What Scientists Just Discovered About Tiger Shark Migration

1:00:00 Welcome back to another episode of the Beyond Jaws podcast. On today's episode, we're gonna be talking to Rachel Graham, who's here to tell us about a study where they recorded the longest Transatlantic Tiger Shark migration ever. And it's 18,000 kilometers there and back from Cape Verde to Brazil and then back. It's gonna be an exciting episode because this is something that is groundbreaking. So it's groundbreaking news, news update. We're gonna talk to Rachel. Let's start the show. Hey everybody, welcome back to another exciting episode of the Beyond Jaws podcast. I'm your cohost, Andrew Loewen here with my cohost, Dr. David Ebert. Dave, the largest Transatlantic migration that we've seen a Tiger Shark do.

1:00:42 This is the second longest migration that we've seen a Tiger Shark do. When you get a shark like this to do what it does or you discover a shark can do this, like from a scientific perspective, what goes through your mind? Like, does your heart start palpitating and stuff? Like what goes through that? Well, what it tells you is these large sharks like the White Shark and the Tiger Shark, they use immense portions of the ocean for their migratory routes. And so you really have this thing crossing across the Atlantic and back, you know, it's 18,000 kilometers. It's phenomenal movement pattern. And you know, the one hand it's not surprising because it's a big shark doing that, but at the same time, you really get an appreciation for like, wow, these things can really cover a lot of ground.

1:01:28 And I think like with the White Shark a few years ago, and we realized like in the Pacific that they migrate from say California out to Hawaii seasonally, you really get an appreciation for just how far, how much territory these things can cover. And so in terms of like from a conservation or from a management stuff, you're basically starting to, you're in an area of like, you know, international jurisdictions beyond boundaries or I'm not using the right term, but basically it's international water. The high seas. The high seas. Yeah, exactly. And stuff. And but you want to, but you know, also like where these things go, because they're certainly not catching them that frequently out there. You might get the odd one here and there, but so they probably are moving at depth.

1:02:10 So they're beyond any typical type of fishing areas as a transit across the Atlantic or in the Pacific, which had an even longer migratory route. But you also can get an idea like, you know, at this time of year, these tiger sharks are probably going to show up. In this location or that location, which is really kind of cool to see. So, yeah, I'm excited about it. I'm excited to hear about Rachel's story about this. And it's been a while since she's been on the show. So it'll be good to catch up with her in general. Absolutely. And just a spoiler alert, she did have another story that we're going to be posting in a few episodes time. So, you know, if you want to, if people here want to listen to that, they don't want to miss it. Just hit that follow button or subscribe button, depending on where you're listening to this episode.

1:02:54 Let's how about we start the interview with Rachel Graham and get into it and find out all the different, the juicy details of how this study began and what they found and what that's that's going to tell us about with our conservation in the future. So here is the interview with Rachel Graham. Enjoy. We'll talk to you after. Hey, Rachel, welcome back to the Beyond Jaws podcast. Are you ready to talk about tiger sharks? Oh, I am so ready. Andrew and Dave, it's lovely to be here again. Thank you for having me on your show. I love it. We can't wait. Well, we have another episode of Beyond Jaws podcast with a powerhouse guest today who has been on our show on our 17th episode back in March of 2022. She's a real true entrepreneur and a real pioneer.

1:03:36 We have the fabulous Dr. Rachel Graham on the show today. In fact, she has so much to share with us today. We're going to make this into two episodes, which will be airing soon. Rachel, just for quick background, she's the founder and director of the Mar Alliance organization, which is a science based conservation organization with field stations in Belize, Panama, Honduras, Mexico, Micronesia, Cabo San Luc, no Cabo Verde. And probably a few other places that I'm forgetting right now. Rachel has her BSC in zoology from Oxford, an MSC from Edinburgh and a PhD from the University of York in the UK. She's worked at a number of places, including the U.N., the University of York, Smithsonian Wildlife Conservation Society. And she's literally worked all over the world.

1:04:19 And she's founded the Mar Alliance in 2014. And she really made a name for herself. We're studying whale sharks. And she did the first PhD thesis on whale sharks from a research in Belize. And they say she's a real entrepreneur. She had a paper come out on tiger shark movements in the Atlantic. So we thought it was time to have her back on. Long overdue. Rachel, welcome back. Thank you. It's a joy to be back. And it's great to be able to talk about something else that has stripes, not just whale sharks. Yeah, that's great. So so why don't you just tell us, tell us, tell us about your study and about these amazing findings you have. Yeah, absolutely. So one of the reasons why this study came into prominence is that a couple of different reasons.

