SciShow Tangents - Coral Reefs

Starting point is 00:00:00 Hello and welcome to SciShow Tangents, the lightly competitive science knowledge showcase. I'm your host Hank Green and joining me this week as always is science expert Sari reilly hello and our resident everyman sam schultz hello i'm just gonna go ahead and assume that they passed the climate bill because otherwise what we could well i shouldn't say because it's possible that they won't but i'm just going to assume yeah hank this is dangerous assuming is dangerous it is very is dangerous. It is very dangerous. We're going to have to record a different intro if they don't. If something goes horribly wrong. But I have to ask you both, what's your favorite part of the climate bill?

Starting point is 00:00:55 Hank, I haven't read any of that. Yeah, this is a horrible question to embarrass us. It's only 700 pages long. Will you tell us some stuff about it? Because I just see and I see some people who are like, one person who's on this podcast who's like, this is monumental. And then other people are saying like, this is such bullshit. Where's the truth?

Starting point is 00:01:14 Where's the truth? Sam, I had a frustrating experience this morning when I listened to New York Times, The Daily. It's a podcast, like our podcast, but not as popular. It was all about this bill that the whole thing was like, this is the big thing. And they talked for what they talked about, what was in the bill for less than two minutes. Yeah.

Starting point is 00:01:34 And then they talked about Joe Manchin's pipeline for more than two minutes. Yeah. I was so frustrated. Like I get it. It's, it's, uh, it sucks that,

Starting point is 00:01:43 uh, a person had to make this all about them but it's not all about them it shouldn't be all about them because there are hundreds thousands of people who worked on the individual provisions in this bill i've been going through it to try and make a video about it there's like a hundred different bills in the bill there are some pieces that take up a pretty sizable chunk but there is a very large chunk of this bill that is like little stuff but like important little stuff things like revitalizing uh urban neighborhoods to make them more walkable like

Starting point is 00:02:16 little stuff like that uh cleaning up ports which is you know tends to be a place that is mostly people who have less live around ports and they uh thus those ports are able to get away with all kinds of doing like polluting things that shorten the lifespans and quality of life of the people who live around there and so there's there's stuff like that uh and there's but my favorite part if you want to know my favorite part it's the it's the methane regulations because almost all of this bill is spending money but the methane regulations are making money because they say hey you built your natural gas infrastructure with a bunch of leaks in it and you're gonna have to fix that or we're gonna

Starting point is 00:02:56 charge you for all the leaks that you're doing and that will incentivize those people to actually fix the infrastructure so it that like this conversion that we did to a lower carbon source of energy which is natural gas which we're going to have to a trend like that's a bridge uh was you know is better for carbon but every bit of that methane that escapes is a really big deal because it is more greenhouse intensive than carbon dioxide now it doesn't last in the atmosphere as long but for the time that it's there, it's more intensive. So, we need to make sure that we don't get it out there, can't leave it in there. And that's like something nobody's talking about. There's also nuclear power money in there.

Starting point is 00:03:35 There's all kinds of funding for research for energy storage and solar panels. It's just a big bill with a lot of stuff in it. It's a lot easier to talk about like the one thing that went wrong than the 85 000 things that went right because there's 85 000 of them the news is so hard now it's hard it's gonna be a fun video though i don't know what to believe anymore so i think my proposal is you just read me the articles and tell me what you think and then i'll know right an asmr live stream of all five or 700 pages of it yeah yeah yeah that's it'll be like my mr beast moment

Starting point is 00:04:10 yes you could live stream the whole thing i wonder how long it would take me to read the 700 page inflation reduction act you'll have something to say about every single freaking sentence i won't shut up about it two years i really like this part look at this you need to do an asmr reading of the whole thing and then an audio commentary track of the reading of it no he wouldn't be able to stop himself sir you know that while he's doing these things um because Yeah, you really can't suggest these things, because I could probably just go ahead and do that. Anyway, that's not the topic of the podcast. Every week here on SciShow Tangents

Starting point is 00:04:50 we get together to try to one-up, amaze, and delight each other with science facts, while also trying to stay on topic. Our panelists are playing for glory and for Hank Bucks, which I will be awarding as we play, and at the end of the episode, one of them will be crowned the winner. Now, as always, we introduce this week's topic with the traditional science poem

