Speaker 1: Welcome to Stuff to Blow your Mind from housetop works
Speaker 1: dot com. For corals that live beneath to see their
Speaker 1: days are marked by celibacy, excepting one night when the
Speaker 1: moon is just right, they engage in a million strong orgy.
Speaker 1: But for them to secure the prize, corals must be
Speaker 1: ever wise, for there is a catch. In order to dispatch,
Speaker 1: their orgasms must be synchronized. Hey, welcome to stuff to
Speaker 1: blow your mind. My name is Robert Lamb and I'm
Speaker 1: Christian Seger. And that may have sounded like the Dr.
Speaker 1: Seuss version of Coral Sex, but actually it was a
Speaker 1: bit from mar j Hart Sex in the Sea, which
Speaker 1: we've talked about on the show before and we're gonna
Speaker 1: do again this episode. Yeah, it's a great book. We
Speaker 1: talked about it in our previous episode that was devoted
Speaker 1: to the weird sexual ways of the Asso Docks, the
Speaker 1: bone Worm, the bone eating worm of Ocean, And in
Speaker 1: that episode, Corals came up and we said, hey, there's
Speaker 1: a lot of stuff to discuss here. Why don't we
Speaker 1: just have you back on in the summer, We'll do
Speaker 1: a whole episode on corals, and we wanted to time
Speaker 1: it for this summer because we're in corals spawning season
Speaker 1: right now, as mar will discuss with us. So the
Speaker 1: way this episode is going to be set up is
Speaker 1: we're gonna give you just like a brief primer on
Speaker 1: corals and their reproduction, and then we're gonna talk tomorrow
Speaker 1: because she's the expert on this, and we really get
Speaker 1: into all the details, especially because Mara just got back
Speaker 1: a week ago from the what sounds like the world's
Speaker 1: biggest conference on coral ecology, so she had a lot
Speaker 1: of like groundbreaking news for us. Yeah, some of some
Speaker 1: of it rather sobering, but some of it very exciting
Speaker 1: as well. You know, I think one of the big
Speaker 1: tay comes here that I got out of the research
Speaker 1: that I hope that that that listeners get to is
Speaker 1: this idea that and I feel like this sometimes lost
Speaker 1: in our media absorption of the information, is that coral
Speaker 1: reefs corals are not just like a background organism. They
Speaker 1: are the bedrock of these ecological systems, making life possible
Speaker 1: in areas that would otherwise just be barren and lifeless.
Speaker 1: I think for a lot of people, the way that
Speaker 1: they think about them is almost as if that they're
Speaker 1: like plant life and I have to admit, even for myself,
Speaker 1: until we sat down and really did the research for
Speaker 1: this episode, I didn't quite understand their anatomy. And so
Speaker 1: maybe that we can sort of help set that up
Speaker 1: for the audience for you out there. And uh, then
Speaker 1: when we talk tomorrow about just how dire the consequences
Speaker 1: are right now for coral ecology, that'll, you know, drive
Speaker 1: home the importance of trying to help these critters out. Yeah.
Speaker 1: I feel like at times we almost have an amateur
Speaker 1: aquarium um view of it, where we think, oh, I'm
Speaker 1: the fish is what I'm excited about. Anything else is
Speaker 1: just like a plant that we throw in, or maybe
Speaker 1: like a ceramic Buddha that flows to the bottom right.
Speaker 1: And then in looking at the coral reefs to we
Speaker 1: we see the finished picture. We see the corals, we
Speaker 1: see all the fish and all the creatures. I feel
Speaker 1: that it's kind of like looking at Las Vegas and
Speaker 1: seeing all this life, all the light and the fountains
Speaker 1: and saying, look at that life is just splendid there.
Speaker 1: It's just going just going splendidly without realizing that without Hoover, damn,
Speaker 1: without the with the necessary um um, you know, water
Speaker 1: system in place, there would be no life there at all. Yep, yeah, exactly.
Speaker 1: Corals are a hugely important ecosystem for and this is
Speaker 1: a stat a quarter of all marine fish species, so
Speaker 1: they're very important. They're not just pretty structures that happen
Speaker 1: to be underwater. They also benefit us, and by us,
Speaker 1: I mean human beings by buffeting coastal regions from strong waves.
Speaker 1: And I'll get into it a little bit further. Uh,
Speaker 1: they promote our economy and huge way is too. So Uh,
Speaker 1: these are super important. And they have totally weird, bizarre
Speaker 1: orgy sex too, which is fun to talk about. So
Speaker 1: let's get into it. Let's talk about coral reefs and
Speaker 1: coral polyps and what's the story here. So they're actually
Speaker 1: made of two things. Now, when we think about corals,
Speaker 1: or at least the way I did, I always thought
Speaker 1: of just the limestone skeletons, right, these these formations. But
Speaker 1: corals themselves are actually tiny little polyps. Uh, and they
Speaker 1: excrete the limestone that creates these skeletons. Now, I said earlier,
Speaker 1: we talk a lot about sort of the dire threats
Speaker 1: that they're facing. They're actually being destroyed at a rate
Speaker 1: that will see seventy of them gone in less than
Speaker 1: forty years. That was one stat that I read when
Speaker 1: we just talked tomorrow. She said ten percent of all
Speaker 1: reefs are already permanently lost are expected to be lost
Speaker 1: in the next few decades. So that's that's the lot um.
Speaker 1: And why is that? Well, we talked to her about
Speaker 1: that as well. But real quick primer, if you even
Speaker 1: shift one degree of temperature in the water that they're in,
Speaker 1: it can damage them, causing them to expel the algae
Speaker 1: that's within them, which they have a symbiotic relationship with
Speaker 1: this and this is the key to their ability to
Speaker 1: colonize these these rather hostile regions. Absolutely, yeah uh. And
Speaker 1: they're also facing external threats from hurricanes, predators, pollution, over fishing,
Speaker 1: and from us. Just talking tomorrow, she did a great
Speaker 1: job of explaining what a bleaching event is, which is
Speaker 1: the actual impact of these temperature changes causing the algae
Speaker 1: to separate from the coral polyps and basically either killing
Speaker 1: them or making it so that they don't have enough
Speaker 1: energy to reproduce. So why should you care? Here's why.
Speaker 1: If you want just a purely selfish reason, If all
Speaker 1: you care about is your own well being. It's import
Speaker 1: to our economy. Actually, uh, they provide jobs for fishing, construction,
Speaker 1: and believe it or not, pharmaceuticals. There's an estimated three
Speaker 1: hundred and seventy five billion dollars a year that come
Speaker 1: out of coral reefs, So that's pretty huge. We don't
Speaker 1: want to lose these, even on just like a purely
Speaker 1: selfish monetary level, outside of any kind of like altruistic
Speaker 1: ecological level. Okay, alright, let's roll into the basic biology
Speaker 1: of corals. Okay, So corals were originally thought to be planted,
Speaker 1: so I wasn't alone in that. And if you're out
Speaker 1: there and you thought the same thing, scientists thought that too.
Speaker 1: But they're actually tiny, little soft bodied creatures and their
Speaker 1: carnivores too. They're fixed to one spot as a polyp,
Speaker 1: and it's they basically have these barbed stinging cells that
Speaker 1: are called nematocysts, and these are what they used to
Speaker 1: capture food, like little tiny fish or zoo plankton. They're
Speaker 1: only about three millimeters long, and they grow to become
Speaker 1: reefs that stretched from miles. When they combine together with
Speaker 1: their limestone and their huge colonies, the polyps themselves are
Speaker 1: basically and and Mara says this as well. They're basically
Speaker 1: just a gut with a mouth that's surrounded by tentacles.
Speaker 1: So it's like a teeny tiny little Lovecraft monster. Yeah,
Speaker 1: the thing that you discredited as a mere plant turned
Speaker 1: out to be closer to your heart exactly. Now, we
Speaker 1: talked about the symbiosis that they have with algae. Well,
Speaker 1: the algae that they live together with are called zoos
Speaker 1: in Theelli and uh Um I believe Mara says that
Speaker 1: it's okay to refer to them as zooks. That's that's
Speaker 1: kind of like the the in crowd nickname that they have.
Speaker 1: But they're an algae that lives inside the cell walls
Speaker 1: of corals, and the algae provides them with byproducts of
Speaker 1: photosynthesis that then feeds the polyp. The polyps subsequently shelters
Speaker 1: the algae and provides them with the chemicals that they
Speaker 1: need for photosynthesis. So up to of the algaees energy
Speaker 1: is transferred into the polyps. So you can see now
Speaker 1: why if that algae is forced to flee because of
Speaker 1: coral bleaching, why the polyp would be weakened significantly. Okay,
Speaker 1: so this energy helps them to do things like produce
Speaker 1: the limestone that they are covered in, and that's made
Speaker 1: of calcium carbonate. They secrete it from their base and
Speaker 1: it creates a protective skeleton that they basically hide in
Speaker 1: from predators. And because they rarely exist alone, they also
Speaker 1: joined together with other polyps as a colony and act
Speaker 1: basically like a single organism colonies. Now I just told
Speaker 1: you one polyp is like three millimeters. Colonies can weigh tons.
