Shark Week: The Podcast

S1 Ep.5: Studying the Dangerous and Dwindling Mako Shark

Episode Summary

Marine biologist Luke Tipple interviews the stars of the Shark Week show, “Mako Nation.” Riley Elliott and Andy Casagrande discuss the mysteries they uncover about the Mako Shark in one of their last strongholds—New Zealand.

Episode Notes

Marine biologist Luke Tipple interviews the stars of the Shark Week show, “Mako Nation.” Riley Elliott and Andy Casagrande discuss the mysteries they uncover about the Mako Shark in one of their last strongholds—New Zealand.

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Find episode transcript here:

Episode Transcription

[MUSIC PLAYING] LUKE TIPPLE: G'day, I'm Luke Tipple. Happy Shark Week, and welcome back to The Daily Bite, the show where we go behind the scenes with the stars of Shark Week, and talk about one of our favorite subjects, sharks. Today, we're joined by one of my favorite New Zealanders, Dr. Riley Elliott.


Last year, we saw him discover massive makos. But this year, he's headed back to an island that's become infamous for its mega tiger shark action. OK. Let's listen to a clip from "The Return to Headstone Hell."


SPEAKER 1: On a remote island in the South Pacific, we're where discarded cow carcasses attract a unique frenzy of gorging sharks.


RILEY ELLIOTT: Wow! This is insane! Look at them all above us!


SPEAKER 1: Dr. Riley Elliott uncovered the highest concentration of tiger sharks ever seen.


RILEY ELLIOTT: 45 tiger sharks.


SPEAKER 2: We're pretty [INAUDIBLE].


RILEY ELLIOTT: Spent four days on the water.




LUKE TIPPLE: Well, the shark action certainly hasn't let up at Norfolk Island. Welcome back to the show, Riley.


RILEY ELLIOTT: Oh, cheers for having me, Luke. Yeah, and you're dead right there, mate. That was one of the most intense trips I've ever had. And I think Kina said it in the show. It was the most intense trip he's ever had. So yeah, it did not disappoint.


LUKE TIPPLE: Yeah, it looked absolutely gnarly. But before we dive into that, I wanted to ask you about how you've been. It's a weird year for everybody. But from what I saw, you had some big life changes. You got married in the last year. What's life, happening?


RILEY ELLIOTT: Yeah, I mean to be honest, I felt kind of guilty. COVID year, for me, has been the busiest year I've ever had. A few Shark Week shows, a few other Discovery shows.


I got married. I moved into a house. (LAUGHS) Not that I wasn't living in a house before. But yeah, but it made me really appreciate how lucky I am to be in this position. And you know, not to take things for granted.


And also, how incredible people can be. We shot multiple episodes and multiple countries right in the middle of COVID. And it was really eye-opening.


For me, personally, living in New Zealand, we've kind of almost forgotten COVID exists. Because we've been living COVID free for almost the whole year. But I had to fly through Miami, through LA, and then was in the Bahamas, for a while.


And it was a big slap in the face, the reality that most of the world's dealing with. And so the thoughts are there. It made me really be humbled and be grateful for what I've got. And wishes to everyone, that hopefully they've got through this year and they can enjoy Shark Week, and get a bit of a smile on their face again.


LUKE TIPPLE: Yeah, for sure. It has been a strange one. But I have to assume your wife is OK with the life of the shark-diving entrepreneur guy who travels around and puts his life in danger the whole time?


RILEY ELLIOTT: Yeah, the good thing is, she's a camera woman. And she got addicted to underwater camera work.




RILEY ELLIOTT: And most of the photos you see of mine, she's taken. So it works well. I try and get her on some of the shoots. But at the same time, it's quite nice to separate work and life, at times.




Luckily though, yes, she is totally on board with me swimming with sharks for a living. Because she enjoys it too.


LUKE TIPPLE: Nice. I just went with the whole, "I know what I'm doing. I'm an expert. Believe me.


And if you come out, eventually, you might realize that it's actually kind of heinous, at times. But you know, it works.


RILEY ELLIOTT: Yeah. My mom, apparently, believes that and lives by that. But I think she just does that to get herself through each day. But yeah, we know sharks are good. Sharks are friends. And we're all still here. So that's good.


LUKE TIPPLE: Well, let's talk about sharks. Before we dive into the return to "Headstone Hell," let's look at your first mission. You went there in 2019, and on some of the dives, absolutely hectic.


You guys found 33 individual identified tiger sharks. And they're pretty enormous. What was your experience like at Norfolk Island? Was that the first time? Did you expect to see that?


RILEY ELLIOTT: Oh look, it was unreal. I mean, I really try and do projects that are novel and groundbreaking. Because not only is it fun because you're exploring.