Starting point is 00:05:05 this week from Sam. I have a question. I'll keep it brief. Tell me, please, what is a coral reef? It goes moo and is full of beef? No, that's a cow. Not coral reef. A giant thing with trunk and leaf? No,

Starting point is 00:05:21 that's a tree. Not coral reef. It's conducted by Beethoven and has a light motif? No, that's a tree. Not coral reef. It's conducted by Beethoven and has a light motif? No, that's classical music. Not coral reef. It's got dusty tumbleweeds and an old sheriff? No, that's an old wild west town. Not a coral reef. Oh, for heaven's sake and also good grief,

Starting point is 00:05:42 it's clear to me that you don't know what's a reef. So stay tuned to this podcast, chief, because Hank's about to ask, Sari, what's a coral reef? Sari, what's a coral reef? So I'll start with what a coral is. A coral is a type of cnidarian. We did a whole episodes about them. They are little polyps with tentacles.

Starting point is 00:06:04 And there are several different kinds of corals, but the two main groups of them are the stony corals, which excrete calcium carbonate or other forms of it, like calcite, and create rocky structures around them. And then there are another group of corals that are soft corals that just kind of anchor themselves. Sometimes they create a hard skeleton, like a tube, but mostly they branch and they float around and they're more soft. And so coral reefs are specifically created by the stony corals, and they're just when stony corals grow and grow and grow and build upon themselves over thousands or tens of thousands or millions of years

Starting point is 00:06:55 and combine with other organisms from fish to mollusks to crustaceans to algae, a lot of algae. And they make a whole reef ecosystem. So the etymology of reef specifically is just a ridge underwater. And it probably came from Old Norse riff, which meant ridge in the sea or reef in a sail. And it means like a rib. So if you have this bumpy reef. Those guys are always talking about the ocean

Starting point is 00:07:25 huh yeah and so they're like oh there's this bumpy bit that's a reef and then later on we formed the compound word coral i don't think it's compound the phrase coral reef um and the first time that was used was in 1745 so it took a while from us using reef as reef and then associating coral with it sure because we had to figure out what coral was i guess we probably knew what coral was we kind of did we were very confused about coral for a very long time i'm still confused about coral i think of any creature it's pretty strange coral is like the one that i cannot wrap my head around i look at pictures of it and i'm just like, what are you doing? It's just, well, you got to imagine.

Starting point is 00:08:07 Here, I hope I can fix you right now. Okay, great. The coral that you see, that's not the coral. Right. That's the coral's little house. That's like an anthill that they built. Right. And then they live in it.

Starting point is 00:08:19 And then, but they build a little house. Do they ever come out? Yeah. If you get real close, you can see them. Oh, okay. They look like, you know, have you ever seen a barnacle, like, do its tongue out? Yeah. That's what they are like.

Starting point is 00:08:30 Less long and more plentiful. Yeah, they're like little anemones. Yeah, more like an anemone. Okay. Oh, that did fix me. Thank you. That was the last problem I had to solve in my life, so. Otherwise, I might be a fraud.

Starting point is 00:08:43 If I can't help sam understand coral maybe i just need to give up you are not the only one who is confused about coral sam humans throughout history have been confused about coral uh what what wild shit did aristotle say aristotle yep aristotle's pupil actually aristotle didn't have a lot of thoughts about it i guess but theophrastus who is aristotle's pupil described red coral in his book on stones so he thought it was rock but then he also described it in his book on plants uh and so he was like still i can't decide what it is and so i'm gonna sneak it into my book on rock and plant and hope no one notices because it's maybe a little bit of both he was kind you know he was going in the right direction ish and then pliny the elder another classic guy

Starting point is 00:09:31 uh yeah he he said well they're not animals or plants but they're a third thing and then he didn't go on to specify what the third thing is he was like, it's not an animal or a plant. So he was also wrong because it's an animal. And then more people just kept guessing. A Babylonian scholar referred to it as a type of tree.

