July 14, 2020 – Dr. Andrew Trites, “Marine Mammals” – ZOOM

Andrew Trites, PhD

Dr. Trites oversees the Marine Mammal Research Unit and a research program that involves captive and field studies of seals, sea lions, whales and dolphins.

His research is primarily focussed on pinnipeds (Steller sea lions, northern fur seals, and harbor seals) and involves captive studies, field studies and simulation models that range from single species to whole ecosystems. His research spans the fields of ecology, nutrition, physiology, and animal behaviour—and is designed to further the conservation of marine mammals. It is also designed to further the conservation and understanding of marine mammals, and resolve conflicts between people and marine mammals. The research program includes researchers, students, technicians, and support staff. The training of students, and the collaboration between researchers specializing in other disciplines (such as nutrition, ecology, physiology and oceanography) is central to the success of his research program.

Q & A Session transcription

Question: How do we differentiate between Northern Resident Killer Whales and Southern Resident?

Answer: They can be differentiated in a couple of ways. The shape of the dorsal fin helps us to figure whether or not it’s a resident-type of whale, which tends to be more curved, versus a transient, the marine mammal eaters, which tends to be a sharper type of fin. To get down to identifying the individuals, we look at any sorts of nicks in their dorsal fins and their saddle patch, the white area behind their dorsal fin, the shape of it, the coloration, and any types of scars on it. Then we go to a catalog of images, so it’s basically like fingerprints. Each whale has a unique dorsal fin shape, a unique saddle patch, and with that we will look at the catalog. We also know just in terms of the areas, where we see the whales, whether they’re likely to be southern or northern. So we use a number of different techniques, but the fact is that every Killer Whale on our coast has a name and is in a book, and so we have mugshots for all of them to match them up.


Question: How would you find the performance of the DFO (Department of Fisheries and Ocean) and are they helpful?

Answer: The funding that we are receiving is from the federal government. It costs a lot of money to do this sort of research. We are finding that from the management side, they are very interested in hearing about what we’re doing, what we’re finding. I sit on one of their Technical Advisory Committees and we’ve had opportunities to share some of our research with them. I don’t think we’d change anybody’s actions so far, but I think we are now putting seeds of doubt into some of the assumptions, and I think that’s part of the process. So, I’d say overall, the relationship is good. I did hold a workshop at UBC, where we were asked by DFO to look at some management needs and questions that they had. So, I think that we have a good rapport. We do work in a different way than the government. We are also working with students, with deadlines to finish and so we tend to push the envelope in terms of using new technologies, in terms of getting our findings out faster perhaps than what the government might, but overall I’d say that we are working fairly well together.


Question: Could you expand some of your comments/concerns around seals and sea lions?

Answer: I don’t know how far to go on here, and I don’t want to go too far off topic either, so I’d say if I don’t get to what you’re looking for, maybe ask a few more specifics. So, in terms of seals and sea lions, we know that, in the fall, they do feed on adult returning salmon and that overall, in a given year, which salmon may make up only 3% of their diet. So, it’s a very small part of their diet, and typically, when you have large schools of fish coming back, they swamp the predator. And so, they can’t have too big an impact on the prey population. The limitations for a seal or sea lion is the size of their stomach. They’re not like a ship, they don’t have a freezer to store it in so they can only take what they can put in their stomach, so we’ve always dismissed them as having a significant impact. And then some of the research that was done through my lab started looking at fecal samples of seals and using DNA to determine what species were in there. Before that we were just looking at hard parts, the bones. What we discovered, using DNA, is that we were missing a lot of very small fish. So, to our surprise, the sea lions were not eating young salmon, but some seals were eating smolts as they were coming out of rivers. At the end of the day, it only takes a few seals to be consuming tens of thousands or hundreds of thousands of fish. So, while it’s a small percent of their diet, in terms of sheer numbers. So, there is some thought that if you were to remove the seals, then more of these young fish would survive to come back to spawn. Well, unfortunately, the models that have been done so far to make these predictions have assumed that the fish are all going to come back as adults to spawn, and they have not considered the fact that seals, in this case, may be just one of the first in the sea food buffet lineup to eat some of the fish coming out, and there are other predators waiting for them. So, I’d say the jury’s out still in terms of what impact they have. The other thing is that, predation by seals is just one of the hypotheses about why salmon such as Chinook and Coho may be in trouble.