But generally, the science and the discovery that comes with that is very poignant. And in this case, it was trying to give the Norfolk Islanders some answers about what's in their waters.




RILEY ELLIOTT: To be frank, no one had ever gone there with that intention before. And not many people actually get in the water there, because a lot of them are just fishermen or surfers. So we really do not know what to expect. I think for a veteran like Andy Casagrande, when you see his face on that show, just being like, mind blowing.


LUKE TIPPLE: He definitely looked pretty enormously surprised by the volume of sharks there.


RILEY ELLIOTT: Totally. It gives perspective for what we discovered and what's amazing is, how amazing Norfolk Island is.




RILEY ELLIOTT: And that was really the big draw card to go back, was this was like, the good Pandora's box, that we had opened. And we really, we had to go back to see what it was all about. And because there were more breadcrumbs going in different directions that really attracted our eye, as well.


LUKE TIPPLE: Well, let's stay with the 2019 show. Because one of the things I was really curious about, and I'm sure everyone else is, is what brought the sharks there? Why did you think that they're existing there, at Norfolk Island? And has there been more research since that show, that you can share with us? Like tagging info, or anything like that?


RILEY ELLIOTT: Yeah. No, totally. Well look, I went there the year before, in 2018, on a tourism shoot.


I'd seen it on a fishing show in New Zealand, from my 5 years before that. The fact that there's this Bay called Headstone Bay, where the locals dispose of fish waste, awful waste. And sometimes through droughts, full animals that have had to be culled.


Because it's just logistically difficult to bury them in land, they don't have concrete-lined offal pits. They don't want to contaminate their water source. So for hundreds of years, this organic waste has gone into the ocean to be recycled.


And the sharks aren't silly. Tiger sharks especially, are very calculated migrators. They turn up at an albatross colony as soon as chicks are fledgling.


They turn up at a turtle hatchery as soon as the turtles leave the beach. Like, within days. Even if that changes climatically, they're there at the right time.


What I really wanted to see was how reliant are they on Norfolk for the animal disposal, the cows? Or are they there because this is just a pure, pristine marine environment? Or is it both?


LUKE TIPPLE: Yeah, because I guess if you look at it from that perspective, you see cows getting dumped in the water, lots of food source. One school of thought would say they're just there for that food source. So perhaps residential, which would make it kind of a strange thing for that species. Is it seasonal?


RILEY ELLIOTT: Yeah. Well, what was cool is firstly, in the 2019 trip, when we tagged them, we saw a very clear indication that they know what Headstone Bay is. And that they ate there and they went away for about 10 days, which is the digestion period for this animal, and then came straight back to Headstone. Then, after a couple of weeks, they then migrated back up to New Caledonia, where they spend the winter.


It was like a pit stop. This is what tiger sharks are known for. You turn up to a feeding event at a certain time of year, eat, get their fill, then move to the next timely seasonal event, to feed there.


Norfolk seems to be one of those which is very unique, in the sense that it's anthropogenic. It's created by people. It's not a natural event. But clearly it's been going on long enough that it's been instilled in the DNA and the memory of these sharks, that they do this year after year.


That's what's cool. Because after this trip, a research trip from Australia, which is exactly what the intention of the Norfolk island trip was for, was to encourage further research by the Australian government. They did that. They went and tagged a bunch of sharks. It was great, because I could look on this app and watch these sharks move and watch them congregate at Headstone the year after, when I wasn't there.


It was like clockwork. In November, when the warmer waters were migrating South, they went there. Like, all of them at once. And all of them to Headstone Bay.


You'd see them feed and distribute. Then you'd see them come back right there, below the cliff. So really, really amazing stuff. And I'm really happy that this show, because it's only like a 2-week field experiment, you can't do an entire research project.




RILEY ELLIOTT: But it catalyzed scientists of Australia, to go there and investigate the space for the first time.


LUKE TIPPLE: Yeah, it's awesome. Well, this year when you went there, you were on kind of a different mission. You're after great white sharks.


I have heard rumors of it. I've seen stuff myself on it and thought, wow, if somebody can go there and get tiger sharks and great whites feeding on the same food source in any type of tolerance of each other, that would be pretty incredible. Tell us about what took you there for this year.


RILEY ELLIOTT: Yeah. The good thing about these small little island communities, similar to Stewart Island or the Chatham Islands, is you get really good pubs. In really good pubs, you get really good bar stories.


When we were there in 2019, I'd be sitting around talking to the locals. Because that's the wealth of knowledge, especially the fishermen. We started hearing great white stories popping up here and there.


I kind of knew of this bit, because I've seen the tracking data from New Zealand, where they go up to the Tropics every year, and Norfolk's right there in the middle. There's nothing else there in the Pacific Ocean.


