
This Gigantic Shark is a Huge Mystery
Episode 6 | 10m 54sVideo has Closed Captions
Explore how we find and tag a massive and mysterious shark: the basking shark.
Jasmin joins PhD student and Minorities In Shark Sciences co-founder Jaida Elcock on her mission to find and tag a massive and mysterious shark: the basking shark. It won’t be easy, so an international collaboration with friends in Ireland might hold some answers.
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Funding for SHARKS UNKNOWN WITH JASMIN GRAHAM is provided by the National Science Foundation.

This Gigantic Shark is a Huge Mystery
Episode 6 | 10m 54sVideo has Closed Captions
Jasmin joins PhD student and Minorities In Shark Sciences co-founder Jaida Elcock on her mission to find and tag a massive and mysterious shark: the basking shark. It won’t be easy, so an international collaboration with friends in Ireland might hold some answers.
Problems playing video? | Closed Captioning Feedback
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Learn Moreabout PBS online sponsorshipWe’re here in the Northwest Atlantic.
We're on a high seas chase for one of the most misunderstood sharks the basking shark.
One might say it's a Shark Unknown.
Today, I'm at Woods Hole Oceanographic Institution.
I'm meeting up with Jada Elcock, an old friend who's been studying the mysterious basking shark.
Basking sharks may be big, but they're actually gentle giants.
They're filter feeders and an endangered species.
But there's a lot of mystery around basking shark migration.
If we can find and tag these sharks, that gives us the critical information that we need to map out their migratory paths and protect not only this endangered animal, but the entire habitat off the coast of Massachusetts.
Hey Jada, wassup?
Hey Jasmin.
How are you doing?
I'm great.
How are you?
Good.
So tell me a little bit about basking sharks.
What's their deal?
I'm trying to piece together a couple of different pieces of this, huge mystery of basking shark migration.
For a long time, we thought that they spent all of their time in, like, temperate and cold waters, especially in the Northern East Atlantic, near Cape Cod.
But it turns out that they're traveling over 17,000 kilometers down into the subtropics and the tropics into like the Caribbean area of the Atlantic Ocean, sometimes even past the equator, which is wild for us to think about.
It's amazing to me that animals so big can be so mysterious.
Yeah.
So they are the second largest fish on the entire planet, averaging about 25, maybe 30-ish feet.
They can get bigger, weighing around 11,000 pounds, which is incredibly large.
They can live to be about a half a century and they're filter feeders.
They look like little old men that have no dentures, with their mouths open, they look like a windsock.
So what's not to love about them?
So cool.
I love filter feeding sharks.
Yes, because it's so funny because people always think about sharks as being these predators and like scary, but there are some sharks that literally just sit around with their mouths open.
The basking shark is not only a filter feeder, but a passive filter feeder.
So they don't even actively suck water in in order to get the food.
They just swim around with their mouth open and hope for the best and get what they get.
Which is honestly the coolest strategy of eating.
I wish I could passively eat.
Just the laziest form.
Just live your life.
Exactly.
And just get nutrients.
Just open your mouth and there you go, snacks immediately.
Snacks!
And they - they're eating some of the smallest things that you can think of in the ocean like little copepod zooplankton.
Do we know where they pop at?
We've got no idea.
No, of course, cause why would we know that?
No, we don't know where they mate.
We don't know where they pup.
We know very little.
This doesn't make sense to me.
So that's what I want to figure out.
I'm like, there's so many things about you.
You're huge.
We have to know more about you.
I mean, that's so exciting, though, because it opens up so many research opportunities.
So the fact that we know little is both frustrating and super exciting at the same time.
Yeah, because that's all science is asking questions, trying to figure out the answers.
So most of science is going, “I don't know, let's figure it out.” Hopefully we're able to do that with some of these tags Yeah, I see you've got a pop up satellite archival tag here.
So this is what you're using to track those long distance movements down to South America?
Yeah, exactly.
So these don't necessarily take geolocation position data, but they take a lot of things like light, depth, temperature data that are collected by this tide can be used to kind of also create some sort of like pseudo path that they've taken so that we can kind of figure out where exactly in the world they are.
So these bio logger tags are actually going to be used more on when they're on the continental shelf when they're close by Cape Cod.
So that can give us a lot of information on their behaviors.
Like how much are you eating, which then could potentially inform us on how are they fueling their migrations.
And this is the spot tag.
These will actually transmit position data of the animal.
Those are some our options that we've got so far.
And also, how on earth do you put a tag on a basking shark because you can't bait them?
This is a passive feeder, so you just like look for them and hope that you see them.
Yeah, so that is a really great question.
One of the biggest challenges is finding the basking sharks and want to make sure that we're able to reliably find them.
But we will go out with a boat and then it's finding a needle in a haystack.