1:05:04 But the main one is that we were doing a large baseline survey in Cape Verde. This is with local fishers, our national coordinators, Eddie Seymour and our communications officer, Cynthia Lima. And what we were finding in this baseline survey is a whole really fantastic diversity of sharks around the archipelago of Cape Verde, especially the eastern islands Salvo, Vista and Mayo, using primarily baited remote underwater videos. But what was popping up occasionally were also tiger sharks. And, you know, we decided we were going to follow up on some of the bruv sightings with some scientific long lines.

1:05:50 So our standardized long line protocol short soak 90, no more than 90 minutes standardized, made at circle hooks, et cetera. And we decided to give it a try up in the island of Salvo, where tiger sharks have been caught by fishermen, sometimes dragged to the tourist docks shown off. I've got some rather egregious pictures of tourists like hauling back the heads of of tiger sharks and all the rest. And we thought, you know, there's not a lot known about tiger sharks in West Africa, especially not in Cape Verde. And so that kind of kick started our study there. And what we found dumbfounded us because as soon as we were dropping these long lines, it wasn't four minutes before the first tiger shark would hit. Then number two, then number three.

1:06:40 I mean, it just kind of went on. And so what we what we did is we really wanted to understand, well, why are they there? What's your spatial ecology and so much more? And so we ended up satellite tagging a whole host of them, actually 12, to be to be precise and not just in Salve, but in some other areas of Cape Verde. And the big finding is that they're not just sticking to Cape Verde, which is, you know, not that much of a surprise, but the cherry on the surprise cake was the a large three meter plus female tiger. When we actually tagged in Boa Vista.

1:07:20 Deciding she was going to hot foot it to Brazil. I guess she thought the Kypereanias were better there than in Cape Verde. And she ended up doing yes, exactly. She ended up doing this incredible voyage going very close to where we had sharks International Jean Passot and his see, and then Fernando de Noronja and and kind of ambled around there for a little while before actually returning to Cape Verde and waters and that entire journey spent almost 18,000 kilometers and about 404 days, which when I was doing a quick calculation, that's like moving 44 kilometers a day.

1:08:05 So you're booking it. You have to have a somehow a sense of purpose. And in fact, you can see that the journey is quite directed. So of course, that raised a ton of questions about, well, is she going there to me? Is she going there to pop? And of course, confirming that transatlantic crossing that had never been fully confirmed previously, it had been hinted at, but never. And it was a double transatlantic. So thankfully, that satellite tag worked long enough for us to see that these animals really need entire ocean basins in order to fulfill their lifecycle requirements.

1:08:50 Did you know that there was such a population of tiger sharks are initially because not some I mean, just people know that Cape Verde's are just off sort of Northwest Africa. Look on a map. But I mean, there's so little known out there. I had no idea there was there was such a these tiger sharks were there any number. So this was really new to us. So we started work kind of 2015 2016 and and as I mentioned, we did a beta remote underwater survey, which is actually published. It's up on our website, Mar lines.org. If you look under resources, we try to make our papers available. So because, you know, people need to access data. And so it makes it easy for everybody to be able to see what's been done in, especially in tropical countries where you can't afford these subscriptions.

1:09:36 So that's another thing to discuss on another podcast in another day is access the information democratization of science. But with respect to to tiger sharks and Cape Verde, you know, based on those initial pieces of work, we started hearing also we did fishermen surveys. All the way back when back in 2016 and some of the information that was rolling in was, you know, there are these catches and that's a catch of tiger sharks. And that's really what put a B in in Dettie's bonnet and my bonnet. And we said, let's go and figure it out. And so the following the following summer, which is the the period of time in Cape Verde, when you have some of the calmest waters, because it can be very rough.

1:10:25 We're talking about the eastern Atlantic directly west from Senegal. And, you know, when you're out there, you're out there. You better hope that your boat has two engines because you're really out in the middle of the Atlantic practically in what it feels that way. So, yes. And that's why we focus that survey on tigers. The other reason, too, is that we were seeing an increase in fishing effort on sharks. And it's one of the reasons why we were concerned that there was ramping up of shark fishing. And at the same time, there was a need for more information based on the national action plan for sharks that had been that was kind of under in the works by Mika Jopin Senegal, who had been hired by the Cape Verdean government to help them with that.