It's right there. It's a pit stop, a perfect one. But stories are one thing. A couple of shark tag tracks are another thing.


But to hear it from the locals, and then to see some photos, and slowly start to gather some imagery, that started to catalyze the idea of wow, number one, this is clearly a special place because what we've seen in 2019. Two. If there's tigers and whites there, that is extremely novel.


Because anywhere where that can happen, generally those two species then separate. The white shark turns up, the tigers move off. Like in Hawaii, where there's that big dead whale and that huge white shark turned up.


There was a whole bunch of tigers there at the start, and they all just went poof. I knew that Norfolk is like, the most tigery hotspot in the world. So how does an individual white shark, or a few migrating, fit into that equation? What was great was I had one of New Zealand's best experienced white shark experts, Kina Scollay, join me on this mission.


Because he spent a lot of time in the preliminary stages of tagging white sharks in New Zealand. So he had a good understanding of what to expect there, how these animals may operate there. The two of us really just were on a mission to find white sharks in Norfolk Island. But we knew we were likely going to have to sift through a whole bunch of tiger sharks to do it.


LUKE TIPPLE: That did seem inevitable, when you think about it. But I mean, for people at home, to put it in context, all sharks we consider to be apex predators. It's not unusual in Shark Week shows, in real life, in all of our oceans, to see these apex predators existing around each other, sometimes competing for the same food source. And you know, we don't really think about it that much.


But when they get big, and when we get towards this scale of apex predator, the tigers and the whites, it's extremely unusual and kind of unheard of. So I'm curious, with knowing what you know about these sharks, did you expect to go and find them in the same waters together, competing, or cohabiting?


RILEY ELLIOTT: Because of what you just said, the answer to that was no. Because generally, I would imagine, that through their inter-species competition, they would have different migratory patterns, in order to avoid each other. And whichever species was the dominant, would have the prioritization of the best time to be in that place.




RILEY ELLIOTT: So what we tried to do was we shifted trip timing a couple of months later in our first trip. We tried to do that to best capture when the white sharks might be going through and the tigers, perhaps, weren't there. But at the same time, we wanted a little bit of overlap. Because the key element we were looking for was perhaps an interaction between whites and tigers.


Because as you say, I rack my brain. I don't think I've ever seen those two really jostling. More importantly, Norfolk has some of the biggest tigers in the world, the most numerous. And that would give what we think is the second-tier species, to the white, perhaps that leg up where they may go head to head. So it was really exciting. And to be honest, we didn't really know what to expect.


But one thing was clear this time around. And it was actually a legal obligation. We needed a shark cage.


Because you can't legally intentionally dive with white sharks, in Australian waters, without one. And for sanity reasons and for comfort reasons. And justifiably, because Kina Scollay has been attacked by a white shark before and just barely survived, we took a shark cage. That really put us in the thick of it.


LUKE TIPPLE: Well, that is a perfect segue way to what we're going to look at right now. Because right in front of the show, we saw some stunning footage of the white sharks feeding on a carcass. This is the Intel that they were acting on. When I saw it, I was like, wow. These guys are in for a treat. So let's check that out right now.


RILEY ELLIOTT: Yeah, g'day mate, how's it going?


SPEAKER 3: Good, good. Just letting you know, there's a couple of big white sharks. They're honed into a couple of cows in the water out in Cascade Bay.


RILEY ELLIOTT: How long ago was that?


SPEAKER 3: Right now. They're there now.


RILEY ELLIOTT: What? Are you serious?




SPEAKER 3: I have my drone up. There definitely was.


RILEY ELLIOTT: Can you send us that footage?


SPEAKER 4: All right, let's have a look at this, bro.


RILEY ELLIOTT: Man, look at that straight away, two white sharks.


SPEAKER 1: But the most recent footage shows great whites feasting on Norfolk's infamous shark bait.


SPEAKER 4: When they see the big animal, they went on the run.


SPEAKER 1: Two white sharks in a known tiger shark hot spot is a unique opportunity to see these two apex giants compete.


RILEY ELLIOTT: No one's ever looked into white sharks and tiger sharks coexisting. That's unexplored domain. White shark behavior is generally, I'm the top dog. I'm the apex predator.


LUKE TIPPLE: That's a pretty rare event to witness at any time. Any time, anywhere. What was your initial reaction to seeing that drone footage?


RILEY ELLIOTT: Well, if you've seen the whole show, you'll see it. I'm losing it. I'm on the boat. We're there, it's like, day 1 or 2.


We're literally in the water, just around the coast, about Headstone, setting up some instruments. And we get a call from a local being like, unsurprised, he's just like, hey man, there's like, two white sharks eating a cow. We're like-- it's hard to believe. Then, with modern technology, it was amazing because he could send us the footage, right then and there. Honestly, I just got tingles at the back of my neck. Because as a researcher and an explorer, you act on whims. You act on a bit of evidence.