Starting point is 00:09:56 There was like a lot of it is a tree, so that went in the plant direction. And then a Persian polymath named Al Biruni classified both sponges and corals as animals because they respond to touch. So he was on the right track around 1048. And then in the 18th century, we actually had microscopes and could look at corals and then saw the cells and were like ah yes that is in fact an animal i also what

Starting point is 00:10:26 it seems weird to me is just picturing theophrastus diving into the water and holding his breath and like trying to get some air around his eyes to like look at coral while it's still under the water yeah he probably didn't do any of that he probably got some guy to bring him some and he was like that looks like a rock or a plant underwater stroke in his beard yeah what could this be you know pliny wasn't always old at one point he i mean he was the elder of the the plinies but like i'd like to picture him as like a 22 year old just just fresh-eyed bushy-tailed trying thinking of like what's my legacy gonna be oh they're gonna make fun of me on podcasts forever i'm just gonna say a bunch of stuff was the other plenty of son

Starting point is 00:11:11 or his brother he was a nephew plenty of the younger was the nephew and plenty of the elder was was the uncle who helped raise and educate him unky pl Pliny. Unky? No, no, that's kind of cute. All right. Before we get any more lost, we're going to play our game for the day. Do you guys want to play a Tangents Coral Truth or Fail? Yes. That's great news.

Starting point is 00:11:39 Corals are contending with a lot at this very moment. We've got warming waters, diseases that have reduced their numbers overall. Scientists have been studying corals to see how we can better protect them from ourselves and the rest of the world, coming up with strategies that might sound strange but could yet prove useful in their protection. The following are three curious coral contraptions designed with their futures in mind but only one of them is real is it story number one sexual reproduction is tough when you don't move anywhere and corals

Starting point is 00:12:11 rely on a number of signals to align the release of eggs and sperm across different colonies to spur the birth of more core to spur the birth to spur the birth of more corals in a way that still preserves this coordination, scientists designed a blanket, I know, it wasn't easy, with slow-dissolving fibers that also hold chemical cues to stimulate the corals into reproduction. So, we've got a... A sex blankie? A sex blankie for the corals into reproduction so we've got a a sex blankie a sex blankie okay could be story number two though that one might be a fake uh story number two is that reefs are usually bustling with activity of many animals but as reefs die they become less populated so to see if they could inject some life back into a dying reef, scientists tried to lure fish towards an area by recording the sound of a healthy reef

Starting point is 00:13:09 and then playing it on speakers set up around the dead coral. Or, or it could be story number three. While fish can enhance the ecology of coral reefs, there are also fish that like to eat corals, like the butterfly fish, which makes its meals out of coral polyps. So to protect smaller reefs, scientists have set up the aquatic equivalent of scarecrows, mounting plastic decoy moray eels along the perimeter to scare off the butterflyfish. So what is it? Is it story number one, weaving a coral sex blanket? Story number two, staging a healthy coral concert to attract the fish?

Starting point is 00:13:44 Or story number three, scaring off concert to attract the fish or story number three scaring off predatory fish with fake eels why would attracting fish help the coral would it i think just that there was like reef infrastructure there and so they were like even though the reef isn't like super vibrant and living it'd still be a good place for fish to come hang out i guess but it might also be that like the fish would along polyps on them, and those polyps could recolonize or something. I don't know. That makes sense. My guess is that it has something to do also with fish poop, like just getting a bunch of nitrogen in the water.

Starting point is 00:14:18 Once fish start doing that, then algae can grow. And then the coral polyps have little friends because they they can't live by themselves they live symbiotically with a little dino flagellate inside them so you need all this stuff to even make coral be able to grow and maybe having fish there helps seed all that stuff okay sex blanket sex blanket that one sounds That one sounds pretty feasible to me. Yeah. You don't think so? It sounds small.

Starting point is 00:14:47 How do you get it? Is it like a humungo sex blanket or do you just say like these corals need the boost? I think that they all dissolve at the same rate. So you can put more than one sex blanket down. Got it. And they all, and if you only do it on the same day, they all trigger the release of the sex. Okay. You're like, I'm going to make this coral horny and I'm going to make this one

Starting point is 00:15:05 a little bit neighbor coral, a little horny too. Yeah, you got to... All right, we're going to pick who the horny corals are going to be. We've got... Suggestions? Yeah.

