As the roll-out of Covid-busting inoculations for people around the world continues at pace, a team of Scottish researchers are about to embark on a project aimed at delivering better vaccines to prevent a deadly disease in fish.
It is hoped their work will lead to healthier ballan wrasse, whose ability to munch on the sea lice parasites of Scotland’s top food export – farmed salmon – is highly sensitive to environmental and other factors.
The researchers will look at how to optimise both the formulation of vaccines and the methods used to deliver them, as part of efforts to protect the wrasse from disease.
Led by Stirling University’s Institute of Aquaculture (IoA) and salmon producer Mowi, with support from Otter Ferry Seafish, Ceva Ridgeway Biologicals and the Sustainable Aquaculture Innovation Centre (SAIC), the research team will explore the range of factors that determine the best possible conditions for delivering vaccinations against Aeromonas salmonicida – a bacterium which can cause potentially fatal outbreaks of disease in cleaner fish.
A core aim of the project is to determine the most effective composition of antigens to produce the best immune response in juvenile fish.
Ballan wrasse are currently vaccinated against multiple health conditions at the hatchery stage.
IoA’s Sean Monaghan said: “Enhancing vaccines for Aeromonas salmonicida could represent a significant step forward in the use of ballan wrasse in aquaculture.
‘Prevention better than cure’
“We know prevention is better than cure and we are, therefore, working towards the development of more effective vaccine formulations and protocols that can be used by hatcheries and producers to improve fish welfare.
“By testing a range of conditions and variables, we are also aiming to identify the optimal process for delivering vaccinations, which can then be implemented across the sector to enhance disease prevention among ballan wrasse populations.”
The project could have a positive impact on the health and welfare of the large numbers of ballan wrasse produced for use across the Scottish aquaculture sector, with improvements in their ability to treat sea lice also improving the wellbeing and growth of large stocks of Atlantic salmon on fish farms.”
SAIC chief executive Heather Jones said: “Ballan wrasse are a core element of our sector-wide efforts to sustainably tackle the challenge of sea lice and vaccinating them against disease is essential for long-term success.
Knowledge-sharing and innovation
“This latest project adds to the range of valuable collaboration projects exploring best practice for cleaner fish, which is a growing focus for both fish farmers and academic partners. Through knowledge-sharing and innovation, we hope to ultimately support the increased use of more sustainable sea lice treatments that will benefit the entire sector.”
Mowi Scotland technical director Dougie Hunter said: “Ballan wrasse, alongside lumpfish, are excellent cleaner fish and a natural solution to effectively manage sea lice on our salmon.
‘We must protect them against stress and disease’
“To give these fish the best environment and welfare we must protect them again stress and disease, including infection caused by Aeromonas salmonicida, which can be observed in wrasse from an early stage.
“Mowi’s collaboration with Scotland’s leading fish health and vaccine experts and SAIC will be vital in finding the best vaccination strategies to enhance wrasse health protection.”
Sea lice are a major scourge of salmon farms globally, costing the industry many millions of pounds in lost output and expensive treatments.