But to see it in the flesh, to realize that your theory is actually happening and it's just around the corner, is so rewarding. But at the same time, I know how quickly the ocean works. And how fluid it is. And knowing that opportunity may vanish very quickly, or that tigers might turn up and outcompete those animals.




RILEY ELLIOTT: That was the fear. It set the tone for the whole show, where we felt like we were just chasing ghosts. It reminded me of Point Break, when Pappas is like, They're ghosts, Bodhi. They're like, so you die, they're ghosts. And it felt like that. It felt like we were chasing the Ex-Presidents the whole time.


LUKE TIPPLE: I mean, you noted that you took a shark cage. It seemed like a very prudent idea. I've spent my fair share of time in the water, in and outside of cages in pretty harried situations. But I've never sat there looking at a cow floating in the water, just kind of hanging there in front of me, just waiting to get nailed.


And I look to that shot of you guys. And knowing that there were tigers, and very likely whites around, you know that animal is just going to explode in front of you. What were you feeling when you're looking at that? It's action. You've got the front-row seat of some pretty severe action.


RILEY ELLIOTT: What was great is to a certain extent, we didn't have to worry too much about ourselves getting caught up in the feeding frenzy. But that quickly turned into the opposite, when we started yelling at each other because we've got this fall-down doors. Like, "Shut the door! Shut the door!"


LUKE TIPPLE: Best-laid plans, right?


RILEY ELLIOTT: Oh my goodness. Because these cameramen, they're very needy. And they've got these huge things.


LUKE TIPPLE: No, cameramen aren't--


RILEY ELLIOTT: And they need to stick them out. And they need a big gap. And I'm sitting there with a tiny little PVC pole, trying to watch Kina's back.


But also trying to do my job narrating, and then seeing what's going on. But I ended up, most of the time, being a safety diver for Kina, so he could get the shots. To give context like that, I was having to be a safety diver for Kina, one of the most experienced cage divers in the world, while we're in the shark cage, reflects how many tigers there were, and how many angles they were coming at.


But to put into context the cow in front of us, look, it's a really weird thing. And I think when we all saw the first Headstone show, I shocked a lot of people. But that's why it's really important to put the context of why the cow was there.


These people are doing this out of practicality. All respect to the animal that is the cow. And the fact that we're not ordering these cows for TV.


This is a natural process that's happening. Especially at that time of year, when it's droughts. These are the cattle populations that feed the island. But they've only got so many resources of water and food for these animals. So this inevitably happens.


LUKE TIPPLE: Let's talk about that. What inevitably happens? You're saying that they're breeding too many cows or they don't need some, or they can't feed them, they can't resource them, so they're culling them and therefore, putting them in the water?


RILEY ELLIOTT: Yeah. I mean, basically, when there's not enough water, there's not enough feed. When you've got a head of 5,000 cows or something on an island, you've got old cows that don't produce milk. You've got old cows that might not produce calves.


Those old cows, their meat may not be actually good to eat because it's too tough. There's only so many dogs to feed. Again, they do use a lot of these older animals for dog food, for the island.


Norfolk Island is a very resourceful people and they don't waste anything. But then when you've got these excess animals, it's just an unfortunate consequence of farming. The reality is, is they don't want to waste them, so it goes back into the ecosystem.


It's clearly feeding a population of near-threatened animals. It's a novel thing, but in my eyes, it's a good, natural cycle. And it's created a phenomenon that has never really been seen before.


What it's allowed, and the whole reason, coming back to your first question is it allowed Kina and I to sit there in front-row seats and just get to see, like every second, a new interaction that you previously hadn't observed before. One thing I really noticed was big Tiger would come and it would get a piece of cow.


As soon as it closed its eyes, covered in synthetic membrane, The little sharks would see that. Like, I'm talking tiny ones.


They'd boost in, get a little bit and then frantically try and get it off. And then they'd bang it out of there before the tiger saw them. It was just very novel interactions.


One thing that also really stood out was how the tigers all worked together, seemingly. There was never aggression between them. And they seemingly just did a big cycle between what I counted in the end, at one stage, 40 tiger sharks. Just cycling, as if it was for a mutual benefit to all of them.


LUKE TIPPLE: There are a lot of sharks down there. Can you characterize what that population looked like? There was obviously some very big ones.


But you also noted those there are some little ones. You've also said there was kind of a ballet dance of going on. So how does a hierarchy work? What did you observe for the tiger shark population behavior?


RILEY ELLIOTT: For context, this felt like a huge step up from the first trip we did. The trip I did with Andy, where we didn't have a cage. So much so that Kina said to me, after our cage dive, was like, you couldn't have done that without a cage.


