A major coral bleaching event took place in this part of the Great Barrier Reef in Australia.

A major coral bleaching event took place in this part of the Great Barrier Reef in Australia.

Coral reefs are crucial to ocean ecosystems — providing food and shelter to a quarter of all marine life. They also support food stocks that feed more than a billion people. This year, reefs around the world are threatened like never before: At Christmas Island near Australia, scientists estimate more than 80 percent of all the coral is now dead. And at the Great Barrier Reef, a similar story is unfolding: More than half of the reef’s coral has died. Scientists point to warming ocean temperatures and successive El Nino events as causes. For this month’s Environmental Outlook, the threat to coral reefs worldwide and what it will take to save them.


  • C. Mark Eakin Coordinator, the National Oceanic and Atmospheric Administration's Coral Reef Watch program
  • Kim Cobb Professor, School of Earth and Atmospheric Sciences, Georgia Institute of Technology
  • Ruth Gates Researcher, ocean science, Hawaii Institute of Marine Biology


  • 11:06:54

    MS. LISA DESJARDINSThanks for joining us. I'm Lisa Desjardins sitting in for Diane Rehm. She's recovering from a voice treatment. Coral reefs around the world are suffering from so-called bleaching events, the scale of which have never been seen before. In Australia, more than half at the coral at the Great Barrier Reef is now dead. Joining me in studio to talk about what's causing the destruction of the world's coral reefs and what can be done to save them are Mark Eakin of the National Oceanic and Atmospheric Administration or NOAA.

  • 11:07:22

    MS. LISA DESJARDINSAnd joining me by phone from Seattle, Washington, is Ruth Gates of the Hawaii Institute of Marine Biology. Also, joining me from Atlanta, Georgia, Kim Cobb of Georgia Tech University. Thank you all for being with us.

  • 11:07:35

    MR. C. MARK EAKINGlad to be here.

  • 11:07:37

    DESJARDINSAnd, of course, you're part of this conversation as well. We'll be taking your comments and questions throughout the hour. Call us at 1-800-433-8850. Send your email to drshow@wamu.org or join us on Facebook or on Twitter. Mark Eakin with NOAA, let me start with you. Remind us, what is a coral reef and coral is actually an animal, is it not?

  • 11:08:02

    EAKINYeah, that's the funny thing is that people look at corals and they wonder just what they are. And it's like the children's game 20 questions. Corals are animal, vegetable and mineral. You've got an animal and living inside of its tissues are these microscopic algae called Zooxanthellae that give them a lot of their food, up to 90 percent of their food comes from these plants living inside them. And the combination of the coral animal and these algae is what allows them to build these skeletons that make an individual coral and make these massive coral reefs you can see from space.

  • 11:08:37

    DESJARDINSThe hard structure we see is actually something they excrete as a sort of shelter, is that right?

  • 11:08:42

    EAKINIt's -- yeah. It's their -- basically, their skeleton and that grows up over time.

  • 11:08:48

    DESJARDINSHmm. Now, Ruth Gates, I want to ask you, where are coral reef found and where are we seeing the greatest destruction of them right now?

  • 11:08:58

    MS. RUTH GATESYes. So Lisa, it's, you know, coral reefs love warm water and so what you find is they're really, as, I think Sylvia Earle said in one of her incredible interviews, they're the jeweled belt around the globe. I mean, they're really found in this sort of narrow temperature region around the equator and, you know, unfortunately, coral reefs, globally, are being affected by warm water and human practices that are really degrading the system. So it really is a global phenomenon.

  • 11:09:30

    DESJARDINSKim Cobb, let me ask you, I'm sure there's some of our listeners who, you perhaps have never seen coral or perhaps have other issues in their lives. They're wondering why should we care so much about this issue in the environment, something under water that they might thing doesn't affect their daily lives. Why is it so important?

  • 11:09:47

    MS. KIM COBBWell, the oceans are a critical part of the marine ecosystem, providing nourishment for millions and millions upon people. Those include the people who depend on this from day to day located throughout the tropics as well as ourselves. Many of the global fisheries rely on coral reefs as nurseries. And the other important thing to remember is that coral reefs are a very important part of the ocean geochemical cycles that keep all of our carbon and nutrients in balance as well. So it's a critical part of the ocean ecosystem.

  • 11:10:17

    DESJARDINSCan you talk a little bit more about that? What does that mean when you talk about the ocean system and talk about kind of top to bottom, you know, what the coral reef system is doing there?

  • 11:10:28

    COBBSo the coral reef provides many, many different kind of functions for the tropical oceans as well as with impacts that spread throughout the global fisheries. And what we can see when we dive on a reef is an incredible diversity of organisms ranging from the top keystone predators like sharks all the way down to the tiniest organisms like Mark Eakin was talking about, the smallest algae and microbes and all of the diversity contained therein. So when you think about the importance of maintaining one of the most diverse ecosystems in the world, you can look no further than the coral reef to understand the role that that plays in the global ocean ecosystem.

  • 11:11:09

    DESJARDINSFair to call it sort of a cornerstone, it's sort of the starting organic ingredient in a long chain in the ocean in a way or is that going too far?

  • 11:11:17

    COBBWell, it's certainly -- probably one of the critical parts of the ocean ecosystem.

  • 11:11:20

    DESJARDINSOkay. All right. Mark Eakin, let's talk about the phrase I used earlier, bleaching events. What does that mean? What is happening?

