Coral Reef Checkup

This is Ask a Biologist, a program about the living world. And I'm Dr. Biology. We talked about coral reefs on this show before. My guests at the time were Diana Lipkin, and in another show, we had Greg Asner on to talk about coral reefs and his high-flying research aircraft that he was using to study coral reefs. So, we've been covering this topic for more than 15 years. Today, we get to talk with a researcher who's been studying corals, not just in the ocean. She has them in her lab. My guest today is Lisa Roger, a professor in the School of Molecular Sciences, and she's also part of the new school of ocean futures at Arizona State University. She's studying how impacts of environmental change on marine life such as corals, anemies, and some cool jellyfish. They're upside down jellyfish. Not only does she study these organisms in the ocean, she's also raising corals and jellyfish in her laboratory where her lab can, as they say, unlock the next level of coral research. It's a new way of exploring and understanding these ocean animals and maybe even learn how to heal corals using some exciting new technology that works at the tiniest scale you can imagine, what we call the nanocale. So, grab your snorkel or at least your headphones and join us for a coral reef checkup. Lisa, thank you so much for joining me on Ask a Biologist. Great to be here. Thank you. >> All right, let's talk a little bit about corals. And even though everybody thinks they know about corals, we always find that we don't all know exactly what a coral is. There are some people that think they're plants. And some of them that see dead skeletons might even think of them as rocks. Let's talk a little bit about corals. Well, there's even people who see live coral and think they are rock. They aren't. So, corals are animals that have a symbiosis with a plant. So, the symbiosis is when two different living organisms decide to work together uh for the benefit of both. So, there the symbiosis between the coral and the plant is actually a bit like uh the Russian dolls, the babushka. You have one inside the other. So the plant cell is inside the coral cell and they work together um to have more energy and most of the energy comes from sunlight. >> Ah so we're taking that sunlight photons. >> Yes. >> The plants are actually converting that into food energy. Right. >> That's correct. >> And our corals they actually those polyps they need that food because they can't make their own food. Right. >> That Yes. So they can't make their own food. So the plant cell again that lives inside the coral cell then exchange this uh energy with the host with the coral and that allows corals to grow in places where there's not much of food in the water in general cuz otherwise the other way the corals can feed is by catching things that are floating in the sea water. So that would be plankton or little particles. And so there are some species of corals that rely on the plant cell a lot up to 90% of their energy. And then you have other species that rely on the plant cell a little bit less. That tends to drive their resistance or their sensitivity to bleaching and so stress in general. >> You bring up the word bleaching. >> Yes. >> And we say that because they look white instead of very colorful, right? What is bleaching? >> So the symbiosis I explained before, the bleaching is actually the breakdown of this partnership, the symbiosis and the white that you're seeing is actually the coral skeleton that is underneath because most of the color of the coral comes from the plant cell. So when they lose their plant cell, their skin, their tissue becomes transparent. And what you're seeing underneath is a skeleton which is white because it's made of calcium carbonate. Calcium carbonate is like limestone. >> Very rock looking. >> Well, it is a rock. It's what we call a biommineral because it's a mineral. So, a rock that is made by a living organism. So, biommineral. Biommineral. >> You mentioned it's a symbiotic relationship. So, we see what the corals are getting from the plants. What do the plants get from the coral? Well, so the plant cell also gets certain things from the coral like waste nitrogen. Um, plants like nitrogen. It's like a fertilizer for them. So, they get some of this from the coral and to some extent the plant cell as well gets to be protected inside this other organism that has, you know, a skin that has all these things. It's still debated whether it's proper protection. I don't think everybody would agree cuz eventually we do know that those plant cells can live in the seawater on their own and they do fine. So they don't necessarily need extra protection but they evolved this um symbiosis this partnership through time cuz at some point it must have been hard to be in the water like that. So, I think it's a partnership that is very old and maybe the conditions are easier now than they were before, but the partnership has remained because they maybe noticed that it was nice for everybody. >> There was an advantage still. >> Yes. When we talk about corals and coral reefs, whether you've gone to the ocean or not, you've seen