I was like, I did that last time without a cage. But I was like, I don't know why.


LUKE TIPPLE: In retrospect, pretty dumb, yeah.


RILEY ELLIOTT: Yeah. I think it also showed though, because the tiger shark is quite a shy, cautious shark, because it's a scavenger. And when I was in the water trying to tag them, they were very shy, until the point where they realized I wasn't a threat. Then it got quite intense.


In fact, they kind of shooed me and Andy out of the water. But with the cage, once they banged into us enough and realized we were just kind of observers, it just became super full on. You would see at the very start, there'd be nothing happening, there's just a cow there.


Then one big tiger would turn up. It was incredible, because this is within 15 minutes of this cow being disposed of. You're like OK, cool. I get it.


There's some tiger sharks that perhaps wait there, at Headstone, for this. And a big one will dominate that area. But as soon as that big shark starts biting into it, I swear it must be a sound thing.


Because at that stage, the scent could have only traveled a couple of yards. Maybe 1,000 yards, max. And within about an hour, you got 40 Tiger sharks around the carcass. Either that's the most dense population of tigers in the world, which already likely is.


Or there's something bigger going on, which I think is sound. Because sound travels miles through the water. And the sound of crunching bone, or it's the hide of the cow, or the tigers themselves are doing something, has to be what can attract that many sharks at once.


Because then they all turn up and there's a very coordinated ballet. And it's the big ones at the top and the little ones at the bottom. For us to inject ourselves in there in a cage enabled us to experience all of that hierarchy because when we were right beside the cow, we were just a battering ram for these tigers. And they had no problem testing out how good the Norfolk Islanders could well.


LUKE TIPPLE: Yeah, they definitely knocked you around pretty good. I mean they, at one point, they were biting on the floats of fenders on your cage. I know you guys went on drop down with two lines. I'm like--


RILEY ELLIOTT: I've got to stop you on the float, man. That, I've seen a shot. And I'm trying to remember who it was. I think it was-- oh, you'd know better. I think it was Brandon, or someone in a white shark cage, and the white shark gets the float. It's a quintessential Shark Week highlight.


I've always been jealous, that what an experience, to be in the front row of something so big. And to have literally, I swear this tiger was 15, 16 feet long. You can see the girth on it when it is biting the float above my head.


There's a shot where it rips the float. Then there's just the mouth silhouette around my head and shoulders. It just gives you this beautiful visual context of what you're being surrounded by.


It's one of the most powerful apex predators on Earth. And just incredible. So I really hope that scene sticks with people.


Because that's when Kina got out and said, "Riley, I really don't think you ever would have got out of a cage in that kind of scenario." And kudos to the sharks. They behave quite differently when you're in a cage. When you're outside a cage, they are very smart and cautious, and they may perhaps not be that bold.


LUKE TIPPLE: It's hard to make a comparison, really. Because people say that all the time. You see these sharks behave in one kind of way. We did this with white sharks, for years.


We're seeing them come in and approach the cage and perhaps bump the cage. Everyone's thinking, you put a hand out there, you're gone. We'd sit there on the deck, going, "Would you swim in that? Would you swim in that? Would you swim in that?"


When we did, it was no big deal. I mean, you're certainly cautious. And in that scenario, I can't say that would have been a good idea.


But maybe it would have been OK. When they see you outside of a cage, you know, who knows? I mean, they're there for a very large food source. Some guy blowing bubbles is not a cow floating on the surface bleeding. You know?


RILEY ELLIOTT: Yeah, it's one of those things, where and I think as you get older, as you have more commitments in your life, you think a little bit less renegade. I had an experience last year with a mako shark that made me change the way I approach certain species.


And Kina, he told me the story of how when he was attacked by a white shark in the Chathams. And heavy stuff, man. I'm like, you need to tell that story on a podcast.


But you get to a point where it's not about the fact that you don't trust the sharks, or you think that they are bad. It's about respect of what a capable predator is able of. And the fact that you're not supposed to be there in the water.


Most humans walk down the street, they say hi, they wave, they're not going to punch you in the face. But there are bad apple. If you run into the bad apple of the ocean, you can't do anything in that scenario.


So it's not about the fact that the sharks are bad or capable of hurting you. It's more about the fact of respecting that you're literally jumping into their supermarket. And you're not supposed to be there. And so like sometimes it's easier to accept to be the observer and use the cage. And to be honest, it was really, really nice sitting in that sweet, welded-up cage.


LUKE TIPPLE: There's nothing wrong with protecting your own limbs. For me, when I look at that, I definitely, I guess I also have to say I've sort of grown over the years. When I was in my 20s and hanging out on the back deck of a white shark boat and jumping in the water, all the things and stuff.


