Host Luke Tipple welcomes shark researcher Dr. Neil Hammerschlag and freediver Fred Buyle to discuss how necessary it is to kill sharks in the name of science.
Host Luke Tipple welcomes two guests to discuss how researchers can kill sharks in the name of science – and whether they need to at all. The first is Dr. Neil Hammerschlag, shark researcher and founder of Atlantic Shark Expeditions, and an expert on data-gathering in the field. He’s followed by explorer Fred Buyle, a world-record-breaking freediver whose innovative methods of shark tagging are explored. Plus, our researcher Sierra tells us about how a 50-year study changed our understanding of tiger sharks – and much of the work wasn’t even done by scientists.
Find episode transcripts here: https://shark-weeks-daily-bite.simplecast.com/episodes/do-scientists-need-to-kill-sharks
00:00:00:02 - 00:00:08:08
Luke Tipple
Up next, do scientists really need dead sharks? And in our shark bite, we'll find out a way that you can get involved in shark science.
00:00:08:10 - 00:00:18:22
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You're listening to the Shark Week Podcast.
00:00:18:23 - 00:00:33:00
Luke Tipple
G’day, and welcome to Shark Week, the podcast. I'm your host, Luke Tipple. And today we'll find out if we need to kill sharks in the name of science. Now, before we get too deep into things, make sure you subscribe to this channel like the video and ring the little bell so you never miss another one of our weekly podcasts.
00:00:33:05 - 00:00:57:06
Luke Tipple
Now, I'm sure we could all agree that science should be based on facts, ethics, morals, and perhaps a higher calling to understand our planet. I'd also like to believe that we live in a world where scientists choose the most effective and non damaging techniques to study sharks. But in the past, that often hasn't been possible. Much of what we know about sharks today has come from destroying sharks.
00:00:57:08 - 00:01:19:08
Luke Tipple
Now, that's a sad and horrible fact, but it's true. And now I don't mean to imply that scientists are going out willy nilly and destroying sharks all over the planet. Many of these carcasses have come from accidental bycatch, but not a small number of them have come from targeted killing or unintentional lethality caused by techniques that are frankly outdated.
00:01:19:10 - 00:01:39:03
Luke Tipple
Right now, we're at a point where many species of shark are globally threatened. And even when a species of shark is not on the endangered species list, the message sent by media surrounding, for example, shark tournaments, that hole in massive sharks for trophies and say they're doing it in the name of science, It conveys, in my opinion, the wrong message.
00:01:39:07 - 00:01:58:15
Luke Tipple
And I think it's time for a change. With me today are two guests that will help shed light on this subject. First up is Neil Hammerschlag. Here was a long time professor at the University of Miami. He's the founder of Atlantic Shark Expeditions and he's a faculty member of the Black Girl Dive Foundation. He's an expert on, among many other things, data acquisition in the field.
00:01:58:17 - 00:02:06:21
Luke Tipple
So, Neil, welcome to Shark Week, the podcast. You are kind of the creme de la creme of scientists around here. Tell us, how do we study sharks today?
00:02:06:23 - 00:02:30:19
Neil Hammerschlag
For me, I think there is no one answer. There's no one tool and a really good scientist is going to have multiple tools in their tool kit. A lot of people think, Oh, you got to tag the sharks. But there's actually a lot of tools in the scientists tool belt. And in fact, I've done a lot of work on just observation, and I'm bringing that up because I think observation is actually kind of a lost art of science.
00:02:30:21 - 00:02:51:09
Luke Tipple
Sure. Now, there has been some sort of perhaps controversy, certainly press involving scientists taking shark carcass fur for research purposes and whether they wanted to actually take them or not. It's been used as justification for certain harvesting that's going on. How often do scientists actually need to kill a shark to learn something about them?
00:02:51:11 - 00:03:10:01
Neil Hammerschlag
My view is that it's probably not as necessary as you as you think. It's really important to try to develop noninvasive or non-lethal ways to study sharks, particularly ones that are relatively rare or threatened with extinction.
00:03:10:03 - 00:03:20:03
Luke Tipple
Let's take it from the perspective of, you know, science and where we are today and how we've gotten here. How much of that is a product of destructive methodologies?
