Fisheries Committee on May 3rd, 2010

[Fin Donnelly, NDP, New Westminster—Coquitlam, BC]

Thank you, Mr. Chair.

Thank you, Dr. Krkosek, for coming today and providing your testimony.

I have a number of questions that I'll throw out at once. If there's time, I may have a follow-up question. You seem quite confident that there is definitely a problem with sea lice affecting wild salmon, whereas we've heard previously at this committee and from other scientists that the evidence is inconclusive, or that it's hard to say, or that there are two camps at opposite ends of the spectrum that essentially don't agree with your conclusion.

So that's my first question: how are you so certain about the conclusion you're drawing?

Second, I'm wondering if you could comment on the tolerance of Slice on the west coast. There's been comment to this committee that there is not a problem in British Columbia. Could you confirm that this is the case, in your opinion? Also, if you happen to know how testing occurs for drug tolerance, could you comment on that, as well as on who does the testing, if you know, and how often those results are reported or published?

Finally, as you recommended management solutions, could you finish by commenting on what your top priorities would be for this industry, if there were, for instance, a recognized conclusion that sea lice are affecting wild salmon and an agreement that sea lice needed to be addressed? What would be the first things that should be addressed?

[Dr. Martin Krkosek]

To answer your first question, my level of confidence in believing that sea lice are a problem for wild salmon comes from working on this issue for eight years. I spend about half my time in the field catching fish, counting sea lice, and doing experiments on the effects of sea lice on juvenile salmon behaviour and survival. I spend the other half of my time analyzing those data and working with mathematical models that tell us the implications of what we're learning.

During that time, I also read the literature. The convergence of evidence would be one where sea lice are a contributing factor to a decline of the wild salmon populations. As for where my colleagues differ, I think the main argument is that they're not the only factor. I would agree with that as well. Numerous factors affect salmon populations. Some of them we've known about for a long time.

I would say that sea lice are a new factor, and that does contribute to the productivity of wild salmon populations. What we've learned from the European experience and in British Columbia is that they can be a major factor affecting salmon populations. It takes time in the scientific community to look at new results like this and time for independent people to do their own work and reach consensus. We're in that stage where these are pretty new results, especially in British Columbia.

But the overwhelming weight of evidence from my assessment, from the literature and from the work that I've done, is that sea lice from salmon farms are a major problem for wild salmon populations. It's not only my work; a lot of other people have arrived at the same conclusions. But it's also a problem that is amendable to management change and management solutions.

The second question is about tolerance of sea lice to Slice. The first possible indications that this is happening in British Columbia come from Nootka Sound, from this winter, where there was a failure of treatment on one or more farms in that area where treatment with the chemical was made. The subsequent decline that we usually see in the sea lice populations on the farms was only small, and the sea lice populations rebounded very quickly after that. Those are the telltale signs of resistance to a chemical.

However, this is all anecdotal, and neither I nor anyone else has done the work with those lice from that area to determine whether or not tolerance has evolved.

Let's move to the next question. That work is being done by the centre for aquatic animal health, based in Campbell River, and I believe they're working not with the sea lice from Nootka Sound but with sea lice from other areas. The way they do it is to expose the sea lice to different concentrations of the chemical, and they determine the concentration that causes 50% mortality in the lice. That's called an LD₅₀, and they look to see how that concentration at the LD₅₀changes. As the lice evolve resistance, it takes more and more Slice to kill them.

Do I have time to address the final question about the management solutions?

[The Chair, Conservative, Rodney Weston]

Very quickly.

[Dr. Martin Krkosek]

Very quickly, early indications are that coordinated area management with chemical treatment and fallowing appears to reduce sea lice numbers. It looks like it's having the desired effect. I think that's a more fundamental change. Moving the farms away from wild salmon migration routes would be far more effective and would relieve the tenuous reliance on chemical treatment. This should be done in the context of spatial planning, whereby areas should be set aside for wild salmon ecosystems where they're not exposed to these risks.

[The Chair, Conservative, Rodney Weston]

Thank you very much.

Mr. Allen.

[Mike Allen, Conservative, Tobique—Mactaquac, NB]

Thank you, Mr. Chair.

I have a few questions for Dr. Krkosek, and if I have time left...I guess Randy said that about Tilly, too.

We'll see how it goes, Tilly.

Welcome. Thank you for being here.

In your analysis when you were doing some of these studies--I'm thinking about baseline data--you said that the sea lice were prevalent in the area, that they're there anyway. What kinds of numbers did you see? Was there any baseline data done, with, then, the aquaculture laid on top of that to kind of understand it?

You did say in your remarks that if there is a non-farm situation, the issue with the small fish is 5%, potentially up to 90% or 100%. What did you determine as a baseline for a sea lice count, if you could ever do that, as opposed to what it would be in aquaculture?

[Dr. Martin Krkosek]

Sure. The rule of thumb that's emerging is that in the absence of salmon farms during the first two to three months of marine life for juvenile Pacific salmon, the prevalence of infection is approximately 5% or lower. That number comes from areas where there are no salmon farms. It does not come from areas before salmon farms were implemented there.

We only started studying this issue after the salmon farms were there and we started seeing these problems. So in order to get baseline numbers, we have to look elsewhere in British Columbia, where there are no salmon farms, and compare spatially--exposed versus unexposed--rather than before and after salmon farms come in.

[Mike Allen, Conservative, Tobique—Mactaquac, NB]

You have those baseline numbers, and as per what the last people talked about, wherever you go, this whole situation is going to be different. On that spatial issue, are you going to run into other challenges? Do you have the data of what that baseline is in a non-aquaculture scenario?

