THE STANDING SENATE COMMITTEE ON FISHERIES AND OCEANS
EVIDENCE
OTTAWA, Thursday, December 1, 2022
The Standing Senate Committee on Fisheries and Oceans met with videoconference this day at 9 a.m. [ET] to examine and report on Canada’s seal populations and their effect on Canada’s fisheries.
Senator Fabian Manning (Chair) in the chair.
[English]
The Chair: Honourable senators, welcome. My name is Fabian Manning, I’m a senator from Newfoundland and Labrador and Chair of the Standing Senate Committee on Fisheries and Oceans.
Should any technical challenges arise, particularly in relation to interpretation, please signal this to the chair or to the clerk, and we will work to resolve the issue.
I will now take a few moments to introduce the members of the committee who have joined us here this morning. We anticipate there will be others joining us shortly.
Senator Busson: Bev Busson, senator from British Columbia.
Senator Cordy: Jane Cordy, senator from Nova Scotia.
Senator Francis: Brian Francis, senator from Prince Edward Island.
Senator Ravalia: Good morning. Mohamed-Iqbal Ravalia, senator from Newfoundland and Labrador. Welcome, and thank you for being here.
The Chair: Before continuing, I would like to ask members in the room to please refrain from leaning in too close to the microphone or remove your earpiece when doing so. That will avoid any sound feedback that could negatively impact the committee staff in the room.
On October 4, 2022, the Standing Senate Committee on Fisheries and Oceans was authorized to examine and report on Canada’s seal populations and their effect on Canada’s fisheries. Today, under that mandate, the committee will be hearing from the following representatives for the Department of Fisheries and Oceans: Dr. Sara Iverson, Professor, Department of Biology, Dalhousie University and Scientific Director, Ocean Tracking Network; Dr. David Rosen, Assistant Professor, Institute for the Oceans and Fisheries, University of British Columbia; and Dr. Carl Walters, Professor Emeritus, Institute for the Oceans and Fisheries, University of British Columbia.
I want to thank all of you, especially the people coming in from British Columbia. We realize it’s 6 a.m. there, and we really appreciate you taking the time to join us here this morning.
I understand that Dr. Walters is feeling a bit under the weather, but any time you are able to contribute to us, we will appreciate it. If you have to leave, we fully understand.
Senator Salma Ataullahjan from Toronto, Ontario, just joined us.
On behalf of the members of the committee, I thank you all for being here today. I understand that all three witnesses have opening remarks. Following the presentations, members of the committee will have questions for you. I’ll go to Dr. Walters first, followed by Dr. Iverson and then Dr. Rosen.
Dr. Walters, the floor is yours.
Carl Walters, Professor Emeritus, Institute for the Oceans and Fisheries, University of British Columbia: Let me just summarize what the situation is with respect to seal harvesting and management.
In B.C., in relation to the impact of seals and sea lions on salmon and other populations, a key factor about our situation in B.C. is that there are twice as many seals and sea lions on the B.C. coast now than there have been for the last several thousand years. Seals and sea lions were hunted intensively by First Nations people as they invaded down the B.C. coast. They probably kept the populations a lot lower. We can calculate seal populations back into the 1880s, and even then, they were only about half of what they are today.
Sea lions, in particular, now consume more fish biomass than all of British Columbia’s commercial fisheries combined; they certainly consume a huge amount of fish. Seals consume much less. The huge increases in seal and sea lion populations began in the early 1970s during marine mammal protection. They were correlated with declines that started back in the early 1980s in the abundances of our most valuable chinook and coho salmon populations that support large sport fisheries here in the Georgia Strait in B.C. More recently, we have seen declines in a few herring populations, as well as in oolichans, which sea lions also target.
We have a plurality of evidence that a big buildup of marine mammals has had a negative impact on the fish stocks.
When the declines started in chinook and coho coincident with the buildup of seals, it was a horrific time for a couple of well-known fisheries ministers. John Fraser had to initiate severe restrictions on the sport fishery. A little later, David Anderson basically shut down the entire coho fishery along the B.C. coast, which meant shutting down a whole lot of salmon fisheries, even beyond those targeting coho, just to protect coho salmon.
So there has been widespread impact on recreational and sport fisheries and closures associated with declining marine survival. We know that it’s declining marine survival, not something going on in fresh water, that’s causing these declines. We track marine survival rates with mortality rate estimation with tagging and so on.
Commercial First Nations fisheries have been proposed to basically restore the original First Nations harvesting system and to bring marine mammal abundances down by at least 50% from where they are today back to something like what they were over much of the 20th century and probably the last several millennia in order to provide both economic value from sustained seal harvesting and to restore some of the economic value of the salmon populations, particularly those that have been impacted by marine animals.
The Department of Fisheries and Oceans, or DFO, has largely ignored those proposals, arguing that it isn’t economical. Right now, First Nations people can get permits to harvest seals and sea lions — 15 per person — but only for food and ceremonial purposes. Simply removing that restriction and allowing them to use those animals for sale would create an incentive for the First Nations people here in B.C. to build a sustainable First Nations fishery again.
That’s all I want to say. I hope I didn’t take too much time.
The Chair: No, that’s fine, Dr. Walters. We’ll now go to Dr. Iverson.
Sara Iverson, Professor, Department of Biology, Dalhousie University and Scientific Director, Ocean Tracking Network, as an individual: Thank you and good morning, everyone.
I was asked to give an overview of my academic background, research and expertise. I received my bachelors in zoology from Duke University and my PhD jointly with the Smithsonian Institution in Washington, D.C. and the University of Maryland. After completing postdoctoral fellowships at Georgetown University Medical Center in Washington, D.C. and at the Canadian Institute of Fisheries Technology Halifax, Nova Scotia, I became a professor in the Department of Biology at Dalhousie University in 1994. I initially held a Women’s Faculty Award from NSERC, or Natural Sciences and Engineering Research Canada, which was followed by an NSERC E.W.R. Steacie Memorial Fellowship, a Killam Prize and a university research professorship.
In 2008, I became the Project Leader and Scientific Director of the Ocean Tracking Network, OTN and have continued to hold this position since its inception. OTN is a global aquatic research, technology, data management, conservation and partnership platform headquartered at Dalhousie University, which has become the world’s foremost aquatic-animal-tracking network, informing the stewardship and sustainable use of aquatic species by providing knowledge on animal movements, interactions and survival in relation to environmental conditions. OTN is now a Canadian Major Science Initiative and the only national research facility in Atlantic Canada.
I have been an affiliate professor at the College of Fisheries and Ocean Sciences, University of Alaska Fairbanks since 2005 and am a member of the board of directors for Canadian Science Publishing, Canada’s largest publisher of international journals. In 2018, I was elected Fellow of the Royal Society of Canada’s Academy of Science.