Starting point is 00:15:19 The most eligible corals of all. Timothy, do you have any corals that you want to be particularly sexy today? Is Timothy a man or a coral timothy's that guy he's one of the research assistants okay okay i get it timothy is attracted to the corals okay now we're getting to the bottom of it i see the last one you can put those plastic owls up all day long, and that's not going to scare any birds away. And a parrotfish. Yeah, but fish are fish. Fish have been around the block.

Starting point is 00:15:51 Fish have been around longer than we've been here. So they're going to know a fake fish. Fish have a finely honed, uncanny valley since I've been here. When would a fish ever run into a fake fish, though? When does a bird run into a fake bird? And they still know. Fish fall for fake worms all the time, though though so i feel like they might be kind of dumb that's a good point they see like oh this thing is wiggly yeah yum yum yum you don't think a fish

Starting point is 00:16:16 could fall for a fake fish i have a i have news about all of the fishing yeah. Yeah, okay. But I don't know if it would be scared of... Fish could never fall for a fake fly. That's just unacceptable. Fish are geniuses. Okay, I miscalculated, I guess. You'd have to clean your fake eels, though. I feel like if they got too overgrown... Then grimy. Grimy, then they'd be like,

Starting point is 00:16:39 that's just another rock. What a lazy-looking eel. He's not gonna come after me. He can't even clean himself up. How do you keep your fake eel clean? Timothy goes down and scrubs it with a sponge just yeah timothy's timothy's scrubbing i think you should electrify them like they're electric moray eels and then they zap off their algae every once in a while let's put a nine volt battery in there yeah that could happen i think i've watched enough cartoons i know a nine volt battery is not very

Starting point is 00:17:06 much but i've watched enough cartoons that i'm like that's just gonna kill all the fish in the reef it's gonna and the electricity is gonna shoot out and then aquaman will have to come in and save the day or something like that and arrest timothy yeah for his crimes against nature i'm feeling sex blanket i just like the way it sounds okay okay sam's in for sex blanket i'm gonna think i think it's the coral concerts i feel like i've heard something about this before i might have been misled but i think it's like if you pretend that the coral are there the fish are there then others are like there's a party happening we We'll come. All right. Well, in the case of sex blankets, nothing like that has ever been done or true. Well, it could be now, though.

Starting point is 00:17:53 The only true part of that is that spawning coral reefs do require a lot of synchronization. Stony corals sexually reproduce by releasing a bunch of eggs and sperm into the water around them. And it's up to the eggs and sperm to find each other once they're in the water so figuring out when to release that stuff requires uh colonies some of which might be pretty far from each other to coordinate using various signals around them like the temperature the length of day and the time of sunset so they're being careful those corals they're paying attention but when it comes to uh coral concerts scientists had previously recorded sounds around the great barrier reef and found that when they played those recordings for juvenile fish the sounds taken from areas after they had begun degrading

Starting point is 00:18:35 were less appealing to the sounds taken before degradation when the reef still seemed to be healthy so they decided to see if they could use the sound of a healthy reef by setting up 33 patches of coral rubble in 2017. They divided those patches into three groups of 11 patches each. One group stayed as is, while the other two were surrounded by loudspeakers. And in one of those groups, the loudspeakers played recordings at night taken at a healthy reef. The researchers described the audio as like a loud crackly sound, like frying bacon. And this is the sound of snapping shrimp claws. There's also various grunts and whooping sounds which come from fish in the reef. The third group of speakers had speakers, but no audio playing, just to make sure that it wasn't the speakers that were attracting the animals. So,

Starting point is 00:19:22 the researchers studied the patches for 40 days, and they found that at the end of that time, there were twice as many juvenile fish in the patches with a healthy reef soundscape and the diversity of the species was also higher. Now that does suggest that sounds might be one way to lure fish to a reef and help build up activity there. But the researchers frame this as just one tool of many that will likely need to be combined

Starting point is 00:19:43 to help us make reefs happier and healthier. What if it had been the speakers? What would that imply? Gotta just go to RadioShack. Yeah. And just sprinkle them in the ocean. Just start dumping them in the ocean, yeah. Yeah.