1:11:19 I have to ask you because Cape Verde, I've actually been there, but it's because it's in the middle of nowhere. Litter. It's like some rocks in the middle of the ocean. Yeah. How did you happen to like stumble on to thinking this would be an interesting place to study the sharks out there? So it's funny, you should say, ha. I've as I started my career in 98 with whale sharks, I was always looking to see where are whale sharks going. And what I was seeing is whale sharks are moving from one feeding site to the next and starting to see these patterns of connectivity migration and connectivity movement connectivity in the Western Atlantic. And that's how I pulled together a whole bunch of different researchers who might be interested in working on whale sharks from the Flower Garden Banks National Marine Sanctuary to Holbox Cancun, Honduras, Cuba and more.

1:12:14 And it's actually whale sharks that initially got me interested in Cape Verde because I was looking at the whole Western the whole West Africa eat and from, I don't know, a Western Sahara all the way down to Angola. What's the status of whale sharks and even manta rays then we didn't know. So I started looking into what patterns of movement might be elucidated there. And so at that time, I went originally to try and study some of the whale sharks and the manta rays. And then, of course, through the fisher surveys and the bruv surveys, we stumbled across all these other species, tiger sharks, a spirit of Luini, the scalloped hammerhead, the regionally endemic perigailous shark as well. So yeah, so really, really, whale sharks kind of lead you to all kinds of other open doors. And for that, I'm very grateful. And we've got actually work coming out on the whale sharks, because we did a lot of work on the whale sharks while we were there, too.

1:13:25 Go figure. We've done the manta rays, you know, fisheries, tiger sharks and whale sharks as well. So yes, whale sharks led us to the tiger sharks. So, so, so there is quite a bit of a fishery there and you've been documenting I presume the species that have been catching it. We got whale sharks, got tiger sharks, perigailous out there, which are weasel sharks. Did you just off the top, just kind of more of my question is what how many species of sharks and rays do you have out there? I, you know, I should have that number off the top of my head and I can't answer you off the top of my head. Okay, I should I should I just prep study for the show. I've got to ask those questions. I just like Dave. Dave's always like, is there any more sharks I could look for?

1:14:12 Can I discover them? So you definitely, you know, you definitely have you definitely have a center for us. You've got fisheries for those. I'd seen pictures of that ages ago. So we definitely based on how the archipelago is is situated and you've got very deep waters around Cape Verde. You do have deep water fisheries and you have deep water. Yeah, yeah, yeah. Okay. Yeah, it's kind of like I said, it's one of those places like you would just wouldn't know about unless you've been there or familiar with that area or you're looking for whale sharks, I guess, as well to kind of stumble. But you know, the fishes were catching everything from spinners and black tips and and a lot of scalloped hammerheads.

1:14:58 They seem to form a lot of the a lot of the shark oriented fisheries in near shore coastal waters because there's another thing too. There's two classes of fishers. So it's a small scale fisher who usually has a tiny little engine like a 15 horsepower or 40 horsepower. So, and they're only really allowed to actually fish within the waters of the island where they're situated. Whereas some of the kind of midsize more industrial commercial fishers actually hot between islands. They're not really supposed to overlap with the small scale fishers and there's near shore waters, but unfortunately they do and that's a conflict that we saw increasing over time.

1:15:43 Those fishers are more low, but they're local fishers. Do you have they have much impact for it? Do you have like foreign fleets coming into fishing the waters there? So there are I mean, there are a host of foreign fleets in much further away. So that's one of the things that we were concerned about, especially when we were looking at tracing the Tigers paths moving in and across several jurisdiction, our boundaries, several country, East Ed's and there's big long line per se net fisheries in that East African area. Yeah. A lot of Portuguese, a lot of Spanish, French. Yeah. The usual suspects generally for that part of the world. It's fishing. Yeah.