In terms of my research and expertise, I lead a research program in physiological ecology that has advanced the use of tools, including biochemical tracers, energetic measurements and tracking studies, to better understand the biology of marine vertebrates and the food webs within which they function. Marine mammals, and particularly seals, have been the primary focus of my research because of their unique reproductive and life history strategies. My studies have also included polar bears and seabirds. For the last 32 years, together with colleagues at DFO, I have co-led a long-term research and training program on the reproductive energetics, foraging ecology and life history of grey seals and, previously, harbour seals on Sable Island, Nova Scotia.
With OTN, the Ocean Tracking Network, and DFO, Department of Fisheries and Oceans, we have also conducted pilot studies using novel tracking techniques to employ grey seals as “bioprobes” to study their movements and interactions with other tagged seals and fish species in the northwest Atlantic. I have also worked on hooded seals in the northwest Atlantic, California sea lions, northern fur seals in Alaska and monk seals in the Hawaiian islands.
Finally, in the context of all this work, in 2004, I led the development of a method called quantitative fatty acid signature analysis that can be used to estimate the diets of marine animals from small biopsies of their fat stores. This method can be used to estimate diets of individuals over timescales that are relevant to ecological processes and variability and is now being used to estimate diets for a number of marine vertebrates, including many seal species, polar bears and killer whales.
With that, I would be happy to answer any questions that I am able to. Thank you.
The Chair: Thank you, Dr. Iverson. Dr. Rosen?
David Rosen, Assistant Professor, Institute for the Oceans and Fisheries, University of British Columbia, as an individual: Good morning and thank you to the committee for the invitation. As a very brief background, I’ve been studying pinnipeds and other marine mammals for more than three decades. My interest focuses on their bioenergetics, physiology and nutrition. I completed both my masters and PhD at Memorial University in Newfoundland. For context, the start of PhD research with the seal colony at the Ocean Sciences Centre coincided with the start of the cod moratorium in 1992.
Since 1996, I’ve been at the University of British Columbia, and I’m an assistant professor at the Institute for the Oceans and Fisheries.
My current research lies primarily in the field of conservation physiology, focusing on threatened marine species, and much of my research uses animals kept under human care in controlled studies under laboratory conditions.
In addition to trying to understand the effects of environmental changes on individual marine mammals and their populations, I also work to develop and test tools and techniques to study animals in the wild. I’d be happy to answer whatever questions I’m able to from the committee. Thank you.
The Chair: Thank you, Dr. Rosen, and thank you to all our witnesses. There’s no doubt in my mind that we have some very experienced people here before us this morning. We certainly look forward to our dialogue with you. We’re going to begin with questions from our deputy chair, Senator Busson, from British Columbia.
Senator Busson: As our chair said, when we were meeting virtually, I had some of these six o’clock meetings as well. I am with you in spirit at six o’clock in the morning. I know how that feels. I hope my question is something you’re interested in and can answer.
Previously, appearing before this committee, representatives of Fisheries and Oceans and other groups explained that current research has largely been aimed at learning how seals and Pacific salmon interact in the Salish Sea region of British Columbia. In your opinion, are there other areas on the Pacific coast that would be of particular interest and utility for seal and sea lion researchers?
Additionally, do Canadian scientists ever collaborate with their partners to the north in Alaska, in the United States, on seal research?
Mr. Walters: There’s a fair amount of collaboration, more with the people to the south, Puget Sound and Washington State. The rest of the Salish Sea, of course, is up in the North.
I don’t think marine mammal concerns have been that great in Alaska, so you don’t see a whole lot of research up there on the impacts of increased seal populations.
There is a concern that keeps getting raised by First Nations people in Haida Gwaii and other areas about severe depensatory mortality on returning pink and chum salmon populations in many small streams on the north coast. First Nations people watch this and argue that a herd of sea lions or seals move in on a stream where salmon are holding and waiting to spawn. They will go upstream to spawn and will just be decimated, in the view of those First Nations people. This year there was a spectacular example when pink salmon couldn’t get into the streams because of low water flows. It certainly is a concern. It has not been scientifically documented. There have been a lot of studies over the years on just how many salmon get eaten by seals and sea lions as the salmon are going into rivers to spawn and where the seals and sea lions congregate to take an easy meal.
The usual number we’ve used in the past, based on accounting calculations of how many fish we started with and so on, assumes there’s been something like a 20% mortality rate due to that kind of predation. That’s not enough to decimate a salmon population. Some of these chinook and coho populations have dropped by over 90%. To do that, there have had to have been big increases in their juvenile mortality rates over their first ocean year.
Mr. Rosen: I agree with the emphasis on where the research with salmon and pinnipeds is taking place: primarily in the Salish Sea. That’s partly because of the interest in southern resident killer whales and how they fit into the entire ecosystem. As the committee probably knows, there are still some large gaps in knowledge of salmon migration outside of the Salish Sea. The interactions with pinnipeds are pretty well a black box because the salmon is a little bit of a black box. A fair bit of work is going on between Canadian scientists and U.S. scientists in Alaska in regards to Steller sea lions, of course, because they are an endangered species in western Alaska, and the B.C. sea lions, which are a growing population, are part of the eastern population, which also overlaps with Alaska.
Senator Busson: To continue my question, I think this might be for Professor Walters. You had mentioned, Professor Walters, that in your research and estimation, the amount of salmon taken by sea lions — I believe you said sea lions — exceeded the number of salmon taken by the commercial fishery.
Mr. Walters: Dramatically, yes. Partly because of the reduced fisheries. But it’s not just salmon. Sea lions eat a whole lot more herring than the herring fishery takes and probably more hake than the hake fishery takes and so on like that. They are a major mortality force out there. That’s not to say it’s a bad thing. It’s just a fact that they eat an awful lot.
I’d like to add something to what David said, and it relates to Dr. Iverson’s work. That Ocean Tracking Network is probably the future of our science in the sense of really trying to understand where and when things are happening, where and when animals are exposed to relatively high predation risks and so on. Sara should jump in here because she may have a few things to say about what’s going on on the Pacific coast in this regard.
Senator Busson: I’d welcome that, if that’s her wish.
Ms. Iverson: I can’t speak as well about the Pacific coast. My work has focused more heavily on the Atlantic. I can speak to that and certainly what we’ve learned from the seals we’ve tagged in the Atlantic.
Mr. Walters: What happens here, just as a very broad piece of background about this whole issue of seal impacts on fish, is that we’re mainly using two kinds of data. We’re using data on the buildup in the numbers of marine mammals that is occurring on both coasts and their diet composition to get estimates of how much they’re eating. Some of those estimates are scary, like I mentioned to you.
