Tales of the riverbank: the Wild Fisheries Fund

Preserving salmon habitats

Last year eight projects were funded, including the West Coast Gene Bank, a partnership between Otter Ferry Seafish and the River Ruel Improvement Association, which helps restore Atlantic salmon populations in the River Ruel by growing young salmon into adults in a hatchery.

 

The River Ruel in Argyll is one of the major rivers on the Cowal Peninsula, flowing into Loch Ruel north of the Kyles of Bute. The typical spate-fed river is an important catchment for Atlantic salmon and sea-run brown trout, with a 12km length of fishable water, and a heritage of angling for the local community and visitors.

 

Surveys of fish populations and fish habitat identified that large amounts of fine sediments reduce the ability of the river to produce optimal number of smolts, which is a consequence of the amount of soil being eroded from riverbanks. To restore the river habitat and improve the recruitment of young fish, a programme of habitat improvement works has been undertaken since 2018.

 

The scheme to tackle erosion on the Ruel, improving the habitat through tree planting and fencing, received a further £10,000 in 2024, marking a third year of funding.

 

Alan Kettle-White, Director of Operations at Argyll Fisheries Trust, says: “Part of this project we’re doing with Salmon Scotland is to reduce the amount of fine sediment being eroded from river banks and clogging up the spawning beds and the juvenile nursery habitat.

 

“We’ve done this over three years now, in terms of bringing in a technique called green bank revetment, and that consists of consolidating eroded banks with a process with untreated hardwood posts using unsold Christmas trees, and relaxing the bank angle, which reduces erosion.

 

“We’ll be back to fence this area off from cattle and also plant some trees. So over the period of three or four years, we should see this habitat come back to life.”

 

On top of this, another initiative on the Ruel received £49,404 from the fund in 2024, this time to start a live wild salmon gene bank at Otter Ferry Seafish nearby in Cowal, with a trial using fish from the river. Organisers hope the project will not only help stock several regional rivers but also become a “blueprint”, paving the way for a wider “genetic insurance” network of banks across the country.

 

The fund’s website explains: “The River Ruel Improvement Association is working with Otter Ferry Seafish Ltd to develop a live gene bank for Atlantic salmon that can be used to improve the health of the salmon population and evaluate the effectiveness of conservation aquaculture in support of pressured population of salmon.”

 

Otter Ferry Seafish, the oldest independent fish farming company in Scotland, operates the UK’s only halibut hatchery and runs trials for the salmon farming sector.

 

By setting up a live salmon gene bank, the project seeks to preserve the genetic material of threatened wild populations, ensuring their survival and adaptability. Using advanced genetic screening, the team will assess the diversity of salmon in the River Ruel and determine the need for egg stocking from the gene bank. The goal is to help restock several regional rivers and set a model for other areas to follow.

 

Alastair Barge, Managing Director of Otter Ferry Seafish, explained in a video posted on the website last year: “The project has moved forward quite swiftly, and is looking quite good. The project started with the fishery biologist electrofishing the river.

 

“We went and joined in that process, which was fascinating.

 

“We managed to catch 150 S2 parr and we put them in our specialist unit, into three tanks. The first challenge was: would the fish settle coming from the river? We took them from the Ruel River, which is only separated by the top of a hill, so our water supply here was quite similar. The fish transferred very well.

 

“We gave them more cover in a tank than we would normally as an aquacultural system. The fish settled in well. We fed them on mealworms, which was new to us. As aquaculture, we would be thinking of straight onto pellet. We’ll wean them off that onto a dry formulated pellet.”

 

Each individual fish will be tagged and genotyped. “Then we’ll be able to monitor the performance of each fish, and we’ll know the parentage of each fish,” Barge says. “So there’s fascinating times ahead, generating data of the wild population now compared to a farm population now.”

 

Currently they are awaiting the results of the genetic testing, says Andrew Barker of the River Ruel Improvement Association.

 

He explains: “When received, we will know inter alia the sex of the parr, and also whether the fish have any farmed fish genes, both of which are factors very much affecting the whole project.”

 

Next the fish will be transferred to saltwater, Barker adds: “We’ll smolt them in April 2025, and we would hope by December 2027, we would have mature fish. We would be taking them right through to maturity. So that would be really the end of the project: producing the eggs from the wild fish, and enhancing the survival.

 

“The 150 fish that we took out of the river, if we’d left them to go to sea and come back to return to the River Ruel, you might have had one of those fish coming back. We’re hoping we might get 50 female fish out of this population, so, calculations, you get an awful lot of eggs compared to that one fish coming back. We’ve got 50 mature females coming back, and genetically that will be interesting to look at.

 

“But the first stage looks very encouraging. We thought that was the difficult bit, going to get the fish from the river and let them settle into a farm situation, but they appear to be doing that very well. And we will see what happens in the next two years. It will be fascinating. 

 

“The River Ruel is a typical west of Scotland river, and this can be replicated for many rivers. 

 

“I’ve lived here long enough to see the demise of wild salmon in the rivers, and it started before we started fish farming. The demise was in place. It hasn’t improved, it’s continued to go down. And there are many causes for that. But if we can start with the rivers, improving the habitats and then helping to enhance the stock, I would be very keen to see some benefit in my lifetime.”