THE successful use of cleaner fish will underpin the development of the salmon farming industry, a summit in Scotland was told yesterday.
At the opening of the three-day event in Glasgow, delegates were given updates from an international line-up of speakers on how wrasse and lumpfish are helping to tackle naturally occurring sea lice at fish farms.
Chris Hempleman of Scottish Sea Farms (SFF) said cleaner fish will ‘change the game’ for salmon aquaculture but the challenge was to have significant numbers, something he believes is ‘in our hands’.
SFF has been involved in a venture with Marine Harvest, the University of Stirling, Otter Ferry and Ardtoe since 2011 to farm wrasse, and relieve the pressure on wild stocks.
However, it had been a ‘steep learning curve’ and although his company now has some sites stocked only with farmed wrasse, wild caught fish are still widely used.
Meanwhile, Olav Breck of Marine Harvest Norway, said his country needs 40 million cleaner fish each year.
Of the 16,4 million wrasse and lumpfish used in 2015, 57 per cent were farmed, but Marine Harvest aims to be self-sufficient and independent of wild caught cleaner fish in 2018, preferably with a fifty-fifty balance of lumpfish and wrasse.
The International Cleaner Fish Summit, co-hosted by the Scottish Aquaculture Innovation Centre (SAIC) and the Norwegian Seafood Research Fund (FHF), is bringing together scientists, producers, feed companies and suppliers from Norway, the UK, Iceland, the Faroe Islands, Ireland and Canada, to improve understanding of the main cleaner fish species.
Heather Jones, CEO of SAIC said: ‘Greater sea lice control has been one of our priorities since day one, as has sharing the insights gleaned from SAIC supported projects with the wider Scottish aquaculture sector.
‘So to see our industry and academic partners exchange the knowledge being gained with their industry and international peers is a truly landmark moment.’
Themes covered at the summit so far include transportation, deployment, conditioning, cohabitation and nutrition. In the final session tomorrow, health experts will explore disease control, new vaccines and treatments and welfare.
The talks will also cover cleaner fish sustainability, standards, sedation and dispatch.
There was much discussion in the first two days of the summit – being held at the University of Strathclyde’s Technology and Innovation Centre – over how to address the challenges of rearing and deploying cleaner fish so that there are sufficient quantities of this biological sea lice control to meet growing industry demand.
Farming cleaner fish species in pens designed for salmon presented many problems, and not enough is known about their nutritional requirements or their behaviour.
Sandra Schlittenhardt, a vet with Marine Harvest Ireland, said there are no licensed vaccines for cleaner fish in Ireland so the fish are all completely unprotected.
Furthermore, because they produce organic salmon in Ireland, cleaner fish have to be treated separately with antibiotics, which involves removing them from the pens.
Also, lumpfish can’t handle the very strong currents prevalent on Ireland’s west coast, and wrasse are prone to injury and have a tendency to disappear from pens.
‘Cleaner fish are hard work,’ she said, ‘but they are absolutely worth it.’
Adam Brooker of the University of Stirling, explaining recent research on wrasse, pointed out some of the differences between wild and farmed stocks, with the former being good at delousing and the latter being more variable.
‘Wild wrasse are the gold standard. Their behaviour is what we want to achieve with farmed wrasse,’ he said, adding that future projects might look at the performance of wild and farmed fish cohabiting, in a kind of ‘wrasse training school’.
A full report of the International Cleaner Fish Summit will appear in the June issue of Fish Farmer.