On the other side of the coin, we look directly at methods for estimating mortality rates in the fish populations according to our tag returns and sometimes from mortality tracking tags and things like that; mostly with salmon we use coded wire tagging.
On the East Coast, I am involved in a couple of studies on the impacts of seals on cod stocks, the ones near Sable Island, the western gulf stock, and the 3NO stock in the south end of Nova Scotia. They use age composition information from the fish surveys and changes in age composition to estimate changes in mortality rates. We try to correlate those changes in mortality rates with changes in mammal numbers. We try to cross-validate the changes to the correlative mortality changes we see with absolute mortality numbers that we calculate from diet and food consumption rates. We do have these two sort of semi‑independent ways of looking at what’s going on.
I want to add one more key thing. While studies using these two different estimation methods have lined up, they do not imply that reducing marine mammal populations would cause a decline in the prey mortality rates. There is a big misunderstanding about that, and the reason is that we don’t know how many of the fish that these mammals are taking are what we call dead fish swimming, fish set up to be vulnerable to predators by virtue of things like diseases that would kill them in a few days if the marine mammal didn’t eat them. We don’t think that’s all of the mortality at all. We think there’s lots of added mortality, in fact. We think that these mammals are eating a lot of healthy young salmon and oolichans and herring and so on.
The only way we can prove one way or the other whether mortality is additive is to do a very large-scale reduction experiment. We have a huge amount of disease research now showing that fish do carry diseases, and fish that are diseased are more likely to turn up in marine mammal diets and so on. That’s purely correlative. It doesn’t answer this question about whether mortality is actually additive.
Those of us who are involved in this on the West Coast are viewing this as a kind of grand what we call adaptive management experiment as being the way to — we don’t need a jillion more detailed research studies on better diet data and things like that. What we need is an experiment. Let’s find out on the ground what works and what doesn’t.
Senator Busson: For clarification, for those of us who don’t have degrees in bioscience, the experiment you’re discussing would help you to draw a straight line between the numbers of marine mammals and the predation levels? Is that what I’m understanding?
Mr. Walters: Yes, the idea is if we reduce marine mammal populations by about 50% on the B.C. coast to levels that would be productive and sustainable for harvesting those marine mammals, we have predictions about how the mortality rates would change, which could be measured through tagging studies and so on and the abundances we see in returning salmon to the streams. So within a few years of that abundance reduction, we should know whether or not an added mortality effect was reduced.
Senator Busson: Thank you very much.
Mr. Walters: I have to emphasize that there is no alternative. In the study of diseases, this is like the old business of Koch’s postulates. In the end, the proof is in the pudding. You have to be able to infect to prove that the disease organism is the causation of the disease.
Mr. Rosen: Without getting strictly into a debate with Dr. Walters about his grand experiment, which we have differing opinions on, I do want to emphasize, though, when we talk about the increasing marine mammal populations, certainly along the West Coast, that the prime driver of that is actually recovery of populations that have been artificially suppressed through human culls and hunting.
There’s a fair body of evidence that the populations now are recovering populations within a changed ecosystem. It’s disingenuous to think about it as pinniped or other marine mammal populations that are out of control. That’s not how the systems work.
Senator Cordy: Thank you to our witnesses, who are up — a couple of you, at least — very early in the morning.
We’ve had witnesses from the fishing industry, and we had witnesses on Tuesday evening from the Department of Fisheries and Oceans. In regard to the fisheries on the East Coast, including Quebec, with the closing of the cod fishery, the expectation was that the number of cod fish would increase significantly once it was closed down, and we heard that this hasn’t happened. The numbers are stagnant, or there has been a slow increase in northern cod; in other places there has been no increase, and in some areas, in fact, there’s been a decline in the number of cod fish. They didn’t show us a correlation between the number of seals and the number of fish, but, certainly, when we talked to the witnesses who were in the fishing industry, they felt there was a direct line between the seal population and the amount of cod that they were eating and the decrease in the cod.
Dr. Iverson, you’re from the East Coast. Do you see a correlation, or is there no correlation between the increasing number of seals and the stagnation of the cod fishery?
Ms. Iverson: Thank you.
The bottom line is it is very dangerous to think about the ecosystem as a two-species ecosystem with one predator, the seal, and one prey. If you look at the food web and all the interactions for Atlantic and northern cod, it looks like a spiderweb. There are so many linkages. It’s really important to understand that, for instance, when the eastern Atlantic cod population crashed and the moratorium started, that was exactly the time that the grey seal population started to exponentially increase. That is when there were no cod.
The thought is that it was the release from predation by cod on really important, high fatty forage fish — like sand lance, capelin and redfish — that fuelled grey seals to return to the population prior to when they were harvested very extensively.
The other important thing to remember is seals are visible. They surface, and individual seals can be seen by fishers. There are many very large species that also eat fish — other fish — whales, such as minke, pilot whales, fin whales, porpoises, dolphins and sharks all have to eat fish, like tuna and swordfish. These are all really important predators of fish in the ecosystem.
To think that the simple solution of just removing one of those predators, being seals, will make things go in a direction we can predict is simply not the case.
Actually trying to conduct an experiment in the open ocean sounds great on paper, but in practice, I don’t think it is possible. Seals, other marine mammals and sharks are very mobile species. We know from our tracking studies that, for instance, grey seals target certain areas and move between them to reach the forage areas they want.
I could also talk to you about some of our tracking studies, where we tracked grey seals and other tagged fish in terms of what happened to them. Regardless, it is a very complex question.
Senator Cordy: We are studying seal populations and their effects on Canada’s fishery, so is there any way we are going to be able to define whether there is a correlation?
Ms. Iverson: Yes, I believe there is. I have worked very closely with the Department of Fisheries and Oceans Canada for almost my entire academic career. We have had a great partnership. There are terrific scientists.
But it has always been my understanding that there is not dedicated funding for seal research. Both academia and DFO scientists have worked really hard to try to cobble together the funding that we need to really understand things like diets, foraging and interactions. For instance, it is critical to know what the diets of all segments of the population are. We know from previous studies that they differ by sex and season, and certainly juveniles will have different diets than adults. Actually, the last large-scale program to determine seal diets is now something like 15 years old.
So while we had that and worked with harvesters to collect various kinds of samples and stuff, we don’t have the resources to actually analyze those. The bioprobe study that I talked about was really a pilot proof of concept where we showed the interactions with grey seals and tagged cod. They were not, by the way, eaten by the seals, but it showed us foraging hotspots. We also tagged tuna foraging in the same areas as the grey seals, presumably on the same kind of prey species.
The ecosystem has been altered dramatically, certainly by human actions, and it is being altered dramatically by climate change and the changes in fish populations. Without the resources to understand what’s happening now, we can’t really make the informed decision that is necessary.