Starting point is 00:19:58 I mean, Amazon's basically giving away Alexa. That's true. So just snap them up. Amazon, just back that truck into the ocean. And as for the fake moray eels, in a 2015 paper, researchers described constructing fake moray eels by printing out two life-sized photos and then gluing them together. No, laminating them. Oh, no. And putting them on strings so they could move them like a puppet.

Starting point is 00:20:20 Oh, no. And they also constructed a fake coral reef around the eel. like a puppet oh and they also constructed a fake coral reef around the eel and the fake eel reef setup was so that they could study how eels team up with grouper fish to lure out other fish to eat i don't know how they did that specifically but it sounds like fun with a laminated life size that's the laziest way to make that eel you could you could make it 3d you could put a tube down there maybe or like fill a sock a tube or a sock would be far better yeah just paint the sock so congratulations sari on your point that gives you a lead as we head in to uh our short break and then we'll be back for the Fact Off.

Starting point is 00:21:21 Welcome back, everybody. Now it's time for the Fact Off. Our panelists have each brought in science facts to present to me in an attempt to blow my mind. And after they have presented their facts, I will judge them and award Hank Bucks any way I see fit. But to decide who goes first, I have a trivia question for you. So as we talked about in our game, many coral species reproduce sexually through a process called broadcast spawning and those broadcast spawners pack their eggs and sperm together in bundles and then they gather together on surfaces increasing the odds that fertilization will happen well in 2016 researchers reported the results of an effort

Starting point is 00:21:56 to count the amount of coral egg and sperm released in one of these spawning events using a soft plastic bottle to collect gamete bundles after they are released in one coral species the researchers counted the average an average of 26.67 eggs per bundle and i'm going to ask you what was the average number of sperm they counted per bundle it's gotta be more right like i would human, eggs to sperm, any other animal. Exponentially more. Yeah. How many sperms does a human have? I don't know.

Starting point is 00:22:32 I don't either. Okay, I'm gonna go first. 20,000. Oh. Oh. 20,000 sperm per bundle. I was gonna say 270,000. Oh. Well, the answer is going to say 270,000. Oh.

Starting point is 00:22:45 Well, the answer is 9,330,000. So. 9 million? Lots. And now you know. So congratulations, Sam. That means you get to decide who goes first. Thank you.

Starting point is 00:22:59 I'm going to go first. Okay. Surely by now, I think we briefly did, in in fact talk about how most coral get a majority of their food via their symbiotic relationship with zooxanthellae is that how you say that word yep yes you got it that's a fun name i'm gonna name my my child zooxanthellae little they're little single-celled fellows capable of photosynthesis, which also give coral its wild colors. While coral polyps can, in some cases, eat stuff like detritus and even little fish, corals with zooxanthellae get up to 90% of their food by sharing the fruits of photosynthesis.

Starting point is 00:23:37 In 2016, scientists pointed lasers at coral and figured out that coral are even structured to especially scatter light across as much of their surface as possible so that all the colony can get a little light snack. And coral will even shift their tissues around to scatter light as effectively as possible as the light changes. And while this research was done on the familiar, fun-colored shallow water coral that everyone loves, this also applies to the paler, less popular branch of the coral family tree, deep water coral. So these coral live, as the name implies, in deep water. And one problem with deep water is that not too much light gets down there. So deep coral aren't as vivacious as shallow coral, growing either all on their own or in comparatively small colonies and lacking the bright colors. Because what good is photosynthesizing zooxanthellae if there's no

Starting point is 00:24:24 light to photosynthesize? Butanthellae if there's no light to photosynthesize? But their lack of color is a bit misleading because while some deep coral don't have zooxanthellae, I think, and basically none of them have enough to turn nice colors, some deep coral do have zooxanthellae. They just keep them inside of them, and they have just as many tricks to spread the sunlight as their shallow water cousins do. So corals aren't just pretty in ways we can see. They also contain fluorescent pigments that glow under UV light. And deep water corals have these too.

