Fisheries Committee on May 3rd, 2010

[Dr. Martin Krkosek, Research Associate, School of Aquatic and Fishery Sciences, University of Washington, Seattle]

My name is Martin Krkosek. I'm currently a research associate at the School of Aquatic and Fishery Sciences at the University of Washington.

I've been working on the sea lice and salmon issue for just over eight years now. I received my doctorate from the University of Alberta for work that I did on this issue two and a half years ago. I've received numerous awards for that work, including a Governor General's gold medal. I've written approximately 20 papers on this topic over the years, including some of the most significant papers in the top journals that have received a large proportion of the media interest on this issue.

I'd like to thank you for having me here. It's an honour to come here and be able to communicate with you on this issue. I have prepared a briefing document for you. Unfortunately there's no French translation at the moment, but it should be forthcoming.

I agree with most of what my colleagues said in the previous hour. I'd say there's been a large focus on what we do not know about this issue and not so much of a focus on what we do know about this issue, and I'd like to speak to that a little bit.

Four key questions are at the heart of this issue, and I've been working on those questions. The first one is whether sea lice spread from salmon farms to wild salmon. Second, if they do, what's the impact on individual fish in terms of their behaviour and in terms of their survival? Third, if infestations are recurrent, what's the effect on the populations of wild salmon that are affected? Finally, if all this amounts to a problem, what are the management solutions that can be implemented, if any? I've been working on all these questions over the last eight years.

The first question is whether sea lice spread from salmon farms to wild salmon. I think there's an overwhelming amount of evidence to indicate that they do. Salmon farms are not the only source of sea lice in the environment; in fact, sea lice are a natural parasite, and they were here long before the salmon farms were here. What's different is the point in time when transmission happens and the magnitude of that transmission.

In the absence of salmon farms, when juvenile salmon leave the rivers and lakes and enter the nearshore marine environment, they do so in the spring, in March, April, May, and June. During this period there are very few natural hosts for sea lice in the nearshore environment. Most of the hosts are offshore; they're adult salmon, and they're out there on their feeding migration. It's not until summertime, in July or August, that large populations of wild salmon return to the coast and bring sea lice with them. This means that there's about a three- to four-month window between the time juvenile salmon enter the ocean and the time they first encounter sea lice. It's during this period that they're smallest and most vulnerable to infection.

There is a key difference when salmon farms are in the water. They provide a very large host population for sea lice during the winter, so when juvenile salmon enter the nearshore marine waters, they encounter salmon farms that host several million domesticated hosts in a region like the Broughton Archipelago, and those hosts support a large parasite population. When the juvenile salmon enter the ocean, they encounter those parasites, and they're poorly equipped to handle them. That is where the concern is: the effect of sea lice on the very small juvenile stages of salmon during their first few months of marine life.

What we've learned is that in areas without salmon farms, the natural prevalence of infection is about 5% on juvenile salmon during this stage of their life. In areas with salmon farms, the prevalence has a wide range, but it's generally higher than that, and in some instances can reach 90%, 95%, 100%. There is sometimes a very high mortality associated with very high infestations.

You don't have to be a mathematician to figure it out. I've been in the field studying this for about six months of the year for the last eight years, and you can see it happening.

The effect of the sea lice on the juvenile salmon can be direct mortality. One adult louse on the smallest salmon is lethal. The more common situation is two or three lice on a medium-sized juvenile salmon, and there, the interactions are much more subtle. There will more likely be sublethal effects that make the fish more prone to, primarily, predators or diseases. It's probably there that mortality happens. The lice change the behaviour of the juvenile salmon in ways that make them more prone to predators. So in reality, in the ocean, long before a louse would kill a fish, a predator would kill that fish because of the infection that was there in the first place.