1:16:26 And going back over to your Caribbean side, have you ever tagged many Tiger sharks over there off some of the central? So actually we do have a growing project on Tigers in the Caribbean. Yes. Okay. Because I wonder if they I guess I'm going to get you is it's too early that you don't have any big ones and big ones. Do they mix it all with the population that you're the Cape Verde population at all? So what we're seeing so far is there either. So what's interesting about the satellite tagging is that we noticed a trend that was also reflected in some other papers, other work that people have done, which is, you know, often once they're tagged, they tend to go deep.

1:17:11 They stay deep for a while. And you see that for on several of the tracks. You don't see them up near the surface, surface transmitting. These are spot tags, right? Not pop up archival tags that we were using. So what we're seeing is that the animals that we've been tagging really go deep and stay deep for quite some time. And then they'll be crossing big stretches of water, but they're not going across the water. So that's clearly a classic the Caribbean or to the other side of the Atlantic yet, but you never know. Well, that's the thing I like, are you going to look at some kind of isotope study or do you take like so we have a lot of yes, we have a lot of things planned actually.

1:17:59 And I also want to look at that because we want to look at their gestational cycle as well, because it's suspected that they might be biennial in their reproduction. But we have so much to learn. And what we've seen is that we're finding with bruv work and even long line work, we'll catch really small animals in a whole host of different places along coastlines. So that whole that whole mention of extended popping areas for tigers appears to be true, at least in the parts of the Caribbean where we've been working.

1:18:42 So if there's a is there a specific site where you're seeing a lot of these neonates, young of the years, we haven't found that yet. Okay, we do know that there are a couple of sites where we can find larger females. Okay. How long and that's what we're going to be focusing on. We're going to be focusing on for stable isotope analysis for ultrasound. So we better understand. Yeah, exactly. Also population analysis, although what's been shown is that apparently there's quite a bit of structuring in the population in the Atlantic. However, you then get these wonderful outliers like kalema, the female tiger shark who then goes and doesn't double back and forth.

1:19:30 And you know, a lot about these large migrations. Does it take for them? Like, did you get the days of like how long it took them to get do that 18,000 18,000? It was 404 days. So 404 days to do almost 18,000 kilometers. And so that's really that's swimming at a rapid clip of about 44 kilometers a day. Yeah, this was the second largest longest track you said for a tiger shark is the Pacific they had some a longer one or yes, but this is the first big transit transatlantic track. Yeah. And just in the one in the Pacific, do you remember where that one went? Do you remember the distance? Like the distance or where it went off the top?

1:20:14 To be honest off the top. My ability to hold facts in my head is diminishing by the decade. Yeah, I, we won't go there for this conversation, Rachel. Andrew, that's where you delete this little piece right here. So we don't sound like we're entirely. Yeah, I would have been able to cite the paper die where they went. I know. I know. Me too. Can't do it anymore. I remember it. I know it's there, but I thought it was in the Pacific, but I just I can't remember the details on it. So maybe somebody out there will remember and posted on our comments when the episode comes out. Well, I mean, it's it's I mean, that's easy to that's easy to that's easy to look up. But one of the things that I really like is that so Kim Holland did a kind of future of tiger shark research.

1:21:02 And there are several things that he touched on, which was, you know, is there a popping aggregation side? Is there are there some mating size? What is the reproductive cycle? There's so many more things that we can discover with tiger sharks and and the differences that lie between, for example, the Atlantic Basin and the Pacific and so so much more. So it's kind of exciting discovery time. It's interesting because, you know, they I think we're learning more of these different tags, like with the tiger sharks with your study, with these things are moving across the Atlantic. And that and I think this gets into this whole thing about, you know, when you're trying to like look at protecting shark species, especially some of these large migratory species that these sharks are moving around a lot.

1:21:48 The bigger the larger ones, you know, we had that there's a study where the the they had a white shark moved from Cape Town all the way out to Indonesia. And and they've had a couple one go, you know, they had another wasn't that Nicole. No, that one went to Niglo Reed Australia. That's right. That's right. Oh, my gosh. Yeah. No, this one went to that's that's a story. I think we're gonna do a separate episode on because it was it was really I actually got involved with that one. Finding the thing that tag showed up in Indonesia and a fisherman had it in the village for a couple of years. Oh, right. Yeah. They just published a paper on it. Yeah. And I think, you know, it's a really interesting story. Yeah. But I think that's the point that I think that's the point that you have that the one that Alison Koch and a whole group of them there and stuff. That was a fascinating story. But but the point that that went all and then you have the one Nicole, you mentioned that went from Cape Town to Nigolo Reef up in Northwest Northwest, Northwest Australia.