videos, documentaries, and they see this beautiful colorful plant and animal. We don't often think about their importance other than, you know, you think if you lose corals, okay, what's the big deal? Well, turns out that corals end up being a key and in this case a keystone to a lot of other animals. What I'm getting at is I think I've read before where they will talk about coral reefs as being the rainforests of the ocean type of thing, right? >> What if we didn't have coral reefs? They're all gone. What's going to happen? Those types of predictions are are really hard to make. I don't have a crystal ball. We know what the corals do right now. And so we can imagine that losing this was going to have quite negative effects like you said on other organisms. So the coral reefs they serve as nursery for baby fish. They are a food source for larger fish. you know, it's a whole ecosystem. So, you have an entire food chain there. If you take it away, everything becomes lopsided. The other thing that the reefs bring is coastal protection. So, all the people who live by the coast where there is a reef get protection from large waves, from storms and cyclones, and the general rise of the seaater. So, as ice is melting at the poles, the level of the oceans is rising, but having a reef there kind of also protects you from all of this. And so, if you take all of that away, we can imagine that it's going to be a problem. Even the communities that fish on reefs, they're going to lose their food source and they're going to lose coastal protection. So, it doesn't necessarily mean that some of these services aren't going to be fulfilled by other systems, but it's going to be a huge loss to biodiversity. The fish won't magically go somewhere else. The turtles won't go and feed somewhere else. um they they might because they they do move, but the level of mobility of some of these organisms that are able to swim away is not necessarily far ranging enough, >> right? So, I don't want anybody to think we're just doom and gloom here because the idea of all coral reefs going away is not necessarily where we're going. We had Greg Asner on the show before and at that time I was thinking okay well all the coral reefs are impacted equally and and that's not true. I think he said there are some winners and there's some losers. So what's the score right now would you say with winners and losers around the world if you can even answer that. Well, I think we are all working at trying to figure out who has the potential to be a winner and who is more likely to be a loser. And here so far we've been talking about tropical and subtropical reefs. So the corals that we've been talking about have this partnership with the plant cell. You have other species that live in deeper waters that don't have this partnership, that don't need sunlight, that aren't suffering from the heat stress that is causing bleaching at the moment in their tropical cousins. So, we might be losing some reefs and some surface area coverage of corals uh in tropical places, but there's other places where it might be growing. But the it depends where you're looking and what you're looking for. Um like you said, there's going to be winners and losers. Um and you have some corals that are bouncing back really well after um a shift in the ecosystem. So where let's say there's marine heat wave, excuse my term, but a lot of corals cook and die. And that kind of leaves space for species who are faster growing to then thrive. So they've replaced the assemblage that was there before. So maybe before there was 10 species and now you go back after this heat wave a few years later and you actually only have three because those three are fast growing and they've managed to pick back up. the slow growers. Again, they are slow growers, so they're going to take much longer to get back to a stage where it would be similar to what it was before. But I think what we're seeing with changes in our ecosystems, whether it's on land or at sea, is we shouldn't be looking for bringing things back to how they were before. We have to know that systems are constantly evolving. Even if the changes that we're seeing aren't, you know, very nice initially, it doesn't mean the whole ecosystem is going to crumble. It is shifting and hopefully it's a shift that can still maintain a good amount of diversity, but it's not always the case. So, this is the kind of work that a lot of people are doing in the field to try and assess which are these corals are able to grow super fast and recover. Do we have ones that are more resistant to temperature? How do they have this resistance to temperature? Or be it another type of resistance that allows them to come back or still be there, you know, having gone through this type of heat wave and still being alive afterwards. What do they have that the others don't? What do they do that the others don't do? >> The super corals. >> Yeah, this is a term that people Well, people scientists, yes, we all have this problem. and those people. Uh, no, but so a lot of scientists are a bit unfortunately tired of the super coral term because um it's been, you know, bundled with Superman