Photos:
Whale Shark:
Blue Spotted Ribbon Ray:
Masked Puffer Fish:
Episode Transcript:
Victoria:
Our guest this week is Royale Hardenstine. She’s a PhD candidate at the King Abdullah University of Science and Technology in Saudi Arabia. She’s originally from Pennsylvania and did her undergraduate degree at the University of New England in Maine. While in Maine, she volunteered at a Marine Animal Hospital, working with sick and injured sea turtles and seals. However, now she’s studying sharks and rays in the Red Sea. She has led the effort to sample using baited remote underwater video systems, which are cameras with bait that they use to look for sharks and rays in the Red Sea for the larger global Fin Print Project. Her main focus is on Red Sea whale sharks. She uses photo identification and different kinds of tags to find out how often they visit different sites and where they go after they leave. She also takes small samples of skin to find out how they are related to each other and other whale sharks all around the world.
The questions this week were submitted by listeners through emails and on social media.
Thank you so much for joining us today.
Royale Hardenstine:
Thank you so much for having me. I’m very excited.
Victoria:
Is there anything you’d like to add to that introduction?
Royale Hardenstine:
No, I think that covered everything, I guess. Yeah, the only other thing is that, recently, we’ve started an effort to gather more, so photo identification photos from a different species throughout the Red Sea. So if you are on Instagram, you can follow us at Red Sea Photo ID. And, we’re going to be posting updates about different animals that we’ve seen over time. So we’re not just looking for whale sharks in this case, but we’re also trying to get more information about Red Sea sea turtles and mantas.
Victoria:
Awesome. And we will link to that Instagram on the podcast’s social media platforms. And it should be really easy for listeners to just click that link.
Royale Hardenstine:
Thanks. Yeah, that was one of my pandemic projects.
Victoria:
Oh, fun. So we’ve got a bunch of questions here to start off with about whale sharks.
Royale Hardenstine:
All right.
Victoria:
(Alex – Is a whale shark a whale or a shark?)
So this first question I think is a really good introductory question. Alex wants to know, is a whale shark a whale or a shark.
Royale Hardenstine:
Yeah, that is probably the most common question I get. And there’s actually a really great cartoon that has an illustrated like comic cartoon that has a picture of a whale shark standing in front of two bathroom doors. And the one has like a little whale’s symbol on it, and a little shark symbol on it. And it’s just kind of like the, “Oh no” emoji face trying to decide which direction the whale sharks should go.
And so whale sharks are actually sharks, and they have gill slits, like all other species of fish. And they need to be with inside the water in order to get oxygen and breathe, unlike mammals, which need to come up to the surface to breed. So things like whales, need to come up to the surface and breathe. And whale sharks don’t need to, they can do really deep dives and they can stay down there for as long as they want and never come up and visit us again if they don’t want to. So on the other hand, like I said, mammals need to come up to the surface and breathe, and they produce milk for their young. Whale sharks don’t do that. And they also have other features of sharks, like skeletons that are made up of cartilage. So, the same thing that kind of in the tip of your nose, how it’s a little wiggly cartilage, and in your ears is also cartilage. So that’s what their skeletons are made up of, while whales have normal bone like humans do. So they’re definitely sharks, but it’s a question that I get all the time.
Victoria:
(Johann – Why are whale sharks called whale sharks?)
This question comes from Johann. Why are whale sharks called whale sharks?
Royale Hardenstine:
So, whale sharks are likely called whale sharks because they are very similar in many ways. They are very similar to whales in that they are really massive creatures. They can be seen at the surface.
There are a whole bunch of species of whales, the baleen whales, right, that filter feed or eat small bait fish at the surface, which is really similar to the feeding style. That whale sharks also adopt. They eat, you know, they filter feed and eat really small things or bait fish at the surface.
And so I think, early on, that’s kind of where the name of whale shark came from. If we really get down into it, well, shark is just kind of like a common name for them, right? So like whale shark is a really general name for them. And so if you go to different places around the world, they probably have their own common name for whale sharks. So I think it’s just kind of like the kind of broad overreaching thing is that, yes, they’re similar in many ways to whales, and that’s probably why they got their name. But then we could go onto a whole tangent about scientific naming and why scientific names matter because it gets really confusing when you have five different common names for the same one species, but that’s, we don’t need to do that today.
Victoria:
(Ellie – How do the cameras with bait work? Do the whale sharks eat the bait eat the bait?)
All right, speaking of your work with sharks, Ellie wants to know, how do the cameras with bait work? Do the whale sharks eat the bait?
Royale Hardenstine:
Yeah, so that’s actually, it’s a really good question. And actually, the surveys that we’re doing with the bait and GoPros is basically what we’re using, isn’t directed at looking for whale sharks.
So, whale sharks are the largest fish and the largest sharks, so they get up to about 20 meters. There’s one that was fish that was 20 meters in length. Although once they get that big, they get a little bit hard to actually measure accurately. So think of your school bus and that’s about how big a whale shark is, usually, the average is more like 14 meters.
But even though they’re so big, they actually eat really tiny stuff called zooplankton. So it’s things like copepods and the best thing to think of, if you want to know what a copepod looks like is, think about plankton from SpongeBob. So, they like to eat tons of little plankton from SpongeBob that live up in the water column. They’ve also been recorded to eat things like fish spawn. So when fish get together, and they spawn, there’s tons of eggs that go out into the water and the whale sharks will come through and suck that up, like giant vacuum cleaners. They also like to eat things like crab larvae and little tiny shrimp. And so, that is all very small critters that are floating in and around the water column.
And so that’s not really something that we can bait whale sharks in for. So when we’re doing the baited remote underwater video, systems also known as BRUVS, work, we’re actually looking for bigger predatory sharks, not always bigger. Sometimes we get baby sharks in our BRUVS footage, but we’re looking for sharks that are attracted to things like gooey fish that we chop up and put into either some kind of cage. We actually, my bait cages, they’re rat cages, are rat traps that I bought, like at a local hardware store.