1:22:45 Yeah. And you're seeing these big migrations being performed a lot of the time by these large adult female sharks. Yeah. And yeah, great way to great way to spread the genes and. Yeah. And of course, there's basket sharks. Now we see we know they move across the Atlantic as well as north and south as now north to south and all the way down to places like Dominican Republic, etc. So it's really remarkable the migrations that they're able to do or even close to the Western Sahara by recall. Yeah. When it goes to speak to their fitness at the time to be able to do that type of track, right, to move at that speed for that distance, like they must be feeding well, you know, in like this one must have fed well and Cape Verde to be able to get across the Atlantic for that speed on like, was it 44 kilometers per day?

1:23:33 Yeah, exactly. And and you're absolutely right. And I think this is where tigers really are are the champions. I think there was a quote saying that they're the climate change champions because they're so adaptable. They, you know, have a very broad thermal range. And not only that, they can eat a whole host of different types of food. So they'll be very opportunistic in the food types. I had a really great moment. Actually, I'm writing up the note at the moment, where my two of my favorite species came together with tiger sharks eating a whale shark off of the coast of Belize. I was like, wow, a triple wind.

1:24:15 So, so, yeah, so considering that they, you know, they have this wide thermal range that they do go to depth. And they're able to utilize that water column is for, you know, feeding for orientation for all of these and behavioral thermal regulation, then yeah, they're, they're pretty awesome creatures, I have to say. And you know, the other thing that also makes them more likely to to survive longer term, especially with fisheries pressures is the fact that they're so hardy on the long line. I was looking at one of the NOAA studies looking at the mortality on long lines and tigers, you know, four hours later and they're still alive.

1:25:05 They're like, they're, you know, kind of, I was like, look at them as like a garbage can with fins. It's like, they're literally like, you know, they eat pretty much anything. They kind of now they seem to go everywhere. They want. Yeah. Just like that. I don't know what the, what the analogy would be for it, but you know, other even things are white sharks, like white sharks are, they kind of croak out pretty easily. If you get them on a long line, they don't leave a lot of lamb, a lot of lamb, lance to lance. Don't do well with cortisol stress, et cetera. But tiger sharks are like, yeah, pass me the margarita or the kyper media in this case. Yeah. Exactly. So they're tough hardy sharks. They're chill. They're very chill. And you know, one thing that I'm really excited and something that we're going to integrate into our work moving forward is they've, they found a new, I wish I, again, it's like, I wish I could remember everybody who writes these amazing and does this amazing work around the world.

1:25:58 But there is a new way to identify photo ID tiger sharks, and it's not on the stripes and dots, which do fade as they get larger. And so it's probably more difficult to be able to identify individuals. And that's kind of what we were focusing on. And I was thinking, what are we going to do? Because I do know that they fade. Well, what's really cool is that line between the gray and the white on the belly is very kind of serrated and edgy. That apparently is not what we're going to do. And so that is the basis for doing ID and technique. Yes. Yeah. And in fact, Jason Holmberg, who was the architect behind all the photo IDs for whale sharks and has now joined the conservation X labs with his wild me outfit just pinged me and said, Hey, we've got a new photo ID thing for tiger sharks we want to try out.

1:26:51 Want to be part of it? And I'm like, yes, yes, absolutely. So yeah. So you see, again, whale sharks lead. Yeah. All roads lead to tiger tiger sharks from disparate sources, especially through whale sharks is perfect. Yeah. Well, you know, it's those stripes and spots again. That's it. That's it. Right? Yeah. I'm not going to say that I'm still like in search of my first whale shark in the field. So I'm just Dave has had some. Oh, Dave, give it up. Come and join me in Mexico. Come on. Yeah. I've been to Mexico and I've never seen him there, but I'll, I'll have to hit you up here some time and go see him. Every time I show up there, they're not there. It's just, um, just my, my, I don't know. They have, they have an allergy to Dave. As soon as he shows up, every day, every day, oh yeah, come here.

