Fishing Lines: Cold comfort down on the salmon farm

Thought I'd uncovered a stomping story this week: a Pacific humpback salmon being captured in a Scottish river. My source claimed it was a fish-farm escapee. This opened conspiracy theories about some cowboy producer illegally breeding American salmon off the Scottish coast.

In fact, the fish wasn't the big story. It was the fact that Bruce Sandison didn't know about it. And for a very good reason: no Yankee humpie (oversexed, overweight and over here) had been caught. I should have known better; if farmed salmon escape in Scottish waters, Sandison knows about it.

For the past four years he has devoted his life to harassing the Scottish salmon-farming industry (motto: "It wasn't us") every time another batch of their progeny goes wild. Whatever the industry claims, it happens all the time. Last year, 731,000 escaped from a farm on the Isle of Lewis. Another 500,000 got away from a Norwegian farm. Only a couple of weeks ago, another 20,000 did a runner at the Isle of Lewis.

You might think anglers would be delighted at this sudden boost in stocks. But it's very bad news. Farmed escapees now outnumber wild fish. In some Norwegian rivers, they represent 80 per cent of the catch.

Disease is the biggest problem. Rumours are doubtless untrue that farms faced with a batch of fish carrying Infectious Salmon Anaemia (ISA) simply release them to save themselves the hassle of trying to treat it. But farmed fish carry all sorts of nasties and spread parasites.

Until recently, the Scottish Executive's salmon report form told people how to spot farmed fish: they would have small heads, be deformed and have diseased gill covers. Pressure from the farming industry resulted in this helpful guide being omitted.

Farmed fish are more aggressive, so they push wild salmon away from spawning areas. They interbreed with wild fish, affecting genetic diversity. If fish are from the same strain, one disease can wipe the lot out.

You might think an American salmon visiting Scotland is ridiculous. But the odd one, almost certainly escaped from a Russian farm, turns up most years. My story wasn't all that wacky. I should have known, though, that Sandison's contacts would have tipped him off. When something untoward happens, in many cases the authorities only find out when he calls for an explanation.

Ranged against him are multinationals, millions at their disposal, and skilled in manipulating the authorities. He has no money, no financial backing; just a website, www.salmonfarmmonitor.org, which attracts 3,000 hits a year, a lot of people who support him and a driving ambition to force fish farms on to land and away from the sea and river mouths, where they can do such harm.

Sandison hardly fishes any more. "I want to stop these big businesses using our waters as their private toilet, polluting our environment and destroying our heritage," he says. Until rumours of escaped Pacific salmon in Scottish waters stop being credible, he is after bigger fish.