So, the whale sharks aren’t what we’re looking for when we’re using the BRUVS. But there are things like little feisty sharks, sometimes, small nurse sharks, which are, they kind of like try to like suck food in their mouth. So they have good jaws for crushing things like, conchs and snails. And so they actually, because those are their favorite foods, they have a really strong suction to try to like suck the snails out of their shells. And so they’ll try to suck food out through the holes on the bait cages. And then we’ll also see things like eels, trying to get at the bait and, you know, sharks trying to get at the bait.
But it’s one of the things that’s made me thankful to have hands and thumbs, because it looks so frustrating to watch them try to eat the bait and not be able to get it.
So we don’t just kind of like put a whole fish out there because even though we only do these surveys sporadically, we don’t want to be actually feeding he sharks. We just want them to come in and say hi, and then go on their way. It’s not like we are feeding them actively, and we survey these areas rarely enough that it’s not gonna get them in the habit of being fed. But that’s something that we try to avoid.
Victoria:
(Natasha – What do you use for bait?)
And a follow-up question about bait, which you kind of answered, but if you want to add some more detail about it, this question is from Natasha. What do you use for bait?
Royale Hardenstine:
Yeah, so what we use for bait is we put a kilogram of bait in our cage. And, we tend to use a fish that’s really wally, because we want there to be a bait plumes. So basically when we put it in the water, we want there to be oils and blood and fish juices that go out into the water column. It’s kind of icky, gooey, blech. but we want there to be lots of goo that goes out into the water column and can get pushed away from where our camera is, to hopefully smell really tasty to some sharks so that they want to come closer and check out what this gooey smell that they’re smelling is, which to them is great, cause it smells like yummy fish. So we tend to use things like, small sardines, it tends to be the usual bait that we pick.
Victoria:
(Lena – How do you attach it to the camera?)
Okay. And another follow-up to that, for the BRUVS system, Lena wants to know how do you attach it to the camera?
Royale Hardenstine:
Yeah, so that’s a really good question. BRUVS are, at their simplest, a camera with a stick that points straight out from it with bait at the end, so that you can look for sharks. And this is something that, you know, there’s even a kid in our local community here, at the university, who will put his own homemade BRUVS out. Because we live right on the Red Sea here, so he’ll just, he has a GoPro that he straps some bait too, and he throws it into the water and sees what he gets on the videos. And so that is what a BRUVS is at its simplest. Technically anyone can build one.
However, when we have these big collaborative projects where I’m putting BRUVS out in the Red Sea, another, person’s putting BRUVS out in Tanzania, and someone’s doing surveys in Australia. We want them to be standardized or we want them all to be the same. So, for this project, we were actually sent the BRUVS that we used. And so there are these big metal frames that have a normal GoPro mount. And then, a bit that comes out, that we just got a big piece of PVC that we hook onto it. And then we dropped them in the water with a rope and a float so that we can find them again.
Victoria:
(Cline – What do you use for your tags? How do you attach them?)
All right. And now we’ve got some questions about the tags. Cline wants to know what do you use for tags, and how do you attach them.
Royale Hardenstine:
Yeah, so that is, that’s a really good question. So, the tags that we’re using, or we have been using here in the Red Sea to study whale sharks are a couple of different kinds of tags, and I’m going to speak on my experience of tagging whale sharks, although these kinds of tags can be used on a bunch of different species of sharks and rays and mammals and turtles. And so, there’s a bit of difference in how people put them out, depending on what you’re after.
So for us, The first kind of tags that were used looking at the Red Sea whale shark population were called satellite tags. So these are tags that, if the shark is at the surface long enough, they will report their GPS location. So it’ll send a coordinate saying this is where I am to a satellite. And then the satellite sends that to us here at coast. And so from that, we can get kind of a little track seeing where the whale shark goes. If you kind of want to see this type of thing in action, Osearch, is a project that tags a whole bunch of different kinds of sharks using things like satellite tags. And so there you can actually go and you can live tracks some of their sharks on their platform, which I can give you the link for so that you can, people can find it. So that’s the best way to kind of like visualize what the data that we’re getting looks like. It’s just one point that tells us this number shark was here at this time. So these tags are then programmed to pop off after a certain amount of time, or, if something goes wrong, they’re also programmed to pop off.
So what’ll happen is they leave the shark and come up to the surface of the water. And while they’re at the surface, they start dumping as much data as they can to us: things like dives that the sharks were doing, so how deep they were going; things like temperature, so the water around them. And a lot of times when they’re doing this massive data dump, it’s kind of bending everything or grouping everything into weeks or daily averages, because it’s one little satellite tag that’s sending information to the satellite until its battery dies and then sends it to us. However, while it’s doing this data dump, it’s also sending us its position. So if we have the resources or if it’s in a place where we can go get it, if we go pick up this tag, we can then get really good fine scale data and know everything about all the dives the shark was taking. And so it tells us, from our aggregation site where we tagged them, where the shark went, what the water temperature around it was like, how deep it was diving, what part, what time of the day it was diving and that kind of information, which is really cool.
The other kind of tags that we use are called acoustic tags. And so what we do is called passive acoustic monitoring. So there are these stations that have a hydrophone in them that are listening for a ping from a tag. And so we put these tags on the sharks and then they send out a coded number that says shark number 10 was here. But these listening stations have a limited range in water. So they’re only, in our location, they’re only good for about 500 meters. And you need to know, so because you have these listening stations out, the tags are only useful in one particular area where the listening stations are. So we know when the sharks have come back to visit us, we know where they’re going around, where our listening stations are, but once they leave, these tags are no longer giving us any data because there needs to be a listening station to pick them up.
And then how do we attach them? So to put these two different kinds of tags on, we basically have a small dart that has an anchor, well, that has like a little line that trails from it, and then hooks onto the tags depending on what kind of tag it is. They all, you basically just run like a braided metal wire through it and crimp it off and hope that you did a good enough job putting your tag together. So, the anchors are then basically inserted under the shark skin with a big needle that’s on the end of a sphere, which sounds a bit ouch. So we basically have these big long spheres that we get in the water and we chase down sharks with a spear.