There was a period of about five years when we had recurrent, very large, sea lice infestations of juvenile salmon in the Broughton Archipelago. Those were the infestations that triggered this issue. During that time, we observed very high mortality among the juvenile salmon. Using standard fisheries and epidemiological tools, we were able to isolate the effect of sea lice from numerous other confounding factors and identified that as a major factor affecting the productivity of wild pink salmon populations in the Broughton Archipelago. During that period of infestation, the productivity was negatively affected so much that the populations were at risk of local extinction.

Since then, we've seen major changes in management. It has moved from a focus on protecting the productivity of the farms to a focus on protecting wild salmon from sea lice. It's a coordinated area management plan; most of this work is still focused on the Broughton Archipelago.

During the spring, when the juvenile salmon migrate out to sea, about half the farms are emptied or are treated with chemical parasiticides to bring the lice numbers down as low as possible during that out-migration season. Preliminary results indicate that this management plan is working. The number of lice on the farms and on the wild salmon have declined dramatically in recent years.

As scientists, with the models we're using, we would predict that this should result in the recovery of those populations. The predictions we made in the past, when we were expecting to see local extinction because of sea lice infestations, now no longer hold. The sea lice infestations have been largely eliminated from the Broughton Archipelago because of this change in management.

The change in management is largely reliant on the use of chemical parasiticides, and this is a situation that is, I think, a little bit tenuous. First, one reason is that the chemicals could have adverse effects on the aquatic ecosystem. This is toxic to crustaceans. That includes shrimp, prawns, crab, and the copepods in the zooplankton that are a key component of the food web. To date, no one has done any work to evaluate what the ecological effects of these chemicals are.

Another tenuous aspect of the use of these chemicals is the possibility that sea lice will evolve resistance to these chemicals. This is an outcome that has already happened in New Brunswick, Norway, and Chile. Based on our experiences in these other areas, we would expect a similar outcome in British Columbia, although that outcome may be slower.

However, this last winter, we had our first evidence that Slice treatment--emamectin benzoate, known as Slice, which is what is used--failed in one area of British Columbia, Nootka Sound, and this suggests that sea lice may already be evolving resistance to the chemicals used in British Columbia.

However, it's not the only explanation. Other explanations are also possible, such as that the dosage was incorrect or that the salmon were not feeding well and did not receive the correct dosage. No one has done the work yet to determine whether sea lice have evolved chemical resistance in British Columbia.

So far, most of the work in British Columbia has been focused on pink salmon in the Broughton Archipelago, and that's where we have made our largest advances in understanding the science of sea lice and salmon and in understanding the effectiveness of new management.

I would like to point out, though, that in all major salmon-farming regions of British Columbia, primarily the Discovery Islands, the Broughton Archipelago, and Clayoquot Sound, we have the same patterns of sea lice infestation and population decline of wild salmon. This includes pink salmon, chum salmon, coho salmon, chinook salmon, and sockeye salmon.

It's likely that the problems we've seen in the Broughton Archipelago are widespread. However, it's also likely that there are management solutions that can deal with this. Those management solutions depend on the long-term sustainability of the chemicals that are used to control sea lice on farms.

[The Chair, Conservative, Rodney Weston]

Thank you very much.

Mr. Dhaliwal.

[Sukh Dhaliwal, Liberal, Newton—North Delta, BC]

Thank you, Mr. Chair.

Thank you for coming here today and making this presentation.

More than a year ago in British Columbia, there was a Pacific Salmon Forum that submitted some recommendations. Do you agree with those recommendations? If so, can these recommendations form a public policy?

[Dr. Martin Krkosek]

I would agree with some of those recommendations, particularly changes in governance of the salmon resource that are more holistic and encompass the entire freshwater ecosystem as well as the nearshore marine environment. Currently, management is separated into too many disjointed units that are not speaking to each other.

They have a recommendation that exposure to sea lice should be minimized during the most juvenile stage of the salmon life history. I would agree with that, but I think there's a danger in over-focusing on those earliest stages. Although those are the ones that are most vulnerable, the older stages are also vulnerable, depending on how many sea lice are in the environment and for how long the salmon are exposed.