There are huge gaps in research that could be addressed and that could help this committee.
Senator Cordy: So maybe that should be one of our recommendations in our final report.
Has there been any work done — I’m from the East Coast so I’ll say the cod fishery — on why the cod stocks are relatively stagnant — a little blip up in one area and down in another but relatively stable after 40 or 50 years?
Ms. Iverson: We have recently gotten small pots of funding and have collaborated with industry, the Atlantic Groundfish Council, DFO, et cetera to start to study that. We have targeted the northern cod populations because they are showing signs of possible recovery.
We got together a collaborative partnership to try not to go out and immediately start fishing them again but to really understand the stock structure, where and when they are spawning, when we need to leave them alone and when we could possibly fish them. That has just gotten under way. Part of the problem was the pandemic, limited field work and limited resources. We now have literally hundreds of cod out there that are tagged. We have placed receivers. We have gliders that, with OTN, carry active receivers. We are trying to understand what the population is, what the size is and how it might be recovering.
This will be really important information to try to develop, hopefully, a sustainable fishery in the future, which is what we would all want.
Senator Cordy: Thank you.
The Chair: Before we go to Senator Ravalia, I want to ask a question as a follow-up to Senator Cordy’s.
The committee heard testimony from researchers that multi‑year funding for research projects is uncommon and that it is much more common to receive single-year funding. As a general rule, has funding for your seal-related research projects been allocated on a yearly basis, or has it been allocated for the duration of the study or project? What are the pros and cons of how the research funding is distributed?
Mr. Rosen: I’m happy to talk from a personal perspective.
In general, the research funding has been piecemeal. It has been short term, which makes it difficult to either plan or sustain the type of research that needs to be conducted. Although our local DFO scientists have worked closely with us to try to acquire the funding, it is very difficult to plan effective laboratory or field studies under those types of conditions.
There is a bit of longer-term funding for certain specific projects, and there are certain requests for proposals, but those tend to be few and far between.
There are scientists outside of DFO who can conduct support research. They have the specialty or the interest, can take the risk and might have graduate students to conduct it. However, this research does not have enough support to enable it at this point, as a general point.
Also, just go back to the previous question in order to emphasize something, Dr. Iverson talked about the complex food webs. She also mentioned — and I think it is important to put these two pieces together — that it is a changing system. We don’t really understand how the ecosystem is going to be changing because of human activities. We also don’t understand how these changes will affect either the predator or the prey population — I’m more concerned with predator populations of seals — and their dietary choices and foraging behaviour.
Ms. Iverson: I concur with Dr. Rosen that research funding is generally piecemeal. For instance, the reason I couldn’t address any questions about Ocean Tracking Network’s work in the Pacific looking at predator-prey interactions of seals is because there simply wasn’t research funding for it; there never has been. So we were able to work off mutual funding that we had in the northwest Atlantic.
OTN is funded for operations and maintenance to serve the research community, but we don’t have automatic research dollars to pair with our infrastructure. Therefore, we are constantly trying to work with our Indigenous partners, DFO and industry partners to try to get together the funding so that we can address the questions that really need to be addressed, particularly in this time of climate change. As Dr. Rosen said, the ecosystems are changing dramatically. Species are moving north. Right now, we have no idea how that is changing the top predators’ diets and foraging habits.
Mr. Walters: I have been to a jillion meetings over a very long career where there were scientists like Dr. Rosen and Dr. Iverson there. Basically, their view of the world is that everything is very complex. You have to be able to understand everything before you can take action, and we need more research money. Fair enough? That’s what you are hearing. How can you possibly do anything?
Think about this: You don’t have a choice but to do something before there is full understanding out there. The choice is not to wait until these scientists give you their answer in maybe 100 years or something like that. The choice is whether you continue to allow some of these populations to be degraded to very low levels or, perhaps, even driven to extinction in situations like the cod stock off Sable Island, or to try some action that may reverse some of these declines.
Right now, here on the Pacific Coast, everyone is blaming the salmon decline on climate change even though the evidence is pretty overwhelming from a statistical point of view that it isn’t climate; none of the climate variables that we know about are good predictors at all of the declines we’re seeing. A lot of those declines started long before some of the climate variables started to change.
We have a kind of smoking gun for one agent of measure of mortality that we can step in and reverse a little bit; we can make things better. That doesn’t mean you’re changing the whole ecosystem or decimating anything. It is just saying that you have to take action before you have complete understanding. We wouldn’t have fisheries at all if these scientists were telling you what you needed to do to manage fisheries, right?
The Chair: Thank you, Dr. Walters.
Mr. Walters: There is no end to the things we don’t understand.
The Chair: Thank you.
Senator Ravalia: Thank you to our witnesses. My first question is to Dr. Iverson.
In the context of the dynamic nature of the ecosystem, have you noticed any changes in the dietary habits of seals and other pinniped populations you have been studying? I ask this question based on information I have received from fisher people who are now saying that, with declining cod stocks, seals are consuming every other species, including crab, which was not part of their diet, historically.
Ms. Iverson: Thank you for the question.
As I said, approximately 15 years ago, the funding ended, but we did some very comprehensive diet studies. Of course, diet studies have to use various tools simply because we can’t usually observe the population feeding underwater. So we used a combination of fecal analyses, stomach contents, fatty acids and stable isotopes. We demonstrated that there was a difference between the sexes and the seasons in terms of variability in diet. It was at a time that things were not changing quite so rapidly, but there has been no funding — I’m sorry — for the last, say, 10 to 15 years to even analyze the samples we have collected.
In terms of recent robust diet estimates, I really can’t tell you during this period of rapid change.
Senator Ravalia: Thank you.
I’ll pose my second question to Dr. Rosen. Again, in the context of your research studies, could you help us assess whether there has been a change in the actual biomass of species that are consumed by seal and other pinniped populations? You talked about your fatty acid analyses and so on, but are we seeing a change in the dynamism of the ecosystem or as a result of some species being overconsumed? Are you seeing a change in dietary habits?
Mr. Rosen: I’m afraid I actually don’t study that in my research. I think perhaps Dr. Iverson looked at that previously. My research, broadly, has looked at how different marine mammal species have changed their diet and other things based on environmental changes. What we have seen in other systems is that both pinnipeds and whales will change their diet when their prey resource changes. But I haven’t studied that specifically in Canadian waters. I don’t know if Dr. Iverson can speak to that.
Ms. Iverson: Again, we haven’t conducted studies over the past 10 to 15 years, so I can’t speak to recent changes.
Senator Ravalia: Thank you.