Whale sharks look so big and slow and graceful, but we get juvenile whale sharks here in the Red Sea. They’re only about three meters. So they’re just kind of like grumpy teenager whale sharks, and they tend to move pretty fast. And so we work to catch up to them and then hopefully get in the right spot to put a tag in. and the right spots to put a tag in is right next to their first dorsal fin. So when you’re looking at a shark that big first fan that comes up from the top of its body, right next to that on their back is an area that’s got a lot of connective tissue and not a lot of nerve endings. So it doesn’t really hurt them to put a tag there. And it’s kind of equivalent to a girl getting her ear pierced. You know, it’s a quick momentary pain. Sometimes I think it more scares them that something touched them and not necessarily that it hurt them. I have bent tagging needles on whale sharks. Whale sharks have really thick skin. It’s about 10 centimeters thick. And so, I have gone to tag them before, and it’s Just bounced off of their skin because either I didn’t have the right angle or my needle was a little dull. And so, I’ve also tagged a shark and it has immediately just kept on feeding. So although there are some sharks that don’t like it and they get scared, they usually just dive for a few minutes and then they come right back up and they’re feeding again and we see them again. So we know that doing this kind of tagging is not overall altering their behavior or kind of traumatizing them for long periods of time.
Victoria:
I really liked that analogy of ears piercing.
Royale Hardenstine:
Yeah. You know, we’re just giving them some shiny jewelry to wear.
Victoria:
(Ryan – How do you take samples of whale shark skin? Does it hurt them?)
All right. This next question is from Ryan. How do you take samples of whale shark skin? Does it hurt?
Royale Hardenstine:
All right. So this is actually really, really similar to tagging. We use the exact same spears for the skin samples or a biopsy, we have these round metal tubes, that are about a centimeter across, and about 10 centimeters deep. And they have three little tiny prongs that face backwards, like towards the back. And then a hole drilled in the side so that when we hit the sharks, the water comes out and then the little barbs are there to hold onto the skin or the tissue that we get.
So once again, we chase down a whale shark, we put in the work, and when we get up to the shark, we are aiming for the same area again. So we’re going for right next to their first dorsal fence, so that big, first fin that pops up from their body, and kind of in that connective, that nice good thick connective tissue that’s by that first dorsal fin, is what we’re aiming for.
And so we get a plug that’s usually, maybe that like an inch or two. And what we do is I immediately separate them. So on top is the black dark whale shark skin. And all shark skin is made up of dermal denticles, which are kind of like little tiny teeth almost. And that’s why shark skin is so rough. Right? If you kind of go back, go like head to tail on them, it’s rough and it feels like sandpaper. But if you actually go like tail towards their head, it can actually, cut your hand. So, it’s why you shouldn’t really be touching sharks, or not cut it, but it can give you like, kind of like a road rash kind of rubbed burn kind of a thing. And so, that skin, that top layer of skin, that’s kind of dark, and it has like the black and white patterning being of a whale shark, is what we want to get a genetic sample. And so I cut that off and then we either throw it immediately in the freezer or we throw it in some preservatives to help keep the DNA nice, and as close to when it was in the shark as we can.
And then we have some connective tissue. So like I said, they have really thick connective tissue on their back. And it’s kind of like this white blubbery, it kind of like whale blubber almost. But it’s just like this white connective tissue that’s looks kind of gooey and snotty. And so that we also freeze and safe because that can be used for studies looking at chemical signatures in their tissue that tells us about what they like to eat. That is a whole other process that I don’t actually do. I just collect the samples so maybe somebody can use one day.
So yeah, it’s similar to the tags. I don’t think. It hurts them too much. Sometimes the smaller whale sharks don’t really like it. They, you know, flinch. But it’s the same situation with the tags where we’ll see them back at the surface feeding minutes after we’ve biopsied them or after we’ve tagged them. So we’re not altering their behavior to a point that it’s harming them, or even stopping them from getting the amount of food that they would normally be getting when they’re just up at the surface feeding.
Victoria:
Sort of like when you go to the doctor, and you get your vaccines to keep you healthy, but it hurts for a little bit, but it ultimately it’s for a really good purpose.
Royale Hardenstine:
Yeah. Ultimately, it’s for good. And, I mean, on the scale of a whole whale shark, that’s, you know, three-meters long, a little one-centimeter, quick puncture isn’t going to hurt them so bad, because we see whale sharks with massive scars from propellers going from their head to their first dorsal fin. And, you know, because the propellers go around on a boat, you’ll actually see like a series of scars going all the way across their back. Or we have sharks that are missing the end of their pectoral fins or missing the entire top, which the pectoral fins, or the little fins on the side. So like they’re kind of arm fins or pectoral fins. So, in the long run, they’re getting either bitten by other sharks or hit by boats accidentally, and that’s doing a lot more damage than we’re doing, and the heal and survive from those kinds of injuries.
Royale Hardenstine:
(Erin – Have you ever been bitten by a whale shark?)
Yikes. All right. This is kind of a fun question, well, depending on your answer, a fun question. This is a question from Erin. Have you ever been bitten by a whale shark?
Victoria:
Yes, well, no. Yes. It’s a funny question and I love it. No, I have not been bitten by a whale shark.
Whale sharks, actually, if you look at their mouths, when they’re open, you can’t really see their teeth. It’s not like a typical set of shark jaws that you think about when it, Oh, the horror, there’s a shark that’s going to attack you or, you know. So they actually have very, very tiny teeth that are vestigial, or it kind of means that they’re really not useful to them anymore. Because they don’t do any biting or chewing. And so, even if I were to get bitten by a whale shark, it wouldn’t hurt. And their throats are very, very small. So it’s not like they’re going to try to swallow me or you or another person whole.
I think there’s one recorded whale shark attack. And it’s one that like accidentally ran into a boat or something like that. So, they kind of, if you think about their heads, they have super wide heads with eyes, kind of like off to the side. So they kind of have a blind spot, like right in the middle of their head. And sometimes they’ll accidentally run into people swimming with them or boats or each other. So they’re kind of big dopey sharks that aren’t out there to hurt anyone.
So. No, I have not been bitten by whale shark. I have not been bitten by any other kinds of shark. I’m trying to think if I’ve even been bitten by any fish, which I don’t think I have. I think the only thing in the sea that’s really gotten me was an urchin. So like sea urchins with their big pointy spines, I hit one with my hand by accident. And so I think that’s the only thing in the sea that’s really been out to get me.