The other is, that the trouble is being caused by hatcheries. While the public loves the idea of hatcheries, I’m sure many people that are listening now, also like hatcheries. The concept here is that we’re just going to take fish, spawn them in a bucket, and then raise the babies and let them into the ocean, so that the oceans are bottomless. Yet it appears that in some of these sites, we’re putting too many fish into the ocean, and that the fish are competing with each other. When the fish compete, it means that as they enter the ocean, none of the fish are going to grow to be big enough to survive long-term, so we’re already seeing signs that many of the hatchery fish coming back into Puget Sound are very small and there’s some thought that if we didn’t put so many fish in, that those that are coming from the wild rivers would grow to be bigger, they would get out into the ocean and survive better, and there’s also some indication that many of the hatchery fish are going into wild rivers and spawning there. You can think of Chinook being your stock portfolio – we had 900 different stocks of fish coming in and some years some would do well, and other years some would do poorly, but overall they were doing well on average. Well now it appears that everything is in sync, so when the market crashes, everything crashes. So, there’s been growing concern and it’s not voiced very much with the public about it, but there is concern that hatcheries are certainly needed in some areas, where people have destroyed the natural rivers, that they may not be the solution and could be contributing to the problems. So, I’m happy to go into more detail on that, maybe through another question, but I think simply, I just want to point out that it’s not clear what impact the seals are truly having, other than we do know that some of them do eat young salmon, but we can’t say that is the cause. Although, there are some models that make the prediction that they are the cause and the solution is to remove them.


Question: what sort of contaminants are found in the southern residents and could this be related to the calf sex ratios?

Answer: Certainly, there are still PCBs (polychlorinated biphenyl) the system, they are residual and still present. There’s also some of the fire retardants that are put into furniture, clothing, and other things like this which is ending up into the marine waters and into the food chains well. So, there’s just a whole host of different contaminants that are there. There is some thought in me that it could be related to sex ratios, but I don’t have any evidence and maybe somebody online would know if you have any cases of other species like humans where you’ve seen sex ratios being skewed because of contaminants. And so I haven’t seen any indication there, but it is certainly a possibility. If this was truly a case, you would expect to see that the Transient Killer Whales which are ten times more contaminated, that they would have a skewed sex ratio too of males to females, and they don’t. Also, the fact that females do have a chance to clean their systems, by transferring the contaminants that are binding with the lipids into their milk to their first born calf, and get relatively clean, so I don’t see it personally that the contaminants are a direct link to what is going on.

Question: What is the response of DFO to your surprising research that Southern whales have more fish than Northern residents?


Answer: So, we presented this at one of the working groups, and people did take notice. But I’d say that they’re waiting for the peer-reviewed paper before thinking more on it. I’m working right now on the draft manuscript. So, I think we’ll have to wait until that comes out and I expect that it’ll probably be published in the fall. In which case, I’m sure that there will be media attention and people asking questions. So, we’ll  have to see but at the end of the day, I think that there’s no single on piece of research that will be convincing, it’s going to be a body of studies that  show consistent results, but I’d say that what we’re finding is consistent with some of the information that we have about generally numbers overall, that over the past couple of decades, there’s been about 600,000 Chinook salmon coming in, and those numbers have been quite constant, and at the same time that fisheries have been restricted, particularly commercial fishing has been restricted on it on trying to keep numbers fairly constant coming in.


Question: I have heard that the latest Minister of Fishing knows nothing about fishing and is based only on the east coast. A golfing buddy of mine who works a lot with salmon is aghast at what the Feds are doing. How can we educate these east coasters?