My final question is for Dr. Walters. You alluded to a doubling of the population of sea lions and seals in the studies you have conducted. You also alluded to the fact that if a commercial seal harvest were restored, there is a possibility that things would balance out. Would you be able to elaborate in terms of timelines? Is there a market for a commercial seal fishery in British Columbia and abroad? Are we missing something here?
Mr. Walters: I will answer a few questions that arose.
DFO has had long-term monitoring programs — an exceptionally good program on the West Coast — for counting seals and sea lions using aerial survey methods. That started in the early 1970s.
Seal populations have gone up by a factor of close to 10; they’re not double. Sea lion populations show a comparable increase. We are talking about huge increases, not double.
Also, DFO has scientists studying all of these fish populations, and they do stock assessments and report them. On the East Coast, there are a bunch of very competent scientists looking at each of the cod stocks. They look at the survey data from those populations, and they use that survey data to calculate changes in mortality rates over time. I have been involved in three papers looking at how the natural mortality rates of cod have changed in relation to changes in predation risks and so on.
There is an awful lot of ongoing background information being collected about at least how the rate processes that determine population change are actually varying over time, not how one might predict them to vary using various models.
What was the other question?
Senator Ravalia: It was in terms of the viability of restoring a commercial seal harvest. Would that help balance the ecosystem, from your viewpoint?
Mr. Walters: Right now, there are roughly 100,000 seals on the coast. If the population were reduced by 50%, the sustainable harvesting theory for population dynamics tells us that we would be able to harvest about 10% of the population. We could get a sustainable harvest of seals about 10,000 a year for the long haul. If the First Nations did manage them in a more or less sustainable way, it’s likely going to be the harvest rate they would achieve on the seals; they were taking about 10% a year.
It is pretty easy to set up a management system that uses the ongoing monitoring data for seal abundance and moves the annual allowable harvest up and down so as to keep the population near target level.
These mammal populations change more slowly than fish, so they are easier to manage on a sustainable basis. They are easier to monitor. They are not invisible under the water; they are out where you can count them. And there are neat things about collaboration with fishermen to gather the survey data and the other stuff.
Senator Ravalia: Thank you.
Senator Kutcher: Thank you very much to our witnesses. You are being very helpful and confusing to us, which is good, because confusion is the first step toward understanding.
I’m going to make an observation: Your testimony has again reinforced how very little we actually know about our oceans, whether it’s how they impact climate change or the life that exists within them. It is with all humility that we approach these issues of how to create sustainable fisheries and how to understand the impacts of carbon capture and release on oceans. I would echo the importance of actually funding all sorts of research into our oceans. But I also understand Professor Walters’ caveat that we can’t wait until we know everything. We do know a lot so we do what we can on that.
My question is on the prey-predator relationship. Correlation is not causality; we know that. In regard to the increase we’ve seen in seal populations on the east coast and the fact that cod stocks have not recovered and salmon stocks are challenged, I’m trying to understand the issue of competitive predation. If I understand it correctly, the seals and some of the other fish feed on forage fish, so we may not see large amounts of salmon or cod in the stomachs of seals because they are not eating the fish directly; they are competing for a third food source. As those food sources change, someone on the water could see the correlation, but it’s not a direct causal link. It is a third-party phenomenon.
I’m trying to understand; does that make sense to you? Is the issue that we’re looking at not so much seals eating fish but seals and fish competing for another population, a forage fish population? I’m just wondering about that. If that is the case, rebalancing seal populations — realizing what we heard about their previous numbers, potentially rebalancing them — would that potentially improve sustainability in cod and salmon? It’s a long, rambling question.
Ms. Iverson: I can perhaps try to address a few of those points. To start off with, we’ll just go to the endpoint. There are numerous examples from around the world and throughout the 20th century of large-scale reductions and removal of seals and other marine mammals from ocean ecosystems. In almost all cases, these removals had either completely unknown or no effects on the fish stocks that were of interest, even in cases where substantial reductions in the marine mammal populations occurred.
Given the enormity of the expense of trying to conduct such a reduction; the unlikelihood that we could evaluate its effectiveness, as the largest predators of fish are other fish; that there are many, many other species out there competing for the same resources for fish; and that these resources are changing with climate change, I don’t see any way that this could be evaluated. Certainly, it would take a decade, at minimum, to evaluate any such response, and it would require a continued and enormous amount of resources to actually conduct such a reduction. That’s sort of my endpoint view.
In terms of the increasing seal populations, there are just so many other factors out there that to do one correlation between one predator species and one prey species is simply not going to get us there.
The way of the future is to better understand how these ecosystems are changing and how the predator-prey interactions are changing. That could at least give us some information. We do know how to do that. We have methods for acoustically tagging numerous individual fish, tracking them by the seals themselves, looking at predation events — if they occur because we can tell whether predation events occur — and also letting them tell us where foraging hotspots are. We actually have a proposal in a large-scale Canada First Research Excellence Fund, or CFREF, that we put in to actually kill two birds with one stone. That is, we would use seals as oceanographers. As they’re tracking other fish, we’re studying who they are interacting with to collect oceanographic information for the UN Decade on Ecosystem Restoration and to help Canada meet its commitment.
There are things we could do to better understand these changing ecosystems, and we are trying our best to do them. Again, I think the simple correlation with one predator species and one prey species would not be the most informative.
Mr. Walters: Could I add something to your question here on this business about predator-prey relationships? One of the things I’m best known for is the development of food web models: mathematical models that try to look at the predator-prey interactions and dynamics of a large number of species in complex food webs.
To try to answer questions like the one you raised, senator, about where the dynamics are going on and what will actually change. One of the things that comes out of managing those models, simulating the management of these complex systems, is it is not true that everything depends on everything else.
You need to be very careful here when you are talking to two scientists who are physiologists, whose knowledge of food web and predator-prey theory is modest, to say the least. What we see in these big models, when we run them and fit them to historical data for places like the Salish Sea, is that you do get dominant interactions. You do get dominant effects of localized trophic interactions, like the severe impact of seal build-ups on coho salmon and juvenile survival where not much else is going on in the rest of the system. A lot of the other mortality agents are taking out large numbers of those creatures, but it’s not rapidly changing over time.
You can target management within complex food webs to target these pathological interactions that develop due to depensatory predation effects and things like that without disrupting the whole ecosystem.
What we are seeing with the seals and sea lions is that they are building up on both coasts, sustained by a forage base of small pelagic species, like herring, and some other things that are relatively productive gadoid species like hake and pollock. That is what is allowing the West Coast populations to build up such large numbers: eating lots and lots of herring and hake and some larger salmon, to put it simply. That is about 90% of the food that they take in.