Victoria:
(Ryan – How many whale sharks are left in the world?)
That’s good. All right. Ryan wants to know how many whale sharks are left in the world.
Royale Hardenstine:
Hoo, Ryan, that is a good question, but it’s a tough one, and maybe you can one day be a whale shark researcher and figure it out.
So, there are population estimates. So knowing how many whale sharks there are left in the world. But there’s a lot of caveats or kind of issues that we have to be aware of when we’re talking about modeling and understanding the population of something like whale sharks.
So, whale sharks are really difficult to study. There are two people who, one of them is Dr. Eugene Gudger. He worked in like the 1920s and 40s, he was writing all kinds of work about really early descriptions of whale sharks. And, there was another, there was a woman named Dr. Fay Wolfson, who also did a lot of work looking at records of whale sharks to understand their distribution and stuff. And neither of them ever saw a whale shark alive. They only ever saw museum or stranded specimens. And so for the first few hundred years of researching whale sharks, there were very few sightings. And it was really difficult to get really good data.
These aggregation sites that we see in places like here in the Red Sea, or off the coast of Australia, or people know about the ones in Mexico, or in the Philippines, are what really made us able to start looking at whale sharks closely, because we know they come and visit us this time of year, every year at this spot. However, that also comes with a bias. Most of the whale sharks that are showing up to these sites are juveniles. So they’re young sharks, and most of them are males. So we’re already only looking at a portion of the population. The Red Sea is really unique in that we get equal numbers of juvenile males and female sharks.
Yeah, basically, this is just a really long way of saying it’s really hard to know how many whale sharks there are in the world. What we do know is that currently the population trend is decreasing. So whale sharks in 2016 were moved from being threatened to being endangered, which means that they’re in more trouble than they were when they were previously assessed.
Victoria:
(Mari – What is an aggregation site?)
(Ellie – Why does it occur?)
Okay, this is something you’ve mentioned a little bit. You’ve mentioned aggregation sites, and so Mari wants to know, this is two questions that go together. Mari wants to know what is an aggregation site, and Ellie wants to know why does it occur.
Royale Hardenstine:
Those are two very good questions. So generally, when we’re talking about an aggregation site, as I’ve kind of mentioned before. It’s, there’s several of these around the world. So, Ningaloo reef in Western Australia is a famous one. In the Philippines, there are a few that are really popular for tourism, as well as, like Yucatan Peninsula in Mexico, and Mafia Island, Tanzania has an aggregation.
And so, when we’re talking about aggregations, what we mean is it’s a place usually they’re associated with the nearby coast, because that’s just where people are out diving or snorkeling or looking at reefs. So there could be aggregation sites in the open ocean and that we don’t know about because we just, that’s not where we’re looking. Right. So, it’s a site where we see multiple sharks at a time usually, and it’s also a site where in general we seasonally, or what we’re beginning to find out is actually in some sites, it’s not as seasonal as we thought it was, see whale sharks. It’s a place where you reliably, usually see whale sharks.
So our aggregation site here in Al-Lith, we know March, April and May, at one particular reef, that’s only five kilometers from shore, so it’s really close to shore, we can see the coast guard station from the reef, March, April, and May, we get whale sharks. We don’t have a huge aggregation. So we’ll only see like three or four whale sharks together at a time. That’s when they like to show up there and eat. There’s other places like Mexico, where they will see hundreds of whale sharks a day at a time. And so aggregation sites kind of scale a bit. But, the main thing is that we can reliably see whale sharks there. And usually, it’s seasonal.
Now, why does it occur, is another really good question. Most aggregations, especially the seasonal ones, are feeding aggregations. So whale sharks showing up to a place because it’s an all you can eat buffet. What they’re eating usually varies between sites.
So, Djibouti, which is just outside of the Red Sea, has an aggregation where they eat, aeroworms or … So there are these little kind of wormy guys that live in the water.
Here in Al-Lith, in Saudi Arabia in the Red Sea, we think they’re eating mostly what are called Lucifer shrimp, which are just these little shrimp. That’s also what we think they’re targeting to eat in Tanzania.
In some places, like I said earlier, they show up when fishes are spawning. So fish will go to a place and aggregate. So they all go and hang out together and then seasonally, they will spawn together. So basically fish are broadcast spawners, which means that the sperm and the eggs go up in the water column and they just kind of do that. And so then there’s all of these like good juicy eggs floating around and the whale sharks just go through and tear through that and eat that.
So a lot of them seem to be based on food availability. So it’s a predictable pulse of food that they show up to eat.
Victoria:
(Will – Do all animals have aggregation sites or just whale sharks?)
All right. That’s fun. Good follow-up question to that. Will wants to know, do all animals have aggregation sites or just whale sharks.
Royale Hardenstine:
So that, yeah, that is a really good question. So like I said, it a bit in my answer about the whale sharks, there are things like, some species of fish that will aggregate to spawn, or reproduce. I guess with aggregating species, that species that are usually quite solitary and then they’re all coming together at once. Right? So in a way, some of the areas where you see large numbers of sea turtles, all arriving at a beach to nest at once could be considered an aggregation as well.
So there are things like fish and sea turtles and whale sharks.
Victoria:
(Kelly – What’s the biggest whale shark you’ve ever seen?)
Cool. All right. Switching gears a little bit. We’ve got a couple of questions about your experience with sharks. Kelly wants to know what’s the biggest whale shark you’ve ever seen.
Royale Hardenstine:
The biggest whale shark that I’ve seen is about eight meters, which is close to about 20 feet. And as we have just figured out, it’s about the same length as a giraffe’s tall. So if you’ve seen those in the zoo, that’s kind of, or in the wild, who knows, that’s going to be equivalent of like the length of a whale shark.
I did not, however, see that in the Red Sea, I saw that when I was traveling and I was at a conference that did a whale shark trip where I got a chance to swim with whale sharks in Australia.
Victoria:
(Daniel – Have you ever touched a whale shark? What do they feel like?)