Speaker 1: These things are huge, uh, and they have many branches
Speaker 1: that form out, and this is what we call reefs. Okay,
Speaker 1: so let's get to the nitty gritty of what this
Speaker 1: is about, all right. That today's episode is about coral
Speaker 1: sex re production. And they reproduce in two ways, or
Speaker 1: they grow in two ways. The first is they just
Speaker 1: keep adding limestone to their base and they secrete upward
Speaker 1: and outward, right, so the reef gets bigger that way.
Speaker 1: The main way what we end up talking to Ma
Speaker 1: about primarily is reproduction, and they produce a sexually and
Speaker 1: sexually a sexual reproduction is where they divide and create
Speaker 1: identical clones of themselves. And we're gonna talk tomorrow about
Speaker 1: why that's not always such a good thing. But they
Speaker 1: can basically make fragments of themselves and then reattached to
Speaker 1: different parts of a reef and then continue to grow.
Speaker 1: Sexual reproduction this is the weird stuff, and this is
Speaker 1: what we spend a lot of time talking with Mara about.
Speaker 1: This is basically when they send out their eggs and sperm,
Speaker 1: and it works like this. Their sexual reproduction only occurs
Speaker 1: once a year, shortly after a full moon. It's called
Speaker 1: broadcast spawning, and this is where the colonies release a
Speaker 1: cloud of rightly colored eggs and sperm into the ocean.
Speaker 1: And these bundles are not only buoyant, but they are
Speaker 1: also attached to their parental polyps by like umbilical strings
Speaker 1: of mucus. Mara describes it as being like this pink
Speaker 1: cloud of snow flakes floating upward. It it sounds kind
Speaker 1: of beautiful, actually, if if you get the opportunity to
Speaker 1: see it. Shrimp and worms that are around there part
Speaker 1: of the ecology of the coral reef. They're gonna eat
Speaker 1: this stuff as it floats upward. But but basically the
Speaker 1: polyps turn pink right before they release it. One of
Speaker 1: the articles that I read for research on this described
Speaker 1: it as milky, pink waters. The eggs are then ejected,
Speaker 1: they float upward to the surface and they wait to
Speaker 1: get fertilized. But they have nothing to protect them, so
Speaker 1: the first twelve hours that they're out there in development,
Speaker 1: they're real fragile. Mara actually describes these globules. She says
Speaker 1: this in her book and in our interview with her,
Speaker 1: and I like it. She says they look like pink
Speaker 1: orange nerd candies, which is pretty fun um and gave
Speaker 1: me like a really good picture because I, I don't
Speaker 1: know about you, Robert, but I've never been to a
Speaker 1: beach area that has coral reefs, and I grew up
Speaker 1: on the ocean. Um. I had not really experienced it
Speaker 1: until earlier this year when I went to Jamaica and
Speaker 1: got to Snarling h with the with my wife and
Speaker 1: see some of it in action, and I was just
Speaker 1: really blown away by it. Because there's one thing to see,
Speaker 1: like the super HD footage and it's beautiful, but it
Speaker 1: seems like another world. It's like watching Avatar, but totally
Speaker 1: to actually poke around there and see it in real life,
Speaker 1: it's it's quite amazing. So one of the things we
Speaker 1: talked tomorrow about that no one quite has the exact
Speaker 1: answer to is how these corals are timing it so
Speaker 1: that they all spawn at the exact same time every year.
Speaker 1: And there's a theory that the solar they're they're taking
Speaker 1: solar cues or wind cues to figure out the month
Speaker 1: that they should spawn in, and then they're taking nooner
Speaker 1: cues somehow to figure out which day they should spawn in.
Speaker 1: Us Alian scientists have recently found out, however, that when
Speaker 1: they're exposed to even tiny little waves, that coral can
Speaker 1: break into identical pieces that can each develop their own larvae.
Speaker 1: So this is the clone process. It's similar their stem
Speaker 1: cells then reassemble and continue to develop. So there are
Speaker 1: a lot of identical twin coral polyps out there. But
Speaker 1: as we talk about with Mara, that's not very that's
Speaker 1: not exactly a good thing if you need diversity to
Speaker 1: sort of protect you from ecological problems. So, but we
Speaker 1: have billions of naked embryos on the surface of the
Speaker 1: ocean during these spawnings, there's a potential to create even
Speaker 1: more clones. When they conducted this first experiment that I
Speaker 1: was speaking of in Australia, fifty of the embryos that
Speaker 1: they exposed, fragmented and then reorganized so they could develop larvae.
Speaker 1: So the cloning thing is is fairly prevalent. Now. Sent
Speaker 1: of the zooks algae corals, those are hermaphrodites, and they're
Speaker 1: basically both male and fee male. They can release sperm
Speaker 1: and eggs, but some are only male and some are
Speaker 1: only female. Uh. Some even fertilize their own eggs internally
Speaker 1: if they can snatch up the sperm. This is called brooding.
Speaker 1: They also release fully developed larvae. Now, the sexuality of
Speaker 1: these uh particular polyps tends to be consistent across the
Speaker 1: different species of corals that we're talking about here. Another
Speaker 1: number seventy of the zooks corals also spawn eggs and
Speaker 1: sperm for external fertilization. So the broadcast spawning we're talking
Speaker 1: about is their majority of their reproductive process. So this
Speaker 1: is this is contrary to the brooding that I was
Speaker 1: speaking about earlier. Now, when species brewed like I'm talking
Speaker 1: about this is when they're fertilizing their eggs internally, they
Speaker 1: can store the unfertilized ova for weeks at a time,
Speaker 1: whereas spawning species requires this very specific time frame of
Speaker 1: hours that we talked about with Mara, sometimes colonies of
Speaker 1: different species spawned simultaneously. This is when hybridization occurs. We
Speaker 1: know that it happens, we just don't really know the extent.
Speaker 1: And as we'll talk about with Mara, most hybrids are sterile,
Speaker 1: but it's hopefully avoided when most species of polyps spend
Speaker 1: their time spawning at different intervals. Um we talk about
Speaker 1: that as well with particular kinds of species the boulder
Speaker 1: coral and what was the other one, lobe star coral
Speaker 1: and and indeed there are also some some interesting twists
Speaker 1: and turns with hybridization that I think everyone will will
Speaker 1: be rather delighted by. Yeah, and we were totally surprised
Speaker 1: by two because it's a brand new research. Another thing
Speaker 1: that's super fascinating about this broadcast spawning. It can happen
Speaker 1: over vast distances. Corals can basically take extended sea voyages
Speaker 1: once they float to the top, and they can survive
Speaker 1: for months before they fully integrate and sink back down
Speaker 1: to the bottom. Now, when an egg does get fertilized
Speaker 1: after the embryo forms, it's it actually swims, so so
Speaker 1: sinking isn't really the right term I should have used there.
Speaker 1: It swims to the bottom to anchor itself. And scientists
Speaker 1: thought until four that all coral reproduction was internal like
Speaker 1: this brooding method. But then in Science magazine somebody published
Speaker 1: a description of the mass spawning event at the Great
Speaker 1: Barrier reef. And here we are now, you know, spending
Speaker 1: an entire episode talking about it. So this is relatively
Speaker 1: new science to humans. A study in a Smithsonian article
Speaker 1: that I read for this that's called watching Coral sex
Speaker 1: indicated that if corals spawn just fifteen minutes out of
Speaker 1: sync with their majority of the rest of their species,
Speaker 1: it greatly reduces their chance of reproductive success. So you know,
Speaker 1: this is why it's so important that it happens all
Speaker 1: at the same time and that the area is protected.
Speaker 1: Just a lot of factors that go into the ecology
Speaker 1: of keeping these reefs safe. Uh. And then to go
Speaker 1: along with Mara's nerd candy example, one of the other
Speaker 1: scientists described it as being a little bit like tapioca.
