Coral Bleaching Across 82 Countries: Why This Global Event Is the Deadliest Yet

0:00 When somebody tells you that a coral reef has bleached, what goes through your mind? Do you think that it only happens over a couple of days, maybe one day, maybe a couple of weeks? And then after that, the temperature goes down and the coral recovers, right? That's what you probably think. Today we're going to be talking about coral bleaching events that happen over years. There's going to be four that we're going to be talking about. We're going to go into a little bit of detail in each one, but we're currently in one since 2023 now to 2025. We have seen 80% of coral reefs globally that have bleached in this span. It's not only in the Great Barrier Reef. It's not only in Indonesia or in the Southeast Pacific. It's also in the Caribbean.

0:41 It's also in the Atlantic. It's also in the Indian Ocean. It's also everywhere. It's pretty much everywhere that we monitor reefs. And this is something that we have to talk about on today's episode of the how to protect the ocean podcast. Let's start the show. Hey everybody, welcome back to another exciting episode of the how to protect the ocean podcast. I'm your host, Andrew Lewin, and this is the podcast where you find out what's happening with the ocean, and what's happening with the ocean.

1:22 And I'm going to show you the whole game of their series and be able to eliminate the other senators. But this is what Canadians do when we do work. We kind of look down every once in a while to check the score to make sure that the leaves are winning. They're losing right now. A little nervous. That's okay. We're going to get back into the episode. Look, we're going to be talking about coral reef bleaching and not just over days. I think what a lot of people think and sort of I thought when I first heard of coral reef bleaching because coral reefs can recover after bleaching. And we're going to go into what bleaching is in just a second. But I want you to understand the urgency of the current bleaching crisis. So we need to look at troubling history of global bleaching events over the past few decades. There have been four major events. Each one have been more devastating than the last.

2:04 So the first one was in 1998 driven by a powerful El Nino combined with rising global temperatures, climate change. It was the first time the world saw mass coral death on a global scale. So not just bleach, but actual death on a global scale. About 16% of the world's reef like across the world were affected with the parts of the Indian Ocean losing up to 90% of their coral. That is a huge amount. Then came 2010. So we had about 12 years in between another intense El Nino like pattern hit and it triggered a global bleaching again. Right. Once again, while it wasn't as deadly as 1998, it served as a warning that these events were no longer rare.

2:46 They were becoming more frequent. So you think about 1998, you have a major bleaching. I remember people like I remember politicians going, especially Ted Cruz going on like a talk show, like a celebrity talk show. I think it was Letterman or something like that. And they were talking about, you know, the quarries. They were talking about bleaching and they're talking about just temperature in general at that time. Climate denial was in full fledged like the Republicans and conservatives here in Canada were just denying everything. Kyoto Protocol was not even really a thing yet. But people were talking about that as like the Paris agreement of the 2000s. But, you know, it was starting to be talked about more and more because scientists kept observing these bleaching events and then also mass die offs and temperature rising. We started to see a pattern change more and more and we're warning people.

3:30 I remember going, I was getting school at this point. I remember scientists and professors were saying, we are in trouble if we do not act in 1998. In 1998, we were going to be in trouble if we didn't act. Look, we are now 2025. We haven't acted as fast as what we needed to. But then, you know, you go 2010, you think you're done, you think you're OK, you think out of it denialism is still hot and ready. You know, people are just still denying. The oil and gas companies are strong in their PR and they just continue to do that. You get another bleach event. Not as bad, but you get another bleaching event. But all this talk about denial, people are like, yeah, well, you know what? You know, we saw a peak in 1980 and then it started to go down a bit. So it's starting to decrease.

4:10 And you know what was happening is if you just looked at from 1998 to 2010, yeah, it didn't look like it was fluctuating and looked like it was going down because 1998 was so high. But when you looked at the entire graph, like for the last 100 or 200 years, you can definitely see from the industrial age, you started to see, whoo, it started to go up and then it started to kind of tail off a little bit, but still continue to rise, which we know today continues to rise, not as quickly, but it's still rising and rising and rising. And so we continue to get hotter and hotter years and break records every single year. We're in a bleaching event. But the third bleaching event happened between 2014 and 2017. This was the longest and most widespread bleaching event on record at the time.

