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  Developing management guidance for supporting a sustainable wrasse fishery in Scotland

   School of Biological Sciences

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  Dr Tara Marshall, Dr Iain Berrill, Dr Nabeil Salama  No more applications being accepted  Funded PhD Project (UK Students Only)

About the Project

Between 2015 – 2019, on average ca. 50t of wrasse have been caught in Scottish waters each year for use as cleaner fish in salmon aquaculture. The fishery is comprised of five species of wrasse (Ballan, Cuckoo, Goldsinny, Corkwing, Rockcook), each with their own life-histories. There is currently limited information about the status of each wrasse species in Scottish waters. Lack of basic knowledge about life histories, population structure and local abundances of wrasse complicates the development of fisheries management guidelines that would ensure the fishery operates within Maximum Sustainable Yield (MSY).

The sustainable management of wrasse is currently based on existing inshore fishing statutes as well as a suite of wrasse-specific voluntary measures established by the salmon farming sector and Scottish Salmon Producers Organisation. From the 2021 season onwards, these voluntary measures will become a statutory requirement for wrasse fishers. Wrasse fishers and salmon farmers have committed to collecting and supplying data on catch going forward. Because current datasets cover only a short-time span wrasse are an example of a data-limited stock. Nevertheless, sustainable fisheries management requires that alternative approaches to fisheries management must be developed.

This project will use the voluntary- and statutory-collected data alongside extensive species-specific knowledge generated through field and laboratory investigations of key life history traits. This information will then be used to develop life-history based approaches to fisheries management appropriate for wrasse including guidance on best practice for fishing activity. For example, the project may look at maturity of the species, fecundity, lifespan, spawning seasons, and spawning locations etc. Such information can be gathered through literature surveys, questionnaires, expert opinion, or through sampling and monitoring of fish from the fishery. This information can be used to determine appropriate fishing seasons, fish size limits and limits to fishing effort. The project will also consider options for assessing the status of wrasse using productivity-sensitivity analysis. This approach has previously been applied to stocks such as elasmobranchs (McCully et al 2013).

Project Aims

Aim 1 Review assessment methods applied to data limited stocks to identify suitable methods for considering wrasse species status in Scottish waters. Use catch data and relevant literature to establish key life history traits for each of the wrasse species.

Aim 2 Through a programme of field and laboratory sampling, enhance our understanding of the biological characteristics of wrasse and of operations relating to the wrasse fishery.

Aim 3 Produce an assessment of the status of data-limited wrasse populations and establish metrics and recommendations in support of sustainable fisheries management.

Candidate requirements

The ideal candidate will have a strong background in fisheries or marine biology, organismal biology, population dynamics as well as experience conducting independent research in the field or laboratory. Desirable skills include scientific writing, statistics, programming in R, fish dissection, field and boat work. Excellent communication and presentation skills will be an asset.

Skills development

The successful candidate will develop in areas of practical biological data collection from the field, and from conducting laboratory work (such as maturation and otolith age estimation). There will also be statistical analysis of data and the training budget will allow for specialised training in the use of fisheries data. It is anticipated that the candidate will engage with a wide range of stakeholders and develop a considerable network of contacts.


This project offers a unique opportunity to conduct research into a growing fishery working in collaboration with industry and government. The project is at the interface of ecology, fisheries science and policy. The results will enable high quality scientific publications and will be used to inform Marine Scotland, salmon producers and wrasse fishers.

Biological Sciences (4) Environmental Sciences (13)

Funding Notes

This is a fully funded project covering UK tuition fees, stipend and a research training and support grant. The project is funded by Scottish Salmon Education And Research Foundation (SSERF) and Marine Scotland.
Applicants are expected to have a minimum of 2.1 at honours level in a relevant subject.
To apply please click 'Institution Website' above which will direct you to our Application Portal:
-Apply for 'PhD in Applied Marine and Fisheries Ecology'
-State the name of the lead supervisor on your application
-State the name of the project


ICES 2012. ICES Implementation of Advice for Data-limited Stocks in 2012 in its 2012 Advice. ICES DLS Guidance Report 2012, ICES CM 2012/ACOM:68, 40 pp.
Marine Conservation Society, “Cleaner Fish Briefing Paper,” 2018. [Online]. Available:
McCully, S.R., F. Scott, J.R. Ellis, and G.M. Pilling. 2013. Productivity and susceptibility analysis: application and suitability for data poor assessment of elasmobranchs in northern European seas. Collected Volume of Scientific Papers (SCRS/2012/079). ICCAT. 69(4): 1679-1698.
Skiftesvik, A.B., Durif, C.M.F., Bjelland, R.M., and Browman, H.I. 2015. Distribution and habitat preferences of five species of wrasse (Family Labridae) in a Norwegian fjord. ICES J. Mar. Sci 72: 890–899.
The Scottish Government, “Analysis of responses to the consultation on Proposed New Mandatory Fishing Measures for Wild Wrasse Harvesting,” Edinburgh, 2020. [Online]. Available:

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