What Is the Future of Coral Reefs in Warming Ocean Waters?

17:18 minutes

Bleached coral in the Great Barrier Reef. From Wikipedia/CC BY 3.0
Bleached coral in the Great Barrier Reef. From Wikipedia/CC BY 3.0

The Great Barrier Reef has been hit by a large-scale bleaching event caused by warming temperatures. Ninety-three percent of the corals in the area have been affected, according to a survey taken by Australia’s National Coral Bleaching Taskforce. Mark Eakin, coordinator of the NOAA Coral Reef Watch program, discusses the causes and effects of such wide-scale bleaching, and David Vaughan from the Coral Restoration program at the Mote Tropical Research Laboratory talks about how reef “seeding” may help to bring back coral to some areas.

Segment Guests

Mark Eakin

Mark Eakin is a coordinator at Coral Reef Watch at the National Oceanic and Atmospheric Administration in College Park, Maryland.

David Vaughan

David Vaughan is Executive Director of the Mote Tropical Research Laboratory  and manager of the coral restoration program. He’s based in Summerland Key, Florida.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow.

Today is the 46th annual Earth Day. So we’re going to check in on the state of one of the key organisms of the world’s oceans, the coral reefs.

The Great Barrier Reef in Australia has been hit by a massive bleaching. That’s when warm water has caused corals to stress out and lose the colorful algae that give them oxygen. 93% of the Great Barrier Reef’s corals have been affected.

So what does this mean for corals worldwide? And how can we help protect these guardians of the deep?

Let me introduce my guest. Mark Eakin is the coordinator of the Coral Reef Watch program for the National Oceanic and Atmospheric Administration. He’s based out of College Park, Maryland. Welcome to Science Friday.

MARK EAKIN: Thanks. Glad to be back on the show, Ira.

IRA FLATOW: You’re welcome. the flyover pictures of the Great Barrier Reef are devastating. What does it look like you out there?

MARK EAKIN: It’s just horrible. Every time I’ve seen the images, whether it’s the flyovers from the Great Barrier Reef. The diving photos of the bleach corals in the Great Barrier Reef. Or some of the extremely bad damage from all the death of corals and Kirobas in the Central Pacific.

These are all heartbreaking scenes. And they’re going on all over the world.

IRA FLATOW: And the cause of this particular bleaching event, is it warming waters?

MARK EAKIN: Yes. In short, that’s exactly what it is.

IRA FLATOW: And we had a very strong El Nino this year. How does this contribute to these events?

MARK EAKIN: So it’s a combination of global warming and the El Nino that have led to what we’re seeing. We’re actually in a global bleaching event that started in June of 2014. So we’ve been going at this for almost two years now. Long before this El Nino started, the bleaching began.

And as that global warming has been raising temperatures and involved with other natural variability that’s gone on, we’ve seen the warming go on in places across the Pacific. And then across into the Indian Ocean and the Caribbean.

And so, when we had that and then we had this massive El Nino that’s come in now, the combination of those two has led to just a major increase in the amount of bleaching.

IRA FLATOW: As a scuba diver, I’ve been diving for a few decades. And there are places I used to dive at in the Caribbean that don’t have any coral anymore. I was just amazed to see that.

MARK EAKIN: Absolutely. And part of the shifting baseline problem is people will go diving there and think it’s absolutely beautiful, having no idea what we’ve already lost.

IRA FLATOW: I once went with– I once went with a dive even in Hawaii. And they said, this is where everybody go out and have lunch and take a look at the corals. And I went down and saw that everything was white.

And I said to the dive master, you know these are all dead? And he said, shh. Don’t tell the other tourists these things.

It’s unbelievable. But bleaching though is sort of a natural event. But the climate has changed a cycle, right?

MARK EAKIN: It is a natural response to warm water. But the problem is the warm water that these corals are seeing over this large an area is not something that they’ve seen before. So the natural response to warming is being hit with this huge amount of high temperature the corals are seeing right now, across half of the southern hemisphere from Africa to French Polynesia.

IRA FLATOW: You predicted this is going to last for nine more months. Is there something that can be done while this is happening? And how do you– where do you come up with that figure for just nine more months?

MARK EAKIN: Well, it’s not just nine more months. It’s at least nine more months, I’m afraid.

IRA FLATOW: At least nine more months.

MARK EAKIN: Yeah. The climate models that we have looking out forward at the temperatures. Because what we do is use we use satellites to look at the sea surface temperatures that cause coral bleaching. And can use that to really predict well where bleaching is happening all over the world. And help people to be ready to respond.

But we also use climate models to look several months in advance. And that’s allowed us to look out at this point through the end of the year and see that we’re likely to have major bleaching going on in the Caribbean as well as other areas of Northern Hemisphere. And this event we’re in now may even bleed back over into the Southern Hemisphere in early 2017.

So we’re looking at an event that’s going to be going for at least 2 and 1/2 years, probably a bit longer.