  • 11:11:28

    EAKINSo we go back to the coral and the Zooxanthellae, the algae living in their tissues. This is a very delicate balance that is hugely important to how the coral makes its living. As I say, they get up to 90 percent of their food from the algae living inside their tissues. When the water temperatures get too high, the little photosynthetic engines inside these algae start to run very, very fast and it actually, for the very short term is a good thing because they're producing a lot of energy.

  • 11:11:58

    EAKINBut because the photosynthetic mechanisms are running so fast, they're being damaged faster than they can repair themselves. So as high temperatures, you know, as temperatures rise, the algae run too fast. They're not able to repair themselves. They start releasing toxic compounds into the coral. The coral senses this. They expel the algae into the water. So they're literally ripping their guts out, spitting out the algae that they're surviving because of. It leaves them white because the coral, itself, is clear.

  • 11:12:30

    EAKINThe algae give them most of their color. And you're seeing straight through that clear tissue to the white skeleton underneath and that's why it looks bleached. So bleaching is this first process where they've ejected the algae. The corals are still alive, at this point, and if the event is short term or mild enough, they can regain these algae. If it's long enough or really severe, the corals will die and, of course, the corals are now weaker so they're more susceptible to disease and my die from that as well.

  • 11:12:57

    DESJARDINSIt's sort of a chilling beauty. I've read some describe it as it looks like a sort of snow landscape under the ocean. But when you see bleaching event, Mark Eakin, what does it tell you about the chances for ultimate survival of that coral? Does that mean that that coral now won't survive or what are the hopes, at that point?

  • 11:13:17

    EAKINAt that point, the coral is very sick. Whether it will survive or not depends on a lot of questions. But, you know, at this point, you're looking at an extremely sick organism. And when you're seeing an entire bleached reef, it's just heart wrenching. You go down and, at first, there's this -- you're right. There's this beauty of all this, you know, stark whiteness and sometimes you have these fluorescent yellows and blues on some of the corals that are the leftover pigments after the algae is gone and it starts to look nice.

  • 11:13:48

    EAKINAnd then, you start looking around and realizing the fish are swimming around looking stunned. Even not just corals are bleaching, but anemones are bleaching and clams are bleaching. And the clown fish that live inside these anemones may not even go for shelter in their anemones any longer because they know things aren't healthy and they dive into the coral instead. Other fish that normally defend territories on the reef may just be wandering around and hiding aimlessly without protecting it.

  • 11:14:16

    EAKINSo you've got this breakdown not just of what's going on in the coral, but the entire reef.

  • 11:14:23

    DESJARDINSAnd recently, I think, we've heard from some scientists in Australia that did a study of the Great Barrier Reef that of the 520 individual reefs that make up that reef, that only four of 520 had no sign of bleaching. That's rather extraordinary. And let me go now to Ruth Gates with the University of Hawaii at Coconut Island, speaking to us from Seattle. Ruth, you've been out recently -- or tell us a little bit about what might be -- is there some hope? What are scientists doing to try and eliminate this problem or try and correct it?

  • 11:14:59

    GATESYeah, I mean, I think that, you know, really at the, you know, pulling right away from the reef for a moment, the thing that we need to do to correct really globally is to make a fossil fuel burning -- that is the ultimate solution to the problem. (unintelligible)

  • 11:15:13

    DESJARDINSAnd Ruth, forgive me for a moment. Ruth, forgive me for interrupting you. I think we're having some trouble with your line, but we'll take care of it and we'll have you back in just a moment. Kim Cobb with Georgia Tech University, you've lead some extraordinary expeditions to what we know as Christmas Island, which is a translation of what the natives refer to the island as. Tell us what you found there that might be reason for hope.

  • 11:15:37

    COBBWell, there's some reason for despair as well as some reason for hope in the results from our last expedition just last month. We were conducting a series of surveys on one of the reefs that has experienced record length and record magnitude of temperature stress associated with this itself record-breaking el Nino event that we've all heard so much about. And when we got in the water and did our surveys at a site that we've been working on for over 18 years, in my case, we saw something we think expected in some part of our brain, but had hoped beyond hope that we wouldn't see, which is widespread mortality, a reef that had been pushed far past bleaching.

  • 11:16:19

    COBBMost of those corals were dead, having succumbed to the record-breaking ocean temperatures during the last nine months that they've had to endure that. The cause for hope was found in the crevasses of this otherwise dead reef in the form of some individuals, mostly small, of certain species only that had managed to make it through this temperature extreme and through the bleaching stresses and avoid the death, the fate of their neighbors sitting right next to them of the same species.

  • 11:16:50

    COBBSo why did they survive and what is the recipe for their resilience is a very, very important questions that drove us forward in our expedition, trying to focus our work on these samples both at the sampling collection moment at the -- during the expedition, of course, thereafter in the lab for years and years of what will drive our research work as a team.

  • 11:17:12

    DESJARDINSAnd now, I'm I right, you've taken these samples, these five percent, these sort of super corals, I guess, and you've brought them back to Georgia? And tell us how you're studying them. Is that right? It's such a fascinating idea from Christmas Island to Georgia to help reefs around the world.

