RIVER workers have voiced fears for the purity of wild salmon in Argyll and Bute after more than 11,000 farmed fish escaped into rivers.

The escape from a 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 one 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 there is “real concern” 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: “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."

Mr Marsh says all Scottish anglers need to now 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.

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: “During a routine fish handling exercise at our site on Mull we identified a reduction in salmon numbers.

“This was reported to Marine Scotland and investigated in line with standard procedure.

“We take the health and well-being of our fish and the surrounding environment very seriously and have reviewed procedures and training.”