1:27:42 No problem. You'll see plenty of them. I show up there. Now I don't know what's going on this year. They're, they seem to be late. And then as soon as I leave, like two days later, they're all, you know what they're doing. They're like, here, let us show you how deep we can dive. Cause we know you like deep diving sharks. Let us show you how deep we can dive. So that's why you have to look for you. Like, where did he go? He's like, oh, I'm going to get him. I'm going to get him. I'm going to get him. I'm going to get him. I'm going to get him. I'm going to get him. I'm going to get him. You got to go. That's innocent. And that puts them in aKkoma. That does result in no effect. That's aauntlet that we all have. And that has become the most incredible and accompanabe, the tensor from this, the lake sense. We did a special incredibly amazing Time volt DEVEX exploded pre pregnancies about their restoration and what did they There was a moment where there's a bunch of us who are kind of like out competing each other to how deep can our whale shark dive according to the technology we have available.

1:28:37 And you know, to be pretty much at 2000, 2000 plus meters, 6,660 feet. That's crazy. That's insane. Crazy. Yeah, that's pretty cool. So big respect to the glumping Labrador sharks. Absolutely. I mean, it'd be kind of interesting to see if you get more data between the whale sharks, the tiger sharks, white sharks, basking sharks, like see if these things have different corridors that they travel when they go travel across the Atlantic, whether it's east or west or north, south. It'd be interesting if they're using, because I know some of the stuff they've shown in the Pacific that where the white sharks go out to Hawaii, the salmon sharks will migrate south, but they don't go quite as far south as where the white sharks congregate. Maybe it's a pecking, could it be a pecking order or a temperature issue?

1:29:21 Hard to say, I don't know. Well, cause they can go a depth, when they're in the open ocean like that, they can move to a depth they can accommodate. They're getting colder, yeah. Yeah, and they, so it's just kind of interesting. Of course, nobody knows why the white sharks are going to Hawaii, other than it's like from, you know, whatever. What do they have in Hawaii? It's not margaritas, what do they drink out there? Mai Tai, Mai Tai's? Mai Tai's, there you go, Mai Tai's, there you go, yeah. Well, we're gonna judge these nodes of connectivity based on the alcoholic drink. On the alcoholic drink. (laughing) That's the title of the paper. Yeah, that's the margaritas in Mai Tai's. This'll be a test on what drink equates to what shark? Yeah, exactly. There we go. From tequila to rum and Coke to, what do we have in Cuba?

1:30:04 What's in Cuba again? Well, it's gotta be rum, like-- With mints. I don't know, I was gonna say, what's a good margarita shark? Oh. Huh. Bull shark. A bull? Yeah. Yeah. Okay, I'll take that one. Is there a long, yeah, there along that coastline. Yeah, I'd rather be having a margarita than diving with bull sharks, so what the heck? (laughing) Oh, come on, Dave. Maybe you need a margarita before you dive with bull sharks. Come on. No, it's not my, I just have my, I don't even-- So we're working, yeah, we're working with bull sharks as well throughout the Mesoamerican Reef and looking at this shark superhighway corridor, but especially between Belize and Mexico's Quintana Roo.

1:30:49 Yes. And trying to quantify the use and the demography of the species using it, also clear popping grounds and reproductive grounds and so much more, but yeah, that will be for another day because we're still in the-- We'll do that another episode. We'll do that another day. You're gonna have a regular episode on this. It's gonna be the "Mar Alliance" show here. Have your own boat, love it. Love it. They're all in a segment here. Yeah. Well, I was just gonna say, with the tigers and Cape Verde, I think one of the things that we're really excited about is that we've really just scratched the surface with this species in Cape Verde. And we're really excited to see this work expand, but onto the West African coast as well.

1:31:34 I'm sure that there's gonna be a lot more. There are several NGOs that have cropped up recently working on sharks and shark fisheries. So you've seen this expansion of work, and also in Cape Verde. When we started, we were the only ones working on sharks. You know, all those years ago in a focused, dedicated way. And I think that more people better, and if we can actually reverse some of the declines, that would be absolutely fantastic. One thing that I didn't mention is, you know, you're asking, why are they in Cape Verde potentially? Well, one thing that they have, especially in Boa Vista and Zal, they are huge rickories on the biggest in the world for loggerhead turtles.