4:54 It struck hard across the Pacific, the Indian and the Atlantic oceans. The Great Barrier Reef in particular suffered catastrophic losses. Parts of it experienced back to back bleaching with little time to recover. So again, coral reefs can recover from bleaching, but if it's too long, you know, if it's one of those times where it's like the temperature stays long, like above 40 degrees Celsius for too long in a row in too many days in a row, we're talking about 40, 50 days, then bleaching will continue and the coral will eventually die because it can't get the products it needs from the algae that's in them. Right. We'll talk about that in just a second. So from 2014 to 2017 was the third event. That's three years. That's three years, right? And you're sitting there, you're like, hold on a second here. That was the longest. Now we're in the midst of a fourth global bleaching event.

5:43 And from 2023 and we're now today 2025. So we don't know when this is ending. It's not ending. It hasn't ended yet. It's already the worst on record with more than 80 percent. 80 percent of coral reefs across 82 countries showing signs of a global bleaching event. And that's why we're talking about the kinds of bleaching. What's especially alarming is that even the most remote and previously resilient areas like Raja and pot and the Gulf of a lot have been hit and are seeing death with their corals. Right. So this isn't just a climate story. This is a biodiversity story. This is a food security story. This is a human story. This is affecting people across 82 countries, maybe even more.

6:24 Each bleaching event chips away at ecosystems that could take centuries to build. And unless we change our course, the next one may even come sooner and hit harder for longer. This is devastating to so many people around the world that depend on reefs for food and for security. Coral reefs are biodiversity hotspots that they contain about a third of the species in the ocean that we know of. There's probably a lot more, but they contain a third of the species that we know of. And so having coral reefs there are very important in particular coral reefs. So like what we call the reef building coral reefs, right? The corals. So the Staghorn, the branching corals, the Montipora, which is the flat corals, sort of the plate corals as they call them, right? Those types of corals are reef building. They build out those reefs. They provide those hiding spots that brings in the biodiversity of invertebrates and vertebrates like fish and so forth.

7:18 Inverbers like crab shrimp and that kind of stuff that brings in all the big fish. It brings in the sharks. It brings in everything. It's this home that is a huge biodiversity hotspot, but it also provides security for the coastline. Back in 2004 when we had the tsunami on Christmas day, right? Christmas and boxing day in the Indian Ocean. They're affected Africa, affected South Asia, and it affected a lot of the islands in the Southeast Pacific. These places were devastated in the places that actually survived the best and did the best from a coastal resilient point of view had coral reefs that were intact, had seagrass beds that were intact, had mangroves that were intact.

8:00 Meaning that they were up and running and they were healthy. A lot of places that didn't have those coral systems or seagrass systems or mangrove systems had huge losses of not only people, but just land because the water just went right over it. There was nothing to stop it. The coastal security that coral reefs provide is dissipation of energy from waves. That means if a tsunami wave comes over, it's got all this energy. It's got all this momentum and it hits a coral reef. All that coral reef with this branching corals and all these different areas, it provides resistance to the wave. So the energy, the speed and the power dissipates as it goes over the reef and then it'll dissipate again as it go over seagrass habitat and it'll dissipate again as it goes over mangrove habitat, especially when it starts to come on land. These mangroves are thick.

8:51 If you've never tried to trek through a mangrove area without those nice boardwalks that sometimes people put through, it's almost impossible. So when a wave hits those, then it really dissipates the energy and it breaks up the waves and it's not as hard hit that city or village or towns that are behind there are not hardest hit. So that's what happened in 2004. But now, like even as bleaching events started to happen and it continues to happen longer and longer periods and getting worse and worse. So in 2014 to 2017, 60% of the corals around the world died. Now it's 80% not recovering guys. This is not recovering very well.

