Revealed, the future of salmon farming

New ‘enclosed’ tanks to cut pollution and sea lice

SCOTTISH salmon could be contained in giant tanks in an innovative move to limit the pollution and spread of parasitic sea lice from fish farms.

Plans to use large containers to separate farmed fish from their wild counterparts – which have been in a catastrophic decline – are being billed as a way to make aquaculture more environmentally friendly in future.

Semi-enclosed vessels are more expensive than open-sided pens but are already in use in Norway and Canada. An application for planning permission for them to be used at a fish farm on Loch Long has now been submitted after a licence for their use was granted by the Scottish Environment Protection Agency (Sepa).

Farmed salmon contributes more than £640million to the Scottish economy, according to an industry report published last

November, and there are more than 200 working fish farms.

But in 2018 an inquiry by Holyrood’s rural economy committee made 65 recommendations for improvement as the status quo was ‘not acceptable’.

One of the main concerns raised was over the high numbers of farmed fish affected by sea lice and the potential for migrating wild salmon to be infected.

Pollution from the chemicals used to treat diseases in the fish was also an issue, and the seabed beneath the farms can also be damaged.

The proposed farm near Arrochar, Argyll, would reduce the waste reaching the seabed as about 85 per cent of it would be collected in the enclosure and pumped ashore for treatment.

The extra expense of running the farm, which would have five encloaquaculture sures, would be partially offset by a forecast drop in fish mortality.

Stewart Hawthorn, director of Loch Long Salmon, said: ‘This exemplary project provides an opportunity to show closer to home what is possible and to secure the future of the salmon farming industry in Scotland. It will reduce environmental impacts while continuing to support vital jobs and economies in rural Scotland.’

If the plans are approved, Loch Long Salmon hopes to begin construction later this year.

Conservation groups have welcomed the development, and hope it will be rolled out across the aquaculture industry. Dawn Purchase, programme manager for the Marine Conservation Society, said: ‘The use of semi-enclosed systems to farm salmon is a great example of the innovation needed to address environmental impacts and challenges of production, such as seabed pollution and sea lice management.

‘We are keen to see this type of farm becoming widely adopted to help deal with these persistent problems.’

Jo Green, acting chief executive at Sepa, which has been working with fish farm companies to reduce the impact on the marine environment, said: ‘We want Scotland to be a world-leading innovator of ways to minimise the environmental footprint of food production and supply, and for aquaculture operators to have a strong and positive relationship with neighbouring users of the environment and the communities in which they operate.’

‘It will address the impact of lice’