Speaker 1: That like, you're basically floating in a sea of I
Speaker 1: think tapioca. It's like swimming and bubble tea essentially. Yeah,
Speaker 1: that's a good one. I like that bubble tea. All right, Well,
Speaker 1: we're gonna take a quick break and when we come back,
Speaker 1: we're gonna call up Mara and discuss coral sex. Hi, Mara,
Speaker 1: thanks so much for coming on the show again for
Speaker 1: a summertime discussion of corals. So we had such a
Speaker 1: great time chatting with you before on the the Oppidas
Speaker 1: episode that we recorded, so it's nice to have you
Speaker 1: back on to discuss corals. Thank you so much for
Speaker 1: having me. I'm I'm really excited to be here and
Speaker 1: to be able to chat with you guys about definitely
Speaker 1: one of my favorite animals, which are corals somorrow. I
Speaker 1: didn't realize this until like almost five minutes ago. I've
Speaker 1: read through the book, We've talked to you before, but
Speaker 1: you have a background as a coral reef ecologist, right,
Speaker 1: that's right. Yeah, They're where I really um got started
Speaker 1: in my career doing me in science. So they hold
Speaker 1: a very special place in my heart. Quarrels and sharks. Okay, awesome,
Speaker 1: Well good, because we got a lot of questions because
Speaker 1: because quarrels have a very strange reproductive practice. This is true,
Speaker 1: they do. They're they're pretty amazing, especially given that they
Speaker 1: can't move, and they are pretty simple animals that I
Speaker 1: don't like to use the word simple, but you know,
Speaker 1: basically they're they're sort of this jelly like blob that
Speaker 1: sits with extending little tentacles out of a little hard
Speaker 1: cup that they manufacture themselves. So for folks out there
Speaker 1: who are familiar with finding Demo um and know that
Speaker 1: he lives in an anemone, which is uh, I don't
Speaker 1: want my it up, and then with me, uh, they're
Speaker 1: they're close cousins of those animals, and so they fit
Speaker 1: in these little cups all day long with their tentacles
Speaker 1: outstretched into into the environment, sort of taking little particles
Speaker 1: out of the water to feed on. But they have
Speaker 1: some other cool tricks up there. The sexual reproduction and
Speaker 1: corals is pretty amazing. Yeah, you you presented so well
Speaker 1: in the book. I almost almost hate to ask you
Speaker 1: described to describe it here, you know, I'd almost rather
Speaker 1: encourage the readers to read it. But can you take
Speaker 1: just a few minutes to describe for us the synchronized
Speaker 1: hotel orgy of the corals? Sure, i'd be to So again,
Speaker 1: corals can't move right, so they're stuck. They're cemented to
Speaker 1: the sea floor. This means they can't go out in
Speaker 1: date to find their mates there. They have to allow
Speaker 1: their gammets, which are their eggs and their sperm, to
Speaker 1: do the dating and meeting for them. And I should
Speaker 1: say there's two types of coral in the when I'm
Speaker 1: about to describe it does this big synchronized orgy. These
Speaker 1: are called broadcast spawners. So they release both their sperm
Speaker 1: and their eggs into the water column. And the best
Speaker 1: way to ensure that their sperm and eggs are going
Speaker 1: to mix the sperm and eggs of other corals and
Speaker 1: be able to make the next generation is to time
Speaker 1: that release with their neighbors. So if you imagine that
Speaker 1: corals are sort of sitting in their little cups, and
Speaker 1: their cups sort of form these big colonies, and then
Speaker 1: there's multiple colonies along the reefs, it's kind of like
Speaker 1: thinking that, um, the sperm and eggs are are getting
Speaker 1: together in a hotel room, right, and these corals have
Speaker 1: to make sure that they're going to synchronize their mate
Speaker 1: their release. But then it's also like that couple in
Speaker 1: that hotel room that synchronizing their release is also coordinating
Speaker 1: with their neighbors maybe in the two rooms on either side,
Speaker 1: and then those neighbors are also synchronizing with their neighbors,
Speaker 1: and so the whole floor of the hotel are all
Speaker 1: coming together and being able to synchronize their climax exactly
Speaker 1: the same time. And then actually, because there's miles and
Speaker 1: miles of reef and millions and millions of corals, you've
Speaker 1: actually got to blow it out to imagine that every
Speaker 1: single hotel room across say, the entire city of New
Speaker 1: York is full of couples that are all climax thing
Speaker 1: exactly the same time. So it's pretty phenomenal when you
Speaker 1: think about the scale at which this synchronization is occurring.
Speaker 1: And you know, given uh sort of bar pop culture,
Speaker 1: and again I talked about you know, if you look
Speaker 1: at any cover of Cosmo, it's all about how to
Speaker 1: you know, connect better with your partner. We we seem
Speaker 1: to struggle to do this on a one on one basis. Meanwhile,
Speaker 1: corals are doing that's across millions of individuals, no problem,
Speaker 1: year after year, down to you know, really really fine timing.
Speaker 1: So we're talking within you know, within moments uh of
Speaker 1: of their their sort of buddy colonies up and down
Speaker 1: the reef, and this is a once a year occurrence,
Speaker 1: it is. So what happens is coral sort of spend
Speaker 1: the entire year celibates, building up the energy and storing
Speaker 1: the energy to make these staddy balls of sperm and eggs.
Speaker 1: So it's called a bundle. And the bundle looks like,
Speaker 1: for those of you who know nerd candies, kind of
Speaker 1: a small pinkish orange colored spear, and it takes a
Speaker 1: lot of energies to pack all these eggs and sperms together,
Speaker 1: so they wait and again. Um, it's a once a
Speaker 1: year event and it normally happens um for different species.
Speaker 1: It'll happen within a two to three day window around
Speaker 1: the full moon, and it normally happens in the summertime,
Speaker 1: so there's likely some water temperature cues. There's definitely cues
Speaker 1: from from the sunset. It often happens at night after
Speaker 1: sunset and moon phase also coordinated around that that full
Speaker 1: moon time, so there's a whole bunch of virominal cues
Speaker 1: that they're using to kind of start to align and
Speaker 1: then and then let it all go. But it's yeah,
Speaker 1: so each coral will only go once they've got one
Speaker 1: little sperm egg bundle to release and that's it. Uh So,
Speaker 1: within a colony you might have one or two days
Speaker 1: of different polyps going off, but in general there's one
Speaker 1: peak night where the vast majority of of all these
Speaker 1: animals are releasing at the same time. Now, of course
Speaker 1: there's a reason for all of this. So what what
Speaker 1: are the core advantages to this once a year sexual blowout. Yeah,
Speaker 1: so again, um, it's really expensive to manufacture these, especially
Speaker 1: the eggs um and all the sperm, and you really
Speaker 1: want to make sure that in the environment like an
Speaker 1: ocean where there's lots of currents and lots of predators,
Speaker 1: so that you are getting your your sperm and eggs
Speaker 1: to mix with other sperm and eggs from your fellow
Speaker 1: species so that you can make next generation. And by
Speaker 1: coordinating the timing really precisely, you up the odds that
Speaker 1: your sperm and eggs are going to bump into another
Speaker 1: coral sperm and eggs and be able to fertilize and
Speaker 1: make make that viable a little larvae. But it also
Speaker 1: helps to release all these millions and millions of gammets
Speaker 1: all at once because it's sort of swamps out the
Speaker 1: predators as well, and the sex facts of coral. That
Speaker 1: sort of starts really peacefully, and it's just really it's
Speaker 1: really quite a miraculous event to witness, and and folks
Speaker 1: can see this because it happens on shaller wreaths. You
Speaker 1: can take a flashlight and even just snorkel um down
Speaker 1: in the Caribbean or off the Great Day or reef
Speaker 1: and be able to actually watch this happen um. But
Speaker 1: it starts off really beautifully where these little bundles form
Speaker 1: and then it's sort of this slow release and the
Speaker 1: sperm and eggs are buoyant that they slowed up, and
Speaker 1: it creates sort of like the snow storm underwater, but
Speaker 1: the snowflakes are bright pink and float to the surface,
Speaker 1: and it's really quite magical. And then all of a
Speaker 1: sudden it turns into this like crazy. I think I
Speaker 1: refer to it as like a rave where shrimp are
Speaker 1: coming in and worms are coming in, and fish are
Speaker 1: coming in, and then bigger fish are coming eat the
Speaker 1: little fish that are eating the corals. You know, it's
Speaker 1: it's chaos. And if you're if you are diving down there,
Speaker 1: you stop is hitting your mask. It's going in your face.
Speaker 1: It's like bumping your regulator out of your mouth. I mean,
Speaker 1: it's like it's a wild all you can eat, say,
Speaker 1: And so for the corals, it's helpful to know that
Speaker 1: everybody else is releasing their stuff too, so that it's
Speaker 1: not just your sperm and eggs that are going to
Speaker 1: get sort of focused on. But hopefully you'll satiate all
Speaker 1: the mouths out there and a couple will make it
Speaker 1: to the surface where they can break apart and and
Speaker 1: sort of mix and and and form that next generation.
