Scientists have created armour-plated salmon in what is being hailed as a massive boost to Scotland’s multi-million pound angling and fish farming industries.
For the first time, thousands of young salmon smolts harvested from the wild but then reared in fish pens are being doused with a chemical treatment that prevents them being attacked by harmful sea lice at the start of their journey to the open ocean.
A three-year experiment has found that as a result of the treatment, more mature fish are returning to their home Scottish rivers in a significant boost to the local economy. Rod catches on the River Lochy, near Fort William, have risen by 10 per cent – an extra 400 fish – an indicator that greater numbers of salmon are returning. On the Carron, in Wester Ross, another river hit by declining numbers, stocks are said to have staged a phenomenal recovery.
Up to 100,000 treated smolts are now to be released over the next three years to build on the success of the trial. A successful outcome will help to remove one of the major barriers to expansion of the fish farming industry on the west coast. Growth of the industry which brings jobs and money into remote rural locations has been severely hampered by evidence that sea lice infestation of farmed salmon in west coast lochs and rivers has damaged wild stocks.
The new technique protects the wild smolts which have to swim past fish farm cages from infestation with the sea lice often found on the farmed variety. Jon Gibb, the manager of a wild fish hatchery on the River Lochy in Inverness-shire, said the trial arose from a collaboration between wild fish and industry interests. Wild salmon fry he collected were raised in Marine Harvest pens before being treated with an anti-sea lice medicine provided by pharmaceuticals company Merck. He said: Two weeks later, mingling with their truly wild brethren, the little treated smolts exit the river on their seaward journey a veritable army of armour-plated young travellers.
The problem of sea lice killing smolts has bitterly divided salmon farmers and campaigners fighting to save wild salmon stocks. The latter maintain that fish bred in cages near salmon rivers are spreading parasites, causing a decline of wild salmon, while leaders of Scotland’s fish farming industry say the complaints are ill-informed and overstated.
Scotsman.com