I mean, tiger sharks all over the world, traveling, doing all this stuff, it was rad. And I love it. And I still do.


But I've definitely done some things I sort of look back on, and would I do that now? The answer is probably. But maybe in different sort of contexts.


I think with anything coming up now I'm like, all right, is there a real reason for us to do it? Is there a scientific, a behavioral? Is there some context that needs to put somebody in the water, other than it makes for a good shot?


You definitely want that good shot. Because the shots enable the research. The money enables the travel and everything we need to do to be able to do these things and share this information with people. So you have to be sensitive to that. But you do also have to think about what you really need to expose the animals to and yourself to. I think you guys played it smart with the cage.


RILEY ELLIOTT: Making those decisions in a place where no one's ever gone and dived like that before. Or swum with those animals. I remember the first time I was at Norfolk, which was in 2018, when I was there, as I said, on a tourism trip. I'm sitting on the boat. I know that no one's voluntarily or intentionally, and especially not in the vicinity of a bunch of cows in the water and 30 Tiger sharks, gone in the water.


Kudos to the tigers. As I expected, even though I got on with the big 2 by 4, a piece of wood, they just vanished as soon as I got in the water, which is very characteristic of tigers. I had to do the cannonball technique and tuck up and make them not be so shy, and it took a couple of hours until they started accepting us.


But yeah, it's respect. That's the bottom line. You grow up enough that I don't need that shot or want that shot to get followers on Instagram. That's not why you're doing it. It's about, as you said, is this beneficial to the reason that I'm here?


LUKE TIPPLE: Yeah, I couldn't agree more.


RILEY ELLIOTT: And for us, having the cage, we were there to look for white sharks, and white sharks in murky water in a feeding event, where you're the smallest guy and they're an ambush predator, yeah, you want a cage.


LUKE TIPPLE: Yeah. Well, let's talk about that. Because seeing that footage, seeing even more tigers, perhaps even larger sizes than you saw last time at a different time of year. It really just makes you think. Whoa, this is this pretty amazing place.


But seeing all that, I wouldn't actually expect to see white sharks. At least, in the vicinity. Perhaps, perhaps on the same island. Perhaps opportunistically, taking on the same food. But not hanging out in the middle of that bait ball. But from your perspective, having been there with your biological knowledge, tell the people at home why we wouldn't expect to see tigers and whites in that same water, perhaps competing for the same food?


RILEY ELLIOTT: Yeah. Well, I mean, there's a variety of reasons. The first big one that stuck out to us was white sharks aren't a schooling shark.


They're not a whaler, like the tiger shark is. Tigers are part of the whaler family. They're a schooling shark. They're very social.


They don't mind being in the vicinity of each other. Whereas white sharks are solo hunters that only aggregate in areas of a localized food source. So when you put into context, you've got this gang of Tigers migrating down to this one spot from the tropics.


Then you've got these white sharks moving individually from New Zealand, in the Chathams and Australia, up to Norfolk. You imagine being, it's like the new kid at school, turning up. And there's all these groups already established. You're not just going to walk into one of those groups and be like "Hey mate, get out of my lunch queue." You know?




RILEY ELLIOTT: You're going to flutter around on the peripheries. Or if the canteen or whatever, the food court's opened early and you're the first one there, yeah, you're going to tuck in. As soon as those cool kids turn up you're going to shy away to your table by yourself.


That's what we expected. Firstly, we saw it in the beginning. Because though we didn't see any white sharks, we just had this video of white sharks right there in the Bay.


We turn up. That cow's gone. There's no white sharks. And then, all of a sudden, there's 30-odd tiger sharks. We're like, OK, this seems like how theory would progress.


LUKE TIPPLE: You did see one at near the fishing pier. Now, to me, that looked like a pretty small shark. But it's kind of hard to tell on the TV with the footage and everything else, and not actually being there. But was that perhaps not a juvenile but sub adult?


RILEY ELLIOTT: Yes. These started adding layers of our understanding, which is the whole premise of going to these places, trying to learn more. When we saw that, for starters, that was incredible. It's like, you go to the wharf as a kid to catch little sprats. Not to--


LUKE TIPPLE: It's a great white.


RILEY ELLIOTT: --see great white sharks off the wharf.




That reflects how novel this place is. But what was really intriguing talking to Nash, the local kid, was that the white shark was there. It was even scared of the gang of whalers that owned that wharf.


It would fleet in and out. Then when the two tigers turned up, the two tigers totally pushed that white out. And it only came in opportunistically.


Which really continues to emphasize that we had, that packs of tigers, at least in Norfolk, are keeping away of whites. Which is very contradictory to global theory. Because we've seen multiple scenarios where there's tigers on a whale carcass.


