Scientists may have found a new population of orcas off Oregon and California coasts

Scientists at the University of British Columbia may have identified a new population of orcas, also known as killer whales, feeding in the deep waters off the Oregon and California coasts, according to a recently published study. The researchers reviewed photos, videos and descriptions made by fishermen, NOAA scientists and a whale-watching tour operator during multiple encounters with the marine mammals over a span of nearly 25 years. Their distinctive appearance and feeding behaviors — including a penchant for hunting sperm whales — are some of the ways they’re unlike other killer whales that forage off the West Coast of North America. Joining us to share more details about this mysterious pod of orcas is Andrew Trites, director of the Marine Mammal Research Unit and professor at the Institute for the Oceans and Fisheries at the University of British Columbia, and a co-author of the study.

The following transcript was created by a computer and edited by a volunteer:

Dave Miller: This is Think Out Loud on OPB. I’m Dave Miller. Scientists at the University of British Columbia may have identified a new population of orcas, also known as killer whales, feeding in the deep waters off the coasts of Oregon and California. The researchers reviewed photos, videos, and descriptions of encounters from fishermen, NOAA scientists, and others over a span of nearly 25 years. They concluded that, in terms of behavior and appearance, this group of killer whales is distinct from any of the known populations. Andrew Trites is a professor and the director of the Marine Mammal Research Unit at the University of British Columbia. He is a co-author of the study and he joins us now. Welcome to the show.

Andrew Trites: Hello.

Miller: When did you first hear about this group of orcas that might be a new and previously unknown population?

Trites: Well, it’s been brewing for quite a few years. In fact, the lead author is Josh McInnes. He’s a graduate student with me here at the University of British Columbia. And he was working on a catalog of killer whales off the coast of California and Oregon. And in building this catalog, he was able to identify most of the individuals as having been associated with each other, and been seen regularly, and they all kind of fit together. But then he had this, essentially, shoebox of unknown individuals. In fact, there were 49 whales that didn’t quite look like the others, nobody had seen them consistently, and they became our mystery whales. And it was only as Josh was coming to me to puzzle over this I began to realize he was on to something. These were in fact different than the others, and likely a unique and unknown population of killer whales.

Miller: Unique from which ones? What are the already identified populations of killer whales off the northwest coast of North America?

Trites: We have three different ecotypes. We call them ecotypes, at this point, not species. Sometimes we think of them as being populations. One of them only eats fish. We refer to them as being resident killer whales. They specialize particularly in salmon, and not just any salmon, they love chinook salmon, the biggest of all.

The second group we call them transients, or Bigg’s killer whales. And they were named in part because they always seem to be on the move. And they only eat other marine mammals.

And then we have this third group that lives far offshore over the continental shelf. And we call them the oceanics. They appear to be specializing in eating sharks and large fish. And part of the clue in terms of recognizing that they eat sharks is because their teeth are ground down, literally like they’ve been eating sandpaper.

So those are the three known ecotypes. They’ve been photographed. They’re fairly well understood, although we know more about the ones that live closest to shore and less about the ones further away. And now we have this fourth group. And we’re not quite sure who they are, if they belong to distant ancestors of the transients, because they eat marine mammals. Or if they can be a stand alone. At this point, we don’t know.

Miller: So I’m curious about the process of putting the photos of these killer whales into that sort of mystery shoebox. How would your grad student even know who these various orcas are in the first place?

Trites: Well, it’s a special skill, and there’s only a few people I think that are really up to this task. Literally, it’s like trying to identify somebody just by looking at their fingerprints. Of course, now we have AI that’s going to allow almost anybody on the water that takes a picture to figure out who they’re looking at. But Josh is one of these individuals who can recognize everything from the subtleties of the shape of a dorsal fin, the nicks and marks on it, the shapes of the saddle patches, grayish white area just behind the dorsal fin. And also looking at the eye patches, these white oval shapes near the eye. And they are just as unique as the fingerprints on your hands.

Miller: Who took these various photos that then he would sift through?

Trites: Pictures come in from all sorts of sources. And often it could be just somebody out on a whale watching boat. It could be somebody in their own pleasure boat. Or we’ve got them being taken during research cruises. And for the most part, people will take a picture, and then they send it to somebody that’s a known killer whale expert, with one question, like “who are these individuals?” We all want to know a bit more about their stories. And with killer whales, it’s now possible, with time, to identify every single animal and give it a name. And not only that, we can then put them into family trees, we can see who is related to who, who are the grandmas, who are the aunts and uncles, who are the cousins, and how they’re interrelated. So over the years, this incredibly diverse story has been evolving. And now we have, in essence, family albums of killer whales.

Miller: Two things come to mind about that. One is just how extraordinary it is that humans have such familiarity with members of the species. The other is, I can’t help but think that part of that is only possible because there are so few of them.

Trites: You’re exactly right. There are few of them. We’re talking overall probably less than a thousand. And the fact is that they do get noticed. To our eyes we can pick up these subtle differences as well. So it’s not quite like looking at a harbor seal, for example.

Miller: More anonymous.

Trites: Yeah, exactly. But I think the one thing that is interesting here is that if you go back to the sixties and seventies, when killer whales were being captured here off the coast of Washington and British Columbia and being sent to aquariums, nobody recognized that there were different types of killer whales. As far as anybody knew, it was one species, they were all the same. They were called killer whales because they were killers of whales. But of course, it turns out now, well, some are completely piscivorous. They only eat fish. And others are specializing in sharks, they’re all specialized. And they’ve got different structures in terms of their social organizations, feeding habitats, dialects. And really, they are as unique as I guess different populations of people around the world.