9:31 And what's going to happen over time is we're going to see a change in the makeup of corals. So we're going to get less of these hard corals, like the staghorn corals, the branching corals and the plate corals. And we're going to start to see more soft corals that maybe are a little bit more heat resistant. So let's get into why that's important to know. So when you look at a coral reef, right, it has this hard body a lot of the times or soft body, depending if it's hard coral or soft coral. But it has this body has this like skeleton and a lot of times like the hard corals are like a limestone skeleton. And over that skeleton, you have this fleshy material, which is the coral and that coral gets its food from this little tiny microscopic organism called a zoo and LA.

10:14 It's basically an algae cell and many, many algae cells within this body within this kind of coral skeleton, if you will. And that algae gets its energy from the sun from photosynthesis. That's how it feeds and the byproducts of that is like calcium and other stuff. Right. And so that calcium helps build the coral reefs. It helps build the skeleton of that course with the fleshiness can stand on top and the food, it gets like the byproducts, it gets and it actually becomes a healthy coral. That's the simplistic version of the coral. And that's the simplistic version of how a coral eats and how it becomes so beautiful in the different colors and the radiant colors. It's the algae inside that reflect those colors, right? That's what we're seeing. Now, if the water gets too hot, those algae are like, I don't like it in here. I'm out of here. And they get expelled. Even the corals like, no, you got to go. It's getting too hot.

11:03 I can't handle you in here. You got to go. I got to start looking at my body and starting to just contain it whatever I can. So it expels the zoo and LA into the water column. As long as the temperature stays that temperature, the corals like, no, I got to get rid of everything. So it loses its color. Eventually loses like the fleshiness of the coral around it. All the polyps, all those little polyps that feed and then the coral can't sustain itself. If the zoo, it like goes away for too long, then it won't come back and the coral dies because it has no way of feeding. If the temperature goes down and the zoo, I thought it comes back. These little algae cells come back. Then it can recover a little bit depending on how badly it's gone or how long it's been bleached. That's why you get the white bleaching is when the zoo and they are out, you lose the color is white. It's bleached. But when it comes back, it can be healthy again. Now we have to even go further down is looking at the different types of zoo and delay. Now the research that I've done a while ago is there's pretty much four different types. You got ABC and D will keep it as simplistic as possible. Now, certain zoo and delay will react at certain temperatures. That's why coral reefs, they're very important to the sea. They're very sensitive to outside changes. They don't like changes. If you've ever had a marine or ocean like or saltwater tank and you've had corals in there, you realize how important it is to keep the water at certain measurements, temperature has to stay within a certain range. PH has to stay within a certain range. The light has to be there for it and it can't be shaded by another rock or

12:33 another coral or even algae that grows on top. It's very specific. And any time those values go out, they can be outside of that range. The coral is not healthy. So if you get the temperature that comes in and heats it up, then the zoo and I get expelled and that happens. So if it happens for over a long period of time, you're not going to get that zoo and deli back and you're going to get death to the coral going back to the different types of zoo and deli. They have different heat signatures. So different ranges of tolerance for heat. So if you think about it, and I don't know for sure. But if you think about a as the lowest range, so it's very specific. So if anything goes above or outside of that range by going higher or even lower, but in this case, it's going higher than those who went there, they were like, I'm out. We're gone. B is a little higher tolerance. C is a little higher tolerance and D is a little higher tolerance, right? And D is what people are looking at and really looking at what corals will like because certain corals like certain zoo and deli. They'll be benefiting more of the coral depending on the type of zoo and deli. So if you have D that only like soft corals and the D zoo and deli are going to be more heat tolerant to a higher temperature, then we're going to start to see more of these soft corals that like the zoo and deli that the type D zoo and deli around in the coral reefs. So we're going to see a change. But if the Staghorn like the branching or the plate corals like are there or the boulder corals like hard corals that are boulders. If they like the type A, which is the lowest range, then a higher temperature range is not going to be suitable for those types of corals. So essentially what's going to