00:03:20:05 - 00:03:33:23
Neil Hammerschlag
Historically, most of what was large about sharks were from dead animals that were, you know, captured during fishing techniques. And that's still pretty common just because of how expensive and hard it is to actually go out and find animals in the first place.
00:03:34:04 - 00:03:43:23
Luke Tipple
Sure. So do you in your own research or in research, have been connected with do you use methodologies that involve removing a shark from the water?
00:03:44:01 - 00:03:44:21
Neil Hammerschlag
Yes.
00:03:44:23 - 00:03:48:10
Luke Tipple
And what type of duress does that put the shark under?
00:03:48:12 - 00:04:07:22
Neil Hammerschlag
So the benefit of why you might capture a shark and actually take it out of the water is because it's a lot easier to work with and it makes the process a lot quicker. So the thoughts that I always have is like, if you can reduce your handling time, you can you can obviously that's better for the animal, you know, and also safer for the researcher.
00:04:08:00 - 00:04:32:23
Neil Hammerschlag
So, you know, when the animal's staying in the water, sometimes a lot harder, it takes longer and you're restricted in what you can do and not increase handling. Time can be also be stressful for the animal. So the other things about it, what I've learned over the years is that different species actually respond differently. Some species, like the great hammerhead and other hammerhead species, we've we discovered that they're extremely sensitive.
00:04:33:01 - 00:04:48:11
Neil Hammerschlag
We couldn't we couldn't even restrain them, let alone take them out of the water. We couldn't restrain them for any marketable amount of time. It used to be we said, okay, 45 minutes or less, we would work them up. If they're in the line, 45 minutes or less, we we would we could process them. And what we learned.
00:04:48:11 - 00:04:51:11
Neil Hammerschlag
And sometimes that wasn't enough. They didn't live.
00:04:51:13 - 00:05:00:21
Luke Tipple
Under what premise would you say that somebody has justification for terminating a fish? You know, a shark?
00:05:00:23 - 00:05:21:00
Neil Hammerschlag
You know, there is only some information from sacrificing sharks. But, you know, when it comes to marine mammals, like we don't sacrifice marine mammals to study them, no one would start killing orcas to learn what their reproductive status. So how do we study them? And it turns out there there were non-lethal tools available for other species that people really care about.
00:05:21:00 - 00:05:37:20
Neil Hammerschlag
You know, big, fluffy, cuddly species. People didn't go kill them when they wanted to learn about them because they developed non-lethal tools. And what we've seen is the community has responded. There are now non-lethal methods to studying these animals, which is really amazing because they weren't available historically.
00:05:37:22 - 00:05:52:05
Luke Tipple
Do you think that was just because people weren't being inventive enough, or was there a bias towards the animal that enabled scientists to be like, yeah, you know, killing one is worth the sacrifice. Whereas they wouldn't have done that to an elephant?
00:05:52:06 - 00:06:06:08
Neil Hammerschlag
Well, you know, one of my arguments that I made in that scientific paper was that there's a lot of dead sharks out there. They're being caught in fisheries. Use those. You know that if there's things that you can only use for dead sharks, why don't you rely on some of the sharks that are already being killed?
00:06:06:10 - 00:06:09:13
Luke Tipple
And is there anything stopping scientists from doing that?
00:06:09:15 - 00:06:32:13
Neil Hammerschlag
So right now, there are no barriers to to working with fishermen or fishers to use sharks that are already dead. I would say one of the big barriers is that a lot of fishers have a mistrust of science because they think that information that's going to be gathered from the specimens that they generate are going to kind of come back to bite them in the butt, that there might be increased regulation.
00:06:32:13 - 00:06:35:00
Neil Hammerschlag
And so there's the general mistrust of scientists.
00:06:35:02 - 00:07:00:10
Luke Tipple
Yeah, you know, I think I think there's a lot of scientists who actually pretty bad fishermen, they don't know how to use fishing tackle properly and they don't know how to take an animal without it being injured. So in talking to these people who might seem a little distasteful to scientists sometimes who are out there like, I'm catching a shark and I'm going to pull in and bloody deck sets and bloody decks, those are the guys who actually do know how to pull them in and release them unharmed.
00:07:00:13 - 00:07:02:15
Luke Tipple
If you gave them that opportunity.