That’s so cool. This next question, you’ve already answered a little bit, but if you have anything to add to it. Daniel wants to know, have you ever touched a whale shark? What do they feel like?
Royale Hardenstine:
So, actually, I don’t think I’ve touched a whale shark. I’ve gotten very close to them, but that’s because I work on them, and I do things like put tags or biopsies on them. But much like, you should, if you’re going out and doing tourism booking to swim with whale sharks, I try my best not to touch them when I’m in the water with them. Like I said, with the, the tagging and the biopsies, yes, it probably hurts, but it also probably surprises them or startles them a bit, because they’re used to being the big guys that nobody really messes with. And so in general, when you’re in the water and you’re doing things like swimming with sharks or turtles or whales or dolphins or whatever, cool animal, you’re interested in, it’s really important to look and not touch. And so, even as a researcher who could get away with touching whale sharks if I wanted to, I try my best, not to.
I guess the question of what do they feel like, I have like held and touched sharks before, they do feel a lot like sandpaper. And so they’re just very rough skinned animals. So I assume whale sharks feel pretty close to what other sharks feel like.
Victoria:
(Johann – What are the dangers whale sharks are facing? Are they on the endangered list?)
Okay. And this is a question from Johann. What are the dangers that whale sharks are facing? Why are they on the endangered list?
Royale Hardenstine:
That is a very good question. So there is a whole bunch of threats to whale sharks. And just, you know, some Marine life in general.
For whale sharks in the Red Sea, our biggest threat is ship strikes and boat strikes. So the Red Sea is a major shipping lane. And so the earliest work on whale sharks in the Red Sea is by that guy I mentioned earlier, Dr. Eugene Gudger, who did a bunch of work in the thirties and forties, collecting newspaper clippings about whale sharks being accidentally rammed on the front of steamships. So the earliest reports of whale sharks from the Red Sea are getting hit by boats. There is a huge dive tourism industry in Egypt, which means there’s lots of boats out in the water and, you know, it can just be an accident. You know, it’s not like people are going out and running down whale sharks with boats, but they swim, you know, a few meters below the surface of the water. If it’s rough, if there’s a glare, you’re not gonna see them. And so you can accidentally hit them with boats quite frequently, and the highest rate of big scars that we have, because one of the things that we do when we’re taking their pictures to be able to identify them as we also take pictures of scars, and a lot of our scars are inflicted by boats.
Fisheries is another problem. So there are still people who are fishing for whales sharks. There’s no one actively fishing them in the Red Sea, but just because that’s not an issue here in the Red Sea doesn’t mean it’s not a global issue for whale sharks. And one of the big ones is by catch. And so they’re not getting caught on purpose, but they’re getting caught by accident. So we had a whale shark here in the Red Sea that was accidentally caught and then drowned in a gillnet. In Djibouti just last year, there was one that was caught in a ghost net that was abandoned and was found by some free divers. And so it’s not just actively targeting them through fishing, but also kind of the accidental catches and stuff that happened that can really be a big threat to whale sharks.
And then, there’s also things like pollution, of course. So like plastic pollution, they can, you know, get caught. Like they can accidentally ingest it, that kind of stuff. And really, because they’re filtered feeding and eating such tiny stuff, things like micro-plastics and that kind of stuff, we don’t even know what kind of effect that might have on them and their ability to filter food or, you know, if they get a big load of microplastics in their stomach, what that could do. It’s research that really hasn’t been explored yet for, because when it comes to looking at stomach contents of a whale shark, it means you need a dead one and it’s not like we’re going to go out and, you know, do that. It’s more, if a dead one washes up that you can then necropsy or necropsy, depending on how you say it, which is basically an animal autopsy, we can then kind of try to look at it and see what’s in its stomach, but, yeah.
So those are kind of the big, big threats for whale sharks.
Victoria:
Oh man. Well, switching gears a little bit. Since you mentioned that you also study rays, we have a bunch of questions about rays.
Royale Hardenstine:
Cool!
Victoria:
(Aaron – What kind of rays do you study?)
(Dalia -How many different types of rays live in the Red Sea?)
This first, this is actually a pair of questions that go together for our first ray questions. Aaron wants to know what kind of rays do you study? And Dalia wants to know how many different types of rays live in the Red Sea?
Royale Hardenstine:
So, when I’m looking at rays, what I generally am doing is the BRUVS surveys, so the baited video surveys. So I’m not targeting one specific species, I’m actually doing what the second question is asking and looking at how many different types of rays live in the Red Sea. But I want to know how many different types of rays live in the lagoons. I would know how many different types of rays live next to the reef or a little bit deeper. And so, there’s about 30 species of rays in the Red Sea. And I say about because there is limited research, so we know the bulk of what is here. But some of them look slightly different than their Indian ocean counterparts, or what’s supposed to be the same species from the Red Sea to the Indian ocean. And this happens with a lot of fish species that are found in the Indian ocean and the Red Sea. They look slightly different. And so eventually you find out either it’s a sister species or, it’s an entirely different species that’s endemic to the Red Sea. And rays in general are a mess a bit taxonomically. So we have about 30 species of rays that live in the Red Sea.
And so generally what I’m looking at is the guys that live on or near reefs. So there’s things like, what’s called a mangrove whipray. So they’re these big, these black rays with these long white tails. What we end up seeing a lot of is a ray that people who dive in the Red Sea get sick of after a while, but they’re very photogenic and pretty, is called a bluespotted ribbontail ray. So there are these round rays that don’t get too big, and have there bright blue spots on them. And, they’re part of what kept me saying during our, we had a, we had a point in time when we were on a bit of a lockdown here, because of COVID, and we would actually go on and walks every night and count how many blue spotted rays we saw along the harbor. And we’re like taking pictures to be like, Oh, are we seeing this? We basically, we did photo ID. We were like, Oh, are these the same rays? Because even when we’re bored and we can’t go out, we need to find some way to be like, tell us more about these rays. I’ve also helped a bit with some work on mantas, although it’s not a major focus of mine.
I guess the best question is I’m kind of trying to learn more about just like rays in general, that live in the Red Sea and where they like to go and who likes to live where.