  • 11:17:24

    COBBWell, this, I have to say, this is part of large team of people that we amassed prior to the -- what was supposed to be a 2014/2015 el Nino event and then went to 2015/2016 el Nino event and that includes my collaborators, Dr. Julia Baum at University Victoria, Dr. Ruth Gates, who's here, hopefully going to come back any minute now, as well as arrests of physical stenographers from University of Hawaii and NOAA. So we have been focused on this site for a very long time.

  • 11:17:58

    DESJARDINSThank you. And I want to remind our listeners. Give us a call, 1-800-433-8850. We're going to take a short break here, but we've got some of the world's best experts on our coral reefs, so stay tuned.

  • 11:20:00

    DESJARDINSAnd welcome back. I'm Lisa Desjardins, sitting in for Diane Rehm. We're talking about the world coral reefs, and I want to go to the phone now and to Ann Arbor, Michigan, and Charlie, Charlie you live in Michigan now, but you have had an experience in Florida. Can you tell us about it?

  • 11:20:19

    CHARLIEYeah, I used to live...

  • 11:20:20

    DESJARDINSCharlie, you're on the air.

  • 11:20:21

    CHARLIEYes, I am on the air. I mean, the radio's not on or anything. It is in the other room. Does that have to be turned off, too? I can barely hear it. I don't know about you. But anyway.

  • 11:20:33

    DESJARDINSGo ahead, yeah.

  • 11:20:34

    CHARLIEOkay, in the '70s, I wintered in Key West, you know, a poor hippie, but we used to do that. Anyway, and we used to go out almost daily out to the seven- or in some places nine-mile reef. And it was like a beautiful aquarium, life everywhere. And now it's just white, dead rock. And at the time, we were blaming the sewage, trying to fight it locally, that was coming straight out from Key West and headed to the reefs, that and the fact that they had -- every year there were new diving boats, you know, commercial diving boats, and there would be dozens of people out there every day, and they would be kicking and touching the reef, et cetera.

  • 11:21:11

    CHARLIEAnd, you know, I want to remind people that we were fighting this out in the '60s and '70s, you know, I recommend Quicksilver messenger service (unintelligible) and some Carole King songs and stuff. By the way, so this isn't a new issue.

  • 11:21:26


  • 11:21:27

    CHARLIEAnd that the revered Ronald Reagan, HW Bush, vetoed the Clean and Clear Water Act several times there, just to toss that, so...

  • 11:21:33

    DESJARDINSWell Charlie, thank you so much for your call. So he makes a good point there, that this is something that's been going on, and he raises this question about causes of coral reef failure and sewage. You know, just in the past week, we saw in Miami a discovery that the dredging of the Miami Harbor to make way for the larger freighter ships that are being built around the world, that that apparently destroyed a significant amount of coral unexpectedly because it went deeper in the coral, was in a spot where sediment was pushed onto it from the dredging. Mark Eakin, can you talk about the possibility of the effect of sewage and also the impact of sort of manmade activities like dredging on coral?

  • 11:22:12

    EAKINYeah, we're looking at a one-two punch that has been going on for quite some time now in terms of what climate change is doing and local impacts. Local impacts include over-fishing or fishing on the wrong fish, various types of pollutant, including not only sewage but nutrients going out on the reef, causing algae to grow, sediments that can choke corals, toxic pollutants, and of course things like ships that run aground or right now countries that are building entire islands on top of coral reefs. In the case of...

  • 11:22:47

    DESJARDINSCan you -- is that the case -- where do we see that?

  • 11:22:48

    CHARLIEThat's the activity going on in China, where they are turning some spectacular coral reefs into basically military bases.

  • 11:22:57

    DESJARDINSMark Eaken from NOAA, thank you. I want to return to Ruth Gates from the University of Ohio and the Hawaii Institute of Marine Biology. We have you back on the phone, we're happy to say, and I want you to talk, Ruth, about your super coral project. We talked a little bit with Kim Cobb, your colleague, about it. But tell us exactly what you're doing, looking at these seemingly very special pieces of coral that survived in incredibly thermal stress around Christmas Island.

  • 11:23:22

    GATESAbsolutely. Actually, you know, the work that we're doing, platforms and about 25 years of basic science, that has told us three things about corals. And, you know, my group and many others around the world are really focusing on, you know, the ones that survive rather than the ones that die. If we can compare their behavior, will we understand what drives the survival, and can we harness that then to develop capacity for climate change adaptation, for mitigating the impacts of stress on reefs?

  • 11:23:57

    GATESAnd what we know, Lisa, is there are three sort of core issues here for the corals themselves. One is just their base genetics. You know, did they come from parents who were just really, really strong performers with respect to the environment? The second is do they have -- Mark mentioned these zooxanthellae inside the tissues, these little plants, the food factory that corals depend on. We know that there are a variety of strains of these plants and that some, when they pair with a coral, make the coral better able to withstand temperature.

  • 11:24:32

    GATESAnd lastly and the one that's really intriguing is the fact that we think a coral that has seen a disturbance, a stress, a warm-water event and survived that stress can then better survive a similar stress in the future. And potentially that memory is now passed on to the next generation. And so, you know, in my group and in many other groups, particularly my colleague in Australia, Madeleine Van Oppen, we -- we've been looking at how to actually take that knowledge and harness it to develop corals that are provisioned for a future that will be warmer and more acidic.