It's easy to produce mortality in juvenile salmon if you expose them to enough sea lice for long enough, and the conditions we have in British Columbia mean that exposure to sea lice for all species of salmon during the juvenile stage can be high and can be chronic. It takes about two to three months for some species of salmon to migrate through a zone of salmon farms.

[Sukh Dhaliwal, Liberal, Newton—North Delta, BC]

For those two recommendations that you agree with, do you see that the federal government has already taken action on them, or do you believe the government should take action, or that we as a committee should recommend that they be implemented?

[Dr. Martin Krkosek]

Particularly on governance of the salmon resource, I'd like to see some of those recommendations implemented.

[Sukh Dhaliwal, Liberal, Newton—North Delta, BC]

The judicial inquiry into the whole diminishing salmon stocks in the Pacific Ocean has been in question.... I mean, it will come in the future. What do you see that we can do immediately, right now? Even when you say management...you don't believe in closing those farms, right? Is there anything that we as a committee can recommend that can be taken care of immediately?

[Dr. Martin Krkosek]

I think the largest risk to wild salmon from salmon farms is disease transmission. It's not just sea lice. There's a very long list of viral and bacterial pathogens that we know are transmitted between wild and farmed salmon.

The current locations of the salmon farm tenures in British Columbia are on the main migration routes of some of the most significant salmon populations in Canada. The salmon farms are on a collision course with the wild salmon migrations twice a year. In the fall and summer, when the adult salmon return to spawn, they pass the salmon farms, and the farmed salmon are at risk for all those pathogens. In the spring, when the juvenile salmon migrate out to sea, they are at risk of infection from those pathogens that may be on the farmed salmon.

Spatial planning of aquaculture in British Columbia needs to be thought about very carefully, I think, certainly if there's continued development in the future. Particularly for the issue of Fraser River salmon stocks, I think, the collection of salmon farms around the Discovery Islands is a very big problem. Situating salmon farms in areas that are distant from wild salmon migration routes would be a key change that could be implemented.

Another one that I would recommend, which follows on the experience from Norway, is setting aside protected areas for salmon ecosystems where salmon-farming activity is prohibited. These would be marine protected areas where the wild salmon have no salmon farms that they are exposed to during their return and out-migration.

[Sukh Dhaliwal, Liberal, Newton—North Delta, BC]

DFO has told this committee they do not know if the fish farms are causing a decline in the wild salmon populations. Would you like to comment on that?

[Dr. Martin Krkosek]

I would agree that the published science from DFO does not show any effects of salmon farms on wild salmon stocks.

I would disagree that science in general shows that. There's a long list of scientific publications that show negative affects of salmon farms on wild salmon stocks; it's just that they're not authored by DFO scientists.

[The Chair, Conservative, Rodney Weston]

Monsieur Lévesque.

[Yvon Lévesque, Bloc, Abitibi—Baie-James—Nunavik—Eeyou, QC]

Thank you, Mr. Chairman.

If I may, I will call you by your first name, which is easier in French than Krkosek. I will call you Martin.

You heard the testimony of the two people who spoke before you earlier on. There is an issue that bothers me and I'm going to raise the subject with you. We discussed a product called SLICE. That is the company name, but not the scientific name of the product.

I would like to know if this product was tested only on sea lice or if it was also tested on fish? We are using a product that attacks the sea lice, but if we are using a sledgehammer to kill a fly, could it not be the product itself in the end that kills the fish?

[Dr. Martin Krkosek]

Is this going to affect the health of the salmon that are receiving the...? Yes?

[Yvon Lévesque, Bloc, Abitibi—Baie-James—Nunavik—Eeyou, QC]

Could it go so far as to kill them?