Victoria:
And we’ll include some pictures to those in the description of the episodes.
Royale Hardenstine:
Awesome! Okay.
Victoria:
So the listeners can see the really pretty blue spots.
Royale Hardenstine:
Yes, they’re very photogenic. And I recently got a picture of one, like looking at it, like face on, and the way that their eyes come up from their head, it kind of reminded me of Jar Jar Binks. I can’t unsee it.
Victoria:
(Ellie – Is the water in the Red Sea actually red?)
That’s so cute. All right. This next question is from Ellie about the Red Sea. Is the water in the Red Sea actually red?
Royale Hardenstine:
The water and the Red Sea. Is not usually read. So, like most other tropical beaches that you’ll see or, you know, tropical places that you’ll see pictures of. And because we are in a oligotrophic area, which means that we don’t have really high rates of products, like primary productivity, so lots of stuff in the water. It’s very, very clear, the water is very clear, and so it’s very bright blue most of the time. And then, you know, once you get over deeper water, it gets, it becomes that really deep, dark, like oceany blue color.
It actually got the name of the Red Sea, because there are blooms or slicks of a cyanobacteria called Trichodesmium. That occur in different parts of the Red Sea. And, we occasionally see them in the same area where we see the whale sharks. And I think it looks more brown than red, but they it’ll basically just be like this thin film of this cyanobacteria that that’s on top of the water and I guess explorers thought it looked red and therefore this sea was red.
So that’s where the name Red Sea comes from, but it’s usually not actively red.
Victoria:
(Natasha – What do rays eat? Are they herbivores or carnivores?)
That makes sense. All right. Back to questions about rays. Natasha wants to know what do rays eat? Are they herbivores or carnivores?
Royale Hardenstine:
Rays eat a variety of foods. It kind of depends on what the ray is.
So, I mentioned manta rays earlier or mantas earlier, and those guys are similar to our whale sharks, so they’re big plankton filter feeders. And they’re there. the cool little they’re called cephalic lobes, but they’re kind of like the little flappies by their mouths. Right. And sometimes you’ll see them kind of wrap them underneath their mouth and they make this big oval. And that’s when they’re feeding and trying to just get as much food into their mouth as they can.
A lot of other species of rays eat things like small crabs, or shellfish that live under the sand. So most rays have flattened jaws, well, flattened teeth. So instead of having teeth like you typically see on a shark, their jaws have these flattened plates that they can use to crush things that are hard, like crustaceans, like crabs that they find under the sand or shrimp that they find under the sand or worms that they find living in the reef. So, the majority of them are eating that kind of stuff. They’re mostly carnivores.
Victoria:
Cool.
Royale Hardenstine:
Although there’s probably a weird one out there that does, it’s whenever you think, a study that came out where, it was found that some bonnethead sharks, which are kind of, bonnethead sharks or mini hammerhead sharks, essentially, we don’t get them in the, I don’t, we don’t get them in the Red Sea. But in a study they were actually find to eat some seagrass. And so their sharks that also eat some seagrass every once in a while. So that’s why I’m like, most of them are carnivores, but are they all?
Victoria:
Yeah, one of them prefers salad or something.
Royale Hardenstine:
Yeah, you know, there’s always that one exception to the rule.
Victoria:
(Brooke – What is the biggest ray you’ve ever seen?)
Yeah. All right. This next question comes from Brooke. What is the biggest ray you’ve ever seen?
Royale Hardenstine:
The biggest ray I’ve seen is definitely a manta. So mantas get very, very big. I have not seen. So there’s two different kinds of main kinds of mantas when people think about mantas. And one is oceanic mantas that like to live out in the kind of broad open water. And then there’s also reef mantas, which are more reef associated. They like to hang out close to reef.
And so I’ve seen some pretty big reef mantas that have, you know, like meter plus wingspans. That’s probably the biggest ray that I’ve seen. Most of the other guys are relatively small, compared to what I think of when I think of big, because I work on big guys. So mostly I work on whale sharks and most everything else, I’m like, Oh, that’s not so big.
Victoria:
Yeah. Compared to the height of a giraffe, you know, three feet is not very big.
Royale Hardenstine:
Yeah.
Victoria:
(Ryan – Is there a particular relationship between the whale sharks and rays?)
All right. Ryan wants to know, is there a particular relationship between whale sharks and rays?
Royale Hardenstine:
There is, I don’t know if relationship is the right word, but at times, sites where we see whale sharks feeding, we also see mantas feeding. Because they have very similar feeding modes, and so they like to feed on the same things, and the mechanism that they use for feeding is also quite similar: they take advantage of the same food pulses that the whale sharks are taking advantage of. So it’s not entirely unheard of for us to be seeing mantas in the same area where whale sharks are being seen.
Victoria:
(Kelly – Can you tell us more about the Global FinPrint project?)
Kelly wants to know can you tell us more about the Global FinPrint project?
Royale Hardenstine:
So, the Global FinPrint project is, something that I was lucky enough to be able to join and participate in. So it is a global, as the name suggests, initiative to use BRUVS as a standardized methods at reefs around the world to look at in particular shark and ray populations. But as you can imagine, it’s out there recording videos. So you can also get sightings of things like sea turtles that swim by, or whales, or because there’s other fish in the area, you can actually do things like look at fish diversity. So Global FinPrint main mission was to survey sharks and rays around the world.
It was initiated by Florida International University, and then there were several other universities globally that were kind of like leading regional work. So, you know, a university that was tasked with the Indian Ocean and the Pacific and the Atlantic in a way.
And so part of this project was people at a bunch of different nations and countries and territories going out and putting hundreds of BRUVS out. And it resulted in thousands of videos and hours of videos. And so several small papers have come, well, quite a few small papers have come out of the Global FinPrint project from specific regions where the research was being done. But the first really big global assessment came out over the summer, which was looking at reef shark populations globally, and is quite possibly one of the largest, or is arguably one of the largest reef shark studies in the world that’s ever happened. So, while I was lucky enough to participate in it, I’m kind of a small cog in a very big machine, that showed that reef shark populations are in a lot of trouble.
