On the heels of a disastrous escape of 300,000 salmon from a massive salmon farm in Washington State (USA) operated by Canadian firm Cooke Aquaculture, it is reported that more than 11,000 salmon that have escaped from a fish farm are threatening wild stocks of the species on one of Scotland’s best-conserved rivers.
The escape from the Scottish Salmon Company farm at Geasgill on Mull was reported to Marine Scotland after employees recorded low numbers during a routine grading exercise.
The Scottish Gamekeepers Association (SGA) fishing group said 11,040 farmed salmon entered rivers, including the river Ba, one of the few rivers in the west of Scotland given a Class 1 rating for salmon conservation.
Ghillies in the area have ordered any farmed salmon caught to be killed and not returned to the river.
Gamekeepers also say that there is “real concern” that cross-breeding between farmed salmon and wild salmon will weaken the wild gene pool.
Greg Marsh of the SGA Fishing Group, who looks after operations at River Coladoir and Loch Scridain, said: “The Ba is a Class 1 river, which means it is rated by Scottish government scientists as having the highest grading for conservation of wild salmon.
“There are now a lot of farmed fish through it and up into Loch Ba. People here are up in arms.
“What effect is this going to have on the wild fish? What will fisheries be offering in three or four years’ time? Fish of unknown genetic purity.
“Those on the environmental side in Scottish government need to raise greater awareness of the dangers to wild fish caused by escapes from fish farms and start doing something more effective about it.”
Mr Marsh says all Scottish anglers need now to be able to identify farmed salmon in rivers to ensure the fish are not being re-released into the system.
One of the key differences in appearance between wild and farmed salmon is that vents on a wild salmon will be reddy/brown and slightly swollen at this time of year.
Farmed salmon have silver vents and their tail and pectoral fins look smaller and are often shredded.
He added: “The likelihood of crossbreeding is a real concern, so people need to know the difference if the impacts of these escapes are to be contained in any way.”
A spokeswoman for the Scottish Salmon Company said: “We take the health and wellbeing of our fish and the surrounding environment very seriously and have reviewed procedures and training.”