  • 11:25:13

    GATESAnd so to do that, we are identifying the strongest performers on the reef, we are selectively breeding them. You know, we've done selective breeding, you know, for -- to our benefit for many, many, many, many, many hundreds of years. You know, our dogs are all selectively bred. We are giving corals in the laboratory simulated experience of what stress will look like in the future, the simulated future ocean. And, you know, we're asking questions about whether the coral that's been exposed and survived that are doing better than the ones that haven't and whether their offspring are also doing better or worse than ones that haven't been exposed to those conditions.

  • 11:25:59

    DESJARDINSIs it going too far to say you're seeing if they can adapt or learn?

  • 11:26:03

    GATESYes, and we're -- well, you know, they can. I mean, the thing is they can adapt, and all organism have to adapt to have survived this long, and let's face it, coral reefs have been on the planet for, you know, over 200 million years. The problem right now is that the rates of change in the environment, the rate at which temperature is going up, the rate at which the water is acidifying, is outpacing the intrinsic capacity of the system to adapt.

  • 11:26:30

    GATESAnd so what we're really doing is attempting to assist the natural systems, to assist them to do it more rapidly. Can we intervene to help them get there as quickly as is needed, really to stabilize the reef system as we now take care of this much larger and much more influential issue of mitigating fossil fuel burning and stopping climate warming.

  • 11:26:58

    DESJARDINSAnd let's take a phone call now from Richmond, Virginia. And Steven, Steven what is your question?

  • 11:27:04

    STEVENHi, thank you all for doing this important work. I know that many of us imagine that you're just diving in the water and having a grand time, but there's also a lot of pretty mundane lab work, I'm sure. So thank you all of your effort. My question follows up on that last point that one of the speakers made about adaptation. And I wonder whether you believe there'll be any new habitable areas in which coral reefs could develop as water temperatures rise globally. Or is this a one-time thing, they can only exist in these places?

  • 11:27:39

    DESJARDINSMark Eakin, this is my go-to, sort of the dynamics of water temperature and the way El Ninos work. So I think without -- for the non-scientist, can you explain is there a possibility of some places in these kinds of changes in water temperature where coral reefs might benefit?

  • 11:28:00

    EAKINAnd there are some corals that are already moving. There has been some movement of the Staghorn, the branching corals along the Florida coast and up to areas in the Gulf of Mexico. We hadn't seen them in thousands of years, probably from warmer conditions, that's allowed them to do this. It's been seen also in Japan, where some species of the same genus of these branching corals are moving up the coastline.

  • 11:28:25

    EAKINBut the problem that you run into is that there's more that corals require than just temperature. And as you go to higher latitudes, whether it's farther north in the Northern Hemisphere, farther south in the Southern Hemisphere, there's also less light. And so it makes it much more difficult for the corals to get enough light, for those algae to be able to grow and give them their food.

  • 11:28:47

    EAKINThere's also the problem of is there the right sort of habitat, the right sort of platform. The U.S. East Coast, for example, as you go up, you start getting into muddier bottoms, where there isn't as much capacity for this. And the other one is as CO2 is rising in the atmosphere and the ocean's acidifying, ocean acidification is happening greater at the poles and working its way south. So corals that try to move north are going to encounter this.

  • 11:29:11

    EAKINSo there's some potential there, but it's not like all the corals are going to be able to get up and run someplace else.

  • 11:29:15

    DESJARDINSOkay, and I want to go back to the phones and Wilmington, North Carolina, a question that touches on something you just said. Anthony, you're on the phone. What's your question?

  • 11:29:24

    ANTHONYHi, thank you for taking my call.

  • 11:29:24


  • 11:29:26

    ANTHONYI'm talking about -- recently I heard about this massive, 600-mile-long reef found at the mouth of the Amazon River, and I guess it goes against everything I learned about coral reefs and in the face of a lot of research. But, you know, typically shallow, clear waters, but they found this thriving coral reef. How did that affect what we know about coral reefs and I guess the potential to find more in situations like this, or yeah, I guess that's my question, thank you.

  • 11:29:56

    DESJARDINSGreat question, Anthony, thank you. Kim Cobb, I'm wondering what you make of that, and that sort of also speaks to this Miami issue, where they didn't think there would be so much coral where it was and this idea that coral needs light, but here it was found at the bottom of the Amazon in absolute mud to the surprise of the scientists there. Can you talk about that? And does that give you hope that maybe there are other longer strings of coral we don't know about?

  • 11:30:20

    COBBWell, I certainly defer to Mark on that point. I know precious little other than that it doesn't really look like a coral, doesn't function like a coral. So Mark, maybe you can elaborate.

  • 11:30:31

    DESJARDINSGreat, Mark Eakin with NOAA.

  • 11:30:32

    EAKINYeah, the study that just came out actually does provide some very valuable information about habitats that coral reef organisms can use to get from one side of the Amazon to the other. But it's not something -- and the authors of the study, you know, will bring up the fact that this does not look like what you think of as a coral reef. These are referred to as marginal reef environments.

  • 11:30:54

    EAKINWe've known for a long time that muddy environments have some corals and some organisms that are reef-life structures, but so...

  • 11:31:02

    DESJARDINSDo we know this is a coral? Is it coral-like?

  • 11:31:05

    EAKINWell, there are corals.

  • 11:31:06


  • 11:31:07

    EAKINThere are some corals. Some of the area has live corals. Some of them have hard corals. Some have some soft corals. It's very patchy environment. It's not -- if you saw a picture of it, you wouldn't say ah, that's a coral reef. You know, it's not like the kinds of places we're talking about.