Speaker 1: So doing it all at once has its benefits for
Speaker 1: a couple of reasons. So, Mara, I got a question,
Speaker 1: just for clarification, can you explain for our audience what
Speaker 1: we mean when we're talking about gam meats. Are we
Speaker 1: talking about the sperm the eggs both? Is this the
Speaker 1: bundle we're referring to, right? Yeah, So gam meat is
Speaker 1: the scientific term for a sex cell, and it's either
Speaker 1: a sperm or an egg, so it counts for both. Yep.
Speaker 1: So the bundles are there gam meats because it's the
Speaker 1: sperm and eggs um sort of tightly wrapped around each
Speaker 1: other in these in these little balls. And when they
Speaker 1: get to the surface, they actually break open and the
Speaker 1: sperm and multiple eggs. Do you have lots and lots
Speaker 1: of sperm and lots and lots of eggs inside each bundle,
Speaker 1: and when they break open at the surface, that's when
Speaker 1: the sperm and eggs can actually bump and mix with
Speaker 1: the sperm and eggs of other coral individual to make
Speaker 1: a new a new offspring. And one thing that I
Speaker 1: think we should quickly clarify here too is you mentioned
Speaker 1: this already, but we're spece typically talking about broadcast spawning
Speaker 1: coral reefs. There's other forms of reproduction for coral reefs,
Speaker 1: right right, Yeah, So corals are They're really cool animals.
Speaker 1: There's hundreds and hundreds of species of coral thousands, I think,
Speaker 1: and um, the ones that build the big reefs, the
Speaker 1: ones that we think of when we think about coral reefs,
Speaker 1: tend to be these broadcast spawners that do these mass
Speaker 1: um spawning events, these big orgies. There are others, however,
Speaker 1: that are brooders, which mean that they release their sperm
Speaker 1: into the environment, but they actually hold eggs so that
Speaker 1: the sperm will have to come into the coral colony
Speaker 1: and fertilized there's also some corals that are so again
Speaker 1: the broadcast spawners are hermaphrodite. They're producing both um sex
Speaker 1: cells right spur and eggs. But there are some corals
Speaker 1: that the colony is either female or male. They have
Speaker 1: separate sexes, in which case they'll release um into the
Speaker 1: environment the sperm, and then the females again hold the eggs,
Speaker 1: and there's tons of varieties sort of in between. UM.
Speaker 1: I just came back from a coral conference, the Big
Speaker 1: Coral Conference happens once every four years and it was
Speaker 1: just last week in Hawaii, and I thought this great
Speaker 1: presentation by Dr Kristen Marhavior who works out of Karmabi
Speaker 1: in Curse Out, and they're finding some corals that seem
Speaker 1: to be doing this weird kind of in between where
Speaker 1: they don't really brood, but they're sort of holding the
Speaker 1: eggs up in the tentacles but not really letting them go.
Speaker 1: So it's like the funky yeah in between. So one
Speaker 1: thing with corals is that they do it all, and
Speaker 1: they seem to do it in lots of different ways
Speaker 1: that we're still learning about. Uh, this seems like a
Speaker 1: good opportunity for us to hone in on two particular
Speaker 1: species you bring up in the book. Yeah, indeed you
Speaker 1: make a special mention of the lob star coral and
Speaker 1: the boulder star coral. Which I found this particularly interesting
Speaker 1: because we're talking about this sort of this broadcast orgy
Speaker 1: of reproduction here, but it seems like it doesn't pay
Speaker 1: to bump into just anybody in a broadcast orgy. That's right,
Speaker 1: This is definitely true, um. And it's again it's not
Speaker 1: something that we mammals tend to have to worry about
Speaker 1: because we are pretty certain of who it is that
Speaker 1: we're mating with, who are gammetes are sperm and eggs
Speaker 1: are mixing with at the time of sects. But for corals, um,
Speaker 1: they don't have that control. Right, they release their sperm
Speaker 1: and eggs into the water column, and they're hoping that
Speaker 1: they do it in the right time period so that
Speaker 1: it bumps into other sperm and eggs of not only
Speaker 1: fit healthy other corals, but corals of the right species.
Speaker 1: So coral. There are corals that are very closely related,
Speaker 1: and the low as a boulder star are examples of that.
Speaker 1: And it is possible that if the sperm from say
Speaker 1: below star coral bumps into the egg of a boulder
Speaker 1: star coral. Uh, you know, they could they could fertilize
Speaker 1: that egg and a barbacaus form. That's a hybrid. And
Speaker 1: hybrids are not always the best outcome for four species
Speaker 1: for a couple of reasons. And and folks may be
Speaker 1: most familiar with, um sort of the cross between a
Speaker 1: horse and a donkey that creates a mule, right, mules
Speaker 1: for sterile, Like a mule can't go on to reproduce,
Speaker 1: And so that sort of idea that hybrids of these
Speaker 1: genetic dead ends, Um, it kind of defeats the whole
Speaker 1: purpose of having sex in the first place, right, which
Speaker 1: is to create future offspring and hopefully that those offspring
Speaker 1: will be fit and create the next generation, the next generation.
Speaker 1: So hybrid sort of um squelched that in many cases.
Speaker 1: And UM, I don't know if you guys want me
Speaker 1: to go into it, but there is actually some really
Speaker 1: cool work that has been done since the book came
Speaker 1: out about some coral hybrid stuff. So we could we
Speaker 1: could talk about that if you want. Yeah, yes, certainly,
Speaker 1: especially because like one of the things that I'd like
Speaker 1: to clarify just from the book itself is like getting
Speaker 1: back to the Lobes star and the Boulder star coral.
Speaker 1: There's very specific ways in which they are compatible, right,
Speaker 1: but it's not always so easy for one to fertilize
Speaker 1: the other. Right. So, because of this risk of forming hybrids,
Speaker 1: corals have come up with a couple of tactics and
Speaker 1: there is a level of screening that happens at the
Speaker 1: level of the eggs um. Some eggs um some species
Speaker 1: are very prude and they won't let sperm in from
Speaker 1: other species or they make it very difficult. But other
Speaker 1: eggs are are much more promiscuous if you will and
Speaker 1: are if sperm from another species is around, it can fertilize.
Speaker 1: So to help kind of create more barriers to hybrids
Speaker 1: and really separate the species corals, the timing of these
Speaker 1: uh orgies is very very specific. So again the load
Speaker 1: star coral and the Boulder star coral are a great
Speaker 1: example of this because they spawn on the same night.
Speaker 1: You know, they use the same environmental cues the warming temperature,
Speaker 1: the moon phase and then the timing of sunset. But
Speaker 1: what happens is with the low star coral there was
Speaker 1: no start with the Boulder star coral. The Boulder star
Speaker 1: are the early birds, so they will start to release
Speaker 1: um it's about two hours after sunset, so if you're
Speaker 1: down in the Caribbean, sunsets may be around seven. So
Speaker 1: the Boulders first start to release their eggs around nine o'clock.
Speaker 1: And it really is that precise. You're on year, it's
Speaker 1: within two to three minutes of the year before that,
Speaker 1: the same colony will spawn at the same time. I mean,
Speaker 1: it's you absolutely could think you're nice your watches to
Speaker 1: it's it's pretty awesome. And then the Lowe Star coral
Speaker 1: is about an hour and a half de lad from
Speaker 1: the Boulder Star, so they would be you know, maybe
Speaker 1: ten thirty leaven ish And that separation and time turns
Speaker 1: out to be just about the time it takes for
Speaker 1: the Boulder Star sperm fizzle out after about an hour
Speaker 1: and a half. So the fact that they go first
Speaker 1: at around you know, say nine o'clock, by the time
Speaker 1: the Lobes Star go off and they release their eggs,
Speaker 1: there's not a lot of the Boulder Star sperm left
Speaker 1: that has a lot of you know, much energy you know,
Speaker 1: to get out there and find their eggs. UM. So
Speaker 1: that hour and a half spacing seems to be just
Speaker 1: enough time to allow the first coral in this case,
Speaker 1: the Boulder star, for its eggs to be fertilized by
Speaker 1: its own sperm, and then by the time the next
Speaker 1: species goes off, there's there's really not too many of
Speaker 1: their eggs left to be fertilized by any new sperm
Speaker 1: coming into the picture from another species, and any of
Speaker 1: the first sperm that are around sort of are a
Speaker 1: little wizard at that point and unlikely to go and
Speaker 1: fertilize the new eggs that are released by the second species.
Speaker 1: So I know it's a little a little complicated, but
Speaker 1: that's why I asked, Yeah, so tell us about this
Speaker 1: new hybrid research that you said that's come out, because
Speaker 1: maybe it answers a question that I was going to
Speaker 1: ask you anyways, which is how frequently are coral hybrids
Speaker 1: actually sterile? Yeah, so it's a it's a really important question.