IRA FLATOW: We’ve had scientist come on. And now that Cuba is opening up a little bit more, it’s getting a little more attention about having some of the most pristine coral in the world. They have marine parks. Areas where the reefs are thriving.

And no one’s allowed to go there. Is that part of the reason they may be surviving?

MARK EAKIN: Well, that’s part of it. I mean, the less local human impact there is, the better shape the coral reefs are going to be. A lot of the reefs around the world have been affected by things like overfishing, like settlements, like nutrients, toxic pollutants. And of course, direct impact. Ship’s grounding, people hitting reefs.

There are a number of things that people tend to do that damages coral reefs around the world. And so the farther than they are away from people, the healthier they are. But unfortunately, when you’ve got a big warming event like the one we’re seeing now, even the most remote reefs are being hit.

So the area worst hit on the Great Barrier Reef right now is the northern third, which is where there are the least people. And the islands of Kirobas around the Christmas Island. And these other islands along the Equatorial Pacific where there are very, very few people. And In some cases, completely uninhabited.

We’re seeing over 80% mortality, plus another 15% percent bleached right now. And so being remote is great and it does a lot for helping the reefs. But it’s not everything when we’ve got this problem of global warming sitting in front of us.

IRA FLATOW: Yeah. World leaders are using this Earth Day as a time to sign the Paris Climate Change Agreements. I think they’re in New York today, at the UN. Will the agreement help the corals?

MARK EAKIN: Absolutely. And you know what was amazing to me. I almost fell out of my chair when I saw that not only was the two degree limit in there, but even the aspirational goal of keeping it below 1 and 1/2 degrees Celsius warming above pre-industrial conditions. Because we really need 1 and 1/2 degrees to help coral reef survive.

So having this agreement is great. Having the signing today is spectacular. Having the ratification in the next several months, even better.

But the important thing we have to do is actually act on that agreement.

IRA FLATOW: Can the corals bounce back if we change our ways?

MARK EAKIN: They can. it’s a slow process. It’s a hard process. In the most remote, most spectacular places we have, after big bleaching events reefs have managed to bounce back in 10 or 15 years. In other areas with more local disturbance it’s taken decades or hasn’t happened.

So we’ve got to do everything we can to protect them locally so that they have the best chance they can to bounce back from these events while we’re dealing with the problem of the excess CO2 in the atmosphere.

IRA FLATOW: All right, Mark. Thank you for taking time to be with use today on this Earth Day. And we’ll all be watching and waiting for see what happens with the corals.

MARK EAKIN: You’re welcome, Ira. And we’ll be watching it through the end of this year and however long it takes.

IRA FLATOW: Mark Eakin is the coordinator of the Coral Reef Watch program for the National Oceanic and Atmospheric Administration based out of College Park, Maryland.

Producing CO2 is the key way to protect these reefs. But scientists are looking at different ways to rebuild the reefs. And my next guest is restoring reefs down in the Florida Keys.

He’s doing it by seeding these corals, kind of like you might do in your vegetable garden. David Vaughan is the manager of the Coral Restoration program at the Mote Marine Laboratory and Aquarium in Summerland Key, Florida. Welcome to Science Friday.

DAVID VAUGHAN: Well, thank you Ira. It’s a pleasure to be here.

IRA FLATOW: Tell us about this program. There are what, two types of corals? A fast growing and a slow growing? What’s the difference between and how they reproduce?

DAVID VAUGHAN: Yes. Our branching corals that many people are familiar with such as the staghorn, it looks like a deer’s antenna– antlers. It is very fast growing. It’s actually evolved to be able to break in a storm and be able to grow back up very quickly.

The rest of the corals are actually slower growing and their sometimes termed the massive corals, or even the reef-building corals. They are the ones you may be familiar with that grow these massive size boulders, mountain coral, or even brain coral.

And those are the corals that most people did not attempt to try and look to propagate. Most worldwide use of coral restoration was only with the branching corals. But we have found a way to grow very fast and in large numbers the slower growing, massive corals.

IRA FLATOW: How do you do that? How have you been successful?

DAVID VAUGHAN: Well, basically, it was one we made a mistake in that we actually broke a small tiny piece of some of the larger corals by accident. I think someone called it my eureka mistake.

And it was one which we found out the smaller the size of the piece, the faster it grows. And of course, then the higher the number of pieces that we get.

So a piece of coral that may have started off as a silver dollar as a small brain coral. We would wait one or two years so it got big enough that we would break it into two pieces. And then it would take another two years.

Now we take that same size coral. Break it into 25 to 100 very tiny pieces, which we call termed microfragmenting. And those seems to be stimulated to grow in rapid 25% to 40% faster speed.

And so we not only get thousands of corals now in a short period of time, but they continue to grow very fast for about a year or two. Just like your skin may grow fast after it’s been broken.

IRA FLATOW: So this is, as you say, serendipity. Something no one had expected or tried before.

DAVID VAUGHAN: That’s correct. There’s been a number of mistakes that have turned out to then take the science into action. And try it again and prove that it actually is a process that could be utilized as a new technology.

