Short Wave - An Ode To The Manta Ray

Episode Date: January 4, 2022

A few months ago, on a trip to Hawaii, Short Wave host Emily Kwong encountered manta rays for the first time. The experience was eerie and enchanting. And it left Emily wondering — what more is there to these intelligent, entrancing fish? Today, Emily poses all her questions to Rachel Graham, the founder and executive director of MarAlliance, a marine conservation organization working in tropical seas.Have you been completely captivated by an animal too? Share your story with us at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. So a few months ago, I went to Hawaii on vacation with some friends, and we decided to go nighttime snorkeling, which is exactly like snorkeling during the day, except you need giant LED lights to see by. And the whole design of this tour was kind of a happy accident. Basically, a hotel on the Big Island had put LED lights in the seafloor to, I don't know, create. ambience. And what they discovered is it attracted plankton. And plankton attracted fish. So I am wearing a wetsuit and snorkeling gear. I drop off the back of the deck of a boat and paddle over to this surfboard that is resting on the surface of the sea, kind of being held in place by a guide. and he tells me to like grab onto these ropes and float on the surface with my face stuck down in the water.

So I'm completely flat and staring down at this like oceanic highway of fish. There is yellow tang, there's butterfly fish, they're all eating. And then all of a sudden like off to our right there comes this like floating shadow specter of a fish. It's like a cloak moving towards us. And it is eerie and silent and a huge. like seven feet across. And it has wings that tip it towards us and then eventually barrel roll beneath us in a somersault. And I realize I'm staring down the mouth of a manterey like inches from my face as it pulls plankton into its belly.

And I can't breathe. I'm actually sucking my stomach into my rib cage because I'm so afraid of bumping the manterey. But the Manta Rui, it seems very, you know, spatially aware. And I realize we're kind of in its turf. You know, so often we encounter creatures in, I don't know, built environments, zoos, et cetera. Here, we're in their home. And I just need to be silent and watch. And that's what we do.

For an hour, we watch Manta Rays feed on plankton. There's this one area of the sea floor. called the campfire, and there are maybe 20 mantrases just circling around like ghosts. And they're so big that they block the light with their bodies, so the lights are blinking in and out, like a momentary eclipse. And it's this beautiful, graceful manteree ballet of these fish gliding over and above and between each other eating. And my friends and I are just just in awe. I don't want to blink. I don't want to miss a moment of it. And I'm filled with so many more questions about them. And I kind of start to wonder, you know, why didn't I know about these

before? How did I not realize that a fish could be so intelligent and social and curious? And I can't tell what I'm anthropomorphizing and what is real, and I just realize I have so many more questions about them. So today on the show, I'm going to get some answers about what makes manta rays so magical and so smart. And what has put them on the endangered species list? I'm Emily Kwong. This is Shortwave, the Daily Science podcast from NPR. All right. Of all the cartilaginous fishes. This is a hot take. Sharks get all the glory. I get it. Sharks have teeth. They're cool and big, and they have a week on Discovery Channel. But come on, we need to show Manta rays some love people. And you know who's a big fan of them too? Rachel Graham. Wow, such spectacular species.

And it's worth noting that their name Manta means blanket in Spanish. And that's what they really look like. They look like flying blankets or carpets. Some of us in the Manta World also call them magical sea flap flaps. Very scientific. Very scientific, because that's what we are. We're all about the science, 150%. Rachel's the founder and executive director of Mar Alliance, a conservation organization based in Belize.

She's been working with threatened marine wildlife for a long time. And when I called her up, just like full of Manta Ray fervor, she totally understood because she had her own Manta Ray meet cute at the Flower Garden Bank's Marine Sanctuary in the Gulf of Mexico. I had never seen a Manta Ray and I just remember the first time I did, I was smitten, absolutely smitten. They are some of the most graceful creatures you can imagine and they grow to be over seven meters in width. So imagine that, 23 feet wide. However, the ones that we saw at that first instance in the flower garden banks were about six, maybe seven feet wide. So two to three meters at most.

And the cool thing is, is that what's come out is that this looks like this is potentially a nursery area for these mantarays. And that's one of the reasons why they're so small, because they're actually born at about between four and a half, six feet maybe. They look like a rolled up carpet when they come out of their mother and they just unfurl and off they flap. A little baby burrito manterey. That's exactly it. You can't get any cuter than that. You really, really can. And you say they flap away on their own? They do. They have to. There is no parental care. So they really have to be self-sustaining from the word go. And that is one of traits of all chondrycteans are cartilaginous fish that include the sharks, the rays, the skates, and the deep-dwelling chimera fish as well. They all have these cartilaginous skeletons,

they have internal fertilization, they tend to have very long lives and really long gestations. But when they're born, they're on their own. So in addition to being very unique, Dr. Grimm, I've also come to realize that Mantir are extremely intelligent. So I wanted to bring up the work of scientists Silla Ari, who's done research on Manta Ray brains. And for one of the studies that she and her colleagues did, they took two captive Manta rays at Atlantis in the Bahamas,

and they placed a mirror in the tank and observed the behavior of these Mantares over an extended period of time. Yes. And they noticed that the Manta Rays spent more time in front of the mirror than other portions of the tank. Right. And demonstrated some odd behaviors.