Speaker 1: And Dr Nicole fogerty Um is studying this extensively and
Speaker 1: and this is her work at all I'll summarize here,
Speaker 1: and she again just presented sort of a new component
Speaker 1: of it just last week at this big coral conference,
Speaker 1: and she has been setting this question in two species
Speaker 1: of endangered corals in the Caribbean called elkhorn and staghorn,
Speaker 1: and these are the beautiful, big branching species that used
Speaker 1: to dominate some of the shallow reef crest environments and
Speaker 1: have been really quite wiped out. They were the first
Speaker 1: um invertebrates to ever go on to the endangered Species list,
Speaker 1: I believe, or one of the few um so they've
Speaker 1: really been hammered and we're trying to figure out why
Speaker 1: and try to figure out what this means for their reproduction.
Speaker 1: And what Dr Bobodies found is if you look at
Speaker 1: the fossil record, which is for corals, really um pretty
Speaker 1: robusts because they create these these hard skeletons. They actually
Speaker 1: are captured really well and represented very well in the
Speaker 1: fossil record. If you go back, you see that hybrids
Speaker 1: between elkhorn and staghorn are very rare. And they can
Speaker 1: look at this by epe colony shape in different um
Speaker 1: aspects of their morphology sort of the shape and the
Speaker 1: way that um polyps are arranged, and hybrids, yeah, they're
Speaker 1: just they're just not around very much. But if you
Speaker 1: come now into and we also know from early surveys
Speaker 1: in the seventies and eighties on coral reefs, there's not
Speaker 1: all the hybrids, but recently there are. We see a
Speaker 1: lot of hybrids going on, and they've done some genetic
Speaker 1: tests and they're actually finding that these hybrids, so this
Speaker 1: is a cross between an elk horn and the staghorn,
Speaker 1: makes a hybrid. These hybrids are actually able to breathe
Speaker 1: with other hybrids and make a second desperation that seems
Speaker 1: to be viable. So that's a really neat kind of
Speaker 1: twist on the whole Hybrids are always bad thing. Now
Speaker 1: the catches we don't know if that second generation of
Speaker 1: hybrids is viable, so we're still sort of aiding to see.
Speaker 1: You know this, this can happen where the first generation
Speaker 1: of hybrids is viable and seems really um fit and
Speaker 1: actually does very well, but then it's kids peter out.
Speaker 1: It is it's like a it is, and it's in.
Speaker 1: What happens also is that these these these vigorous hybrids
Speaker 1: can often compete with their parents, right, So they're competing
Speaker 1: with the elk horns and the stag horns that maybe
Speaker 1: aren't doing as well, and if they start to take
Speaker 1: over those environments, but they don't have the ability to
Speaker 1: reproduce successfully for multiple generation. Then you wind up with
Speaker 1: hybrids actually being another threat to the parent. Now, to
Speaker 1: put another spin on it, which is what corals love
Speaker 1: to do, these hybrids can also meet back with the
Speaker 1: elk horn or with stag horns, so you get what's
Speaker 1: called a back cross, which gets even you know, you, guys,
Speaker 1: your guys show is stuff to blow your minds and
Speaker 1: get really so wait, I'm trying to envision this, given
Speaker 1: that the elk horns and the stag horns release at
Speaker 1: different times on the same night, do the hybrids release
Speaker 1: like somewhere in the middle there, You know, that's a
Speaker 1: really good question, and I I don't know the answer
Speaker 1: to that. They are going to be spotting the full
Speaker 1: moon this month. July is a big month for elk
Speaker 1: horns and stag horns July in August, so I can
Speaker 1: I will send you guys an update or maybe we
Speaker 1: can throw it in the comments, but I will ask
Speaker 1: down there doing the study right now. But that's a
Speaker 1: really good question. I'm not sure whose timing they take
Speaker 1: or if it's a combination. There their shape is definitely
Speaker 1: um a range of in between the two parents between
Speaker 1: the elk horn and stag horn, that there's sort of
Speaker 1: a whole variety of shapes that these hybrids seem to
Speaker 1: be taking. And when the hybrid back crosses, so when
Speaker 1: the um the combo coral of of elk horn and
Speaker 1: stag horns, then fertilizes or mixes with an elk horn
Speaker 1: or a pure you know, stag horn and make this
Speaker 1: sort of back cross species um, they tend to have
Speaker 1: slightly different shapes and sizes as well. So the good
Speaker 1: news on this is if there's not too much competition
Speaker 1: with the parents and there's not too much back crossing,
Speaker 1: the little bit of gene mixing and the little bit
Speaker 1: of hybridization that's happening could actually really help the species
Speaker 1: and could be a way that this species, the two species,
Speaker 1: the elk horn and the stag horn, are trying to
Speaker 1: adapt to these changing environments and are actually dealing with
Speaker 1: some of the impacts. It's one way that species may
Speaker 1: be evolving, and we do see some you know, Dr
Speaker 1: Brogan is starting to see some very preliminary evidence of
Speaker 1: higher disease resistance, higher heat tolerance to you know, with
Speaker 1: some of the global warming issues and mass teaching issues.
Speaker 1: This is a positive um and and that we will
Speaker 1: be able to see new forms of these branching corals
Speaker 1: based on this hybridization, or it could go the other way,
Speaker 1: where again these hybrids actually wind up to be not
Speaker 1: viable multigeneration and multiple generations down the line, and they
Speaker 1: wind up contributing to the decline of the two parents species.
Speaker 1: So it's UM, it's something that she's studying really intently
Speaker 1: and watching and it's a fascinating um sort of I
Speaker 1: don't know who. I don't know who to root for, really,
Speaker 1: but it's important for us to keep an eye on,
Speaker 1: especially given the threats to coral ecology that are going on.
Speaker 1: So I've there's a lot of biologicals sort of hypothetical
Speaker 1: question for you, because you say in the book the
Speaker 1: same question that immediately popped into my head as I
Speaker 1: was reading it, which is, if corals don't have brains
Speaker 1: or eyes, how is it that they're seeing light, how
Speaker 1: is it that they're uh sensing lunar patterns things like that? Um,
Speaker 1: And my question was we just did a piece here
Speaker 1: recently about new research that came out about two months
Speaker 1: ago on underwater slime and algae and that they're able
Speaker 1: to on a cellular level sense light and move toward it.
Speaker 1: That like each cell on its own can quote see
Speaker 1: light and then like subsequently sort of crawls forward. And
Speaker 1: I'm wondering if you think that maybe is something like
Speaker 1: that possible with corals. That's fascinating. I will have to
Speaker 1: go and listen to your story because I don't know
Speaker 1: much about the the how that kind of a a
Speaker 1: slime can do that. That sounds really cool. With corals,
Speaker 1: they definitely have light sensors, Um, I'm not up to
Speaker 1: speed on like the the detailed physiology there for whether
Speaker 1: it's at a cellular level, whether it's um sort of
Speaker 1: a very primitive kind of organ nolle that that we
Speaker 1: see in some worms that can you know, tell if
Speaker 1: a shadow moves across, you know, light and dark. But
Speaker 1: they definitely definitely have a way of sensing the light.
Speaker 1: But I'm not sure exactly how it works, to be honest, Um,
Speaker 1: I can I can dig into that a little further.
Speaker 1: But the reason why we know it's cued by light though,
Speaker 1: and pretty specifically is not only because the timing happens
Speaker 1: after sunset year on year so precisely, but it's also
Speaker 1: that we've done some experiments, um, and these were initially started. Yeah,
Speaker 1: the garbage bags, right, so simple as best in science.
Speaker 1: And Dr Nancy Knowlton, who's now runs the the Marine
Speaker 1: Science Hall over at the Smithsonian. So when she was
Speaker 1: studying some of these systems, she was like, all right, well,
Speaker 1: if we wanted to see whether or not these corals
Speaker 1: can actually fertilize one another, and what's going on between
Speaker 1: these different species. She looked at the Lobes and the
Speaker 1: Boulder Star corals and was like, okay, well they're delayed
Speaker 1: about an hour and a half apart, so what would
Speaker 1: happen if we tricked the Lobes Star coral, which is
Speaker 1: the later spawner in the thinking sunset happened sooner. So
Speaker 1: they took colonies and they put black garbage bags over
Speaker 1: them about an hour and a half before sunset, so
Speaker 1: they sort of faked the corals out into thinking that
Speaker 1: sunset had happened at day six o'clock rather than seven thirty.
Speaker 1: So low and behold it right. An hour and a
Speaker 1: half later, when they were que to go off, they
Speaker 1: went off. And what they were able to do by
Speaker 1: by kind of sort of shifting the time of sunset earlier,
Speaker 1: they were able to actually get the Load Star coral
Speaker 1: and the Boulder Star coral colonies to spawn at the
Speaker 1: same time, and then they were able to check and
Speaker 1: see sort of what happened if if that were to occur.