But one of the things that was part of this was looking at areas that can kind of be considered hope spots. So areas where there’s, fisher like shark fisheries are closed, or there’s marine protected areas, or the entire nation is shut off to shark fishing since the shark sanctuary. And looking at those success stories where shark populations are doing well, and saying, okay, so these nations where it’s not going well, which one of these measures would be most efficient. So it kind of had this big complex model that said, this is what the populations look like, this is the main fishing threats, and then here are the success stories, which way this was successful works best for these other nations where shark populations aren’t doing well.
It’s, yeah, it’s a massive effort. And, I was really happy to be able to kind of lead the push for the Red Sea for it.
Victoria:
Oh, that’s amazing. That sounds like a great project to be a part of.
Royale Hardenstine:
Yeah. It’s, I think we need more big global initiatives and collaborative networks. Because I think we’re what’s realized is like, yeah, you can stay in your own sandbox in a way, but some of these bigger questions and stuff, we really need to have a much wider viewpoint, and I am not at all knocking people who, you know, hone in on one area and get the central baseline data because the big collaborative product projects don’t work without the baseline data to back it up.
Victoria:
(Alex – When you were helping turtles and seals, how did they get hurt? How were you able to rescue them and make them better?)
Yeah. Switching gears again. Alex wants to know when you were helping turtles and seals, how did they get hurt? How were you able to rescue them and make them better?
Royale Hardenstine:
My undergraduate university, the University of New England, used to have a Marine Animal Rehabilitation Center on campus. And so I think it was my second year of undergrad, I did the training to volunteer and work at the Marine Animal Rehabilitation Center. And so I was just a volunteer, I am not any kind of, you know, veterinary technician, veterinarian all, and so I was mostly my rescuing and making them better was making sure they were fed and making sure that the pools and the areas where we were keeping them was clean.
So I mean, the thing is, when you have, so, I guess the question of, you know, when I was helping them, how did they get hurt? It was a variety of things. so we had a couple of seals come in that were entangled in fishing gear. There was occasionally seals that came in with shark bites, or other injuries. And so it, you know, it can sometimes also just be like some kind of internal issue that you don’t realize, and they’re just, you know, sick. And once they’re sick, they lose a lot of weight and then, you know, it just kind of snowballs from there. So sometimes you get really skinny, really not doing so well seals, and you try to like, you know, obviously I wasn’t trying to figure it out, but the people that we worked with were trying to figure out what was wrong with them. There was one seal that I remember that ate a whole lot of plastic. And so that was mainly the seals that we were getting. And then, well, that’s kind of like the background of the seals that we were getting.
The main seals that we would get starting kind of like late spring into summer. So I stayed there for two summers to also work on this to volunteer, and I was doing other university stuff at the same time. But while I was there, it’s spring and summer, we get baby seals, it’s baby seal season. And, during baby seal season, a lot of what’s happening is some are abandoned by their mothers, some are sick and injured, but there was also a lot of negative interactions with well-meaning people or tourists. So, Oh, this seal is by itself. Where is its mother? Why is it not in the sea? It’s okay. They rest outside of the sea if they’re supposed to be there, but people would try to keep dragging them back into the water to return them to the ocean, and would exhaust them. There were some people who are very well-meaning but took a baby home and put it in their bathtub.
Victoria:
Oh my gosh.
Royale Hardenstine:
So, stuff like this happened, it happens, people are well-meaning and they just, they don’t realize that they’re doing something that’s actually not good. And so they needed the volunteer force and why I volunteered was because during baby seal season, we could have 30 to 40 babies and we can’t bottle feed them. We’re trying to limit them getting attached to us. We want them to be able to go out and live in the world. And so we actually would tube feed all of them. And because they’re babies like baby humans, or if you’ve had like a kitten or a puppy that you’ve had to take care of, that for some reason the mom wasn’t taking care of, you know, that you have to feed them every few hours. And depending on the seal species, some of them, you have to feed every few hours and it has to be like really fatty foods. So like, we would make special formula for them. And then we would eventually put them on like formula and basically fish milkshake. I accidentally swallowed some of the fish milkshake ones, and I will say it did not taste good. It got washed at my face, and it ended up in my mouth cause I was probably talking.
Victoria:
Oh my gosh.
Royale Hardenstine:
So, yeah, so we basically all of the prep that goes into getting their food ready. And then if there’s adults, you have to get their fish ready and all that kind of stuff. So my main helping them feel better was just taking care of them and keeping, helping keep the place clean.
A lot of the turtles that we got, because I went to University in New England, were brought to us from Massachusetts, or along the US East coast in the North where turtles will get cold stunned. What can happen is it can get really cold. And because turtles are reptiles and reptiles’ body temperature is determined by the environment surrounding them. If the water, if the sea temperature gets very, very cold or gets colder than they’re used to, they actually kind of just get stunned. They become very, very sluggish. Their heart rates go really low. And if that happens, they kind of just float around at the surface and then they can get a lot of biofouling. So a lot of mussels and gunk growing on them. And what essentially happens is they’ll sometimes be found by boats or the washup on the beach. So particularly like in like at the cape in Massachusetts, people will walk those beaches looking for turtles. And so we would get mostly turtles from there and bring them up, get them back up to a nice warm toasty temperature, get them eating again. And then in the spring, if the temperatures were warm enough, released in there, but a lot of times they would do a turtle caravan down to like North Carolina or Georgia or somewhere like that to release the turtles in nice warm waters.
So, yeah, it was, it was a really, that was one of, kind of like the experiences that got me to go, Oh, I really love marine science. This is what I like doing.
Victoria:
(Brooke – How did you pick the whale shark to study?)
Well, I think that leads into this next question really nicely. Brooke wants to know how did you pick the whale shark to study?
Royale Hardenstine:
I kind of accidentally got to whale sharks. So during my time in undergrad. And I highly recommend if you have the financial means or if you can get some kind of scholarship to do it doing a semester abroad. So, my university had a really good global education office and I applied for all of their scholarships. So I got several scholarships throughout my time at University of New England. One of them was to do a semester abroad in Tanzania. I also was lucky enough to do a travel course to the Galapagos and Belize. So, I recognize there’s some privilege in that.
