Loch Duart
Cleaner fish
WHEN the cleaner fish team at Loch Duart discovered what ballan wrasse could do for their sea lice problem, it was a ‘eureka’ moment, said operations director Mark Warrington. That was five years ago and the company, like most salmon producers at the time, was struggling to keep sea lice numbers down.
Regular treating was having little effect and when they heard the results other farmers were achieving from wrasse, they decided to run their own trials, setting up a few local fishermen with equipment.
‘We were aware that wrasse had a history in aquaculture but had only used them on a very small scale as there had been problems with sourcing them and rumours of aggression to salmon,’ said Warrington, who has worked in the industry since the mid-80s.
‘We knew Wester Ross was doing very well and we were invited to speak with them to learn the basics and then we started to apply that on our own farms.’
In January 2015, after months of trials with all wrasse species, cleaner fish manager Lewis Bennett re-captured 200 ballan wrasse from a mix of pens on the site and focused them all into a single pen of about 12,000 salmon on the site at Badcall Bay.
Within two weeks the lice loading had halved and within four weeks the pen had a count of 0.0 adult females and all other lice stages.
‘That was the turning point for us; we said, okay these things work, this is the way forward,’ said Warrington.
Sourcing the best quality and the volumes of wild wrasse they needed was the next big challenge. They set up a number of fishermen in the Sutherland area initially, but that wasn’t getting the numbers they needed , nor would it ever be sustainable.
‘We had to spread the supply out and reduce pressure on all fishing grounds,’ said Bennett..
Then Warrington had what he calls ‘a bit of a brainwave’. One of Loch Duart’s employees, Ben Jennings, had worked at the lobster hatchery in Padstow in the south-west of England and he knew many fishermen in the area.
He and Warrington headed south and, going round the ports, were soon astounded by the number of wrasse the fishermen said they caught down there.
‘They were catching them as an unrecorded bycatch. They were so plentiful the guys were using them as creel bait,’ said Warrington.
‘You were looking at all these bait tubs in all these ports in the south-west of England, ballan wrasse of a kilogram or more, chopped up into bits to be used as bait, it was soul destroying!’
But the fishermen were making a good enough living from crabs and lobsters and were not that interested in working a new fishery with different equipment.
‘We wanted to do it properly, on a smaller scale, and we wanted to work with fishermen who were going to give us absolutely the best quality wrasse we could get,’ said Warrington.
By luck, they met a couple of fishermen at a fish factory in Falmouth who knew Jennings. Cameron and Ivor Hendry are ‘switched on, innovative’ fishermen who worked closely with the inshore fisheries bodies and could see the need to preserve the fishery for future generations.
Their father was from Shetland, and while in the merchant navy got stranded in a storm in the south-west, met a local girl. and settled in Cornwall.
Warrington, who worked for many years in Shetland, said they hit it off straight away. The following months were spent working with the family, weighting creels, trialling various fishing grounds, improving fish holding practices, putting transport in place and focusing on how to fish properly in the south-west for this new species.
Bennett, who joined Loch Duart in 2014 after graduating with a degree in aquaculture from the University of Greenwich, said the fishermen were an integral part of the team and without them it wouldn’t have been possible to achieve such results.
‘We have developed excellent working relationships with all of our fisherman, in many ways treating them as staff rather than just as suppliers. We provided training, equipment and transparency,
so they knew our best practices, goals and strategy.
‘We’ve flown fishermen up to the north-west of Sutherland, so they can see what we’re doing, what salmon farming is about, the scale and what it takes to achieve the results at sea.’
Warrington said they wanted to apply the same principles to the fishing in Scotland and standardise the fishing practices and concrete a new income for small fishing operations.
Last year, about 20,000 wrasse were supplied to the company from Scotland and 10,000 from the south coast. These numbers were down 50 per cent from English sources and 35 per cent from Scottish sources.
‘The projections for 2019 are that we will be purchasing considerably less in 2019 as a result of fantastic lice control and continuous improvements in survival and best practice,’ said Bennett.
The focus is always on quality. Loch Duart pays higher than any other farmers for its ballan wrasse which, Bennett admitted, has caused some controversy, but they have no plans to change their strategy.
‘It allows us to be very particular about the stock we purchase, so we’re actually making sure the quality is the best it can be.
‘It keeps the fishermen very happy, as they know that the few fish that they are catching are bringing in a good value per fish and making the price reflect the efforts.
‘The price also makes up for the catch and release of all other species, targeting one species, reducing our annual requirements of wild wrasse and our own historical expenses on sea lice control.
‘Our colleagues at all levels thought we were mad, clearly, but the results easily justified the outlay and strategy.’
Loch Duart also transports its fish differently, to meet the needs of the wrasse and not to cut costs, said Bennett.
The company uses Frontfish UK, based in Devon. Managing director Neil Fuzzard and his team have more than 20 years’ experience transporting a wide range of marine and freshwater species in the UK and Europe.
‘They have shown a great way of meeting our needs and share our ethical views on meeting the highest fish welfare standards,’ said Bennett.