Miller: And given that it’s now been a few decades where scientists like you have started to identify and recognize these distinct ecotypes, these distinct populations, what went through your mind when your grad student came to you and said “I think this is actually a new one, this is a distinct and separate population?” I guess a short version of my question is, did you believe him?

Trites: I think part of the process in science is initially to be a skeptic. And to challenge what’s being said, and then putting the onus back to let’s put the pieces together. But as we went through it and looked at all the different reports that had come in, the photos as well, I was convinced, as were the other seven people who are co-authors here, that we were onto something unique. It was time then to announce that this is something that’s occurred over 24 years. We’ve had 49 photographs, and there’s something going on here. But it’s in a piece of the ocean that is so far from shore, that so few people have gone out. And literally, if we were to go today to go look for them, it’s like looking for a needle in a haystack. It’s a huge body of water to cover. But there are people out there, and people are encountering them. In fact, since our paper’s come out, we’ve had about another 20 photographs been sent our way saying “by the way, we saw something, we didn’t know this might be important. What do you think?”

Miller: And does that new data that you’ve gotten, does it corroborate what you already had? Or complicate it?

Trites: So far it’s consistent with what we’ve been saying. They do look similar to these other ones. But it’s going to take more time, and ultimately we’re going to need some DNA, genetic evidence as well to really sort out their evolutionary branch, and how they’re connected to the other killer whales that inhabit our waters.

Miller: So as you noted, you started with skepticism, a necessary component of effective, meaningful science. What were the different parts of the evidence that made you believe that this was a distinct population?

Trites: Well, there’s a few things. One would be just their physical appearance. And while to the average person, it looks just like a killer whale, and there’s no doubt that it is a killer whale, they have similarities with the transient ecotype, as well as with the offshore ecotype. They look almost like a hybrid of the two. So that was one thing.

Another was where they were seen, in really deep waters. And for the most part they were seen off of the continental shelf break, which is this huge plateau until it drops off into the abyss. And the species they were feeding on were sperm whales, pygmy sperm whales, leatherback turtle, we had one encounter [with] Risso’s dolphin, elephant seal. So big big animals that they’re feeding on, enough to feed a family and have leftovers.

And probably one of the most curious things of all was seeing that 46 of the 49 animals, this 95% of them, had cookie cutter shark marks on them. So cookie cutter sharks live in tropical waters. They are a parasite which means they feed off of other species but don’t kill them. And in this case here, these cookie cutters appear to be latching on with their upper teeth onto the body of a swimming killer whale. And then they use their lower teeth to pull out or scoop out this mouth sized chunk of flesh and blubber. And to our eyes, you see both the scars as well as the holes, literally like someone took a cookie cutter to punch it out of the animal.

So 95% have got cookie cutter shirt marks. The animals we were seeing were reported in Oregon and California waters. They are in fact spending time in more tropical waters as well, so maybe coming up here more seasonally. We just don’t know yet. But that’s one thing that makes them stand out as being really different from the other whales we’re familiar with.

Miller: You were talking earlier about, for the other populations, the ability of scientists to know about the families, about the social structures, about the relations. Do you know anything like that for this group?

Trites: Not a whole lot, other than they seem to be in fairly large groups. If you look at the ecotype, the transients or Bigg’s killer whales that feed close to shore on seals and sea lions, for example, they tend to be in twos, threes and fours. And these groups we’re seeing, we had one encounter, it was 12 killer whales taking on nine female sperm whales. And later on, the group grew to about 35 killer whales that came in. And it was interesting that the way that sperm whales have evolved to deal with predation, in this case by killer whales, is that they form a rosette. Often the calves, which are the most vulnerable, will be in the center, and the females will put their heads into the center and tails outward to try to thwart off the attack. So clearly, these are encounters that they’ve had over time. They have evolved strategies here to try to protect themselves, but most notably to try to protect their calves, which would be the most vulnerable and easiest for killer whales to take down.

But does it appear that when in the open ocean, when in essence, there’s no bottom you can force to push an animal into, that is going to take larger numbers to contain and to have a coordinated attack. And as a result, if you’ve got large numbers, you’re gonna have to take down larger species so that everyone gets a benefit from the hunt.

Miller: I’m curious, what’s at stake in this? What would it mean to the scientific or conservation communities if it turns out that, let’s say you are able to get the DNA from the living needle in the haystack, the moving needle in the haystack, and you find that this is a distinct population. How significant would that be? What would that mean?

Trites: As a scientist, what we live for are the “aha” moments. We love to be the first to make a new discovery. We share with a few people in our lab and then we start to talk about it more openly. But it’s always exciting to find something that we didn’t expect, and particularly when we’re finding out things about topics such as killer whales. One might assume by now we must know everything about them.

I think this also points out that the open ocean is literally our last frontier on the planet. There’s still so much more to be discovered. There are species still to be discovered. It’s really exciting, but it’s also a very expensive part of the planet to go to, to learn about it. But it does tell us that, in this case, the fact that the ocean’s top predator is making an honest living out there, that it is clearly a very productive part of the world, part of the ocean. And there’s more there for us to discover and learn about, and ultimately to protect it.

As an example, we’re hearing a lot of talk about ocean mining, dredging the bottom. And that could cause huge effects to the entire ecosystem, and ultimately have an impact on killer whales. So I think in some respects, the world does pay attention to species like killer whales, top predators. And it’s often through the eyes of a killer whale we begin to appreciate the entire ecosystem, the food pyramid that exists there. It makes people more aware and ultimately people care more, and I think then voice their opinions about how we want to see the oceans developed and used, because ultimately we need to be concerned about all the species that live there.

Miller: Andrew Trites, thanks very much.

Trites: Thank you.

Miller: Andrew Trites is the director of the Marine Mammal Research Unit. He is a professor at the Institute for the Oceans and Fisheries at the University of British Columbia.

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