IRA FLATOW: Give me an idea how fast– how fast they grow from these tiny little pieces. How big did they get in the period of time?

DAVID VAUGHAN: Well, for instance, with some of the other corals like elkhorn coral or even the mountain coral, we have also been successful in raising them from egg. In the past, that’s only been possible for a couple out of every million to survive. Now we’re getting thousands of them to survive.

However, for the first three years they grow very slow. After one year they’re only the size of a pencil eraser. After two years about the size of a nickel or dime. And it takes three years to get the size of a quarter.

But if we take that quarter size, we can break it into 50 little tiny pieces back down to the size they started. And each one will now grow to the size of a quarter in three to four months instead of three to four years.

IRA FLATOW: Wow. That’s amazing. Let me just remind everybody that I’m Ira Flatow. This is Science Friday from PRI, Public Radio International. Talking with David Vaughan of the Mote Marine Laboratory and Aquarium in the Summerland Key, Florida.

So you can now seed the coral beds? Or do you have to grow them into larger pieces first?

DAVID VAUGHAN: Well, we usually are taking this technology to first propagate thousands of pieces for outplanting. And we let them grow up to about the size of a, again, a silver dollar before outplanting. And that’s been very successful.

But it’s been successful of putting out thousands of small, what I can term baby corals, that will still take 25 to 50 years to get up to the size of a basketball before they’re reproductive. But a new technology actually taking place by one of my scientists, Christopher Page, showed that you can actually plant these small fast growing pieces next to each other. And when they grow fast enough to touch and completely touch around themselves, since they came from the same parent coral, they will refuse back into a parent single colony.

So we now plant 10 or 20 pieces of the same– from the same parent in an area the size of that basketball. And in one to two years, they will grow up and touch each other and fuse back into a coral that would have taken 25 to 50 years or more to grow.

IRA FLATOW: Wow. Are these coral as sensitive to the warm waters we just talked about in the Great Barrier Reef in Australia? Why are these not being hurt? Or is the water not the same?

DAVID VAUGHAN: Well, two things. One is we’re using the corals that have made it through these past few years. So we’re using the resistant, naturally resistant strains that are here today.

And second is we have an ocean acidification and high temperature simulator system. Sort of an ocean pretesting system here at the lab. So we can actually test the conditions that we think these corals might be in 50 or 100 years from now. And see which one of these strains, there are many good genetic strains of each of these species, are naturally resistant to the future conditions.

IRA FLATOW: That’s terrific. And you’re planting this out in the oceans now. How many of you planted? Can we go see them?

DAVID VAUGHAN: Yes you can. Between our branching corals and our reef building corals, we’ve probably planted over 10,000 corals in the Florida Keys. But that is just the beginning.

In my calculations, we could literally have hundreds of thousands in one to two years. And my personal goal is to plant 1 million corals back in the ocean before I retire.

IRA FLATOW: Wow. And who’s paying for all of this?

DAVID VAUGHAN: Well, most of this has been started with early testings from places like NOAA. We also get some funding from the same place that Doctor Mark Eakin is from for our coral bleach watch program.

But we have had a lot of private investors and private donors. Philanthropic people that want to see the reefs back. And we get funding from our Florida Protect Our Reefs license plate as well.

IRA FLATOW: Maybe you should start an adopt a coral program. You know, like adopt a highway? Adopt a coral.

DAVID VAUGHAN: Instead of adopting one coral, our real intention is to adopt a whole giant coral head. For instance, if we have plenty of coral heads the size of a Volkswagen, we could literally plant 1,000 of these coral baby clones on it. And in one to two years get that 300-year-old coral head to come back to life.

The other most amazing part about it is as we take these little babies or seeds and put them together, once they get to the size that would’ve been a 25 or 50-year-old coral that would have been reproductive, they also are reproductive. So in our laboratory we’ve been able to mature a coral to be reproductive in as little as one year that would have taken 15 or 25 years. This will let us, in the future, make replicates of these to test for new resistance strains.

IRA FLATOW: Well, Doctor Vaughan, we wish you great success in your million coral march there. Thank you for–

DAVID VAUGHAN: Thank you very much, Ira.

IRA FLATOW: Good luck to you. David Vaughan is the manager of the Coral Restoration program at the Mote Marine Laboratory and Aquarium in Summerland Key, Florida. And talking about some hopeful stuff about corals on Earth Day.

And since it is Earth Day, why don’t you go out and estimate how many insects are in your backyard. This month our Science Club is all about taking a sample. And you can learn more at sciencefriday.com/scienceclub. And tweet us what you learned with #takeasample.

Charle Bergquist is our director. Our senior producer, Christopher Intagliata. Our producers are Alexa Lim, Annie Minoff, Christie Taylor. Luke Groskin is our video producer. And our digital team includes Julie Leibach, Chau Tu, Brandon Echter, and Daniel Peterschmidt. Rich Kim is our technical director. Sarah Fishman is our engineer at the controls here at the studios of our production partners, the City University of New York.

I’m Ira Flatow in New York. Happy Earth Day.

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