1:32:21 And boy, tiger sharks love them. They love those loggerhead turtles. Exactly. So they're there, especially during the mating season for the turtles. And that happens to be when you're seeing the tigers hanging around as well. Yeah. Interesting. What policies would you like to see enacted, you know, as this research comes out, especially in West Africa, especially in like Cape Verde? So I think what would be great, it's hard. It's hard because the policies that we might have in some parts of the world where people are not dependent on shark meat to survive, is one thing.

1:33:03 Right. So in West Africa, you have in coastal communities, the need for protein and poverty levels that would you give up a tiger shark if you know you're going to be feeding 30, 40 people. So the policies that I would like to see is if because they have such great resistance and resilience, especially when they're caught, is potentially releasing large females and releasing pups. They grow pretty quickly. So is it to that level, do you think like is it to that level where, you know, the local people are catching those sharks for their own consumption?

1:33:47 Is it to the level where it's dangerous, like they're catching both? Yeah, that's both. Yeah, there's captures, there's captures for local consumption subsistence. And then there's, and then there's a larger industrial fishing vessels that are catching a difference in the policy. So if it's substance, then it's fine. If it's, or better, but then if it's more commercial, then maybe have a little bit more. Well, you're seeing a lot of seeing some of the loopholes potentially being able to be closed up with the BBNJ, which is biodiversity on national jurisdictions. So this, you know, this paper on tigers came out at just the right time, because BBNJ in in their, in seeking even more signatories to make it even more robust as a treaty are also looking for data and case studies that demonstrate the use of these kind of these areas that belong to everybody and and nobody all at the same time in order to be able to try and formulate either moving protected areas, where there are going to be rules and regulations against fishing these kinds of these highly migratory species or more. So we're really grateful to tiger shark kalema for for highlighting the use of entire oceanic basins and and supporting the the BBNJ treaty.

1:35:16 Absolutely. Yeah. So I think there's a lot of things on the on the horizon that will be coming out. I think there's a long way to go, unfortunately, because who's going to patrol that who's going to so many questions to ask so many questions and more. So, yeah, but maybe she should become a bit of an icon for that for the for the BBNJ, right? Absolutely. She could be one of one of their flagship species and animals. Yep. There you go. That'd be awesome. That'd be great. Well, well, Rachel, thanks so much for coming on and sharing the story about the tiger sharks. We're going to be back with another episode here talking about your next big discovery here and we'll we'll share that when you come back on here in the next episode. So, okay.

1:36:01 Absolutely. Thank you so much. We appreciate it. Thank you so much. And thank you for having me. That was brilliant. Of course, you bet. Thank you, Rachel, for joining us on today's episode of the Beyond Jaws podcast. Dave, what an exciting discovery. Like this doesn't happen every day where you get this type of discovery of the longest transatlantic 18,000 kilometers to Brazil and back from Cape Verde. Phenomenal type of story and and from from an organization like Mara Alliance to be able to publish this with their collaborators. This is huge. This is such a big thing for them. Oh, yeah. This is a huge. I think it's a huge story and obviously got a lot. It did get a lot of media attention when it first came out here a few weeks ago. And yeah, I mean, you're like this kind of said in the intro, you suddenly realize these these large predators have huge territories that they cover and you know where they're going to be at certain times of the year and and and why they're going there, why they're particular this migratory route. That's fast. That's another whole series of questions you can ask.

1:37:04 Why this? Why? Why? Why do they know to go from here to there on that route? But but it's fascinating that they cover such an immense area and they turn up these different different locations. Um then you can start seeing what are they feeding on? You know, is there some of these areas that they for a good are they for uh uh mating purposes for birthing or the nursery areas? Uh you can start to you get kind of peel the the curtain back a little bit on things like tiger sharks because otherwise you just know they certain times of the year they'll show up in this one location. But now it's kind of another little piece of the puzzle um as to where these things go. Yeah. And um you know, as we know too with a lot of these species, they tend to segareat by size and by sex. So the immature ones may go one place. These are like an adult female like this may go a different location. Um you know, males may turn out somewhere but you know, at some point they gotta get together and make little babies little baby tiger sharks show up. Yeah, no for sure. Well, I mean, it just goes it goes to show that we we still have a lot of species that are there. We still have so much to discover.

