Scaling up production and implementation of farmed cleaner-fish in the Scottish salmon industry15th May 2015

Scaling up production and implementation of farmed cleaner-fish in the Scottish salmon industryPhoto: Institute of Aquaculture

SAIC has kicked off an applied research project, worth almost £4 million, to upscale the use of farmed wrasse in commercial salmon farms in Scotland. The partners in the 42-month project are: Marine Harvest (Scotland), Scottish Sea Farms, BioMar, and the Institute of Aquaculture, University of Stirling.

Launched in May 2015, the project won the prestigious Innovative Collaboration Award at the Scottish Enterprise Life Science Awards 2016.

The context

Atlantic salmon is the UK’s largest food export, with an export value of over £500 million in 2014. The Scottish Government has set increased production targets for 2020. Progress on the use of cleaner-fish to control sea lice on fish farms will support the industry’s work to reach these targets.

Cohabitation of salmon with cleaner-fish, such as wrasse and lumpfish, has been shown to significantly reduce the sea lice challenge to salmon – an issue that has hampered growth in the industry. It can also help to reduce the usage of licensed anti-lice medicines on farms.

Sea lice are a naturally-occurring parasite that attach onto salmon, both wild and farmed. The fish farming industry uses a variety of measures to control them, called integrated sea lice management, a suite of practical management strategies including licensed medicines and husbandry techniques.

The use of cleaner-fish is a powerful ‘biological’ addition to integrated sea lice management since these fish will remove ectoparasites, such as sea lice, from other fish. Wrasse – in particular ballan wrasse – are currently the most popular choice as cleaner-fish in the salmon industry, although research is also being carried out using lumpfish.

The previous use of wrasse in fish farms has largely involved the collection of wild wrasse, a solution which is not sustainable. However, knowledge of the biology and life cycle of the wrasse is limited; the culture of wrasse is in its infancy in the UK, and production challenges have restricted the deployment of farmed wrasse.

The project

This collaboration between Marine Harvest (Scotland), Scottish Sea Farms, BioMar and the Institute of Aquaculture, at the University of Stirling, brings together major salmon producers and academics leading wrasse research in the UK to solve the bottlenecks limiting productivity, and to improve the quality and delousing efficacy of farmed wrasse.

The Scottish Aquaculture Innovation Centre (SAIC) has awarded grant funding of £831,530 to the project. This has leveraged contributions worth £3.01 million from the industry and academic partners.

The 42-month project will be based at the Marine Environmental Research Laboratory at Machrihanish on the Kintyre peninsula, on Scotland’s west coast, and will focus on the production, husbandry and deployment of farmed wrasse.

Given the importance of the project to the UK salmon industry, the project will operate under the principle of open knowledge exchange.

Work has been organised around four work packages, each with a set of specific R&D objectives:
1.     Broodstock management, egg and larvae productivity. A series of studies to investigate the reproductive physiology, behaviour and performance of ballan wrasse broodstock, aimed at developing new commercial protocols to enhance egg productivity and quality.
2.     Larvae/juvenile nutritional requirement and growth potential. This work package will aim to refine hatchery protocols for live feed management, weaning and on-growing to maximise the robustness of fish produced and growth performance.
3.     Health management of cleaner-fish. This will include the development of tools to monitor immune response in ballan wrasse and improve disease resistance.
4.     Conditioning and optimisation of cleaner-fish welfare in commercial cages. This will include building understanding of optimal timing of deployment and stock ratios, and the validation of practical on-farm health and welfare indicators.

The impact

Building on proof of concept established in previous research, the SAIC project will extend current knowledge through to upscaling of hatchery technologies; optimisation of cleaner-fish welfare in salmon cages; and prototyping in the commercial environment.

Project outcomes will include commercial protocols, research tools and a new knowledge of the biology of the ballan wrasse. This will permit production of a handbook that individual farmers in Scotland – including SMEs – can use as a beginning-to-end guide on the breeding and husbandry of farmed wrasse.

Those outcomes have the potential to increase productivity on salmon farms and reduce the use of medicines in the industry.

The deployment of farmed wrasse to control sea lice on farms could also lead to the creation of new jobs in rural communities, not just in salmon production, but in wrasse production and management.

Steve Bracken, Business Support Manager at Marine Harvest (Scotland) Ltd:

“The deployment of wrasse as a means to control sea lice should increase the availability of farm sites, reduce medication costs and increase production efficiency. All parts of the industry – from large companies such as ourselves, to SMEs – will see benefits from this, and the already-excellent reputation of Scottish salmon will be enhanced.”

Professor Hervé Migaud, Professor in Fish Physiology and Director of Research at Institute of Aquaculture, University of Stirling:

“The Scottish Aquaculture Innovation Centre’s support and funding will enable us to extend this project from proof of concept to the commercial environment. The impact of the research will be considerable in both scientific and economic terms. In addition, PhD and Masters students at the Institute of Aquaculture have the opportunity to gain research expertise in one of the aquaculture industry’s most pressing issues.”


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