A white turns up, poof, they've all gone. What was really intriguing, and this didn't actually make the show, but those two tigers that turned up at the wharf that scared away the whites, they started getting frustrated with the whalers that started nipping and stealing their bits of food, to the extent that Nash told me one of the tigers turned around and grabbed a whaler, ripped it in half and killed it, and then just spat it out and continued feeding on the fish carcasses that were being thrown off the wharf.




RILEY ELLIOTT: Which shows you that dominance, that Norfolk is the land of the tigers, you know.


LUKE TIPPLE: Yeah. I mean, that's incredible. He didn't get that on film, did he?




RILEY ELLIOTT: I was asking. Trust me, man. I was getting my wallet out, like, "Come on, man."


LUKE TIPPLE: Yeah, yeah, we'll take it. Whatever footage you got. I mean, that's pretty amazing. I'm curious though, do you have enough tagging data to be able to see if that gang of tiger sharks only happens at the island?


Or if this whole gang is actually traveling on their whole migratory path? Because I wonder if it's a confluence zone and they all kind of go their own way?


RILEY ELLIOTT: Yeah. Well, I was watching. It's been 2 years now, I've been watching the Australian tags that they put out. it was about a dozen sharks. It was really cool.


It was like you say. They're all literally, at New Caledonia. What happens is when they migrate, all at the same time, they go to a focal point.


Then they start distributing and hanging out for the season, and doing their own thing. Then literally, I remember it because it was the day after my birthday, November 3rd. They literally went from there to boom, at Norfolk, at Headstone Bay.


Then they started dispersing. But they've constantly, in their own time, returned to Headstone Bay. Based on probably, how much food they got. So it was very much like a seasonal pack, that would hit this focal point at the same time, redistribute, and then move again.


Whereas the white sharks, we know they migrate in a much more spread environment. I just finished doing a white shark show, down at Stewart Island, after Norfolk. We noticed the sharks were their way later than usual.


It wasn't just the big ones, like we had expected. There was all the way down to the little ones. Talking to a whale scientist at my university, she said the whale migrations are very spread out as well. It used to be like, 2 months. Now it's like, 6 months.


What that means, I think, is these white sharks are much more individually turning up to Norfolk, perhaps. The tigers have just been like all right, boys, you got no chance.


LUKE TIPPLE: Yeah. If you're not bringing your crew, don't come mess with us.


RILEY ELLIOTT: Yeah. We had looked a lot at historical footage, from people in Norfolk. It was a great book. I think we even put some of this in the show.


Where the white sharks have very much been at Norfolk, for a long time. They know what Headstone is. There's a photo of one eating an entire horse, that got dumped off there back in the day. So you don't know till you go.


The second round of Norfolk really opened our eyes. One thing I've really got to emphasize is, we're looking for whites. But this year, the tigers were bigger. So much bigger than we saw in 2019.


There was one particular tiger-- and you probably hear my voice just raise up 10 octaves-- but people will tell you off as a scientist, being like, "That tiger is 16 feet." Just be like, "Bro, they don't get that big."




RILEY ELLIOTT: It's very hard to estimate animals underwater. But when you do this, as you know, for a living, you get pretty good at it.




RILEY ELLIOTT: And this one tiger, it makes a big cameo at the end. It's got these big scars down its back. It was so big. I said it was over 16 feet, and I stick by that. It was huge.


LUKE TIPPLE: That's pretty gigantic for that species, for sure. What do the locals think about all this? Obviously they've worked with it for many years. But as you say, it seems like they're not using the water much for surfing or diving, or anything like that.


They're more kind of a fishing community. But is that driven by the sharks? Or is it like, do they want to get rid of them? Are they OK with them being around?


RILEY ELLIOTT: Yeah. No, not at all.


LUKE TIPPLE: You could argue if they'd just feed them less, and maybe they'd go away?


RILEY ELLIOTT: Yeah. I mean, that was the premise of the first show. It was the opposite to that. The locals were scared of the Government of Australia stopped them dumping cows, would the sharks turn off and be like, "Oh, where's my migratory meal?


That surfer now looks like something that's appealing." That's what they're afraid of. So ultimately, emphasized the fact that you can't really stop this thing that you've been habituating without some real serious science. That's why it was good to see Australian government start doing some science there.




RILEY ELLIOTT: But as far as the locals go, no, these people are very, very integrated with the ocean. The reason why there's not that many people in the water is it's such a small island community. They all work like one little ecosystem themselves.


With people who grow food on land, people who do art, people who run the shop, people who are the mechanic, people who the fishermen. It's not really like let's just go out and have fun and recreate in the water.


They're trying to survive out there. So they all go do things for a reason. So there's only a handful of fishermen who go out commercially to feed the restaurants and the tourists.


