Dr. James Butler is a Fisheries Biologist in Wester Ross, Scotland.


What’s the nature of your research out here?

We’re basically monitoring the populations of salmon and trout in the local rivers here and trying to figure out what’s restricting their numbers. Many of the populations here are far, far below their potential. We’re just trying to figure out what the problems are, sort them out, and bring the populations back to their original, healthy state. There has been close to a 90% decrease in a period of 20 years in the abundance of adult fish. Now, as far as the freshwater side is concerned, in many of the rivers there aren’t enough adult fish to actually fill up the available productive space in the river. What that means is obviously that the population is way below its viable level and is more prone to extinction. Certainly the small river systems are very, very close to extinction. You’ve got one, maybe not even one adult fish coming back every year to spawn. That’s a situation that is very serious.

What is the connection with salmon pens?

It’s not just our research; it’s the government’s research as well, which is showing that the real problems are in the sea, not in the freshwater environment. The freshwater environment has remained more or less stable for centuries. What we’re seeing is a very sudden decrease in the marine survival of smelts. Those are the young fish that are going off to sea to feed, and that applies to salmon and sea trout. Now the question then is what is affecting them? There’s got to be something in the marine environment that has come along relatively recently.

The answer is unfortunately complicated in that there is definitely a decrease in the productivity in the sea in general. That applies to the Pacific as well as the North Atlantic. Consequently fewer fish are coming back. But on the West Coast of Scotland we’ve got another problem that is exacerbating this and making it far worse. Although seals are increasing in numbers, although other predators are increasing in numbers, we do know that salmon farming has come into the sea lochs very recently. There are problems associated with salmon farming that are making the situation far worse than it is elsewhere.

What evidence have you found to suggest that salmon farming is having an impact?

What we’re really concerned about is the impact of a parasite we call sea lice. These parasites are specific to salmon and trout. They don’t live on any other fish species. We are seeing elevated levels of sea lice on fish around the coasts. In this case you’ve got a river that flows out four kilometers away from the local salmon farm. What we’re doing today is sampling young fish at the mouth of the river to count the numbers of parasites on them. What we see here is a very close correlation of numbers of lice on the fish according to what the production cycle is in the local salmon farm. If the local farm is being fallowed, like it does every second year, then there are very low levels of lice. When the farm has been running for a couple of years, the numbers of parasites on the farm are built up, and consequently you end up with high numbers of lice on the sea trout as well. When I say high, I mean fatally high. So you’re talking about a lethal level. These lethal amounts are about 30 lice per fish, but we’re getting upwards of 200 lice per fish up and down the West Coast of Scotland.

Is it true that in certain lochs, where there are no salmon farms, lice is less of a problem?

Let’s look at populations of fish in different sea lochs. In rivers that flow into sea lochs without salmon farms, the populations are depleted. But they are not as depleted as they are in other sea lochs where they do have fish farms. We know that lice levels are higher on wild fish in sea lochs with fish farms rather than without. So clearly there does seem to be some circumstantial evidence that the situation is worse in areas where there are salmon farms.

What is the industry doing to try to cut down on the incidence of lice in their net cages?

It’s acknowledged now by the industry and by the wild fish side that something needs to be done about the lice and it’s not just as simple as throwing chemicals at them. The chemicals clearly have an effect on an extended area of the environment. So what we’re all trying to suggest to them is that they approach it in a different way. We’re putting forth ideas with alternative production cycles that would reduce the numbers of lice at particular times of the year. Also we suggest moving the cage sites to more exposed areas where the lice problem would be diluted and cages would be further away from the river mouth.

What does the industry say to questions about why they are sighting their net cages so close to a river mouth?

They need sheltered water and the technology isn’t there yet for them to use bigger, stronger cages further out to sea where the weather is rougher. When the technology comes along, we hope that they’ll be able to do that. But at the moment, they say they don’t have the financing available to go into offshore technology. Consequently they have to stay in these more sheltered areas, which inevitably is where the rivers come in.

What’s the social value to the local community of restoring and sustaining a thriving salmon and sea trout fishery?

