Short Wave - Florida Corals Are Dying. Can A 'Coral Gym' Help Them Survive?

Episode Date: October 11, 2023

Coral reefs in Florida have lost an estimated 90% of their corals in the last 40 years. And this summer, a record hot marine heat wave hit Florida's coral reefs, exacerbating that problem. Scientists are still assessing the damage as water temperatures cool. And one researcher is taking coral survival a step further: Buffing up corals in a "gym" in his lab. Reporter Kate Furby went to South Florida to see the coral reefs up close and talk to the innovative scientists working to save them. Questions about the science happening around you? Email [e-mail] — we'd love to hear about it!See 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. Hey, shortwavers, Regina Barbara here. Joining me today is reporter Kate Furby. Hey, Kate. Hey, Regina. I hear we're going to talk about corals, getting very close up and personal. Yeah. And I'm going to dive right in.

It was a hot summer of climate catastrophes. And the ocean was no exception. The Florida coral reefs have suffered through a marine heat wave. Wow. a marine heat wave sounds serious, but also like counterintuitive. I'm used to jumping into a pool to cool off. Yeah. This feels more like a hot tub.

I went down to Miami in August for a reporting trip, and the ocean temperature on some reefs was 94 degrees Fahrenheit. Wow. Too hot for a coral. Too hot for me, too, honestly. Yes. Yes, definitely. And I should say a coral is an animal that has a microscopic plant-like algae roommate, and they kind of work together to build a rock.

So it's an animal with a plant best friend, and with their powers combined, they create a rock. Yeah, they are such cutie weirdos. And they make up most of the structures you see when you think of a coral reef. And talking to Ian Enoch's, the lead researcher for the coral program at the National Oceanic and Atmospheric Administration, or NOAA,

they're a huge part of the ecology and economy in places like Florida. You know, I could take this, perspective and say, you know, coral reefs are the rainforest of the sea, the highest biodiversity, but let's be entirely anthropocentric and selfish for a second here. Corals provide billions of dollars to the South Florida economy through tourism, through fishing, billions more through the protection that they provide through our coastal infrastructure into buildings from storms and waves.

That coastal protection looks like slowing erosion and absorbing the energy from storms. Basically, they decrease the impacts, like flood damage. So billions and billions of dollars and the protection of your cities, your towns, people's livelihoods, economies, hotels, restaurants, bars, people, places, and things. That's what's at stake. It doesn't end there, unfortunately. We're already hearing reports that the red sea corals are bleaching. And the bleaching predictions have. have scientists all the way in Australia worried.

There's about 100 countries that rely on coral reefs for economies. Wow, really? Yeah. So, Regina, this isn't just a story about saving corals. It's about saving humans, too. And some scientists are trying to help us and the corals by buffing up corals in, get this, a coral gym. I am so excited to hear about what a coral gym is.

Okay, so today on the show, how extreme heat is expediting our loss of corals. And why this pessimistic biologist-turned-reporter has hope. Good. You're listening to Shortwave, the science podcast from NPR. Okay, so, Kate, how did you end up in Miami? I have a friend and colleague there, Shereen Rahimi, and she invited me to join a mini expedition of artists and storytellers who are there to create art that documented the corals. Wow, that's really cool. Yeah. And many of the artists, like,

like Lauren Shapiro, they were pretty struck by the deaths they were seeing. I find it like an incredible thing to witness to see that exact moment when they're about to die because of the bleaching and have it stand out in stark contrast to the ocean background. It's like incredible to behold. We could see the corals from the boat. They were so white. They almost glowed. Aren't they usually like orange and pink and brown?

Yeah. So we knew before we even got in, the corals. corals were in pretty bad shape. But when corals look white like that, that's coral bleaching that people talk about, right? Right. So bleaching is what happens when the coral gets so stressed that its little algae roommates die and or get expelled from the coral. Wow. Okay. And those algae are what give the corals their color and most of the corals energy.

So without algae, it's like seeing their bones? Essentially. And what temperature a coral reef bleaches at depends on the reef and its location. Ian Enoch's, our NOAA scientist, says you can see this at his research site where he's monitoring corals. 100% of the corals are bleached absolutely white. Can they ever recover the algae? Yeah, if the stress stops. So if the water temperature goes back down in time, the algae can come back and the corals survive.

Wow, okay. But the issue with Florida right now is that the bleaching started so early in the summer, and the Florida summer is long. So the scientists were really worried that there wouldn't be time for the temperature to come back down before the corals died. And talking to Katie Lesnesey from the NOAA Florida Keys National Marine Sanctuary, that's what's been happening. When she and her colleagues went to check on the local corals in August, they saw some corals dying in a really weird, chilling way. But as you actually get closer and you really look at it, it is dead tissue that is still kind of clinging to the skeleton, I've certainly never seen that in the wilds, and my other colleagues have also said they haven't seen that before and were definitely shocked. That sounds horrifying.

It's a phenomenon that Katie and her fellow researchers hadn't seen before. They're still investigating it, but they think it's indicative of a new level of coral catastrophe. To us, and while we do need to study this more, it almost seems like there was a step missed. So the coral didn't even have a chance to undergo bleaching where there's still coral tissue left, but everything just died essentially simultaneously. And because the water is so hot, parts of the coral are just immediately dying. So there's less chance of the recovery we talked about. Wait, what? This sounds awful. Like, okay, so if I'm understanding right, the corals have this evolutionary adaptive survival mechanism.