and all these heroes that can do everything. What this super coral category actually does, they seem to be um very well suited at doing one thing. So, they're not allrounders. they have kryptonite. And so, for example, if one of your corals is a super coral, let's call it that, okay? Um, and its superpower is resistant to temperature, the temperature changes aren't the only thing that we are going towards. There is also ocean acidification, pollution, and other mechanisms like even the decrease of oxygen in the seawater. So while they might be very good at resisting temperature, they might not be good at living in a low oxygen environment. So they will still suffer soon. So maybe in this time window, maybe a short window, they are a super coral, but tomorrow the kryptonite will hit them. >> Got it. Makes sense. So, what's interesting about your work is, and full disclosure, I got to go to your very cool lab the other day, and uh it's interesting because you don't think about studying corals in the desert. >> Why not? >> Uh well, we don't have any oceans around here, but uh you make your own, right? >> That's right. And so let's talk a little bit about your research because this is this is where we're getting into is what makes a coral a survivor and for those that do survive or or maybe even those that aren't just surviving well, what can the doctor do in this case to help them recover? Just like if we get sick, how do we go to the doctor and what do we end up getting to make help us get better? What's your lab been doing? So, we're actually looking into the superpowers that the super corals have or some other organisms that are able to do something cool that the corals aren't very good at doing. So, this is why we have the upside down jellyfish and the sea anemmones in the lab. They happen to also have a partnership with a plant cell. So, both these organisms and the coral and it's the same type of plant cell. The only thing is they do this partnership differently. So the CNME for example it has what we call a facultative symbiosis. That means that the partnership can be on or off. You know they are fine with a partner with a plant cell. They are fine without. So how are they able to switch this on and off? Because if you compare this to bleaching, it's like if they are completely fine being bleached. So could we make corals be completely fine being bleached? Because most of the time when a coral is bleached, it will die. It's very hard for them to recover from that. So maybe if we understood better this on and off switch, then maybe we could make corals flip the switch. Then the upside down jellyfish, they actually grow or live in mangroves. So, mangroves are on the coast. Um, they have a lot of trees. Mangrove trees are pretty cool. They have roots that go into the sea and their branches and their trunks come out of the water. And so, they protect the coastlines as well, these mangroves. But what you have in mangroves is a system that doesn't have much uh flow. So, the water doesn't move very much in there. This is white cocoa slime, by the way. And so you have warmer waters, lower oxygen, higher nutrients, so there's more nitrogens and things like that. The pH can also be a little bit more acidic. However, these jellyfish love living there. Their entire life cycle is there. So how are they able to maintain the partnership with the plant cell in these conditions? Because not many corals like to live in mangroves. There's a handful of species that do that and they would probably also fit in the super coral category. So, we're interested in understanding how they do these things and whether these are things that we can make the corals do. You know, could we make a coral do jellyfish tricks? We're not talking living upside down, but we are talking symbiosis. And the same with the C anemone. So the first part is this is trying to understand what are these tricks that uh special organisms have evolved to have and then once we know that can we make the corals do these things the other angle that we are working on is actually developing what we call nanome medicine for corals that's where the coral doctor comes in. Ah, I wanted to know about that. We're talking about giving an aspirin or are we talking about band-aids? >> Uh, we're actually talking about both. While I'm not uh into making band-aids, there are some labs that do that. They're actually developing materials that um so not sticky like a band-aid, not made of plastic like a band-aid, more something we would call a biioaterial to help corals recover, heal from injuries, and grow better. What we're looking at is more the aspirin route. And so we're looking at some of their ailments. Of course, they have diseases, but we're more looking at signs of stress and can we reduce the stress using medicine. Some of the things you might have heard around is antioxidants. So you have antioxidants in grape juice for example. You have antioxidants in orange juice. Um, so all of these are natural antioxidants and they're here to address something that goes on in your body when you're struggling a little bit. Um, it could be from heat. We also get too hot, right? Um, I