00:07:02:15 - 00:07:23:12
Neil Hammerschlag
Absolutely. And have an appetite. Look. Absolutely. My boat captain right now in Nova Scotia, the one that we're doing the white shark research with. He was a shark fisherman for 25 years. Tremendous amount of knowledge. And in fact, one of his best phrases he always likes to remind me is that he always said that a scientist can give you the square root of a pickle jar, but he can't open it.
00:07:23:14 - 00:07:32:11
Luke Tipple
I think he's dead on with that. So we started this podcast with the idea of, you know, do we need to kill sharks to learn about them? What's your answer to that?
00:07:32:13 - 00:08:06:08
Neil Hammerschlag
No, I don't think we need to kill sharks to learn from them. In fact, I don't even think we need to tag sharks to learn from them. I think it depends what you want to learn. So what people have done is, for example, looked at tissues that historically were were the golden standard and taken through lethal means, like, for example, a liver or heart sample, and then compare that to values in like a thin clip or muscle biopsy, and they can figure out what the relationship is between concentrations of toxins or chemicals in those non-lethal methods and compare it to the lethal methods to figure out, oh, you know what?
00:08:06:10 - 00:08:21:13
Neil Hammerschlag
There is there's this certain type of relationship. And now looking at values in the liver, comparing it with values, you know, in the blood, and then saying, oh, now I know what that means. And now I can all I will only work with the blood and therefore don't have to go kill any more sharks.
00:08:21:15 - 00:08:41:08
Luke Tipple
Makes a lot of sense. In Australia, if we want to know how your liver is, we just take you out drinking. To continue this conversation, my next guest is Frederick Buyle. He's a world champion free diver and he is awesome. His methods of tagging and gathering information from sharks have had real world results in the protection and preservation of endangered species.
00:08:41:13 - 00:08:50:14
Luke Tipple
Now, Fred, welcome to the Shark Week podcast. It's really good to see you again, dude. I think the last time I saw you, we were underwater in Guadeloupe, surrounded by a great white sharks.
00:08:50:16 - 00:08:52:16
Fred Buyle
Yeah, that was back in 2009.
00:08:52:20 - 00:08:55:03
Luke Tipple
Actually, was it that long ago?
00:08:55:04 - 00:08:56:17
Fred Buyle
Yeah, that long ago.
00:08:56:18 - 00:09:13:17
Luke Tipple
Wow, dude. Okay, well, I wanted to bring you on today to talk about your free diving work, specifically with tagging sharks, because it's kind of a niche that you've really carved out for yourself. I know that, you know, a lot of us use spear guns and stuff underwater, but you specifically have achieved some fairly unique results.
00:09:13:19 - 00:09:38:06
Fred Buyle
So the idea when we tag sharks, we need to tag specific individuals. And that's where freediving comes very handy, because usually to tag sharks you have to fish them out of the water and it's a guess because you never know which animal you're going to get. By freediving, I can choose exactly the animal I'm going to tag so it can be a small male, a large female, pregnant female.
00:09:38:08 - 00:09:57:22
Fred Buyle
That's what the marine biologists are asking me to do. And to do that, I use the freediving skills. And when you free dive, you know, you're very silent. So you can approach the animal. You can even get them curious to come to. And that's the best situation, of course, because then you don't have to run behind the animal to take it.
00:09:58:00 - 00:09:59:16
Fred Buyle
So you just explain that.
00:09:59:16 - 00:10:03:08
Luke Tipple
How are you getting the shark curious about you and getting them coming towards you.
00:10:03:10 - 00:10:28:05
Fred Buyle
Because somehow you're very silent. You're going to stop and wait. And then the sharks would come. And they are curious because you you are something they don't know. So they will approach very slowly and try to gauge you. And that's when you have a better time to to place your shots in and really being accurate. So that's what I tried to achieve to get the animal close instead of following the animal.
00:10:28:06 - 00:10:48:02
Luke Tipple
Yeah. So if we're going to talk about results, you know, kind of comparing, we've been talking about more traditional methods of tagging a shark. It's potentially fairly traumatic for the animal in terms of results. What is the comparison between your methodology and more traditional sort of hook and line float type methodologies?
00:10:48:04 - 00:11:00:06
Fred Buyle
Yeah, in fact, it depends of the team because some teams are quite reluctant to use divers of free diver because they're afraid that the tag won't be inserted properly and they will lose tags. Yeah.
