crustaceans and birds and provide a food source for humans. Understanding reasons for changes in mussel abundance and distribution is essential to design and develop successful restoration efforts, so as to optimise conservation efforts and to inform assessment of increased risks to ecosystem function and human food security.

Timelines

The closing date for applications is 17:00 BST Friday 9 January 2026, and applicants must be available to start in October 2026.