live in the desert. I live in Arizona, so we can get hot. And so the process of this stress that happens is what we call oxidative stress. You have molecules that have oxygen in them and they're very reactive. We normally make them because we are aerobic. So we breathe air. That's why they have oxygen in them because there's air there's oxygen in air. And so these molecules are very active and we have our own antioxidant system in our body that is there to meet this baseline production. When we get stressed or we're tired, we haven't slept enough or we're too hot or you know when you're not comfortable, when something's going on, you can produce more of these to a level that is not met by your homemade antioxidants. That's when a glass of orange juice could help. So, we're looking at what is the glass of orange juice for Carl's. Um, and the reason we're talking in the nano scale, so the very very small scale. So let's say you're making pasta and you have to put salt in your pasta. Are you going to put a giant block of salt in there or are you going to put tiny little crystals of salt there? And which one do you think is going to work the best? So, it's going to be the little ones that are going to dissolve faster into your pasta water and that will actually give some flavor to your pasta. The big rock of salt is not going to change much. So, for the medicine, our approach is the same. We want something that will work better, that will be easier to get in the system because also you're not going to be eating a giant block of salt. If you put salt on your food, it's also tiny little crystals. So, the idea is to make medicine. So here antioxidants that are teeny tiny that we can deliver to the corals or uh put in the water so that the corals take them up and to make them feel better to reduce their oxidative stress. >> The interesting thing about that is when you're giving them this medicine, they're in a liquid in the ocean. >> That's a hard part. >> Right. Right. Right. Well, if it was easy, we would have done it already. Right. Yeah. >> Absolutely. So, how do you get around the the the challenges of that? Because I can see two things. One, right, it diffuses. It it just it doesn't get to the the corals in any kind of quantity because it gets washed away by all the other water. The other thing is what about the other animals that are around? You know, you know, you have to think about they might be just fine. Are we doing anything that could be detrimental or damaging to them? >> Yes. So there's um there's the two part to this is one is it depends on the type of antioxidant that you're trying to deliver cuz you can make different ones. There are some natural ones and you have some that while they made of natural compounds, you know, that are chemicals or or molecules that are found around us, it might seem odd to be putting that in the water. And then there's the aspect of getting the treatment to the coral. So the first one depending on the type of antioxidant you're trying to deliver. So this one the the first trials we did because it it was initially science is we're trying things right and we're trying to see whether our idea works or not. So the first idea we tried was to make these nanop particles that are actually serium dioxide. So it's one sera with two oxygens. So, what this does is it is a metal oxide. That's what it's called. And this is the kind of thing that most likely the EPA, the Environmental Protection Agency, would not let us put in the ocean. However, you have oxygen everywhere. You have Syria in a lot of places, well, serium. So, you know, there shouldn't be alarm rails, but because it's a metal oxide, there's a good chance we would not get the green light for that. So, pivoting, we've been looking at greener sources of antioxidants. So, things that are already made by nature that are antioxidants. We make our own, the corals make their own, the plant cells make their own. You can get it out of orange juice. Vitamin C is is an antioxidant. So, that's the kind of thing we're looking at. packaging in a tiny tiny form and seeing how the corals respond. So again, we're not doing bulk. We're not doing a giant rock of it. We're doing teenytiny things. And these ones, because every system that breathes in any way, even underwater, um will have oxidative stress. Whoever eats it, they'll be fine. Ah yes >> there is no negative effect to antioxidants >> right unlike pesticides and other things >> exactly this is not um it chemistry is a tool that allows us to design these because they are made of chemicals and compounds and um so they are molecules um but it's not a pesticide it's not a negative compound um it's it's an antioxidant we all we all need them and then the other portion for the delivery um that gets a bit more kind of um that's going to show my age maggyver style, right? Where you have to think how could we bring that to the coral because sprinkling fairy dust from the surface is most likely not going to get us there. It's not going to be efficient. >> A lot of fairy dust you'd have to get out. >> Well, yes, a lot of fairy dust. and how again you know what is the dose that the