14:04 happen is we may not see the loss of corals completely, but we're definitely going to see a shift in the makeup. Of what the coral reefs will look like and that may affect what type of fish, what type of invertebrates are on these types of reefs, what protection it gives because there's a real difference between a soft coral and a hard coral. When you think about hiding spots, a soft coral is a little bit more permeable to moving around a hard call it breaks. It's hard. If you try to get in there, if you're fish trying to get like a crab or shrimp, it's very difficult to get in there. If these corals are, you know, not protecting or if these corals are soft, it's easier to get in. I can move it around with my fish. I can move it around with my snout or I can, you know, move it around with my jaw, whatever you need to do. But if it's hard, it's really difficult for some of these fish to get in there without getting cut or out getting damaged. So having that shift could pose a lot of problems and shift what we think coral reefs look like in the future. And that's where it becomes a problem. So if you think about it, we may not lose corals altogether, but we're going to lose the corals that we know and love and then provide the coral reef biodiversity as well as security for our coastal systems, which we need more and more and more as climate change.

15:10 But change gets bigger. So what do we do? Andrew, you're telling me a lot of depressing stuff. What do we do? Look, we've gone through the problem. We're looking at the science, looking at the biology and the ecology. Now, what do we do? The biggest thing is we got to talk to our government officials. We got to say we need to lower down greenhouse gases and we need to do better when we're looking at this stuff, right? Because coral reefs are affected because the heat's rising because the greenhouse gases are going up and it's because of a lot of developed countries or industrialized countries who are providing that type of pollution or it's providing that type of greenhouse gas that's affecting the global temperatures. We need to reduce those. That's not a quick turnaround. It's not a short term solution. We need to do that as a long term solution, but we got to stop voting in these people who are in these governments that love to go against the grain and start calling climate changes a hoax. They don't know anything about science. They're not educated in science and they're not practical and they're not looking at renewable energies clean and clean and they're not going to be able to provide energy that will not provide CO2 or methane gases in the atmosphere. Everything else needs to change. We need to change the way we think we need to change the way we do life, which is not easy, but we're getting in trouble here, folks. We are in trouble. We're seeing wildfires. We're seeing droughts. We're seeing flooding.

16:28 We're seeing tsunamis. We're seeing earthquakes. Volcanoes are increasing and that could be linked to climate change, which I'll cover in the next episode. We are seeing some problems and it's not going to go away. So we need to do something about it. If you love coral reefs, we need to do something about it. We need to reach the way they are. If you are a diver, if you are a surfer, if you just love the ocean and you want to see more of these corals, we need to act by speaking to your government representatives as a community, as a region, as a country, as a world population. We cannot take these governments that are in that are not doing anything about climate change. In fact, going backwards and making it worse. That's what we have to do and it's on us to make sure our governments do it.

17:10 We need to vote them in and if they're not listening to us when they're voted in, get them out the next time you vote. I know it's a long period of time, but you gotta get them out because we are in peril. This is not a joke. This is not exaggerating. These coral reefs, 80% of them have died. Even the ones that are remote that we actually thought, hey, a few years ago, the ones that are remote actually do okay because there's less cumulative effects. I remember covering them on stories. Nope, not anymore. It's too much now. Too much, too high, too long, temporary. The temperature is just too much. So that's what we have to do. That's the call of action act. Speak to your government representatives and that's the episode for today. If you have any questions or comments, leave them in the comments below. If you're watching this on YouTube, if you're listening to this on audio podcast, which I love, because this is the way I started and I just continue to love it, please get ahold of me either, go to speakupforblue.com, hit the contact page, fill out the form that goes right to my personal email or you can go to Instagram. Hit me up on app, how to protect the ocean. That's it.

18:26 That's it. I'm Andrew Lewis from the true north strong and free. Have a great day. We'll talk to you next time and happy conservation.