  • 11:31:23

    DESJARDINSBut it's a different form of coral?

  • 11:31:25

    EAKINSome of them are some of the corals we know that are very mud-tolerant. Also just some of the area is hard bottom that doesn't have much coral.

  • 11:31:35

    DESJARDINSOkay, great. I want to go back to Ruth Gates, and this sort of brings up the question of what exactly does coral look like. First I want to let our listeners know, I'm Lisa Desjardins, you're listening to the Diane Rehm Show. And Ruth Gates, tell us about the experience of diving on a reef as a scientist. Obviously you're there also as an observer and a human being. But what are you doing, repairing sensors? How does this work? What is your work like? Bring us into sort of your world.

  • 11:32:09

    GATESAbsolutely. I mean, I think I -- you know, we -- and, you know, I want to stress here, Lisa, that the work that I do is really the sum of a team of people at all different career stages doing all kinds of different things. And what we do is we go out into the water on SCUBA, and we do what everybody does when they get in the water and see a reef is we're pretty awed to start with and just overwhelmed, I think, by the enormity of the structures and the beauty of the place that we're in.

  • 11:32:39

    GATESAnd then we are really looking for the individuals on the reef that are staying dark brown when all others around them turn white. And the ones that stay brown and keep their color are the healthy ones. These are the corals that are the ones that we are really heavily focused on. And we will do things in the water like measure them and monitor them over time, but we'll also use these as brook stock to bring back into the laboratory, where we bring them into either an outdoor experimental facility in Hawaii or a massive indoor facility that's being used to do parallel work in Australia.

  • 11:33:19

    GATESAnd there we explore how they behave and perform when we expose them to simulated future ocean conditions. And we assess their responses by doing a huge number of measurements, from understanding how quickly they breathe, how they are able to use their plants to photosynthesize, how much they grow, how dense their skeletons are, you know, what and who are they partnering with, what are the -- what are the other microbes in the system, the bacteria and these tiny plants. You know, who are those? And how are they using their basic genetic material?

  • 11:34:00

    GATESAnd because corals are these incredibly amazing organisms, they're clonal so you can essentially take a coral and split it in two, and you have an identical individual that you can put into different experimental conditions, perhaps simulated future ocean conditions versus today's conditions. And we can assess by comparing the identical individual, how they are actually performing in those conditions.

  • 11:34:26

    GATESAnd, you know, by doing that then, we can -- we can identify who are the strongest performers and now start to explore how to selectively breed. How do we bring the eggs and sperm of those individuals together to produce the millions or thousands of tiny coral babies that could potentially, you know, within the next year I would suspect be cryo-suspended or could be used to scatter onto tiles that can be planted back out on the reef.

  • 11:34:57

    DESJARDINSFascinating. Fascinating, and...

  • 11:35:00

    GATESSo we do so many different types of things.

  • 11:35:01

    DESJARDINSThank you, Ruth Gates with the University of Hawaii. Let's go back to the phones quickly and John in Miami, Florida. What is your question?

  • 11:35:09

    JOHNI've heard on various visits to the Caribbean that sun block is causing the coral to die and that people snorkeling or swimming in the water wearing various sun blocks are actually causing the problem to exacerbate. Is that true, or is that just a myth?

  • 11:35:25

    DESJARDINSJohn, that's a great question. We're going to find out. And he's the second person with that question. Who has an answer, Mark Eakin with NOAA?

  • 11:35:33

    EAKINSure, the experiments that first were done were rather limited in their value, but there was some work that recently came out that actually has shown that some of the oxybenzone and similar compounds that are used as major sunscreen ingredients can be very harmful to corals at various stages of life and in very small amounts. So in fact going out and finding those sunscreens that are mostly based on zinc and other, you know, natural -- not these very complex chemical compounds may be more beneficial.

  • 11:36:08

    EAKINAnd so, you know, if you live in Kansas, you can use anything you want because it's a long way to the reef. If you live in Miami, actually choosing those sunscreens that avoid those compounds could be helping the reef.

  • 11:36:21

    DESJARDINSAnd we also talked earlier, I think the caller from -- that had lived in the Florida Keys was talking about tourists stepping on reefs. What happens when someone steps on a coral reef, Mark Eakin?

  • 11:36:30

    EAKINWell, it's causing direct damage to the corals. It's damaging the organisms, the corals themselves. It's scraping at the skeletons. It may be breaking off pieces of coral. And it's very damaging. And when that happens over and over, it causes a lot of problems. This is the reason why divers are supposed to stay back from the coral far enough that they don't touch them, don't bump them, don't break them. Snorkelers should never be standing on corals or hitting them with their fins.

  • 11:37:00

    EAKINWe need to be careful because these are organisms that bruise and break very easily.

  • 11:37:04

    DESJARDINSDo you think most people realize that these are animals, that there's -- there's an actual moving, digesting creature that they're stepping on?

  • 11:37:12

    EAKINI think most of them think they're stepping on a rock.

  • 11:37:16

    DESJARDINSThat's interesting. Thank you, we're going to take a short break here, but please give us a call. Tell us what you think about coral reefs and give us your questions for our panel. That number is 1-800-433-8850. You can email us at drshow@wamu.org. Or join us on Facebook or Twitter. We'll be right back.