Speaker 1: So we know that the light queue is key because
Speaker 1: if you, if you sort of could unquote mess with
Speaker 1: when sunset happens, it literally shifts exactly the timing of
Speaker 1: the release of the sperm and eggs. So it was
Speaker 1: pretty cool. Indeed, Now in discussing these elaborate reproductive methods
Speaker 1: that the coral use, Um, there's a weakness in all
Speaker 1: of this, right now, how does this reproductive strategy make
Speaker 1: corals so vulnerable to pollution, climate change, and these other
Speaker 1: influences that are are making so many of them threatened. Yeah,
Speaker 1: so there's a lot of reasons why corals are vulnerable
Speaker 1: to to these threats and why they're being threatened. Um,
Speaker 1: but when it comes to their sexual strategy. So this
Speaker 1: idea of the broadcast spotting these mass orgies, the real
Speaker 1: issue is that it all depends on everybody releasing their
Speaker 1: egg and sperm at the same time, and that all
Speaker 1: these neighbors are coordinated across the reefs, so we know
Speaker 1: that it's not only are there their cues from the
Speaker 1: moon phase and the sunset, but as the actual release
Speaker 1: is happening, there's likely some some level of chemical communication
Speaker 1: to really get that timing very very tight and very exact.
Speaker 1: And what happens is corals are starting to decline due
Speaker 1: to threats such as overfishing um which is creating more
Speaker 1: algae on the reefs, and there's climate change which is
Speaker 1: warming the waters and acidifying the waters, and all of
Speaker 1: these things um pollution and runoff that they're wiping out corals.
Speaker 1: So coral colonies that are still left are spaced farther
Speaker 1: and farther apart. This means that their ability to really
Speaker 1: sink up and their ability to get their spermag bundles
Speaker 1: to meet and mix at the surface is it's harder
Speaker 1: and harder to do that the farther apart their space. Again,
Speaker 1: if you think about the hotel example, it's easier to
Speaker 1: coordinate with your partner when you're right there with them,
Speaker 1: and it's definitely if you were to try to coordinate
Speaker 1: with your neighbors, you know it would help to be
Speaker 1: able to see where they were in the process, and
Speaker 1: and and no kind of what that timing was like,
Speaker 1: so you could adjust. And the farther and farther apart
Speaker 1: these these species are the coral colonies are spaced, the
Speaker 1: harder it is to do. And this is this is
Speaker 1: known as density dependence. So the the amount of corals
Speaker 1: in in proximity to each other actually affect how successful
Speaker 1: their fertilization rates are. And the farther apart there's space,
Speaker 1: that level of fertilization goes down. So it's sort of
Speaker 1: a double whammy. Not only are you not only are
Speaker 1: we wiping out coral colonies, you know, putting less less adults.
Speaker 1: Less adults are out there able to spawn because they're dying,
Speaker 1: but the ones that are left or space farther apart,
Speaker 1: and so there are odds of having successful sex go down.
Speaker 1: So it just winds up being a double whammy. Now,
Speaker 1: some listeners might be wondering, well, if the if the
Speaker 1: corals can reproduce a sexually, then that's their backup plan, right,
Speaker 1: Why doesn't cloning solve the problem? Yeah, And it's a
Speaker 1: really good question, because coral colonies grow through a sexual reproduction.
Speaker 1: So you start with this one little larvae that settles
Speaker 1: down on the sea surface will swim down attached somewhere
Speaker 1: on a hard up straight on the hard bottom rocky
Speaker 1: botty um but old reef and creep this one single
Speaker 1: cup with this one polyp, and then that polyp will
Speaker 1: divide and divide again and again in ace and that's
Speaker 1: the a sexual reproduction. It clones itself. But um clones
Speaker 1: are genetically identical, so there's no diversity in that coral colony.
Speaker 1: All those individuals are individuals that they have the exact
Speaker 1: same genetic identity. So this helps the colony grow, and
Speaker 1: there's benefits to being a big colony, but it doesn't
Speaker 1: allow the species as a whole to have variety and
Speaker 1: genetic diversity. And diversity is nature's insurance policy against all
Speaker 1: the changes that are are rough against us. So if
Speaker 1: a new disease develops, you need genetically diverse individuals in
Speaker 1: the population, some of who may have a natural resistance.
Speaker 1: If um there's a big shift in in uh, say
Speaker 1: predator or prey, say there's there's a different food supply,
Speaker 1: you need individuals who might have slightly different morphology or
Speaker 1: slightly different genetic ability to digest a different type of
Speaker 1: food source so that they can survive. So as these
Speaker 1: different changes occur in the environment and different threats arise,
Speaker 1: that genetic diversity is really critical that the species as
Speaker 1: a whole can survive. And genetic diversity is created through
Speaker 1: sexual reproduction, not a sexual reproduction. So it's when the
Speaker 1: sperm from one individual mixes and meshes with the eggs
Speaker 1: from another that a whole new DNA blueprint is formed.
Speaker 1: And that is where the diversity of genetic uh, that
Speaker 1: is where the diversity that these scis needs comes from.
Speaker 1: Without sex, there's no diversity. So given what we learned
Speaker 1: from you today about what's going new research that's going
Speaker 1: on with hybridization, I'm starting to wonder now if maybe
Speaker 1: that's the role of hybridization in some species is to
Speaker 1: further the diversity. Yeah, and I think it might be.
Speaker 1: I think that's that's one of the questions that Dr
Speaker 1: Folky is really um digging into to say, could it
Speaker 1: be that under certain circumstances, hybridization does work to help
Speaker 1: increase that genetic diversity in a way that allows for adaptation,
Speaker 1: that allows for species to withstand a changing environment or
Speaker 1: changing threats so that it can then move forward and
Speaker 1: maybe it will form a new species eventually. That's you know,
Speaker 1: collected over time from the genes from the two two
Speaker 1: parents prior to it, you know, in this case of
Speaker 1: tag Horn and elk Horn. Yeah, I think it's still
Speaker 1: it's possible, and that's what makes it a really intriguing
Speaker 1: space to investing. Eight Um, but we we just don't
Speaker 1: know yet, but it absolutely is possible. So where are
Speaker 1: we right now in terms of coral loss? So well,
Speaker 1: what are we doing and what can we do to
Speaker 1: fix them or at least to address the problem. Oh yeah,
Speaker 1: So you know, this is where I try to find
Speaker 1: that balance between staying optimistic while also being really honest
Speaker 1: that the data coming in it's sobering. So last week's
Speaker 1: conference again, Um, it's really alarming how quickly we are
Speaker 1: losing coral reefs and they are being hit by every
Speaker 1: it's sort of a perfect storm. So, um, we're losing
Speaker 1: them due to over fishing, which has removed a lot
Speaker 1: of the grazers on the reefs, so the equivalent of
Speaker 1: the cows that chomped back the seaweed. So we're getting
Speaker 1: corals overgrown by seaweed because we've taken out things like
Speaker 1: parrot fish and sea urchins. Um, we're losing corals extremely
Speaker 1: quickly now to bleaching events. These are um the result
Speaker 1: of global warming. It's when waters warm. Corals exist naturally
Speaker 1: right at their edge of thermal tolerance. Um. You know,
Speaker 1: they don't have air conditioning or heating systems in their houses,
Speaker 1: so they live right at that perfect window where they
Speaker 1: are just warm enough. And if you crank up the
Speaker 1: heat of the ocean too much and we're talking one
Speaker 1: to two degrees celsius, so not a lot of change,
Speaker 1: coral stress and that stress um disrupts a really unique
Speaker 1: relationship that they have with a tiny microscopic little algae
Speaker 1: called those in selly you can calm zoaks, and these
Speaker 1: zooks are food factories for the coral. They actually live
Speaker 1: inside the coral tissue and they photosynthaesize just like a
Speaker 1: tree eat um, turning sunlight into energy. And the energy
Speaker 1: and the new in the sort of uh nutrition that
Speaker 1: those those lly produced are what the coral can then
Speaker 1: use to have extra energy to build their really massive
Speaker 1: and impressive skeletons. Because the truth is the water environment
Speaker 1: where corals exist. The reason why that water is like
Speaker 1: that amazing clear, beautiful tropical turquoise blue that we all
Speaker 1: love to swim, swim through and see for hundreds of
Speaker 1: feet because there's nothing in it. It's a desert, which
Speaker 1: makes it ideal for the right, right, which makes it
Speaker 1: perfect for that this coral algae relationship, because they can
Speaker 1: make their own nutrients and be able to build build
Speaker 1: these reefs and have really clean clear waters. And when
Speaker 1: we throw pollution in there, it disrupts that that relationship,
Speaker 1: and when we heat the water, it especially disrupts that relationship.