Basking sharks migrate in the spring and in the fall, but you have to be as lucky as you are good to tag them.
And today we're going to go looking for these elusive animals.
So, Jada, where do you think we're going to find these basking sharks?
So I think there's a potential to find them around here.
Around the outer cape.
But I've heard anecdotally, too, that some fisheries have seen them around here in Nantucket Shoals, Woods Hole’s over here so we've got to make it out here a little bit.
It's going to be a bit of a ride.
You ready?
I'm ready.
Let's go.
Let's do it.
While basking sharks may be big, they're an endangered species.
There's so many shark species out there that are actually endangered that we are hunting basically to extinction.
And I know basking sharks, there is a big issue with the livers.
They were hunted really heavily for their liver oils and they're still endangered and their populations are still decreasing, which is really unfortunate.
If we can find and tag these animals, that is going to give us some crucial information to use to map out their migratory pathways and potentially protect not only this endangered animal, but the entire ecosystem within those zones.
But they're not always the most reliably found.
So it's not going to be easy.
We're just looking for a dark blob in endless shadows and glares.
But my grandparents were born and raised in South America and Guyana, and so my sharks are going to the Caribbean.
And I'm like, “Take me with you.” So I personally want to do my best to make sure that we have as much information as possible to better protect basking sharks, to make sure that they're around for a while.
I have so many nieces and nephews and I would love for them to live in the world with a basking shark because everyone deserves to experience recognizing that we share the earth with so many really amazing creatures.
It's been a long day.
I mean, we've been at this for hours without here for a while, for sure.
Jasmin, I think we got to call it.
Yeah.
The sun is going to be going down soon and unsuccessful trip this time, unfortunately.
But science happens.
I know.
Yeah, next time or whenever, we’re going to find a basking shark.
Or we’re going to die trying.
I saw that the Irish basking Shark Group has been getting some really cool footage.
I'm going to reach out to our friends in Ireland and see what kind of luck they're having.
Hello.
Hi, how are you?
I'm really excited to talk to you today.
I just went out with Jada to look for some basking sharks, although I learned that it's harder to find a basking shark off the coast of Massachusetts than off the coast of Ireland.
I mean, they're very elusive.
Even in Ireland, they'll just sort of disappear.
Okay.
Tell me a little bit more about what you're trying to find with the basking shark.
Part of what I was doing is I developed an individual based model or an IBM.
It's kind of a unique type of modeling that we don't really use a lot in marine research.
When you use an IBM, you can have unique individuals within your population.
So each of the sharks in my model is its own unique little individual and it makes its own choices based on its limited knowledge about sort of the environment around it.
And then what I want to know is what drives these aggregations that we see.
Every time there's a shark that's yellow, it's actually sharks aggregating together.
So you can see there's actually three sharks with this yellow shark.
So they have these big aggregations and we don't know if they're driven by food or if they're driven by kind of like a social driver.
So something like reproduction.
So what I found was that there's some kind of social activity happening that they're not just gathering together coincidentally because of food availability, but that they're intentionally seeking out other sharks.
It does seem to indicate that they're gathering together for some kind of courtship or reproductive purposes.
So it seems like there is evidence that the basking sharks are at least able to recognize each other and may even be exhibiting some sort of social behavior?
They're definitely exhibiting social behavior.
We observe that in the wild.
We see that they swim and like really intentional behaviors.
So we have like that Taurus behavior, which is where they swim in concentric circles, which I think is really interesting.
And sharks aren't always eating when they're doing this kind of behavior, which again, lends itself to the idea that this probably has something to do with some kind of intentional social behavior, maybe courtship.
Some of our preliminary data seems to indicate that maybe sharks do have friends and it happens a lot off the coast of Ireland.
So Ireland is a hotspot for this kind of activity.
So the basking sharks that are in Ireland, are some of them the same basking sharks potentially that Jada would be seeing off the coast of Massachusetts?
Absolutely.
We have documented some of the same individuals have gone from Ireland all the way across to the east coast of North America.
So absolutely, they can very well be the same sharks.
This is clearly documented that they do cross the ocean like that.
Wow.
That's cool.
So then could potentially be studying some basking sharks in Ireland and Jada could be seeing them at a different stop on their migration route.
Yes.
Jada, get the data.
I hope you see a basking shark, because I’ve still never see one up close.
Please, please find some basking sharks and then get me the data because I desperately want to know what they're doing for my model.
I know it's really hard to find a basking shark, and it's like a needle in a haystack.
But, I mean, if we’ve managed to find each other and we found other black women in shark science, right.
We can find some basking sharks.
I think that if we found enough women and gender minorities of color to make Minorities in Shark Sciences a thing, then we can find a basking shark.
This program was made possible in part by the National Science Foundation,
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Funding for SHARKS UNKNOWN WITH JASMIN GRAHAM is provided by the National Science Foundation.