Whenever you have a big predator at the top of a food web like this, that is a generalist predator that can continue to sustain itself on a wide variety of prey types, especially when it can switch and target — Sara mentioned the very specific spatial targeting of aggregations of one prey or another — the dynamics not only get really complicated, but the predator becomes pathological with respect to its potential impact on any one of its prey species. It can end up nuking one. Its remaining at abundance is much higher than you would get in a simple predator-prey system. When it knocks down one of its prey, it will switch off and leave that prey alone. Hopefully, that will allow the prey to recover. We’ve seen that in a couple of the herring stocks on the west coast of B.C.
One of the problem situations we have on the West Coast is that the predation we are seeing on juvenile chinook and coho is not targeted predation. It is just that they eat them when they happen to run into them. It’s incidental predation. So, chinook and coho are being caught in the crossfire of that ecosystem change that’s going on. They are collateral damage, if you like.
Mr. Rosen: I certainly acknowledge Dr. Walters’ expertise in ecosystems, but I do want to clarify a couple of points.
One, Dr. Iverson mentioned the history of large mammal culls. That’s not just a matter of opinion. In fact, there’s a DFO paper that came out that provided the history of that type of management. Dr. Walters talked about not needing more information; we know what to do. To some degree, I understand that concept, and I certainly agree with it, but he is also viewing the inevitable conclusion as being that we need to change the ecosystem and, in the parlance that’s often used, rebalance it. I take exception to the term that we need to rebalance the ecosystem. Partly, the idea that the ecosystem needs rebalancing by humans is what I find difficult. Also, we have to remember that what we’re really talking about is ecosystem engineering. We’ve talked about the complexity of the ecosystem. To think that over a 20-year period we could put in a management strategy to successfully change the ocean’s profile to match what we desire seems a little out of our scientific reach.
Mr. Walters: You’re not here as a scientist talking today. You’re here as a person expressing his personal value choices.
You ask me that same kind of question and I’ll tell you that trying to have an ecosystem that produces lots of human values is the best ecosystem to have out there, rather than one that has reached some kind of natural equilibrium that isn’t necessarily healthy.
These things will keep changing. We’ll never manage them completely successfully. We’re always learning, making mistakes and learning from those mistakes. The best we can hope to do is to find policy options that are most likely to take us in a better direction for at least some period of time. Right now, that’s what is not happening.
Senator Kutcher: I am a different kind of doctor than these doctors, and I know when I’m out of my lane, which is now.
Do we have the type and quality of data that we need to do some of this modelling on the East Coast and be able to ask the models — I realize that the models have limits too. I immersed myself in climate change modelling over the summer and gave up in despair trying to understand how the models work.
Do we have the capacity? Do we have the data we need? Do we have the sophistication of the analytical tools that we need to do some of that modelling? I don’t know the answer to that.
Mr. Walters: Yes, there’s a fairly large ecosystem modelling team led, I believe, by Alida Bundy, a professor trained here at UBC. There’s an ecosystem research group.
These models are pretty dicey. In particular, the basic trophic linkages that we put in, the rates of consumption of things by other things — Sara will tell you in a second — comes from inadequate, incomplete and often outdated diet composition information. The first place we go to figure out how strong the effect of each creature is on each other creature is that diet composition data. As I mentioned earlier, there are problems with additivity of mortality impacts in such calculations.
Yes, there is an ecosystem research team that is trying to piece together some of this information and trying to look at policy alternatives. There are also ecosystem modelling teams on the Pacific coast in DFO that are doing the same thing. They are being, as far as I can tell, actively discouraged from even looking at scenarios involving predator manipulation. Some of their statistical models don’t even include predator abundance as statistical predictors of mortality change.
There’s a whole bunch of science bias, at least on the Pacific coast, in that regard.
Ms. Iverson: If I may, Senator Kutcher, yes, we do have the modelling expertise that could tackle some of these questions. Unfortunately, we do have gaps, and much of our information is what I would consider to be out of date because of the rapid changes that have occurred over the last decade.
We also have a huge gap in knowledge of things like juvenile mortality and juvenile foraging and diets. They make up a really important numerical component of these seal populations, certainly on the East Coast. We know virtually nothing about that. Those are critical to put into these kinds of predation models as well as recent diet.
We do have the capacity. It’s just modelling would tell us where we were ten years ago.
Senator Kutcher: So you have answered the question. There are substantive issues around the quality and quantity of data that you actually need to feed the models, let alone the type of models being used.
Ms. Iverson: The quality of the data is good. It’s in part out of date and in part there are gaps in the population that I think are really important to fill, because juveniles are going to feed very differently — they’re smaller, so they’re going to feed on smaller prey. They’re probably going to feed in different spots because they might be outcompeted by adults, certainly by adult females.
We also know that the phenology of birth, for instance, in grey seals, has changed by a phenomenal amount over the last three decades. They’re giving birth earlier, and so the juveniles are leaving to feed earlier. That’s right now a black box.
So, yes, the data is attainable. We just don’t have it right now.
Senator Kutcher: Great. Thank you very much.
The Chair: Before we go to Senator Ataullahjan, I want to delve into the research once again, because the committee has heard testimony from researchers that government-academic research partnerships are clearly the way to go. I’d like to pose this question to Dr. Rosen first.
However, the committee also heard that there are many administrative hurdles for researchers to overcome when applying for grants or being awarded contracts to conduct research for Fisheries and Oceans Canada. For example, the committee heard that:
We, in academia, are, of course, dependent upon grants and contracts. Sometimes organizing those and getting those through the two bureaucracies — the DFO on one side and the university on the other — can be an almost nightmare combination, which directly interferes with what we accomplish on a year-to-year basis.
We also heard that some research contracts are awarded with the stipulation that they not increase the workloads of departmental scientists, which is difficult for academics to adhere to or manage.
Have you experienced similar concerns when collaborating with Fisheries and Oceans Canada on seal research projects? What has been your overall experience with the department on specifically seal research projects?
Mr. Rosen: Well, I’ve been somewhat fortunate in that my research that’s come through DFO for seal research has come through not normal requests for proposal systems that have been targeted. Certainly, we do run into problems when we want to coordinate research with DFO scientists as far as paying for technicians and things like that. It’s difficult with some of the grants that are offered, as far as getting lab time or getting technician time, just because of the administrative hurdles.
Part of the problem is that DFO is not usually set up as a granting agency. Personally, I have not found, in my research, that it’s any more difficult than many of the other agencies I work with. But, again, my direct funding from DFO has been pretty minimal over the years.
The Chair: Thank you.
Dr. Iverson, what’s your situation?
Ms. Iverson: Yes, my interactions and collaborations with DFO, both as a professor and as the scientific director of OTN, have been extremely fruitful, collaborative and successful. Yes, there are hurdles that get in the way of moving forward, including the usual red tape; I get that. We’re all working with limited resources.