[Dr. Martin Krkosek]

I would say that it would be 5% of infection right now, which appears to be about the limit of what we see on juvenile salmon during their first few months of marine life with Lepeophtheirus salmonis, which is the salmon louse.

Now, there are other species of sea lice out there that do tend to be more prevalent during this phase of their life history, but the salmon louse is the species that is the problem, and the baseline levels for this species are approximately 5% in areas without salmon farms.

[Mike Allen, Conservative, Tobique—Mactaquac, NB]

Again, without the numbers, I would only have to draw the conclusion that you're saying it would be 20 times the amount of lice. Is that what you're trying to say?

[Dr. Martin Krkosek]

In areas with salmon farms?

[Mike Allen, Conservative, Tobique—Mactaquac, NB]

Yes.

[Dr. Martin Krkosek]

It depends on numerous factors. The range in areas with salmon farms is anywhere from approximately 5%, when management is effective, to 95% to 99% when management is not effective.

[Mike Allen, Conservative, Tobique—Mactaquac, NB]

You talked a lot about the pink salmon. As we noted before, Mr. Pennell said there have been huge swings over the years in terms of the pink salmon returns and what that means.

Was there any correlation done between those returns on salmon--let's talk about over the last number of years--and different impacts, whether it be climate change or whether it be other factors? Also, here's the second part of that question: have you assessed anything on the sockeye?

[Dr. Martin Krkosek]

Yes, we have done those analyses, and in epidemiology we'd call it a matched case-control study, where you have two sets of populations that are experiencing the same environmental conditions. One subset experiences the infestation, the other does not, and you look to see if there is a change in their productivity.

In an analysis, we've applied that kind of structure to pink salmon populations on the central coast of British Columbia, looking at changes in productivity of these populations, before and during the sea lice infestations, in relation to an unexposed area just to the north of there. The structure of the analysis allows us to control for other compounding factors that are environmental and affect the populations as a whole---so that would be large-scale climatic fluctuations. The model we used is a non-linear stochastic model, which allows us to control for environmental noise as well as density-dependent mortality.

With this analysis, we're able to isolate the effect of the sea lice infestations on the productivity of those populations. We've done that for pink salmon in the Broughton Archipelago. I'm part of a group that has now finished a similar analysis for coho salmon in this area. We're beginning to put together analysis of chum salmon in the Broughton Archipelago.

We're also starting to assemble the data to look at the relationship between sockeye salmon productivity in the Fraser in relation to aquaculture production, but we're only in the early stages of assembling the data for that.

[Mike Allen, Conservative, Tobique—Mactaquac, NB]

How much time is left, Chair? Four minutes? I'll turn it over to Ms. O'Neill-Gordon.

[Tilly O'Neill-Gordon, Conservative, Miramichi, NB]

Thank you, Mr. Chair.

Welcome.

As you know, as a group we have certainly been acquiring a lot of information on this topic and we've been hearing topics on both sides of the issue.

Here's my question for you today. Of course, as we know, the committee was told there were significant differences between the sea lice living in the Pacific Ocean and those living in the Atlantic Ocean. Coming from the Atlantic side, I wonder what these differences are, and what is their relevance to the infestations in farmed and wild salmon, respectively?

[Dr. Martin Krkosek]

I think that's a really interesting and important question. The differences between the Pacific and Atlantic forms are genetic.

[Tilly O'Neill-Gordon, Conservative, Miramichi, NB]

I see.

[Dr. Martin Krkosek]

They've looked at the genes of these different groups and have determined that they're sufficiently different genetically to constitute different species.

Now, that does not mean that there is any meaningful difference in the traits or the ecology of these species. No one has looked to see if there are differences in the life history of these species, in their pathogenicity, in their host specificity, and so on. In general, they have the same life history, the same life cycle, and similar sensitivities to temperature and salinity.

I think there's a lot we've learned from the Atlantic form that is transferrable to the Pacific; we just have to be cautious about how we do that.

[Tilly O'Neill-Gordon, Conservative, Miramichi, NB]

What is the origin of those differences? In your opinion, are the two types of sea lice different species or are they the same species but with different genetics?

[Dr. Martin Krkosek]

Well, it's subtle. It depends on how you define species. When taxonomists separate populations into different species, they look at the genetic divergence between them. They're sufficiently genetically divergent to constitute different species, because they've been isolated for a long time.

[Tilly O'Neill-Gordon, Conservative, Miramichi, NB]

Thank you.

[The Chair, Conservative, Rodney Weston]

Thank you.

You have two and a half minutes, Mr. Calkins.

[Blaine Calkins, Conservative, Wetaskiwin, AB]

Thanks, Dr. Krkosek. My name is Blaine Calkins. I'm a graduate of the University of Alberta with a zoology degree. I'm going to ask you a couple of questions.

I want to know about the life cycles of the five different species of anadromous salmon in the Pacific Ocean. I specifically want to know at what point they re-enter the Pacific Ocean with the various lice. We know from previous testimony that the sockeye are much larger, and the pinks are much smaller. Can you comment on the other three species and let us know?

I would like to know about the shelf life or the bioaccumulative toxicity of Slice. I would like to know how persistent it is in the environment and how long it persists after its the application on the farms.

I'd also like to know the infestation-to-mortality ratio of the lice. As the infestation rates or prevalence of the lice on a particular salmon increase, do we see that once they get to four or five, it starts becoming lethal?

Also, do you have any other information about the indirect mortality caused by sea lice? I would like you to elaborate on that.