Speaker 1: And the bleaching is literally the coral kicking out the
Speaker 1: zoaks and it turns the coral white. They get their
Speaker 1: color from having these symbiotics algae in there, and so
Speaker 1: when they bleach, they don't necessarily die. The coral does
Speaker 1: not necessarily die right away. Sometimes they can recover, but
Speaker 1: oftentimes they will die. And even if they do recover,
Speaker 1: it can take them several years to regain those symbionts
Speaker 1: and regain enough energy to them be able to reproduce,
Speaker 1: because again, producing those sperm egg bundles takes a long
Speaker 1: a lot of energy. And you know, it's just like
Speaker 1: us if we're sick and we're not healthy, We're not
Speaker 1: going to do the the extra things, you know, we're
Speaker 1: gonna every all the energy we have goes through just
Speaker 1: esic survival and sex is not basic survival, so production
Speaker 1: of sperm and eggs drops or the number of sperm
Speaker 1: you know, sperm and eggs that are produced will go down.
Speaker 1: So all of these things, and climate change, especially UM
Speaker 1: is really really threatening the reefs. The Great Beery Reefs
Speaker 1: off Australia, the largest restructure in the world. UM. We
Speaker 1: just had the worst bleaching on record UM. So it
Speaker 1: was their summer right in February in March, and we're
Speaker 1: seeing rates of severe bleaching that are just off the charts.
Speaker 1: We've never seen it like this before. I mean we're
Speaker 1: talking well over half the reef UM and that's really
Speaker 1: really alarming. You know, some of these colonies are hundreds
Speaker 1: of years old and if they go, it's going to
Speaker 1: be a long time before that, you know, before a
Speaker 1: new coral colony can can take over that role and
Speaker 1: perform all of the benefits that that type of structure
Speaker 1: can provide. Clarify for our listeners, and my understanding is
Speaker 1: even at their growth rate when they're they're broadcast spawning
Speaker 1: something like that would take thousands of years to regrow
Speaker 1: a reef. Oh absolutely, I mean coral colonies are slow.
Speaker 1: These are slow growing. Think of an old growth forest,
Speaker 1: you know, where where your tallest trees are hundreds and
Speaker 1: hundreds of years old. UM. To get that level of
Speaker 1: perplexity takes for for centuries and centuries. And to build
Speaker 1: something as big as a gray faery reef, absolutely, a
Speaker 1: thousands You can drill down and scientists will core down
Speaker 1: to see, you know, colonies that have built and staffed
Speaker 1: up on top of each other over over time, and
Speaker 1: it's thousands and thousands of years. So it's um a slow,
Speaker 1: long process that has worked really really well and has
Speaker 1: allowed them to withstand quite big changes, you know in
Speaker 1: the environment. I mean we we've had big changes in
Speaker 1: the past, but those changes haven't happened so quickly. And
Speaker 1: so the problem with you know, climate change caused by humans,
Speaker 1: caused by us, is that it's happening very very quickly,
Speaker 1: and so the ability for these corals to adapt, um
Speaker 1: seems to be pretty compromised, and we're seeing some pretty
Speaker 1: pretty sad state of affairs. UM. I think there's over
Speaker 1: six hundred species of coral now that are being considered
Speaker 1: for threatened or endangered status UM because of the losses.
Speaker 1: So that's that's a bummer, But there is some good news, um,
Speaker 1: you know, it's I definitely and we can talk about
Speaker 1: that UM for sure, because it's it's not the kind
Speaker 1: of situation where we should throw our hands up and say, oh, well, um,
Speaker 1: it's the bummer that my kids won't get to dive
Speaker 1: on a cool reef, because that's that's not necessarily the case.
Speaker 1: You know, the door is not closed UM with coral
Speaker 1: restoration uh in places where they're actually it's sort of
Speaker 1: like I VS. For corals. They go out when they
Speaker 1: when the corals spawn at night, and they they're collecting
Speaker 1: some of the sperm and eggs and they're bringing them
Speaker 1: back to labs um and and going through a whole
Speaker 1: process that actually increases the fertilization rate. And then they're
Speaker 1: rearing the larvae and then the juvenile corals up to
Speaker 1: sort of a bigger size so that they'll they'll have
Speaker 1: a better chance to survive on the reef and not
Speaker 1: get overgrown by algae or not get eaten by a predator.
Speaker 1: And then they outplant these corals and they're finding that
Speaker 1: they're really successful and some of the ones that they've
Speaker 1: done over the past two to three years, those corals
Speaker 1: now are spawning in the wild, which is great. So
Speaker 1: there's some really neat um examples of coral farming for
Speaker 1: for restoration that are are helping to sort of repopulate
Speaker 1: areas that have been hit hard by by some of
Speaker 1: these events. There's also um a lot more work in
Speaker 1: attention now and fishering management to protect herbivores. So like
Speaker 1: then these are the grazers the cows of the reefs.
Speaker 1: And you know, for the listeners out there who do
Speaker 1: like to eat fish, do not eat parrot fish. That's
Speaker 1: one great thing you can do to help corals is
Speaker 1: encourage folks to leave parrot fish um on the reefs
Speaker 1: where they can be doing their job to eat back
Speaker 1: this algae. And you know, we can talk more extensively.
Speaker 1: There's some great resources out there, but you know, using
Speaker 1: tourism dollars if you want to go to the Caribbean
Speaker 1: or go to the Great Theoryes, support those countries that
Speaker 1: have good management and plates that do abide by certain
Speaker 1: fisheries policies, that do have protected areas that do enforce
Speaker 1: their their pollution and clean water rules so that the
Speaker 1: reefs there are given the best chance they can and
Speaker 1: we have seen that. While we've seen that local management
Speaker 1: can make a difference, it's absolute be a way to
Speaker 1: help corals resist and get through some of these these challenges.
Speaker 1: That said, without addressing climate change, there's no way. So
Speaker 1: we have to deal with climate change. We have to
Speaker 1: support you know, legislators and policies that are really progressive
Speaker 1: at this stage, and there's fantastic proposals out there, there's
Speaker 1: great clean energy technologies. Really its political will at this point,
Speaker 1: and that actually can be a very hopeful thing because
Speaker 1: that means all of us we get together kind of
Speaker 1: like the corals do and synchronize our actions. We can
Speaker 1: actually turn turn down feet and try to change the
Speaker 1: tide on this um. And it's really important that we
Speaker 1: do so. So that I'm trying to think of I
Speaker 1: like that that's a nice boat to put on. It
Speaker 1: isn't like for us to be able to help them
Speaker 1: out so that we can continue to have this ecosystem together.
Speaker 1: We need to sort of learn and how to behave
Speaker 1: like them. Yeah, sink sink up a bit for bigger impact. Another,
Speaker 1: I know, you know, it's always nice to give very
Speaker 1: practical things. Um. Another really important, uh, especially coming into
Speaker 1: summer here in the Northern Hemisphere, that folks can do
Speaker 1: is when you go to the beach, if you are
Speaker 1: swimming or diving in areas around coral reefs, don't use
Speaker 1: sunscreen with oxybenzonate benzonate. Excuse me, oxybenzonate is um oxybenzone.
Speaker 1: I think it's also called They're finding more and more
Speaker 1: that the impacts of sunscreen, especially very sort of shallow
Speaker 1: bays with lots of tourists is significant. And again that's
Speaker 1: a local impact we can all be much more conscious of.
Speaker 1: And if you just google you know, coral safe sunscreen,
Speaker 1: you'll there's you know, tons that come up. Um, this
Speaker 1: is new work that's been done. We just didn't realize
Speaker 1: how sensitive again that that coral's works of these chemical inputs.
Speaker 1: So just be smart about your sun screen choice. That's
Speaker 1: a really simple way, um, to try to be more
Speaker 1: conscious and give give corals a bit of a leg up.
Speaker 1: Cool And is here a particular organization Coral Advocacy group
Speaker 1: that that that that one should follow or even you know,
Speaker 1: contribute to monetarily that can also help. Well, those are great,
Speaker 1: that's a really great question. There there are several really
Speaker 1: excellent groups out there that are doing wonderful work. UM.