corals need and is it going to be met. So the idea there which we haven't you know gotten to the stage of trying out yet just because we got to find a compound that works before we try these things. Do you know how they we're actually going to go back to pesticides but how they spray pesticides on fields or how you spray weed killers in your garden. They use these kind of sprays or they use planes to go and spray entire areas. So underwater, we don't have underwater planes, but we have tiny robots. So could it be a tiny robot that is fitted with a spray system that you're able to remotely control guide all the way to the reefs and then it just swims over the reef and sprinkles with also knowing the flow of the water. So you would do it slightly, not upstream cuz there's no stream, but up uh the wave motion so that then the waves casually carry your compound across the reef and spreads it and takes it into the lagoon. So you would do that for example on the reef front. If you're thinking about a barrier, you would do it in front of the reef. That way the waves that are coming in towards the reef are washing it into the reef and into the system. And then that gets circulated and we spread the love around. >> Right. So you pay attention to the tide then you know is the tide coming in the tide going out. >> Yes. You do things like that and and um you can model wave motion, wave dynamics, oceanic currents. There's times of year where it would be better to do it compared to others. So there's there's a lot of logistics involved in this. You can do remote sensing as well to look at how or when it would be best to sprinkle your fairy dust. So, this gets us back to your lab and the reason why you're doing all this research in your homemade ocean. >> Yes. One of the things that we do that not many labs do aside from growing corals in the desert is we work on cell cultures. So, corals are been studied a lot. It's not a new thing, but a lot of people come from an ecology angle. Um and so there's little work that has been done on how the cells work. And the also the reason for that is that we don't have great protocols, great methods to have the cells in the petri dish to study them. We have this in humans and this is why we know so much in terms of human medicine and diseases and things like that because in humans we're able to call a seed bankank and order liver cells and they arrive frozen. you thaw them and you can do your experiments and you can have a really good study with a lot of work being done without having to poke hundreds of patients to get liver cells out of them or even taking their entire liver which is great cuz we don't want to be doing that. >> I would agree. >> So with the corals we don't have that. I can't call a seed bankank and say hey I need coral cells send them to me. So this is why we have the corals in the lab so that we can take small pieces of coral, take the cells off of the skeleton and then study those in a dish. So that gives us this new level of research where we're able to dig in deeper into how does the partnership work. Um we're able to do it now as well in the anemmones and the jellyfish plus the corals. And don't get me wrong, the method isn't fully figured out. We're still working out the kinks, but this allows us to dive deeper and even once we have these medicines designed, we can test them in a petri dish instead of having hundreds and hundreds of corals in tanks and killing half of them because we got the dosage wrong. >> Right. >> And so we have a little bit of culture in the lab. >> Yes, we have loads of culture in the lab. >> All right. So Lisa, before you get to go, all my guests have three questions that I ask of them. So, are you ready? >> Yes. >> Yes. >> The very first question, when did you first know you wanted to be a scientist? >> Uh, I don't know if it was to be a scientist specifically, but I've always wanted to do marine biology. I was a TV generation. I was born in ' 85. So, that's when you started having documentaries on TV that took you in the sea, >> right? They perfected scuba diving gear and underwater cameras. So, Jacusto, those documentaries were huge. I was glued to the TV watching those and that's what I wanted to do. I didn't know if it was actual science that I wanted to do, but I wanted to be in the ocean and look at stuff down there. >> Right. Drawn to the ocean. That is a common magnet, I would say, for a lot of people. But you are actually there. >> Well, not right now. I'm in Arizona, but I have tanks in in my lab. So, you know, if I need a bit of ocean and low tide uh sense, I can I can go and have a whiff in the tank room. All right. So, this brings us to the next question and uh this is again a thought-provoking question and that's what would you do? I'm going to take everything away from you right now, right? You're a scientist. here that marine biologist slashdrawn to the ocean taking it all away from you. I'm going to take away your teaching too because almost all my scientists love teaching. What would you be or what would you do? Well, actually when I was younger I I had um there was two things I was really passionate about. So there