We’re standing here at the mouth of the River Ewe, which is the biggest river in Wester Ross. At the moment it employs about four or five guides, and these are people who take folks out fishing for salmon and trout. Now only 15 years ago this river supported 15 or 20 guides during the summertime, and that was when the fishery itself really wasn’t being exploited fully. Tourism and fishing tourism wasn’t advertised fully either. What we’d like to see is a return to those days, but better still where tourism is built up and promoted around local fishing. This could potentially be absolutely fantastic, and could rival New Zealand and Russia and so on. But it’s very difficult to get that going when you don’t have any fish. That’s what we’re trying to deal with and initiate. We want to get some fish here first and then move on to providing a thriving local economy based on fishing tourism.

When you compare that with fish farming, the farming will become more and more intensive and less and less labor will be tied up in the industry. That’s inevitable with any farming industry. At the moment, the fish farm here is employing five people. It used to employ 15. That’s not because of the lack of fish; that’s because they’re becoming more mechanized. As the economy is scaled that would inevitably reduce this even further. In the long run, wild fisheries are certainly the way to go. They are much more sustainable, and should be able to provide jobs consistently over a long period of time, rather than just boom and bust, which unfortunately is the case with aquaculture.

Some people say that salmon farms are creating high-level jobs. Jobs created for biologists, engineers, researchers, and university people. Care to comment on that?

It’s recognized that further in the field, where you have processing plants and research laboratories, there will be employment as far as fish farming is concerned. But on the local level, employment is really going down. It’s not necessarily long-term, in terms of sustainable employment and contribution to the economy. What we’d like to see is a happy marriage between the two where there’d be small-scale fish farming that would be truly sustainable and thriving fisheries as well. The two actually do complement each other very well.

So what is the way forward in terms of cooperation between the two sectors?

There’s no question that the two sectors should be able to live together and in fact complement each other. Some fish farms are already helping some rivers with restocking and so on. So there clearly is a mutual benefit for the two sectors to live side-by-side. At the moment, what we’re trying to promote on the West Coast is to get voluntary agreements between fish farmers and local river owners, and try to sort out some of the problems at the local level. That’s a very slow process, because there are often lots of people involved. Many of these rivers are owned by anywhere from five to nine different parties.

Trying to get consensus between river owners alone is difficult. Then when you add all that to the fact that several fish farm companies are operating in one sea loch, you have to get consensus between them as well. So in some areas it has been a very difficult process. In others it’s been a relatively easy process. But the critical thing is that setting up an agreement is just the first step. What we really need to see after you’ve got an agreement is real action as to how to get to the bottom of these problems, both on the farmed fish side and the wild fish side. Unfortunately I think that’s going to take a long time. Perhaps in some cases, the fisheries and the fish populations themselves aren’t going to wait that long.

What is the status of local fish stocks? Are they in jeopardy?

There is a lot of variation; some stocks are okay. In the River Ewe, salmon stock is okay but the sea trout population has collapsed. There are smaller rivers where the salmon population is effectively extinct. There are some juveniles there that were spawned three or four years ago, but not enough to actually produce returning adult salmon. So in the next five or ten years it’s quite likely that in some of the smaller river systems, species like salmon will be going extinct.

As an estimate, we figure that in some of the larger rivers around here there used to be 2,000 or 3,000 adult salmon running back into them every year. Now we’re down to about 400 or 500. In some cases, that’s barely enough to fill up the freshwater juvenile habitat. In some cases, it’s less than that. So we’re ending up with rivers being far below their potential. So the salmon won’t make it to the adult stage; they’re much more vulnerable to extinction.

How do the salmon populations on the West Coast compare to the salmon populations on the East Coast?

What we’re seeing is far higher marine mortality of salmon populations on the West Coast as they go out to sea and come back again. Until recently, there was no hard evidence to actually give a figure on that, because the government never had fish traps and research projects set up in the West like they have in the East. On the East Coast, marine mortality has definitely increased. You’re getting maybe 6% of fish coming back to the rivers. On the West Coast, we’ve set up some traps now, and very recently we have found that as few as 1% is coming back. So there’s a definite difference there. There’s an overall decline of salmon coming back from the high seas, but on the West Coast it’s about a 5% to 6% bigger problem than it is on the East Coast.