Speaker 1: There's a group called REEF which is the Reef Environmental
Speaker 1: and Education Foundation. They do a lot of science but
Speaker 1: also volunteer work, so folks can go check out reef
Speaker 1: dot org. UM there's coral monitoring monitoring networks and groups
Speaker 1: like the Nature Conservancy and others, especially in the field
Speaker 1: of Nature Conservancy in the US Virgin Islands and the
Speaker 1: Nature Conservancy of or to Are do call on on
Speaker 1: volunteers to help UM monitor for bleaching. So if you're
Speaker 1: someone who goes diving or snorkeling or wants to take
Speaker 1: a trip, you can go and report what you've seen
Speaker 1: so that we can help keep track of where bleachings
Speaker 1: occurring and and try to understand those patterns better. So
Speaker 1: I think it's called Coral Reef Watch, and I believe
Speaker 1: it's run UM by Noah, which is the you know,
Speaker 1: the US government's federal arm that studies oceans. But again,
Speaker 1: folks like the Nature Conservancy I know, help train volunteers
Speaker 1: to execute on that program. So those are those are
Speaker 1: some that come to mind that are doing you know,
Speaker 1: direct work with corals. UM. There's other great work by
Speaker 1: UM groups like Moat Marine Lab in Florida that are
Speaker 1: doing some of these UM farming and restoration techniques. So
Speaker 1: if you if you're sort of more towards wanting to
Speaker 1: support UH some of the science behind how we're studying
Speaker 1: and learning, there, they're a great a great place to look.
Speaker 1: There's a lot, but I would say that UM that
Speaker 1: those are the ones that kind of immediately pops pop
Speaker 1: into my head. UM. Oh, there's another there's a wonderful
Speaker 1: initiative by um UH the Weight Foundation called the Blue
Speaker 1: Halo Initiative, and this was initially started by a woman
Speaker 1: named doctor Ayana Johnson and they it's island wide Marine
Speaker 1: policy um in marine sort of management for Caribbean countries.
Speaker 1: At this point, it's in the Caribbean, but it's really
Speaker 1: great because it's it combines education and outreach, it combines
Speaker 1: fisheries management, and it combines sort of typical conservation all
Speaker 1: into one so that these island governments are actually implementing
Speaker 1: a very holistic policy that works to protect their waters.
Speaker 1: But all so you know, support fisher livelihood, but make
Speaker 1: sure that they're they're taking all interest into account. So
Speaker 1: that's another really neat initiative to look into or again
Speaker 1: see where the blue Halo projects are and support going
Speaker 1: to those countries, um for you know, for your vacation,
Speaker 1: because they're ones that you know, um, your your tax,
Speaker 1: your tourism tax is going to two governments that are
Speaker 1: really trying to do the right thing. Um. Trying to
Speaker 1: think if anything else comes to mind, Um, well, if
Speaker 1: any additional ones come up, you can always you shoot
Speaker 1: them to us via email and will include them, uh
Speaker 1: you know on the landing picks for the episode. Yeah,
Speaker 1: there's I think there's. Um. The last thing I'd say
Speaker 1: is there is the Coral Restoration Foundation, which is I
Speaker 1: think just Coral Restoration dot org. And they do some
Speaker 1: really great work as well, um in terms of trying
Speaker 1: to against farm out corald and I think they might
Speaker 1: also have volunteer opportunities, which is it's fun. I mean,
Speaker 1: they're it's neat to get to go and spend your
Speaker 1: vacation helping to grow baby corals or outplant them honor
Speaker 1: reef or ten to ones that are out there. It's
Speaker 1: it's a nice nice way to really feel like you're
Speaker 1: just like going and doing um, you know, tree plantings.
Speaker 1: On Earth Day you can go do coral plantings and
Speaker 1: and help reef to recover cool well. Um, is there
Speaker 1: anything else you want to get out there before we
Speaker 1: close it up here? Um? Um, I don't think so.
Speaker 1: Just for folks to know that, unlike so much sex
Speaker 1: and to see coral spawning is something we can actually
Speaker 1: see pretty easily. Again, it happens in the shallows. You
Speaker 1: just need a mask, you don't even need thin go
Speaker 1: right offshore. There's lots of places in the world that
Speaker 1: are you know, face and easy to get to and
Speaker 1: and you can just swim out with a flashlight water
Speaker 1: waterproof flashlight. Um. And you can watch this. It happens
Speaker 1: right after sunset and it's starting now, I mean from
Speaker 1: now through October and the Caribbean there will be different
Speaker 1: mass spawning events. And if you go online and google them,
Speaker 1: there there are schedules and you can go and and
Speaker 1: watch this happen. And it really is. Um. Not only
Speaker 1: is it magical and sort of mystical and ethereal and
Speaker 1: just how it looks visually, but there's something that I
Speaker 1: find incredibly uplifting and inspiring. And knowing that despite all
Speaker 1: the threats, despite all the negative impacts that we are
Speaker 1: having on these animals, every year, they continue to soldier on.
Speaker 1: These mass spawnings still are happening, and that rhythm of
Speaker 1: nature that has been established for thousands and thousands of
Speaker 1: years continues to hold strong so that the next generation
Speaker 1: can be possible. And you can witness that, and you
Speaker 1: can see all that potential and all that hope floating
Speaker 1: up right before your eyes. And it's um to me,
Speaker 1: It's it's what it keeps me going cool. Well, Sex
Speaker 1: and the Cy is the book. It is currently out
Speaker 1: on hardcover, e book, audio book, and UM. As we've
Speaker 1: stressed a several different times on the podcast on past
Speaker 1: podcast episodes, it's just a delightful, insightful read full of
Speaker 1: just some mind blowing but also entertaining content. We've recommended
Speaker 1: it as as just a perfect bit of summer reading
Speaker 1: for our listeners. Yeah. In fact, we just did our
Speaker 1: summer reading episode a couple of weeks ago, and uh
Speaker 1: we recommended this book Maraw to our listeners. And and
Speaker 1: also I just want to say that I really appreciate
Speaker 1: the work that you put into your prose in this book.
Speaker 1: And just the analogies and similes and metaphors, the kind
Speaker 1: of work that you do there make it so much
Speaker 1: more readable than the hundreds of articles that we read
Speaker 1: on similar topics and really kind of picturesque too. Yeah, oh,
Speaker 1: thank you. I appreciate that, and appreciate so much the
Speaker 1: support you guys have have given for it, and I'm
Speaker 1: I'm just hopeful that your listeners will find it entertaining
Speaker 1: and inspiring and hopefully some really good cocktail party fodder.
Speaker 1: So definitely unfacts around the barbecue, all right. So there
Speaker 1: you have it, a whole lot of coral biology, a
Speaker 1: whole lot of coral sex, if you will, and some
Speaker 1: some sobering but indeed hopefully optimistic information about where we
Speaker 1: are in terms of coral loss and um readjusting pivoting
Speaker 1: if you will, to try and um and and and
Speaker 1: say these species that that do so much for our ecology.
Speaker 1: And one of the things that I really loved about
Speaker 1: this interview is that while we had done research ahead
Speaker 1: of time and prepton, we'd read her book, and we
Speaker 1: were we were ready to have this conversation. You know,
Speaker 1: Mara in just the last week could already looking new
Speaker 1: stuff because the science is moving so fast. So you
Speaker 1: heard it here first, folks, or maybe maybe there are
Speaker 1: some articles that came out of that conference she was mentioning.
Speaker 1: But you know, I'm glad that we were able to
Speaker 1: talk about all these changes with hybridization that scientists are
Speaker 1: realizing about. Indeed, yeah, some some really cool data from
Speaker 1: the book and and and some stuff that has just
Speaker 1: come out in the last couple of weeks. So Okay,
Speaker 1: you out there, maybe you have an experience like Robert
Speaker 1: where he went to Jamaica. Have you been up closing
Speaker 1: personal with coral reefs? Tell us about it based sent
Speaker 1: us your pictures, let us know what you think about
Speaker 1: the coloral bleaching effects that are going on. You can
Speaker 1: do that on social media. We are all over the
Speaker 1: place on social media. Were lousy with social media, as
Speaker 1: Josh Clark likes to say. We're on Facebook, Twitter, Tumbler,
Speaker 1: and Instagram as Blow the Mind. And you can always
Speaker 1: visit us at our home base at stuff to Blow
Speaker 1: your Mind dot com. And I want to throw into
Speaker 1: you know with Facebook, the algorithm is always changing. Uh,
Speaker 1: if you would visit us Blow the Mind on Facebook,
Speaker 1: visit us there. Make sure that you're subscribed, but also
Speaker 1: make sure that you've hit the adjustment so that we
Speaker 1: show up in your fee, because that's going to ensure
Speaker 1: that no matter what changes in the Facebook algorithm, we
Speaker 1: can still get our content to you. Yeah, And basically
Speaker 1: this is so that you can be updated whenever a
Speaker 1: new podcast episode comes out, or we can let you
Speaker 1: know when Robert or I or Joe have recorded a
Speaker 1: video about something related to the show or published an article.
Speaker 1: And if you're fed up with all the social media stuff,
Speaker 1: as one can can be in this day and age,
Speaker 1: there's always email. That's the way to get something directly
Speaker 1: to us, no in between third party, and you can
Speaker 1: reach us via email at blow the Mind at how
Speaker 1: stuff works dot com or more on this and thousands
Speaker 1: of other topics. Is that how stuff works dot com.
Speaker 1: Fou