‘We move the captured wrasse more regularly, with fewer than five days in holding – it does cost more in transport but the quality you get from moving
“I’m confident that what we’ve done with the wrasse here we could do with any big company”
them more regularly suits us, the fishermen and, ultimately, the wrasse.
‘They use more focused life support systems, which meet the health requirements of the wrasse in transport, and the quality of the wrasse is vastly improved.’
Farming with wrasse
The need to look after the demands of salmon and wrasse together require a mixture of scientific and practical expertise, said Warrington.
He and Bennet have managed a quick roll out of the cleaner fish programme to all the sites, taking less than two years to achieve results, with ‘vast reductions’ in use of medicinal treatments.
‘This has been easy, given our company size, the ease of communication and our site teams quickly seeing results in our farms, one after the other.
‘They know the alternatives, and the work involved, and quickly decided it was easier to go down the cleaner fish route.
‘From having to go out every three or four weeks to not having to treat fish for whole cycles allows us to concentrate on growing even better fish.’
Bennett said when they began using wrasse back in 2014 and 2015, they were using stocking densities of five to six per cent of all wrasse species. This had varied results and now they are achieving more effective control with as little as 0.4 to 2.0 per cent.
‘Our requirements for wild wrasse have decreased by over 60 per cent annually since we upscaled in 2015- a combination of using ballan wrasse only, our price per fish premium, , improved nutrition, better survival rates at sea and improvements in efficiency,’ said Bennett.
Loch Duart uses wrasse up to 28cm, stipulated by regulations set and mixes the sizes within the pens, which helps reduce aggression as the ballan wrasse are a territorial creature.
Welfare is key, and a happy and healthy wrasse will exhibit the behaviour of a natural grazing species, ‘which is what we need’, said Bennett
‘They are opportunistic feeders, their requirements change with the seasons and therefore we need to adapt our management to meet these seasonal differences,’ said Bennett.
In the summer, ballan wrasse exhibit more of a predatory behaviour, during the day spending much of the time roaming around the pen. During the night they reside in the habitats provided.
Nutrition has been a chief focus, adapted to find new feed options to meet the varied diets of the species.
‘We have used live diets in the past, which include crushed molluscs and green crab, but this has its limitations for the ballan wrasse, as our varied sizes of fish present some fish with limited nutrition,’ said Bennett.
‘A 10-15cm wrasse could, in theory, could survive on net growth and small invertebrates, whereas a larger ballan wrasse over 15cm will require more substance on a regular basis to maintain optimal condition.
‘In 2018, we exclusively used the BioMar symbio block diet, and the wrasse took to this very well. Later in the year, we made the change to a new diet developed by Vita Aqua Feeds; this is a grazing block made under cold extrusion, which preserves the nutritional value of the ingredients and comes a range of different sizes and forms.
‘The diet is better suited operationally. It’s delivered in recyclable buckets, reduces labour and doesn’t need chilling due to its shelf life of two years.’
Bennett said that since trialling the diet, they have recorded an increase in survival rates, a reduction in feed costs and good responses from all the site teams. Survival rates are about 60plus per cent - because the focus is on smaller numbers and re-using these valuable fish, with health checks carried out prior to re-use.
‘We don’t believe the results achieved are specific to the scale we farm,’ said Bennett. ‘All
“We wanted to work with fishermen who were going to give us the best quality we get” could
our sites vary and include locations in Uist that They looked at the mechanical delicers, and did a lot of research on the although produce smaller tonnage, still replicate effects of crowding on the fish. One finding was that a high percentage of larger industrial producers in terms of tidal flow adult lice and eggs are released from salmon during crowding. and location. ‘We were a bit wary of many of those mechanical methods. We didn’t
‘We know we can get this to work anywhere want to go down that route. when you get the buy-in from site managers and ‘I’m a strong believer in as little intervention in the fish as possible once staff, and they realise how effective it is.’ they’re in the sea, I think that’s the key thing,’ said Warrington.
Warrington said: ‘There is a very specific way to ‘The industry’s problem comes back to the scale at which they operate use cleaner fish. Due to the scale we farm and the and being able to keep on top of the problem. scale of the wrasse project here, I’m confident that ‘ We’ve been really lucky because we’re a small management team, we’ve what we’ve done can be done the same at any big proven on a small scale on a few pens that wrasse would work well for us, company, any size of pen and any location.’ and then it was just a case of scaling that up.’
Both he and Bennett stressed the importance Warrington described the implementation of Loch Duart’s wrasse strateof sticking to their strategy, putting faith in the gy as ‘a career highlight’ for him. wrasse, and being patient. ‘From a business struggling under the pressure from sea lice to what the
‘We had to change the thinking of the old days team have achieved today is nothing short of miraculous in fish farming.’ where we kneejerk react and we want to treat,’ Bennett agreed. Although it had been difficult ‘trying to turn around a said Warrington. position of sheer terror in the summer months to one of a relaxed non
‘In the past, we would have intervened regularpanic’, belief in the strategy has paid off. ly- with bath treatments and so on- treating fish ‘Fish farming always throws up its challenges, and there is rarely a silver every three or four weeks, the same as the rest bullet solution. But for the time being, cleaner fish has given a level of of the industry.’ control which has been hugely significant for Loch Duart.’