Starting point is 00:24:53 Some of this fluorescence is used to lower in food. But scientists have thought for a long time that deep coral fluorescence might be playing a part in photosynthesis. So in 2022, I guess we finally had cameras that were small enough to shove into a coral because that's what scientists did. And they discovered that deep coral, in this case, chalice coral, have chambers of fluorescent cells that absorb the blue-green wavelengths of light that make their way into the deep ocean and re-admit that light as orange-red light, which is much rarer on the ocean floor but better at getting like deeper into the coral's tissue so using this trick deep sea coral seem to be able to get their

Starting point is 00:25:32 zooxanthellae friends about 50 percent more of that good good orange light food and i guess the lesson of this is while shallow water coral get all the attention for their flashy exteriors deep coral is just as beautiful on the inside so sometimes these corals don't need zooxanthellae at all and they can sort of like make their way down deep but sometimes they still do have this mutualism from what some articles said deep coral eat stuff and do not photosynthesize but i think this might be challenging that but i couldn't quite get like yeah because that's what that's what I understood as well. Yeah, I think that this is making them rethink how they get food instead of being like, no, couldn't possibly.

Starting point is 00:26:10 Wikipedia still says that deep coral do not have zooxanthellae, but what do they know? As long as it got through peer review, it might be time to make an update to the Wikipedia page on deep coral. All right, Sari, what do you got for me? to the Wikipedia page on deep coral. All right, Sari, what do you got for me? Pistol shrimp, also known as snapping shrimp, are one of the more internet-famous residents of coral reefs, and we talked about them in the soundscapes.

Starting point is 00:26:32 They live in nooks and crannies and have one relatively giant snapping claw, which is where they get their name. They can clamp it shut so powerfully that a cavitation bubble collapses, a huge pop echoes underwater, and they shoot a water jet to stun or kill their prey. It's pretty dang cool, but I would argue that there's something even

Starting point is 00:26:51 weirder about the Synalpheus genus of pistol shrimp, their complex social behaviors. A typical colony of Synalpheus regalis shrimp lives within coral reefs inside the hollows of sea sponges. And instead of just one or two shrimp living side by side, there could be hundreds of them crawling around. Somewhere in those masses, you'll find one large female shrimp whose body is full of eggs and whose snapping claw maybe isn't as bulky because she doesn't need to defend herself. to defend herself. She's the shrimp queen, which sounds just like ants or bees or termites or naked mole rats because it basically is as far as we can tell. The other S. regalis shrimp have various roles in the colony from workers who care for the future generations, soldiers that defend the sponge from any predators with their snapping claws, or a male that impregnates the queen. And instead of all fighting each other to pass on their genes, it seems like reproduction in the non-queen females

Starting point is 00:27:49 is repressed somehow and everyone gets along just swimmingly. There are about six or seven other species of pistol shrimp in this genus that show the same kinds of social behavior to varying degrees. Some colonies have multiple queens or battle for the position and more average snapping claw sizes to facilitate that conflict. And almost all of the research, starting with a paper in Nature in June 1996, is led by one marine biologist named J. Emmett Duffy and his colleagues. And the most recent study I could find was published in March 2018, where 353 egg-bearing females from 221 colonies of six different species of shrimp were compared to see how their body plans varied. But there's a lot we don't know because studying these shrimp colonies is relatively recent in the last couple decades. And we have so many questions about how their social structures form and get enforced and how the juveniles grow up because we've been studying bees and ants and stuff a lot longer.

Starting point is 00:28:45 And we can only do that as long as coral reefs exist to house them. And so there's so much life in the ocean. Who knows what other weird mysteries are hiding in the nooks and crannies of coral reefs. If anybody seems like ants, it's shrimps. That makes total sense to me. Sam's on board board whereas i'm like no unacceptable that's not how evolution works how do you pick one one matriarch and there's

Starting point is 00:29:13 other females i imagine do they also get eggs no i don't think they don't get eggs in the colonies sometimes like some some of the social shrimp have like some competitions still but mostly uh like in this species in s regalis it's one big big honking queen that has all the eggs i guess do they protect her do they have to keep her safe yeah so the the i think the workers are a mix of female and male but the soldiers are mostly male and they've got really big strong snapping claws and so they they stand century around her uh and if anything tries to come at the sponge what the hell the sponge holes they snap them away all right that's real weird is she uh and there's one there's one but sometimes more than