There's a few recreational guys. But as far as the diving goes, there's only a handful of guys. Mitch, who was one of our safety divers, started up a dive operation there for tourists. And they never see the sharks.




RILEY ELLIOTT: That's the amazing thing.


LUKE TIPPLE: I was actually wondering if you could just, back of my mind, thinking commercial shark dive operation. Seems like a no-brainer there. You know?


RILEY ELLIOTT: Yeah. Well, you could, if you started baiting--


LUKE TIPPLE: You'd call them cow trips.


RILEY ELLIOTT: Yeah, if you started doing that. But that is one thing where then, I come back to then, the surfers. There are surfers there.


They're really cool guys. And as surfers, we respect that. And we actually had a meeting with the surfers.


Because they were understandably curious and nervous, to understand what we are doing there. A bunch of people come in and start working with sharks, you want to know what you're doing. What was great is we eased all things in their mind when I just said, "Boys, I totally understand where you're coming from.


We are not changing anything. We're simply putting a cage in the water and observing what you guys are naturally doing," which is disposing of fish frames off the wharf, and disposal of cows at Headstone, how. "We're not manipulating anything. Because we're here to observe what you guys are ultimately creating in your backyard."


They were instantly like, "Cool. We've never had a problem here. We've never had a shark attack. We don't even really ever see them. So if you don't come and change anything, we're happy with that. That's all good."


Then I left. And that was great. The problem is, the guy was kind of like-- we all know this of surfers. He's like, "What can you do to help ease my mind though when I'm out surfing?" I was like, "Nothing."


LUKE TIPPLE: Nothing, mate.




RILEY ELLIOTT: Put it in the back of your brain.


LUKE TIPPLE: That's the only thing, you know?


RILEY ELLIOTT: You know, as surfers, you just got to put it out of your head.


LUKE TIPPLE: It doesn't matter how much you know about sharks. If you've got your feet dangling in the water over a piece of fiberglass, you're just as vulnerable as the next guy.


RILEY ELLIOTT: Yeah. See, Luke, I thought getting into shark science as a fearful surfer was going to help me. But in fact, it's probably made me more scared when I surf. Because I know all the things I'm doing wrong.


As you see that, you're sitting there not doing all the rules we know when we swim with sharks. We're ultimately letting the sharks sit there and go jeez, you really look like the Big Mac that I eat around here, because this is the vicinity of where I get Big Macs. And I can't ask you, I can't touch you, unless I nibble on you. You can't blame them.


LUKE TIPPLE: I do the same thing, mate. "Yeah, this area could be great for that and that and that." Instead of just going out enjoying a nice right-hander, it's like, OK.


You start getting a little weirdly sketchy. But I just wish for a mask, so I could dive under and see them, you know? I think that was definitely an adventure for you guys.


When you go to Norfolk, next time, I want an invite. As long as the world's like, able to travel and stuff again. Because I'm convinced you can go at a certain time of the year, and probably get what you're after. You know, the white sharks and the Tigers together. Do you feel the same way?


RILEY ELLIOTT: Firstly, you're going to have to line up behind Andy Casagrande. Because he was so pissed he couldn't come back.


LUKE TIPPLE: Oh, Andy owes me one. He'll let me go.




RILEY ELLIOTT: But look mate, you're spot on we're already working right now, to try and get back there, for August, September. Because we realized-- and it was because of COVID, that was the original window we wanted to hit. But we got pushed out because of COVID.




RILEY ELLIOTT: In fact, on this trip, during COVID, we had to get a couple of private jets at times, to get me and Kina back to New Zealand. We nearly got stuck out there. And we would have been stuck there for three months because of our MIQ setup.


But luckily, we got back. But yeah, September/August seems to be that peak. It seems if we wanted to get the whites-- because look, we got whites through footage.


We got whites through reports while we were there. We got whites, in the sense of our bait boxes were bitten by whites and tigers and the cameras were all removed. It was super infuriating and frustrating. But as you know in marine science, you go for two weeks to a place, man, you can't expect to find gold the first time.




RILEY ELLIOTT: And it really gave us some more stepping stones to figure out how to go back and be more calculated and talking to the locals, using their footage. And looking at the tracks when the tigers aren't there, like before November, it seems, has given us this window that we're going to go try and hit this coming September, October. Because I think Norfolk is that much of a tiger hot spot. The white sharks have to find their own time to capitalize on this area.


LUKE TIPPLE: That makes sense. Well, mate, good luck with that. Thanks for joining us. It's always awesome to chat with you and share in your knowledge.


And for the people at home, that's your Daily Bite. And thanks so much for joining us. You can subscribe on Apple Podcasts, Spotify, or wherever you get your podcasts. Till next time, guys, happy Shark Week.