  • 11:40:01

    DESJARDINSWelcome back. I'm Lisa Desjardins sitting in for Diane Rehm. We're talking about one of the world's most spectacular biological sites. And in fact, what might be one of the oldest living organisms on the planet or organic matters on the planet, coral reefs. Let's go back to the phones and to Alexandria, Va., and Denise. Denise, what's your question?

  • 11:40:21

    DENISEMy question is about seeing the coral reefs to revive them and for larger problems about pods that can actually, I'm told, be placed on the very, very, very sick larger reefs to actually bring them back.

  • 11:40:41

    DESJARDINSGreat question, Denise. And this -- she's not the only one that mentioned this. We have an email from Rob, who's asking, "Can we farm, plant or regrow coral?" And this speaks to the super coral project that we've talking about. We've talked about just the beginning and where scientists -- two of whom are on this panel -- have been collecting surviving coral in places where there have been bleaching. And then, Mark Eakin, can you take it from there? I guess the plan is to then seed these corals and try and regrow them. Is that realistic? How much can that do?

  • 11:41:12

    EAKINSo right now we're in such a dangerous situation with the corals that we need to be doing everything we can. And these different nursery projects that are in place have been great things. The work that's been done in the Caribbean with the branching corals there, to -- which were put on the threatened species list over a decade ago, they've been trying to get them back. And have been doing quite well growing them and putting them back out.

  • 11:41:37

    EAKINAnd some work being done at Mote Marine Laboratory, one of the nursery facilities in the Florida Keys, has found ways to even take this low-growing mass of corals and bring them back into -- by breaking off tiny pieces, putting them too close together on a tile, like if you were putting cookie dough too close together. Since they're all from the same thing…

  • 11:41:59

    DESJARDINSAnd you force them…

  • 11:42:00

    EAKIN…they all grow back together, you suddenly have a much larger coral. And that now is able to reproduce sexually. So rather than waiting 15 years for sexual reproduction, they can get it in a year and a half. So there's a lot of great stuff that's going on and it's been a real success story. The problem is one of scale. So this is great and we can do this. But let's look at this year's -- or the current bleaching event alone.

  • 11:42:25

    EAKINSince mid-2014, we've had a bleaching event that has been going on around the world. This is a global event. It's the first time it's lasted for more than a year. And…

  • 11:42:34

    DESJARDINSAnd potentially record-breaking in its scope.

  • 11:42:36

    EAKINIt already is, yeah. It's already more spatial area then we've ever seen before…

  • 11:42:41


  • 11:42:41

    EAKIN…if you combine these years. And also, we've had these back to back years. Ruth has just experienced 2014 and 2015, back to back bleaching in Hawaii. We saw the same thing in Florida, back to back in those two years. And likely to see it again this year. So we've got a lot of bleaching going on all around the area -- around the world. The area that has seen the high temperatures that cause severe bleaching and mortality of corals so far is about the size of the state of New Hampshire or Vermont. So just let that sink in.

  • 11:43:14


  • 11:43:14

    EAKINThe size of a state. Now, mind you, the northeastern states are fairly small as states go, but even so, we're talking about replanting that entire area.

  • 11:43:23


  • 11:43:23

    EAKINSo this is why it's really an issue of scale. We're also dealing with the problem spatial distribution of corals around the world. And, in fact, this could be something interesting for Kim to speak to. Is, you know, where they've seen all of this loss, 80 percent of the corals around Christmas Island dead. And these are many islands across the island chain of Kiribati that people don't live on. They're very remote. And even getting her research team out and back is very difficult. So the thought of being able to go through and do this sort of seeding in a remote place like that adds additional challenges.

  • 11:44:01

    DESJARDINSLet me do send that to you, Kim Cobb, with the University of -- with Georgia Tech University. And can you talk about the personal experience of going out there, the challenge of getting out there and speak to the point here, is it possible to reseed this large of an area that is struggling?

  • 11:44:20

    COBBYeah. So working on Christmas Island is not for the faint of heart. So you're talking about an island that is in the geographic middle of the Pacific Ocean. You have to fly down from Hawaii. And then you hope that they come get you, which they actually didn't last month for a whole week. But at any rate…

  • 11:44:36

    DESJARDINSWait, so you were, you were stranded in an area with no transportation because it is so remote.

  • 11:44:42

    COBBYes. There's a once-a-weekly flight that didn't fly. That's for whole other conversation.

  • 11:44:45


  • 11:44:46

    COBBBut we got a lot of science done in between the satellite phone calls to Fiji Airlines. At any rate…

  • 11:44:52


  • 11:44:53

    COBBAt any rate, it's why do I put myself and my research team through this? Because it is an extremely valuable site, not only for the coral ecology, but for climate science. There's no other island in the world that is more impacted by El Nino events that come and go quite frequently. And of course, this year bringing it to the epicenter of the current event, with the maximum warming located right at Christmas Island.

  • 11:45:20

    COBBSo as we've seeked to understand temperature extremes in the ocean and their effects on coral ecology and coral reefs, both in the short term and the long term, this is a very important site. As Mark noted, very, very sparsely inhabited islands. Christmas Island has a small population of people on it, but it's a big place. And all those reefs got hammered this year by the warm extremes. So this is a great place to look at how pristine reefs, kilometers and kilometers away from local impacts are impacted by climate, a global-scale climate change, as well as looking at the impacts on the ecology.