But my collaborations with DFO have been tremendous and through OTN. Right now more than ever, DFO and academics recognize how much they need each other. I think in the olden days, it used to be fairly proprietorial. I think that’s really changed over the last few decades. Now, it’s clear that DFO can profit from academia, and academia can profit from working with DFO.
Personally, from the standpoint of OTN, one of our mandates is to help DFO meet its needs. So, if there’s anything we can do to help DFO scientists answer some of their questions through our infrastructure, we are completely at the table. Yes, there are lots of hoops to jump through, but that’s the nature of the beast right now.
Mr. Walters: I have nothing to add. I agree with what Sara said; I think that’s bang on. Basically, things are getting better. They’re complicated and shifting.
One of the things is that specific focal units like the OTN, the Ocean Tracking Network that Sara is involved with, and a comparable network of scientists working on disease impacts here on salmon on Pacific Coast have provided is a much more powerful collaborative environment for setting up shared funding opportunities and so on than used to be available with DFO.
Ms. Iverson: I would like to also add that a lot of our “scientific grandchildren,” as we like to refer to them, who have come out of, for instance, my programs, my lab as a professor as well as OTN’s programs are now those scientists who are at DFO. So we see on-the-ground expertise that DFO is benefiting from.
The Chair: Thank you.
Senator Ataullahjan: I’m new on the committee, but based on what I’m hearing, am I correct to understand that seals are being used as a scapegoat to explain dwindling numbers of certain types of fish? How can we better approach this topic with fisheries that have expressed frustration on the matter? My question is to all three of you.
Ms. Iverson: I’ll go ahead and start. Seals eat fish, there’s no question about it. They eat a lot of fish, just like a lot of other marine mammal predators and predatory fish.
Seals are simply visible, whereas other marine species are not, so they might get targeted. I’m not saying they aren’t making an impact, but so are other species, and they all interact.
We can understand this better, but it’s a lot of work to try and understand ocean ecosystems and what exactly is going on and how it’s changing. We do have the tools.
Mr. Rosen: Dr. Iverson summed up what I would say, as well.
The Chair: Dr. Walters, anything to add?
Mr. Walters: There’s a long history in the management of commercial sport fisheries, sport fishermen and commercial fishermen sitting there like Shiva gods with six arms, pointing at everything except themselves as the cause of declines and things. Yes, it’s perfectly normal for them to blame other creatures. I think it’s perfectly normal, especially when some of the impacts of marine mammals are directly on the operations of fishermen; they are taking fish directly out of the nets and so on. That makes them very visibly a competitor to fishermen. So fishermen have tended to blame them over the years in a variety of circumstances. Marine mammals definitely got a bum rap from the fishermen.
Given what we’ve been focusing on recently, there are very specific situations where it doesn’t look like we can ignore the marine mammal effect. The cod stocks that are collapsing in the western gulf, southern Nova Scotia and on the East Coast, and the coho here in B.C. are just too extreme to pretend there isn’t a serious effect there.
Senator Ataullahjan: What impact is the loss of sea ice having on the seals?
Ms. Iverson: That’s obviously something that’s unfolding before our eyes. For the populations that are traditionally land‑based, seals have to haul out on land or ice to give birth and nurse their young. For instance, grey seals on Sable Island are unaffected. Grey seals in the gulf that formerly bred on ice are trying to move to local islands, but there is increased mortality of offspring.
With harp and hooded seals, this is going to be a major impact on them, because they totally require ice. As it disappears, there will be increased juvenile mortality. There’s simply no question about that.
Mr. Rosen: Although we’re concentrating on the animals in the gulf and the animals in the more temperate regions of Canada, such as here in the west, we should not forget the responsibility for the polar species. That’s going to have a huge impact on species like ringed seals, polar bears and walruses. We’ve been concentrating on other species because of the interactions with fisheries, which are obviously more extreme in the south, but if we’re talking about species management of marine mammals under Canadian jurisdiction, it’s the polar species that are currently being affected and will be more directly affected in the future.
The Chair: Thank you.
We’ve heard from people involved in the fishing industry, the harvesters themselves, that they have a major concern with seals. I’m from Newfoundland and Labrador. We’re seeing seals in the southern parts of the province where we’ve never seen seals before. We’ve seen videos of seal stomachs being full of cod and crab.
We attended the Seal Summit in St. John’s a few weeks ago, and the latest numbers we received from DFO were 2019 numbers that showed a population, from their estimates, of about 7.6 million seals off the East Coast. I’m talking about harp seals.
The removal of those seals for the past five years has been around 425,000 seals. The average removal is a little over 29,000, giving the total over five years of a little less than 150,000.
From a committee point of view, part of the impetus for our study is the context we’ve had from people involved in the industry and the concerns they have with the seal population. In our interactions with people like you, we’re hearing, yes, there’s no doubt seals eat fish. We know they don’t eat chicken. But we’re trying to determine the impact that the increased seal population is having on the other species. I realize there are other things, such as climate change and other predators, and we don’t have the knowledge that you people have. Maybe the question can’t be answered, but how do we, as a committee, get to the determination of the impact that the increased seal population is having on the cod fishery, in this particular case, or other species of smaller prey?
I ask the question because that’s the answer we’re looking for or part of the answer we’re looking for. I find the more discussion we have, the more complicated it’s getting in obtaining that answer. Again, I realize that it may be very complicated, but I just need to get it off my chest.
I’ll start with Dr. Iverson.
Ms. Iverson: Well, I can say I don’t envy you and your committee, because it is very complicated. I guess that is something that we collectively have all been trying to study.
With the changes that are taking place, prey species moving north and also sharks — certainly we’re seeing large numbers of great whites increasing, which are presumably then also able to eat seals. Then with the changing temperatures and loss of ice, we could see carrying capacities reached for any of these seal populations and then start to decrease with changing climate.
It’s to reiterate what you just said, senator, that it’s very complicated, and it will be difficult to definitively determine the impact.
The Chair: Thank you.
Dr. Rosen?
Mr. Rosen: I, unfortunately, can’t make your task any easier. I think in my answer I might be making it more difficult.
Dr. Walters certainly has emphasized the importance and the power of ecosystem modelling and how we are filling in a lot of boxes. If we haven’t gotten to the point, we’re getting to the point where we can talk about what the impact is, but then that’s different than predicting the future, predicting what the ecosystem will look like given some change, whether that is climate change or some sort of management decision. That just, unfortunately, makes the question more difficult to answer, because you’re not talking about a steady state anymore.
The Chair: Thank you.
Dr. Walters?
Mr. Walters: I think you should change your question. You say you need to make a determination from the committee’s point of view about whether or not there’s a problem with seal predation on certain fish stocks. We’ve just told you that it isn’t possible just now to do that unambiguously with the science that’s available, and it won’t be possible when a lot more science data has been collected. There will still be just as many uncertainties, but just about different parts of the system.