Answer: It’s a good question. I had the fortune with the last two ministers, to get a chance to meet them and speak with them. Our past minister was from North Vancouver. I found that he was very well-informed. And of all the ministers, I was quite struck by his grasp of science, his ability to simulate a lot of information, and he was listening, but at the same time, there’s a lot of people talking to them. In terms of the east coast Minister, I have not met that minister yet. I thought we were fortunate, we did have a west coast Minister who understood the issues. But, I don’t know, and of course the Covid virus has changed everything in terms of our abilities to interact one on one.


Question: Interdisciplinary cooperation/interest from other faculties, e.g. commerce, law, etc.?

Answer: So, I think the question is asking whether or not if we have cooperation with others. So, we are working with the Faculty of Forestry, and they’ve got a lot of salmon research, and Scott Hinch, a professor there, he’s heading up some of those trackings that I showed you. I think it would be interesting to have discussions with people involved with commerce and law and just see because in many ways, the SRKWs have become the poster child for everybody’s campaign. If you don’t like pipelines, cruise ships, dams, whatever, it seems that people are linking their causes to SRKWs. I think there would be value in having some of these discussions.


Question: What are the primary concerns with the NRKW population taking over the SRKW population? I assume there’s a concern with reduced biodiversity but could you go into more detail? Can the populations interbreed?


Answer: We don’t know why SRKW are separate. They are related genetically, they can interbreed, they share a common culture in terms of being maternally-led, their preference for what they eat, so there’s absolutely no reason why they could not be interbreeding, but perhaps just like with some families, they just keep apart.  We do know that they do not interact. And I can’t say anything more than that on there. I think that as the Northerns get bigger, so at 309, they’re going to have to either find more food, stop reproducing, or find more territory. I think just through the fact of the sheer numbers, I would not be surprised to see  them push further south, and perhaps become the resident population that feeds in the Salish Sea, and perhaps even exclude the Southern residents. Time will tell on that one if that comes to bear. But as you see even among people, as their population gets bigger there’s a tendency to expand, and emigrate, and to take over their neighboring territories.


Question: Have you been engaging and working with First Nations in your research?

Answer: On this one, we have not had any direct involvement in terms of having First Nations on board with us or doing some of the research. We’re talking with a couple of groups, one in particular from Vancouver Island about their interest in  potentially trying to moor and maintain, such that putting fish finders on the bottom of the ocean so we can be doing real-time monitoring of Chinook as they’re coming in, and there’s some interest there. So, it is about trying to find areas where you have people, and areas that can support research and help provide some of the data. Ideally, we’ll see over time, some of their youth coming to universities to get training to lead research program. Most of my involvement with First Nations has tended to focus mainly on salmon-related questions. Salmon are extremely important to all of our coastal and even many of our interior tribes.


Question: Do the Transients ever prey on the Resident populations?

Answer: The transients have not been preying on the resident populations, although there was an incident that was reported about two years ago of a transient killer whale killing a calf. I can’t recall at the time if it was a resident calf or perhaps another transient calf. But sometimes, when we see these sorts of behaviours, it isn’t representative. It’s really abnormal behaviour to see that sort of thing happening. So overall, they do not prey on the residents.


Question: Any concerns with fish farms?

Answer: There are certainly concerns with fish farms in terms of the health of salmon, and I’d say that the biggest concern has been over whether or not the fish farms are a source of disease that are infecting wild populations. Through some of the DNA techniques, they’ve found linkages between some viruses, but I’d say there’s still some research to be done. DFO was the lead organization doing that research, but that has been the biggest concern – the potential effect that it has on wild fish and there’s been no connections made between farmed fish and killer whales. Putting the disease aside, when I go into the supermarket, I’m always struck that despite how people speak about their dislike of fish farms and how we should be eating wild fish, when I go to the markets, I see the wild fish being put into people’s baskets and very few people are purchasing wild fish. I think a lot of it comes down to just the cost of it and at some point over time, there’s a need that if we all want to be able to enjoy and eat salmon, that aquaculture is part of that future. But, it needs to be done in a way that doesn’t do harm to our wild fish.


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