And it's basically short-circuiting. So now what? Now the scientists are really worried. Ian says that they're seeing so much bleaching in death that it's really affecting them. Again, I don't want to be melodramatic, but like have been crying as a response to this and, you know, yelling underwater because it's just so bad. And I've never seen people so galvanized. Well, if people are so galvanized, is there a way to fix it to help corals survive? Yes.

There is some light at the end of the tunnel. Good. Let's do it. Right now in Florida, there are many labs, institutions, non-profits, volunteer efforts. They're all working to create, maintain, and move coral nurseries. Coral nurseries, as in a place to raise little corals? Yeah. Excellent. I'm so excited. Let's talk about this. People are growing small fragments of corals in labs and aquariums and then planting them on the reef,

with the hopes of increasing the amount of corals, closer to historic levels. So if you were to take a photograph of a reef looking from top down, what we're seeing right now is only about 2% of that area being covered in hard coral. And that's very, very low compared to typically healthy reefs or Florida reefs in the past that have had 50, 60, 70% coral cover. Ooh, that is really low. So the goal is over the course of this project to go from an average of 2% coral. cover across these sites to 25% coral cover. I love it. But the waters are getting warmer in Florida. What if it's just not going to be a good place for corals anymore?

Like where and how can corals stay cool and safe? That's a great point. Where the restoration efforts choose to focus is critical. Corals generally have a really narrow temperature they can survive in, like mid-70s to mid-80s. Okay. And this latest marine heat wave was so important. intense in the mid-90s that many of the previously chosen nursery areas had to be relocated, at least as many as they could carry.

We have been undertaking operations to move corals from this very shallow, warm nursery to this deeper cooler nursery. And so that they don't have to move these corals again in a few years as the oceans continue to heat up, the researchers are starting to think deeper and maybe even on land, like in an aquarium, hopefully just until things cool back down. Wow. Okay. But can they test the corals to see how hot of an environment they can actually handle? Yeah, they do. Okay. Ian does this and a kind of training at the coral lab he runs in partnership with the University of Miami. One of the things that we do in this lab is subject them to different environmental conditions and evaluate who's a little bit

stronger, just like you might be able to run faster than I may be able to, you know, Definitely not. Definitely not. Sag C might be a little bit... Oh my God, these are the coral gyms we're talking about. Mm-hmm. They're trying to understand which corals survive and why, and hopefully, massively scale it up. It was very wally meets finding Nemo in there. I really want to go.

That would be so amazing. Like a lot of high-tech equipment and robotic arms, bubbling, whirring, whirring, worrying science, all to see how to help corals get stronger. Ooh, okay. Ian's coral gym is trying to be. trying to take advantage of the coral's natural ability to adapt. So if a coral reef has a history of temperature changes, they will be better at surviving future change. And so Ian is looking at exposing them to different temperatures to see if he can make them stronger afterwards. And corals are pretty strong already.

They've been around since before the dinosaurs. They already have so many amazing things in their survival toolkit. They can reproduce in all kinds of different ways, sexually, asexually. They can be male, female, hermaphroditic, which is both. They can live for hundreds of years. They can partially die and they can regrow. They are amazing. Wow. When you put it like that, they sound pretty strong already.

They are. It's just that, unfortunately, climate change is now outpacing the natural ability of corals to survive in some areas. And Florida is really on the front lines of it. There's just so many precious lives, not to mention, expensive real estate, perched on the edge. of this continent just exposed and at the mercy of the ocean. Do the scientists you spoke to in Florida ever feel like it's a lost cause? Not according to Ian. This is a wake-up call that is like, now is the time.

Saying it's too late is a cop-out, in my opinion. It just means that you can sit home at your couch and give up and be sad about something. And I'm motivated. I know other people that are motivated. And I think everyone should be motivated. Too much is at stake. I love that. Me too.

So Katie and Ian are still assessing the long-term damage. Surviving a big stress like this can also cause secondary effects in coral reefs, disease outbreaks, for example. But the water temperatures in most areas have dropped back down to a cool 87, which is the bleaching threshold for Florida corals. In the face of a lot of coral death, Ian has also reported seeing corals regaining their color and recovering from bleaching. Wow. That's amazing. Yeah. It's promising that some areas have recovered. And Katie sees some small hope already. The corals have spawned. And if the babies survive, which is not guaranteed, but if they do, it would help regrow the reef. Wow. I think that is so important to let people know it's not a completely foregone conclusion that the coral reefs will disappear. Yeah, me too.

And honestly, I think this is the crux of reporting on corals. Treading the line between how urgently saveable corals are, and also how extremely precarious and close to completely losing most corals globally we are. And we lose everything reefs give us, all that coastal protection, the ecosystem that supports our fish. So it's a matter of helping these corals innovate and tackling climate change and the industries that are responsible now. Kate, thank you so much for coming to talk to us about coral reefs and Florida's fight against climate change. climate change. Yeah, it's been so awesome to chat with you. Thank you. This episode was produced by Kate Furby and Burley McCoy. It was edited by our managing producer Rebecca Ramirez and fact-checked by Kate and Susie Cummings. The audio engineer was

James Willett's. Bet Donovan is our senior director of programming and Anya Grunman is our senior vice president of programming. I'm Regina Barber. Thanks for listening to Shorewave from NPR.