Maybe the question you need to ask is how to proceed. What is the best recommendation you can make concerning the development of marine mammal harvesting systems, given the information you have now, in terms of the potential value of those marine mammal harvests as fisheries in their own right and also the benefits that they may have for some fish stocks?
If you feel like you have to get a solid, single answer, you’re going to be like the Cohen Commission here on the Pacific coast 12 years ago, where they were going to get a bunch of lawyers to determine what had caused some sockeye stocks to decline. They brought together some scientists to discuss this report beforehand, and we said, “Lawyers? If we can’t agree amongst ourselves — you have eight scientists here with eight different ideas about what caused the decline — why do you think you’re going to get something out of a bunch of lawyers?” So the Cohen Commission ended up being largely a complete waste of money. A lot.
Senator Kutcher: Like I said, thanks for confusing us. This is an important issue because we’re trying to have an understanding of the complexities of the trophic interaction between predator and prey. This is an issue for people whose livelihood depends on us having some understanding of that interaction and realizing we can’t wait forever. We’re trying to grapple with what it is that can be done to help people out, realizing that that itself is going to add the complexity back into this web. Whatever it is that changes in the human ecosystem and the relationship between the human ecosystem and the life in the ocean is going to have all sorts of cascading implications, and, frankly, we know that we don’t know how that’s going to end up. We don’t have the hubris to think we know that.
Therein lies the rub. We realize and hear from you that these ecosystems are in a state of flux, and they all will do that because otherwise they go into entropy, and the last thing we want is our ecosystems in entropy. What can we do as human beings at this point in time, understanding the critical impact of the differences in prey-predator relationships, for the people who live in these communities? How do we address that? We would appreciate your wisdom there.
Ms. Iverson: I’ll go ahead and start. As I’ve said before, we do have the tools, and we’ve shown proof of concept. I will just point to the proof-of-concept study we did with grey seals on the Scotian Shelf, where we tagged a number of fish species with acoustic tags — cod, salmon, eels and various others. Again, we had limited funding available for those tags, but we got enough out there. Then we tagged a number of seals with satellite tags and then also a little package of a mobile receiver on their back.
When the seal swims around, when it comes within a certain range of any tag — other tagged seals or other fish species — it registers that. When the seal surfaces, that information is relayed to the satellite tag and uploaded in real time to the satellite, and we have that data: where the seal is, whom it has interacted with and whether there are any predation events.
From our initial proof-of-concept study, we showed that seals were collecting ocean data at the same time they were — We also have this way of analyzing the movements, whether they’re moving fast, which is largely between prey patches, or slow, which is where they’re probably finding hot spots and foraging patches. It was actually when they were travelling and moving fast that we got most of the detections with the other fish species — the cod, the salmon, the eels — and there were no predation events on those tagged individuals.
It was when they were in the foraging patches moving slowly that they were interacting with large bluefin tuna, looking like they were sharing similar ecological niches. As an aside, a number of years ago I was working with tuna scientists that were on board tuna fishing boats to collect samples, and they cut open a bluefin tuna and there was a fully intact seal pup in its stomach, which we think was accidental, that they were just foraging in the same area and the tuna simply swallowed the seal.
In any case, through studies like this, we can demonstrate where these species are, who they’re interacting with. We even now have predation tags where the tag changes its frequency number when it’s ingested and beginning to be digested by something like a warm-blooded seal.
We have those tools. We have never applied them to harp seals or hooded seals simply because we haven’t had the resources to do so, but we have the capacity. As I’ve said, we have a proposal in the works that we hope to start, putting some of these tags on harp and hooded seals to start getting at some of these answers. In order to look at the interactions with prey, though, we would need a tagging program.
With any of these seals that we capture upon tagging, we can take a small biopsy of their blubber and put them through the fatty acid signature analysis and get estimates of diet.
We have tools. We just don’t have the research program planned for such a venture.
Does that answer your question?
Senator Kutcher: No. It is fascinating and essential; I understand that. From the data we already have, realizing the data is old and will have to be expanded and be much better, and with the tracking data from the OTN, can you give us any advice? The issue here, frankly, is this: Should there be some way of decreasing the seal population? If there were a decrease in the seal population, how much of a decrease should there be, and would that have an impact on the rebounding or changing of fin fish stocks for human consumption?
Ms. Iverson: To make the extension from those studies to what the effects of a seal reduction would be is impossible, I’m afraid.
The other thing is we know that all of these species that are feeding on this suite of prey, including cod, are very mobile. If we tag a seal on Sable Island, it moves throughout the Scotian Shelf up to Newfoundland into the gulf. Tuna and great white sharks are moving all across the Continental Shelf up into Newfoundland, the gulf and even across into Europe. So, we would not be able to say what effect reducing predator population locally would have. That has been the problem in the past with any of these efforts that have been conducted to try to reduce marine mammal populations.
As Dr. Rosen said, there is a published paper reviewing all those attempts at marine mammal reduction and the consequences — or unknown consequences — of those. I would be happy to forward that to you and any of the papers that came out of our OTN work.
Senator Kutcher: If you wouldn’t mind, yes, thank you very much.
Ms. Iverson: Absolutely.
The Chair: To follow up, any information you think would assist us with our work here, please forward that to the clerk.
Ms. Iverson: Absolutely.
The Chair: That goes for Dr. Rosen and Dr. Walters as well.
Senator Ravalia: To follow up, we have heard that in certain international jurisdictions, Norway and Iceland in particular, they have managed their seal populations in a more judicious manner than we have. Given that their ecosystems are probably just as complex as ours, I’m wondering whether you have done any collaborative work with them. Do you know if what’s happening in the North Sea and in and around Norway and Iceland is different than what might be happening off Newfoundland and the coasts of the Atlantic provinces?
Ms. Iverson: I’m afraid I would not be able to speak to that.
The Chair: Okay. That is another good question that we’ll have to go somewhere else to get an answer.
Anyway, that’s it for questions from our senators. I want to take the opportunity to once again thank each and every one of you for joining us this morning. There is no doubt that your work is extremely important, not only to the work we are doing here as a committee but indeed to the fishing industry of Canada. We wish you well as you continue to do this work. Hopefully, we can find the resources. As mentioned, the tools are there; it is just having the resources to use the tools. I think we are contemplating at least a recommendation or two in that direction as time proceeds.
You have added much to our discussion this morning, and your wealth of knowledge is second to none. Whether we are any clearer at the end of the day, I’ll leave to my colleagues to determine at a later date, but you have brought forward this morning will help with our discussions. I wish you all a good day. Thank you.
(The committee adjourned.)