[Dr. Martin Krkosek]

I think that at sufficiently high doses it could cause a problem for the health and well-being of the fish. But at the dosages they receive to control sea lice, it's not a concern for the health of the fish that receive that treatment.

[Yvon Lévesque, Bloc, Abitibi—Baie-James—Nunavik—Eeyou, QC]

I was asking you if the product was tested on fish as well as on sea lice? Is it a product that was strictly tested as far as the elimination of sea lice is concerned, and in using it, are we attacking the fish itself at the same time? Is that possible?

[Dr. Martin Krkosek]

I think it's a product that has been examined largely for its effectiveness in killing the parasites, and less so on the health and physiology of the salmon, though some work has been done on that as well.

[Yvon Lévesque, Bloc, Abitibi—Baie-James—Nunavik—Eeyou, QC]

So we have not done studies to see whether or not the product is contributing to the declining fish stocks. If the fish stocks are diminishing at the same time as the sea lice numbers, which are perhaps more resistant to the product than the fish itself, we are increasing the number of lice in comparison with the remaining salmon.

[Dr. Martin Krkosek]

That's an interesting question: is the chemical itself a problem for the wild salmon? I doubt that the chemical itself, through exposure to wild salmon, would cause them a problem.

Where there may be a problem is in the effects on the food web of wild salmon, because the chemical is toxic to crustaceans. That includes copepods that live in the zooplankton and are an important component of the diet of juvenile wild salmon. If the chemical residues in the environment are sufficient to affect those copepod populations, then that could lead to a decline in the food resource for wild salmon.

However, this is all speculation. No one has done this work.

[Raynald Blais, Bloc, Gaspésie—Îles-de-la-Madeleine, QC]

Thank you, Mr. Chairman.

Thank you sir.

Quite frankly, I would say that your presentation and the answers you are giving us have brought great clarity to the issue. I understand much better thanks to what you have said, and I'm anxious to read your document, once it has been translated into French. In your presentation, at the very beginning, if memory serves me well you mentioned that there were four factors to take into consideration. We discussed one factor, that being the location of the aquaculture sites in relationship to the wild salmon. There were three others. What are they?

[Dr. Martin Krkosek]

Well, when I started, I said there were four main questions at the heart of this issue. First, do lice spread from farmed salmon to wild salmon? Second, what is the effect of sea lice on individual juvenile salmon, on their survival and behaviour?

Third, what is the effect on wild salmon populations of the infestations that happen recurrently, year after year? It's a big step to go from effects on an individual fish to the productivity of the population. Then, finally, there is the fourth question: if we believe that we have a problem, what are the management solutions to this problem?

[Raynald Blais, Bloc, Gaspésie—Îles-de-la-Madeleine, QC]

There may be other factors that are causing problems for the wild salmon, including all species. We talked about climate change, and normal animal behaviour. There may be many other factors to consider. Among those other factors, setting aside the issue of sea lice, what would be the other factors that we should study, in order of priority?

[Dr. Martin Krkosek]

Certainly, there are numerous factors that affect salmon populations, varying from population to population. In some cases, it would be the loss of freshwater habitat. In other cases, it could be pollution. In other cases, it could be dams. In others, it could be disease from aquaculture facilities or hatcheries. In others, it could be problems with the harvest and overharvesting. Another important factor is climate change, and that's a very big, looming factor.

All of these things contribute to the decline of wild salmon in British Columbia. Not all of these things are amenable to management solutions. If I were to rank the factors we were to focus on, I would look at disease transmission from aquaculture as a very important factor.

I would do so, first, because our experience from the rest of the world indicates that we should expect problems; second, because we are seeing problems in B.C.; and importantly, third, these problems are amenable to management change and solutions. Other problems such as climate change are a lot more difficult to deal with.

[Raynald Blais, Bloc, Gaspésie—Îles-de-la-Madeleine, QC]

Thank you very much.

[The Chair, Conservative, Rodney Weston]

Thank you.

Mr. Donnelly.