But the semester in Tanzania, part of my semester there was to do an independent research project. And so I had found another student’s independent research project, where they went and looked at whale sharks at this small Island called Mafia Island. That’s off the coast of Tanzania. And I had recently seen a documentary where they were doing photo ID on whale sharks. And I went, I can do this. Spoiler alert, I was terrible at it. I’m much better at it now. But I look back at, you know, every once in a while, the memory comes up like this many years ago in Tanzania, you took this picture and it was like my pride and joy whale shark picture. And I look at it now and I’m just like, Oh my gosh.
But I got a ticket to go to mafia Island and you have to take like a really small puddle jumper flight there. At that time, the airport was not paved on the Island. But yeah, so while I was in Tanzania, I went to do this project on whale sharks, you know, my independent research project, I kind of designed it on my own. I went to this Island by myself to try to do science. I wasn’t not great at it, but honestly I think one of the best ways to learn for science is to kind of just like, you have to mess up, which in the long run stinks, cause sometimes your data isn’t exactly what you want it to be then. And, you know, time, money and resources get poured into it. But I went out there and I tried my best to do surveys with tourists. I tried my best to get photos of whale sharks and estimate size. And a few years later actually ended up finding out that there was still research, proper research, not my little project, ongoing with whale sharks there. And that’s how I ended up finding my supervisor at KAUST, was through happening to go and do this dinky whale shark project that I designed at this Island.
Victoria:
(Dalia – Do you scuba dive to observe the whale sharks too?)
Oh. All right. This next question is from Dalia. Do you scuba dive to observe the whale sharks too?
Royale Hardenstine:
All of my whale shark work is snorkeling when I’m looking for whale sharks. Like I’ve mentioned a couple of times, we’ve got small guys, we’ve got skinny guys, they’re fast, they can turn really quickly. And trying to put on dive gear to get in the water with them, and then, we lose them times. Like we can’t out swim a whale shark. And so having to then get back on the boat with all your dive gear on and then get back into what, it’s just impractical. So we do all of our whale shark work snorkeling.
That doesn’t mean that there’s not places where they do whale shark work diving. The Galapagos work is done almost entirely on scuba. And they’ve actually been able to, because they can dive next to these big, slow moving sharks, they can do things like do blood draws. They can, they’ve been taking ultrasounds of the whales because some of the whale sharks there had like really big, like protruding stomachs. And so they thought they were potentially pregnant. And so they were doing underwater ultrasounds on whale sharks to try to figure out if they’re pregnant. It turns out, I don’t think they’ve actually gotten a pregnant one yet, so they might just be chubby. And so perhaps, like with people, you should not ask a whale shark if it’s pregnant, if you don’t know.
And so, yeah, so our work is all on snorkel. But throughout the Red Sea, a lot of sightings reports that we get a whale sharks are from divers in Egypt, who a whale shark just shows up at the reef that they’re diving at.
So, I guess, one of the things and you know, it’s one of the things I always like to mention is if you’re interested in marine science, and it’s something you want to work on, but you don’t know how to dive, and you don’t know how to swim, that doesn’t mean you can’t do marine science. There’s plenty of things that you can do, like all the BRUVS work that I talked about, you just have to be on a boat and be able to drop a camera in the water. So, or you can just watch the footage of it, and you’ll still have all that knowledge of what fish species this is, what shark species that is. But you don’t have to know how to swim to be able to do that. And so I think it’s really, it’s really cool that, you know, people are really passionate about diving and snorkeling. I am too, is some of my favorite stuff to do. But a lot of people I know who were like potentially interested in marine science, they’re like, Oh, well I don’t dive, you know, I can’t swim. Why would I, why would I do Marine science? You don’t need to be able to do that, to do marine science.
Victoria:
(Ellie – If you could be a sea creature, what sea creature would you be?)
That is good to know. And this is our very last question. This is such a fun question from the Ellie. If you could be a sea creature, what sea creature would you be?
Royale Hardenstine:
I was so excited for this question. So I already picked it out, I’m ready to go.
I have a soft spot in my heart for kind of awkward, weird, little, little creatures. So, you know, whale sharks have a special spot in my heart. They’re kind of big clumsy things. But it’s not the sea creature I would want to be. I would want to be a masked puffer fish.
Victoria:
Oh.
Royale Hardenstine:
So, those are here in the Red Sea. They’ve got little raccoon-like burglar masks over their eyes; they’ve got these cute little, like, faces that pout out; and they’ve got little beaks cause they kind of like munch on corals; and then they’ve got like, you know, this little round squat body with like two fins that pop up; and they’re just, they’re super cute. I think they’re, I think they’re adorable. And one of my friends who has, you know, within the last year really gotten into diving, also adores them. And I feel much more validated in my choice of loving them. So yeah, I, I love them because they’re awkward little guys.
But then also, the second part to that is that I have like a special spot in my heart for puffer fish in general. Because my mom, and she will probably kill me for saying this if she hears this, has a reputation at work of being a puffer fish. So she floats around and gets along with everybody. Everything’s fine. Nothing seems to phase her. And then one thing just like sets her off and she puffs, right? So she’s, when she gets mad, she puffs. And I realized, I think I’ve got that same temperament. So, I guess, I too am a puffer fish. And so then it was just picking which puffer fish I am, and the most adorable mask puffer fish was then the obvious choice.
Victoria:
Oh, that’s awesome. And we’ll put a link to one in the episode description so everyone can see it.
Royale Hardenstine:
Perfect! Yeah. They’re, they’re very cute.
Victoria:
All right. Well, that is all of our questions. But do you have any questions or comments of your own for the listeners?
Royale Hardenstine:
I don’t think so. Well, I want to know what people would be if they could be a sea creature.
Victoria:
Ooh, good one. A week from today, there will be a Facebook post that you can respond to about what sea creature you’ll be.
Royale Hardenstine:
Also, thank you. Those were really good questions, and it was a lot of fun answering them. So thank you to all of the listeners and all of the students for submitting such great questions.
Victoria:
Awesome. Well, thank you so much. This is good.
Royale Hardenstine:
Thank you for having me. It was fun.
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