Scottish salmon farmer pumps more funds into gill health research

Stirling-headquartered Scottish Sea Farms said that it plans to lead a second applied research project focused on increasing understanding of gill health in farmed salmon, as part of its “prevention over cure” approach to fish welfare.

Photo courtesy of Scottish Sea Farms

The GBP 601,000 (USD 724,329, EUR 660,241) project – of which Scottish Sea Farms will fund 62 percent – will be the salmon farmer’s second such collaboration with academics at the University of Aberdeen, feed specialist BioMar. and the Scottish Aquaculture Innovation Centre (SAIC). 

Combined, the two projects bring the company’s investment in applied research into gill health to almost GBP 750,000 (USD 903,918, EUR 823,967) since 2018.

In the last five years, it has spent GBP 10 million (USD 12.1 million, EUR 11 million) on fish health research.

“The gills are hugely important to the overall health and wellbeing of Atlantic salmon, yet the factors affecting these vital organs are as highly complex as they are little understood. This second gill health project seeks to explore further the early insights gleaned in our initial collaboration, helping increase knowledge of the key risks and how to pre-empt and avoid them,” said Dr. Ralph Bickerdike, head of fish health at Scottish Sea Farms.

The project team will focus efforts on two key outcomes:

• Exploring the effect of geography and seasonal influences on gill health, in order that additional preventative and continuous measures can be identified and deployed

• Testing the accuracy of a range of new biomarkers; a suite of veterinary tests which help indicate the health status of fish and will enable more informed decisions. 

Its findings will be shared with the broader industry.

“Gill health has become one of the biggest challenges facing salmon production – not only in Scotland, but in Norway and internationally. SAIC is supporting a range of projects across Scotland, drawing on the expertise in our academic institutions and industry to understand the issue and develop innovative solutions. The new knowledge gained will be shared across the sector, helping salmon farmers to maintain healthy populations of farmed fish,” said Caroline Griffin, SAIC aquaculture innovation manager for the gill health project.

Scottish Sea Farms’ Lismore North farm in Loch Linnhe experienced unusually high mortalities of 22 percent during the last crop as a direct result of complex gill health disorder.

“When seawater temperature rises, even by something as seemingly slight as 0.5 degrees, more marine organisms grow. In the summer of 2018 – the joint hottest summer on record for the U.K. – we experienced a phytoplankton bloom in the Loch Linnhe area which resulted in a challenge to gill health. Increasing our understanding of what more we can do to pre-empt and prevent these kinds of challenges is a priority,” said Bickerdike.

The same site also experienced 15 percent mortalities earlier in the same crop due to saprolegnia – a health challenge which arises at the freshwater stage. This contributed to an overall survival rate of just 59 percent for the total crop, compared to survival rates in excess of 90 percent for the previous three crops.

Bickerdike said that the average end of crop survival is now “a strong” 87.2 percent across the company’s farming estate.

“The challenges experienced at Lismore North, whilst isolated, are precisely the reason why we continue to invest and build our knowledge in order to fully deliver our ‘prevention over cure’ approach to fish welfare and boost survival rates even further,” he said.