It is worth emphasising that Fisheries Management Scotland used to be the Association of Salmon Fishery Boards. It has never been our position, either as Fisheries Management Scotland or previously, that fish farming is the only problem or pressure that wild fish face. There are a series of them. I mentioned earlier that the marine issues—again, I mention the “black box” issue—are a significant problem, whether in the east coast, the west coast, Norway or anywhere in the range of the Atlantic salmon.
However, the work that has been done to look at the effect of sea lice means that we can look at things in isolation. I do not want to go into a big long explanation about how it has worked but, essentially, two cohorts of fish are released into the wild. One cohort is prophylactically treated to protect the fish from sea lice and the other is not—it is the control. All the other pressures that happen in the marine environment will affect both of those experimental groups equally. Those experiments, which have been done in Norway and in Ireland, have shown that on average—there is a lot of variation—about 20 per cent fewer fish return to rivers from the control group compared with those that have been treated for sea lice. We can therefore look at the issue of sea lice in isolation from all the other issues, which affect both groups equally.
Last week, there was a lot of discussion about whether we can read across from Norway to here, and about all the things that make Norway different. I do not disagree with any of the points that were made. Norway has a very different geography, a different level of production and all the rest of it, but so does Ireland. It has a much smaller industry than we have in Scotland, and it does not have the fjordic sea lochs that we have here or the big fjords that Norway has. However, the experiments that have been done in Norway, which point to, on average, a 20 per cent reduction in returning adults coming back to the rivers, have also been done in Ireland with broadly the same results. Although I agree with everything that was said last week about the differences between Norway and Scotland, I do not agree with the conclusion that we cannot draw broadly from the results of those studies.
However, it is important to know what happens at a very local level, because we do not manage sea lice on a Scotland-wide level or a Norway-wide level; we manage them at local level. Also, we do not manage salmon stocks at Scotland-wide level; we manage them on an individual river level. What is actually important is what happens at the very local level as the fish pass out of the rivers and pass the farms.