  • 11:45:57

    DESJARDINSBut, you know, Kim Cobb, what do you say to this idea that the scope is monumental and it'd be very difficult to reseed, to replace what is now sort of a deteriorating coral system?

  • 11:46:11

    COBBWell, I absolutely agree. But I believe, I'm sure like many people who study coral, I believe what Mark said, which is you need an all of the above approach right now. So we need to be thinking about how we can get the message about climate change out there, to help so-called bend the curve on our emissions trajectories and convince people that early and aggressive action is warranted if we want to give reefs the best chance.

  • 11:46:36

    COBBWe need to be, as Ruth talked about, cryogenically preserving samples that we may need in decades and decades from now in some kind of sci-fi world. We also need to be furthering these small-scale nurseries to understand how we can begin to regrow. Keeping in mind that the ocean is an immense place and these islands are very sparsely -- kind of sparsely dappled across the Pacific. But ocean currents have the potential, of course, they do transport larvae between sites. And you can envision a world where the ocean could help us out and through natural processes in this way.

  • 11:47:09

    DESJARDINSOkay. Mark Eakin?

  • 11:47:10

    EAKINYeah, right now in the country of Singapore, they've been looking at our forecast and seeing the likelihood of severe bleaching again this year. And they have actually started a program where they're going out, they're sampling their corals to gather as much biodiversity as they can, putting them in aquaria, trying the cryogenic freezing, things to preserve biodiversity before this event comes in. Something they didn't have a chance to do in Kiribati.

  • 11:47:35

    DESJARDINSThat's fascinating.

  • 11:47:36

    EAKINBut, you know, this is the kind of thing we need to be doing, looking at all these options that we have.

  • 11:47:40

    DESJARDINSAll right. Back to the phones now, and to Gulfport, Fla., and Dave. Dave, what's your question?

  • 11:47:45

    DAVEHi. My question is about -- concerning all the cruise ships that generally go through the coral areas, particularly here in the Caribbean area. There's dozens of them every day and there's 3,000 to 4,000 people aboard. The laundry is being done 24 hours a day for all the sheets and towels and linens. They empty their pools and spas every night. And with all you can eat, there's food particles always being ground up and dumped so there's extra nutrients.

  • 11:48:17

    DAVEPlus, the wake that they're leaving, the churned up water with the air bubbles, it leaves a trail for hours, just like a jet trail. So surely they are interrupting something with the coral and all that going on.

  • 11:48:30

    DESJARDINSDave, what an interesting question. I want to go to you, Ruth Gates. You're in Seattle today, but your laboratory for the University of Hawaii is off the island of Oahu, on basically a research island. I'm sure you are familiar with the concept of cruise ships, living in Hawaii.

  • 11:48:46


  • 11:48:47

    DESJARDINSDo cruise ships have an effect here?

  • 11:48:51

    GATESWell, so I think there is this bigger issue of what the cruise ship is doing. You know, essentially a lot of stuff that is associated with our activities is ending up in waters where you find coral reefs. And frankly, one thing that we know and we categorically have known this for a long time, that a healthy coral, one that isn't exposed to chronic pollution, will do much better when faced with these more ubiquitous issues associated with climate change. Things like warming waters and more acidic waters.

  • 11:49:22

    GATESSo the cruise ships in the Caribbean -- the Caribbean is a basin. Essentially everything that happens in the Caribbean affects all over the Caribbean. And so, you know, it's all these human-related pollutants are definitely causing problems for coral reefs and the overall health of the system. So could we do a much a better job at dealing with those issues? The answer is absolutely. Should we be doing that? Absolutely. We can change human behavior better and more easily than we can modify the biology of a system to adapt to rapidly changing environments.

  • 11:49:59

    DESJARDINSRuth, we've been talking about the concept of super coral, which you and many of your colleagues, including Kim Cobb, are working on. But, you know, I also read about a concept called patch reef, which I believe the University of Hawaii has had some success with. Can you explain what that it is and how that's worked?

  • 11:50:16

    GATESYes. Actually, so, you know, a reef, you know, how you describe a reef, you know, an aggregation of a number of coral colonies can be considered a reef. And, you know, in the bay in which my research facility operates, in fact, we have over 50 tiny patch reefs that are naturally formed. But you can actually -- and they really just are subsurface circles of coral reefs that are a really shallow reef going down about 20 or 30 feet. And they function to aggregate to fish around them. You see a lot of biodiversity on them.

  • 11:50:52

    GATESBut you can create those kind of little reefs using a lot of artificial structures. And this is something that's being done in the last 40, 50 years all over the world. You see underwater sculptures that are covered in corals that are places where biodiversity, other fish and other organisms that live on reef, collect around. And so, you know, this is really going back to a question that was asked earlier. Can you put down structures and then grow corals on artificial structures in the event that the reef in the last is destroyed.

  • 11:51:25

    GATESThe answer is yes, you can do that. But you have to sort of temper the expectations of what that will look like, you know, in the context of this bigger problem of, you know, the water is warming and it's becoming more acidic at a rate that is, is very fast. And we are doing a lot of pollution in our inland waters. And so the chances for survivorship of those artificial reefs then becomes questioned by our activities, frankly, by the activities of humans. And let's not forget, we are a part of the biodiversity on the planet.