The mantrase performed these unusual and repetitive movements that they describe in this study as contingency checking where they're basically checking themselves out in the mirror and doing things like blowing bubbles at the mirror and flipping to look at their bellies, which I also do in the mirror. I look at my belly. I see how big it's getting from all the treats I'm eating during the pandemic. Yeah. And this was cool, too. Giant mantarays at least have this behavior where when they meet new individuals, their white spots expand and contract. But these two mantarays in front of the mirror didn't display that behavior, which suggested to the scientists that they didn't register the reflection as another manterey with whom they should be social. That's right. And this suggested there was some kind of like evidence of self-awareness.

Though I talked to Dr. Ari and she said, you know, it doesn't prove self-awareness. And she wanted to be really clear about that. Absolutely. And what the mantarays were doing was very similar to we will maybe pass by a mirror and then kind of take a step back and go, wait, what? And you might have thought that was somebody or you were passing by a glass window. and you get confused as to whether that's somebody on the inside or that's you. So is it proof of self-awareness? Not entirely, however, all indications show that they have an incredibly complex brain.

Dr. Carey Opaq is a kind of top brain researcher as well who's looked at cross-comparative work with a whole range of different shark and race species. and the mantaray has a really well-foliated or developed brain, which also reflects how incredibly social these animals are as well. And one of the aspects that, you know, when you were asking me about how was my first encounter with mantarays, and I mentioned the flower garden banks, it was there that I actually had one of my most insightful and arresting encounters with mantarays. What happened?

Well, it was literally snorkeling next to a Manta ray that I had actually just tagged. It then kind of did a loop around to see what was that? Somebody did something in my back there, came around and then hung with me for 40 minutes. And it was this wonderful, incredible dance and curiosity where it would move ahead and then it would wait for me. And it then literally brought me back towards the boat that we were diving off of. And I could have easily swam with it for another two hours. Yeah. You know, it's interesting to hear you talk about this because, you know, shortwaves,

we've reported on the mirror test and the work of the person who developed it, Dr. Gordon Gallup, Jr. You know. Oh, yes, in 1970. And I don't know. for me, I think the bigger question is, do we even need to prove self-awareness in order to care about the future of an animal? Absolutely. And you start looking at more and more of these animals very closely.

Look at octopus, incredibly smart, a sentient being, and now they're talking about putting restrictions on octopus fisheries, for example, just because they know how intelligent these animals are. And I would say that it's the same thing that people, a lot of people are actually proposing to curb any fisheries that have a significant take of mantarays, be they targeted or bycatch. And unfortunately, mantarays do not do well in nets, and they do not do well when they are released from nets. The mortality after they've been caught is incredibly high. And so we're seeing a big loss from manta ray populations

via targeted and bycatch fisheries. Yeah. It's rough. There are two known species of manta ray, and they're both in trouble, right? So we've got the giant manta ray. It's endangered.

The reef manta ray is classified as vulnerable, both by the IUCN, the International Union for Conservation of Nature. And broadly speaking, shark and ray populations have declined by around 70% since 1970, mainly due to overfishing. So given all of this, what do you want people to know about the relationship between humans and race? So there's a couple of things I'd love to tell people.

One is if you do ever get the opportunity to travel to a tropical country where manta rays form part of a community-based tourism, do so because by showing communities that you are putting money into their coffers and that you're doing it because you want to see manta rays elevates the value of manta rays and it brings money across the communities to many families boat captains guides and more if you're able to do that if you're not then my my big desire is for people to really think hard about the seafood that they eat and to potentially eat less of it. Because really, many of the threats that we're seeing facing mantarays are due to fisheries. That will make a huge difference to mantarays and all the other large, long-lived marine wildlife in our seas.

Dr. Graham, thank you so much for coming on to talk about Manta rays with me. It's been such a privilege, and they really are the most magnificent, thought-provoking animals. Hearing about Manta Ray mortality from overfishing and other human-led causes was tough, especially after swimming with them. But moving forward, I want to hold both realities in my memory. To marvel at the Manta and to also take responsibility for the impact we.

humans have on our oceans. Dr. Graham told me that swimming with mantas connects her to the sea, giving her purpose in the work that she does. The conservation is hard, but mantas make it all worthwhile. This episode was produced by Rebecca Ramirez, edited by Sarah Saracen and fact-checked by Rasha Arredi. The audio engineer was Josh Newell. Special thanks to Aaron Fulton, Adrian Wilbur and Big Island Divers in Hawaii. Shout out to Captain Mike, Justin, Cosmo, Casey, and the rest of the crew. I also want to thank Silla Ari, who has contributed groundbreaking research to our understanding of Manterei and Mobula brains and behavior.

I'm Emily Kwong, and you're listening to Shortwave, the Daily Science podcast from NPR.