00:11:00:08 - 00:11:02:17
Luke Tipple
Yeah. Because it doesn't penetrate deep enough or whatever.
00:11:02:18 - 00:11:16:20
Fred Buyle
Yeah, but with the results we have, basically there's like probably ten 15% of the tag that don't stay in the animal. And it's almost the same rate when you fish and hook. So there's not much difference.
00:11:16:22 - 00:11:42:21
Luke Tipple
I think one of the things that you noted that was really significant to me is the selectivity of what you're doing. You know, being able to go and select the certain kind of animal. Have you seen any data that couldn't have been achieved by other traditional means? And by that I mean like if somebody saying, hey, I specifically want to study a, you know, 14 foot rabbit tiger shark.
00:11:42:23 - 00:12:02:08
Luke Tipple
That would be an extremely difficult and perilous thing to do because you'd be injuring that animal if you actually managed to hook it. It would probably be traumatized. It might lose its pups. I don't know if you've ever done anything exactly like that, but is there any data that you've collected that is extremely unique that wouldn't have been got it in any other way?
00:12:02:10 - 00:12:31:01
Fred Buyle
Yes, we can take the example of the pregnant female scalloped hammerhead We've been tagging in Galapagos or Malpelo Island in Colombia. I mean, Malpelo, we did the first three or four expedition that did there, specifically targeting these big females because we wanted to see where they're going to have the pups. And we saw that these females were going on the on the mainland, on the coast, in the mangrove.
00:12:31:03 - 00:12:51:07
Fred Buyle
And thanks to that to these data, they could protect part of the coast where these animals were giving birth. And to be able to do that, you need to have a diver, a free diver, because you need to target that specific animal and also a hammerhead that's very difficult to fish the scalloped hammerheads because they don't bites usually.
00:12:51:12 - 00:12:55:12
Fred Buyle
And the one by the line is usually smaller individuals.
00:12:55:14 - 00:13:00:03
Luke Tipple
Right. Do they actually protect that area after the results of the paper?
00:13:00:05 - 00:13:10:12
Fred Buyle
Yeah, they were. Yeah. They created the marine reserve in the mangroves and they're on some coastal area and to protect the coastal habitats and that helped a lot of course.
00:13:10:14 - 00:13:19:23
Luke Tipple
What would you say the the most unique or surprising piece of data that you've personally been able to collect is.
00:13:20:00 - 00:13:45:17
Fred Buyle
I mean, here in, um, I’m based in the Azores since a few years. And here we've developed a totally noninvasive way of tagging blue sharks. Basically a free dive and put a collar around the neck of the sharks, the free swimming shark. And we have a multi-platform sensor tag that stays on for 24 to 48 hours on the shark recording the depth salinity acceleration.
00:13:45:19 - 00:14:08:04
Fred Buyle
Uh, we even have an on board camera and then we recover the tag, download the data and deploy again. And with that we, we could really see the daily routine of these blue sharks. So basically all day they go up and down the water column from 0 to 400 meters to hunt. Then they come back to the surface to reheat and then again and again.
00:14:08:06 - 00:14:23:12
Fred Buyle
And that's something we've never experienced before. We couldn't get this kind of data in another way. And it was really interesting to see their daily behavior because we were seeing these sharks every day on shark dives, but we had no idea what they were doing.
00:14:23:13 - 00:14:42:18
Luke Tipple
So, I mean, you're obviously a big proponent for this noninvasive or minimally invasive techniques. Yes. Is this something that you're training other people to do? Can people reasonably expect that they might be able to learn to do what you do? I mean, let's face it, you're a world record holder. What you do underwater is perhaps not achievable so much by most people.
00:14:42:18 - 00:14:56:06
Fred Buyle
No, because in fact, you don't need to be super good free diver. You need to be good with the animal, Understand how it works. But the actual time we spend on the water to tiger sharks, it's maybe 30, 40 seconds. It's very short time.
00:14:56:11 - 00:15:10:09
Luke Tipple
That sure sounds like it. So we started this podcast with the question of, you know, can we truly study sharks without killing them? Now, there might be some case for mortality within shark research, but what is your opinion?
