Unprecedented opposition is being claimed against plans for a new fish farm in the Sound of Jura, as the wider industry faces a threatened crisis over the chronic problem of sea lice infestation.

The weight of Scottish farmed salmon fell in the final three months of last year by 4 per cent compared to the previous year, because sea lice. This meant them being harvesting younger. Industry giant Marine Harvest estimate that it could have lost 1,500 tonnes out of 40,000 tonnes of annual production last year because of the parasite.

But the planned Sound of Jura development at Dounie, just south of Crinan on the mainland, would grow rainbow trout.

A dozen 100m circular cages are proposed by Kames Fish Farming Ltd (KFF), whose HQ is in Kilmelford south of Oban, and says it would create much needed jobs.

However local SNP MSP Mike Russell, normally supportive of fish farming, has written to the Cabinet Secretary for Rural Economy and Connectivity Fergus Ewing saying:

"I have never experienced the weight of objections to a fish farm proposal that I have seen in this proposal." It would require "very special and very careful consideration."

The fish farm would be in a Marine Protected Area (MPA) specifically designated to conserve common skate in local waters. Sea lice, chemicals and escaping fish are seen as threats to the species as well as to wild salmon and trout from a local river. There is also the issue of increasing visual impact, with a number of fish farms already in the wider area which is famed for its beauty.

The Friends of the Sound of Jura has been formed. One supporter Jane Smith explained: "Our group is a platform for local

people and visitors to collectively voice concern over a proposed fish farm sited in an entirely inappropriate place. Dounie is in the heart of the Knapdale National Scenic Area with Scotland?s highest form of landscape protection."

Winter swimming enthusiasts from the Mid-Argyll Wild Swimmers recently swam at the fish farm site.

One of the club's 50 members Iona Barr said: "I have been swimming in the Sound of Jura all my life. It is quite simply the most beautiful place in the world. I am horrified that Dounie could become the site of an industrial and intensive fish farm. No one would want to swim

anywhere near here with all the fish sewage and chemicals polluting our clean water."

Stuart Cannon, KFF managing director, said the plan was still a long way off being approved. It had to be considered by he Scottish Environment Protection Agency (SEPA), Scottish Natural Heritage, Marine Scotland and the planners. "This is just the SEPA application. It is very early days. We have a small Scottish family business which we would like to expand. It would create four permanent jobs and probably two part-time, maybe more, and would help us support the 25 we already employ."

Experts at the Scottish Association of Marine Science (SAMS) were being employed to assess the environmental risks, he said.

"We want to do this responsibly. We have been in production for 45 years, and are not going to suddenly pollute the whole of the Sound of Jura. Sea lice are not nearly the same problem for rainbow trout as salmon."

The sea lice issue is not new to fish farming, but has deepened as the parasites become resistant to the chemicals used against them. Production has reduced. However this combined with a global rise in demand, pushed the price of Scottish salmon up by 81 per cent.

Marine Harvest doubled its profits despite a 16 per cent drop in volume for the fourth quarter of 2016.

Scott Landsburgh, chief executive of the industry body Scottish Salmon Producers Association, said sea lice were the subject of scare stories from campaigners against fish farming.

"Sea lice is a natural phenomenon, albeit that it's made more odd because it's in a farming environment. All livestock on farms, terrestrial or marine, are encountering some kind of parasite or a tick, and they're dealt with. And that's part of livestock farming."