1:38:04 I mean, even from the beginning of this study, which wasn't a tiger shark migration study, it was let's find out as much as we can about the sharks in Cape Verde in that archipelago and then they found so much diversity in there. It's it's just goes to show we just we there's so much more we need to find out about sharks and their diversity and then we we can discover more about their conservation. We can you know, like if you think about a tiger shark that travels there to Brazil and back from Cape Verde, you look at how like what they're doing. And then you kind of look at where do they stop on the way? Are they stopping on the way? You know, what are they doing on the way there? Can we put you know, now with the high seas tree, can we put marine protected areas in certain spots where they might aggregate with other animals? You know, we're looking at distinctive areas where it might attract sharks on their way. It could be an upwelling that we didn't know about. It could be anything.

1:38:56 Um maybe even a they're in a far south of the coast and have the energy to do that migration, right? There's so many questions after that. Oh yeah. Again, this is just one data point. You know, you might tag another one and it might go to it might go to it might go to Canada for all we know. Who knows? across these ocean basins, they're probably traveling at a depth where they can't, they're not being caught, but it's where they turn up.

1:39:39 Right. That's where you probably, because tire sharks are known to be coastal, as well as oceanic, but it's when they get into the coastal areas that their vulnerability in terms of fishing comes into play. No, absolutely. I mean, you know, we've seen, you talk about, you know, where sharks will go. I mean, we've seen with O-Search and the sharks that they tag, you know, some great whites will, you know, do their regular pattern in the Atlantic going from, what is it, up in, what's the, loss of words, this is the island up in Martha's Vineyard. Or Martha's Vineyard. It's Martha's Vineyard. (laughs) Yes. Yeah. Is it Cape something? Is it not Cape something? It doesn't matter. Martha's Vineyard, and they go down to Jacksonville, like in the winters.

1:40:22 Right. But, and then every once in a while, you'll see one go out to the Mid-Atlantic, like, rich, you know, and so you're just like, okay, where did that one go? And why did it go there? Did it get lost? Like, is it there for a reason? So yeah, there's a lot of stuff that we need to know. And maybe that just kind of introduces another study where we start looking at tiger sharks in the Cape Verde area or even the Brazil area to start tagging them more, just to find out where they're going and what that means for conservation purposes. We know sharks are the top of the food chain in many of these ecosystems and they play a very important role. So I would hate to see them get caught, you know, on the way over.

1:41:21 Yeah. And then you're like, okay, these tiger sharks are going to show up in an approximate this location in Brazil at this time of year. That's where you can really look to do something. I just think it's going to be really tough to try to put together some policy for when they're transiting across there. Yeah. But if you know they're going to be in this location at this time of the year, then you can do something. Because then you're more dealing with, you're within national boundaries with economic occlusive zones. Yeah, absolutely. So you can do something there, I think. But it's fascinating study. I'm really glad we had Rachel on to talk about this. And as you mentioned, we're going to get a couple episodes up here.

1:42:02 We're going to have her on back on for another exciting talk about Sawfish, which I'm really, that was a bonus for us talking to her. This one, we found out like, oh, there's this other study we need to have her on for. So anyway, stay tuned. I have to say when we first brought Rachel on our first attempt to do the recording, we ended up talking so much, just about everything that we spent about probably two hours talking. And never recording an episode. And she's like, hey, can we do this another time? Cause I've read it at a time where like, yeah, no, no. So we, and then we brought it back. And then she's like, we could talk about this. Then we have this other study. Then we have this other study. It's like, let's just bring it on for studies. And this is just like, I want people, if you've been listening for this long, I want people to know if you're in shark research or shark science or shark conservation and you have a story you want to talk about, you know, get ahold of Dave and I Dave, if people want to get ahold of you, where will they go?

1:42:53 Go to a law shark guy on Instagram or Facebook law sharks. And then the best ways, or if you get ahold of me through the university Pacific shark research center at San Jose state university. Yeah, for sure. And then if you want to get ahold of me, just, well, if you want to contact both of us, you can do that at beyond just pod on Instagram, but if people want to get ahold of us to get more content out and they want to, they want to talk about their research project, as long as it has to do with sharks or around that topic, feel free. We can't guarantee you'll be on, but we'd love to hear from you and see what you're up to. But thank you so much, Dave. And thank you so much, Rachel, for, for sharing that story with us. A great study. And we look forward to hearing from all of you next time.

1:43:35 Thank you so much for joining us on the Beyond Jaws podcast from Dave and I have a great day. We'll talk to you next time and happy conservation.