00:15:10:11 - 00:15:38:18
Fred Buyle
Yeah, it's like everything. I mean, the science is there. Will it be always invasive of thing in science and more in marine biology? But I think we can limit the impact and the way we tag them and and the species we target. We know there are options that are very fragile. Some other sharks are like bulletproof. If you work with bull sharks, they can stay a long period of time being investigated.
00:15:38:20 - 00:15:52:19
Fred Buyle
But I'm I'm an advocate for the the less invasive possible methodology. And that's why somehow I started doing the shark tagging because I thought free divers or divers could help to do that and minimizing the impact on the animal.
00:15:52:21 - 00:16:14:21
Luke Tipple
So there you have it. We've heard from two industry professionals who found really innovative ways non-lethal and non-invasively to gather data from sharks. I think our need for information as scientists has kind of been leveraged by some of these special interest groups. You know, these fishing tournament organizers who say we're going to go out and catch sharks and donate the carcasses to science to further our understanding of the species.
00:16:15:02 - 00:16:36:16
Luke Tipple
Well, isn't it time that we say, no, we don't want you dead sharks anymore? We've already got that information and we're developing techniques that don't require lethality anymore. So let's take away that media talking point that they have and the justification for really what they're doing, which is just making money off of dead sharks. Both Fred and Neil pointed out that in many ways we don't need lethal take anymore.
00:16:36:18 - 00:17:01:08
Luke Tipple
And in fact, any type of interaction with the sharks that's invasive is at least non desirable and perhaps unnecessary. Yet we have over the years learned a lot from dead sharks. But I think it's finally time to say we don't need a dead shark anymore. And it's time for today's shark bite, where our researcher, Sierra, brings us a cool ocean fact to end the show.
00:17:01:10 - 00:17:03:04
Luke Tipple
What have you got for us today, Sierra?
00:17:03:06 - 00:17:15:08
Sierra Kehoe
Yeah. So I know we just finished chatting with Neil and Fred about how they tag and study sharks, but there's actually this program out there where a lot of people who aren't scientists or marine biologists do a lot of the tagging.
00:17:15:10 - 00:17:17:06
Luke Tipple
Very cool. Let's hear about it.
00:17:17:08 - 00:17:34:02
Sierra Kehoe
Yeah. So it's this Citizen Science program. It's called the Cooperative Shark Tagging Program. It's one of the longest running and largest operations of shark tagging in the world. And it's this huge effort between recreational anglers, commercial fishers, biologists and know fisheries.
00:17:34:04 - 00:17:36:12
Luke Tipple
Sounds great. So what type of tags are they putting in?
00:17:36:14 - 00:17:46:21
Sierra Kehoe
So there's two main types that they use. The first is the dart or M tag, which is usually used by fishers, and then there's the fin or roto tag, which is usually used by the biologists.
00:17:46:23 - 00:17:58:02
Luke Tipple
Yeah. So those are fairly basic ID tags that enable you to see if a fish has been captured before and tagged. And then you can enter that into the database as a recapture. That's pretty cool. What are they finding?
00:17:58:04 - 00:18:14:09
Sierra Kehoe
So since 1962, there have been almost 300,000 sharks tagged. And one of the crazy things that they found from this was that tiger sharks actually crossed the Atlantic. They didn't find this or discover this until the program was 34 years old.
00:18:14:11 - 00:18:23:19
Luke Tipple
Oh, wow. So they obviously they tagged a tiger shark and it got recaptured across the other side of the Atlantic. Yeah, that's awesome. Tell me the name of the program again.
00:18:23:21 - 00:18:26:14
Sierra Kehoe
It's the cooperative shark tagging program.
00:18:26:16 - 00:18:34:20
Luke Tipple
Okay. So if you're fishing and you're catching shark, then you really should be part of this program because obviously some really good scientific data can come from it. Thanks so much, Sara.
00:18:34:22 - 00:18:39:08
Sierra Kehoe
Yeah, any time.
00:18:39:10 - 00:18:50:14
Luke Tipple
Okay. That's it for another Shark Week, the podcast. Thank you for joining me. And I really want to thank my guests, Neal and Fred. We really learned a lot from you today, guys. Until next time, I'm Luke Tipple. I'll chat to you soon.
00:18:50:16 - 00:18:54:00
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You’re listening to the Shark Week Podcast.