was the ocean and then there was horse riding. So maybe something related or associated with horses. The only thing once I needed to start making up my mind for real was with horse riding, I like to ride. And if you're an instructor, you're actually not riding that much. You're standing in the middle freezing your toes in the sand or cooking depending on, you know, the temperature where the climate where you are. Um, it's the others who are riding and, you know, that's not what I was interested in. I wanted to be the rider. So, I thought, okay, I'll keep that as a hobby. But yes, it would have been something with horses. Um, yeah. >> Very good. All right, last question. >> Mhm. >> What advice would you have for a future scientist? And sometimes it's the young ones that are coming up, but it's also people that maybe were always, well, maybe one of those people that was watching the documentaries all their life and they decide they want to switch careers. Um, well, I think for me the thing is I'm stubborn. So, people told me I couldn't do it, but I proved them wrong. So, I think it's that if you want to do it, however old you are, um, I don't think it has anything to to do with anything. If it's something you want to do, there's a way to do it. Mostly is going to involve a bunch of swings and roundabouts, but you can get there. did take me a while to get here. I think these these swings and roundabouts as well are helpful. They can forge character to some extent, but they also give you some life experience that maybe others who have gotten there in a straight line don't have. >> Um, so in my book, they did it the easy way. And you don't learn as much if you do it the easy way. >> In essence, we're going to be, you say stubborn, you could say tenacious. >> Yes. It's perseverance cuz one of the things that I say often is so I grew up in France and in France in middle school they start pointing you towards three different general fields let's say one is more uh literature and languages one is more economics and one is more sciences because I already knew I wanted to be a marine scientist I wanted to go in the sciences but they did the selection for that through maths and I was pretty average. So they were telling me no. On top of that, I was bilingual French and English cuz my mother is British. So like you're bilingual, just go go and do languages and go do literatures. No. Uh that was not what I wanted to do. There's there was for that one a lot of philosophy to do every week. I couldn't find them philosophy. No. um I I need data. Uh I can't just, you know, go off thoughts of different people. So no, I I wanted to be in in science and they very early they told me, "No, you can't do that because you're not good enough." So I didn't end up going into science, but I didn't end up going into literature. So I went for the middle one, economics, which still had a little bit of science, but much less. Um that meant that later on I had to catch up. And it wasn't easy because the step was quite high cuz once you selected into either of those three, you lost a lot from the others. So catching up was tricky. But eventually, you know, I found a fit in a university program that worked really well. That opened the door to having an internship in Australia with the Australian Institute of Marine Science. That opened the door. I ended up working for them for several years. And then I was already in Australia on campus, decided to do my PhD there. And you know, so the the things took time to click into place, but they did click. It's like when you you know, you have your um padlock on your locker and you're you're trying to find the right combination or you don't quite remember the digits. So I was playing with the digits for a while. Let's just say that. But I found it, you know. Well, Lisa, I want to thank you so much for sitting down on Ask a Biologist to give us an update on corals and the cool stuff you're doing. >> It was a pleasure. Thanks for having me. And come and see our critters again anytime. >> Oh, and we forgot to mention that we're going to be doing a virtual tour of your lab. >> That's right. Yeah. So somewhere in the I would say the beginning of 2026 it would be if not earlier you'll be able to go to your lab and people can see all the cool things that you're doing. >> Yes, >> we'll put the the link in the show notes for those that listen to this later on. We'll add that later when we have a direct link to it. In the meantime, thank you again for being on the show. >> You're welcome. Thanks for having me. You've been listening to Ask a Biologist and my guest has been Lisa Roger, a professor in the School of Molecular Sciences and she is also part of the new School of Ocean Futures at Arizona State University. As always, we'll include links to anything we discussed on this episode, so make sure you check out the show notes. The Ask a Biologist podcast is produced on the campus of Arizona State University and is recorded in the grassroots studio housed in the School of Life Sciences, which is an academic unit of the College of Liberal Arts and Sciences. 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