  • 11:51:58

    DESJARDINSI'm Lisa Desjardins. You're listening to "The Diane Rehm Show." And let's talk about this notion that has sort of woven throughout this conversation, the role of climate change here in coral reefs. Obviously, it's not the only factor. Our panel's talked about pollution, many other things going on. But, Kim Cobb, you've been diving on coral reefs for close to two decades now. And looking at you through Skype you look great for all that sun. But in terms of the devastation that you've witnessed, how much is owning to climate change? And how much is result of El Ninos, the different kind of series of warmings in the ocean waters?

  • 11:52:36

    GATESLisa, that's a great question. And something I expect we'll be focusing a huge amount of effort on as a community going forward. But there is absolutely no doubt that warming ocean temperatures associated with the rise of greenhouse gasses in the atmosphere is driving a good portion of this coral bleaching and coral mortality event around the world right now. Certainly, this extreme record-breaking El Nino has pushed more reefs to the point of bleaching, Pushed more reefs to the point of mortality, including the research site that I currently work at.

  • 11:53:06

    GATESBut it's very important to remember that in the not too distant future we would expect even a normal year to begin to push these reefs systems over this breaking point. So really what we've seen is a fast-forward view of what we would expect to see in 20 years, at our doorsteps this year, brought here by one of the most extreme El Ninos in history, which in turn may be linked to climate change as well.

  • 11:53:29

    GATESSome of the research in my lab would indicate that greenhouse gasses are causing intensification of this natural climate cycle, driving it towards greater extremes. Certainly a subject for active research going forward. And I might add, a very important role for these super corals, in having recorded and laid down this event so that we can use these super corals to unlock an archive of this El Nino event and compare it to a long record my lab has been building using coral skeletons over the last centuries to look at how El Nino is changing today.

  • 11:54:01

    DESJARDINSMark Eakin, from NOAA?

  • 11:54:02

    EAKINYes. This event that's been going on since June of 2014 has been going on because the waters have just been so warm. We had 2014 the warmest year on record, 2015 the warmest year on record, 2016 may do it again. The El Nino didn't start until well into 2015. And it really hadn't gotten up to speed and fully formed until later on in the year. This event had already been a global scale event before that El Nino came in.

  • 11:54:32

    EAKINSo while the El Nino has played a role, and it certainly in places like Kiribati and Christmas Island, it's, you know, been the epicenter of that, what we've been seeing is that the areas away from where that El Nino's occurring have been much warmer than normal. So this is an event that is largely driven by climate change and punctuated by this huge El Nino.

  • 11:54:49

    DESJARDINSAll right. And let's take one last phone call. This is St. Louis, Mo., and James. You're on the line.

  • 11:54:55

    JAMESThank you so much for my call. I've been reflecting on your wonderful comments that I've heard so far. And I had the great privilege about a year and a half ago to actually make a retreat out on the Great Barrier Reef off of Cairns, Australia. And I went there to hear about the ecology/climate change issue, reflecting on actually Pope Francis' document, "Laudato Si" on the earth as our common home and climate change. So I wonder, kind of pray over that, reflect on it.

  • 11:55:18

    JAMESAnd then when I had the experience of actually snorkeling over the Great Barrier Reef out in this particular area, I just had this amazing, like, spiritual experience, being overwhelmed with God's grandeur. So I guess I ask the speakers there today, if in the midst of all this science and study, which is wonderful, do you ever take time to consciously reflect on, like, this amazing creation and sort of a spirituality of what you're observing and studying?

  • 11:55:47

    DESJARDINSJames, thank you for that call. Quickly to each of you. Ruth Gates, you live in Hawaii. Can you just talk to us a little bit about, you know, when you have those moments and what you see under the water?

  • 11:55:57

    GATESYeah, I mean, I think the answer is absolutely yes. They are -- we are -- I am a passionate advocate for coral reefs. It is a place that feeds my soul. And there are very few people, I think, who've been on a reef who are fundamentally affected by that experience.

  • 11:56:16

    DESJARDINSAnd then, how about you also, Mark Eakin of NOAA?

  • 11:56:18

    EAKINWell, as not only a scientist, but also as a Christian, I feel that the -- it's very important for us to not only appreciate all of what God has created, but also look what we can do as the people who are supposed to be taking care of God's creation. And so in looking at these reefs and thinking about the damaged that's being caused because of our selfish and thoughtless actions, it's -- really just shows where we really have a long way to go as a human species.

  • 11:56:49

    DESJARDINSKim Cobb, you do a lot of diving. What do you see? What strikes you when you go down there, whether the coral is white or if the coral is thriving, what do you see?

  • 11:56:59

    COBBWell, just to echo what the other panelists have said, when I was first exposed to these remote reefs that I now work on, it was overwhelming. It was the most spiritual moment of my life, actually. And I'm -- feel very privileged to have dedicated the rest of my life to trying to understand these reefs and help them in a climate change world, indeed.

  • 11:57:18

    DESJARDINSThank you to our panel. You've been listening to some of the world's most foremost experts on climate change, people who work with it month by month. Mark Eakin of NOAA, thank you for joining us. Ruth Gates, a researcher from the Hawaii Institute of Marine Biology at the University of Hawaii. And Kim Cobb, climatologist with Georgia Tech University. Thank you for joining us. And thank you all for listening. It has been my honor to sit in for Diane Rehm. I'm Lisa Desjardins, you're listening to "The Diane Rehm Show."

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