Hansard

I thank Maureen Macmillan for bringing this important topic to the chamber for debate. Richard Lochhead has already reminded us of the good news that we read about in The Scotsman today: Tweed salmon-rod catches are at their third-highest level since records began. That is good news, but we have to contrast it with a story in Scotland on Sunday recently, in which we read:

"Wild Atlantic salmon stocks will be wiped out within decades because of interbreeding with escaped farmed stocks".

It can be difficult at times to make sense of the two different pictures, but they are just two facets of a highly complex issue that we need to understand better. NASCO has a key role to play in helping us to do that.

To be honest, it is quite amazing that there are any salmon left at all, because most salmon species are in rapid decline. This anadromous fish, which makes incredible journeys from oceans to rivers, has always had the odds stacked against it, primarily because of the length of its migrations and the huge and varied predation pressures that the fish face at all stages of their life cycle. Despite that, the salmon species are incredible and have survived for millions of years until now, when many of those populations face extinction. There are many possible reasons for the decline, but I suggest that all of them are man-made. They include overexploitation of fishing, loss of habitat and the agrochemical and aquaculture industries. New research has shown that a single exposure to a commonly used agricultural chemical during the juvenile freshwater phase of the Atlantic salmon damages their gills and reduces their survival at sea by 40 per cent. Those pressures are real—they are in the environment and are affecting our salmon stocks.

Despite that, there is evidence that on the east coast the salmon stock is fighting back and returns over the past few years have been good. However, on the west coast, the wild populations are declining at an alarming rate. Unfortunately, that decline correlates well with the relentless growth of sea-cage aquaculture, which is often sited on the migratory routes of wild fish. The most significant cause of the demise of the salmon on the west coast has been the growth of parasitic sea larvae that are released from farmed salmon. Juvenile post-smolt salmon and sea trout have to swim past farmed salmon to reach the ocean. Some fish have been found weakened, with more than 1,000 lice on their bodies. If we combine that with the danger that is posed by agrochemicals and other pressures that exist in the environment, such fish have very little chance.

We must continue to acknowledge that there are problems with aquaculture, such as those of chemical and nutrient pollution. As was reported in Scotland on Sunday, every year millions of fish that escape from farms interbreed with wild fish, thus diluting the genetic strains that have developed over millennia. There are signs that the industry is reducing chemical inputs; I know that some companies have been co-ordinating fallow periods on some sea lochs, but we must pay attention to the industry's own code of practice, which says:

"It is important that fin fish farming continues to operate within the capacity of the receiving environment and minimises interaction between farm stocks and wild fauna."

There are ecological limits, which we ignore at our peril.

NASCO is doing its best to protect and save the salmon, but it is powerless to make its voice heard above the intensive and powerful lobbying from the agrochemical and aquaculture industries. We call on the minister and the Executive to give NASCO the resources to fund the research to provide the evidence that we need if we are to continue to save the salmon.