Starting point is 00:30:04 one per colony yes those little guys kind of stick together this is nice i like this but it's weird that they stick together it's like they didn't it's not really how it tends to work and somehow they did it evolutionarily they didn't just decide like like oh let's hunt together it's like no we're gonna live in this sponge together and all care for each other very deeply yeah which i guess is how ants work you know so i guess that's not that weird in as much as ants are very weird like if that's weird bees are also weird yes i think which are they are what's weird and surprising is this is the first ocean creature we found that does it

Starting point is 00:30:43 so everything else has happened on land the point of the elder should have taken his little nephew down there and swam around and figured that out for us thousands of years ago yeah all right well i'm gonna i i have to give it to sari because i think it's weird and she already came in with one point yeah um though the fact that we got a fact so good that we might have to correct Wikipedia is also very good, Sam. And that means that Sari is the winner of the episode. And it also means that it is time to ask the science couch

Starting point is 00:31:15 where we've got some listener questions for our finely honed couch of scientific minds. At Cammie J Boy asks, do artificial reefs actually help? Yes. They must if we put some boom boxes down there and play them pistol strip noises yeah we actually just did a side show on this uh and i was surprised by one of the ways that uh artificial constructions can help fish which is that it prevents trawling so like the illegal fishing that trawls the bottom if you put enough like heavy stuff down there if it's like jagged it will catch the nets

Starting point is 00:31:50 and the the the fisher people will not be able to do that thing anymore which is why oftentimes you have really big fish around uh sunken shipwrecks because they can't get caught by the big nets because you can't trawl a net over a big shipwreck anyway that's what i got from a sideshow episode that we just did well that's on my list too yeah reducing trawling um like we talked about giving more space for fish to populate the structures especially fish that need hidey holes to feel safe reproducing. Though there's an asterisk on that. To feel safe reproducing.

Starting point is 00:32:32 So you're saying like a little- A little sex dungeon. A little lover's nest. Okay, a little sex dungeon. I shouldn't let you say it. That was nice. Lover's nest. But there's some research trying to figure out whether that actually increases fish populations over time or if it just causes fish to gather and become more dense from across the ocean.

Starting point is 00:32:56 And that's kind of a hard thing to study because it is notoriously difficult to estimate populations across the ocean because it's so vast and you can't just like drive a submarine and count and the other pro is knowing that humans like to look at coral reefs both for research and for pleasure to observe the sex dungeons artificial reefs can help reduce the pressure on natural reefs. If people just, tourists want to come down, see some fish, you can do that in an artificial reef and it can be less disturbed by that traffic and alleviate some of the pressure on the natural reef. So people leave it alone, it can flourish and people can still have the vacation of their dreams. One of the cons of it is this idea that we were kind of discussing in our debates with the with the Torf, which is that if fish come to an artificial reef, what happens to the coral polyps?

Starting point is 00:33:59 Like, will the coral polyps repopulate? And that is a big, long-standing question. For example, one paper studied maybe the oldest artificial reef because it was an accidental artificial reef. And researchers compared that to a nearby natural reef, and the artificial reef had a lot less biodiversity. There was different coral species dominating, fewer species overall, and had less interspecies interactions of like corals, anemones, algae, and whatnot. Yeah. I mean, it's never gonna... Reefs are just so complex and overlapping and changing. And also, I remember stories of like, I i don't know this is definitely a thing

Starting point is 00:34:46 where in florida they just were like well if we just dump the tires into the water then like it'll be like a reef and then they dump the tires into the water they did this they dumped the tires in the water and then it was like oh the animals don't like that because it's a bunch of rubber yeah which has a bunch of like toxic chemicals in it and that turned to be a bad idea and probably if your head went from we have a tire problem and we have a reef problem and i know the solution to the reef problem and the tire problem tire reefs that's maybe a little too convenient yeah gotta watch out for that yeah don't just throw your garbage in the ocean and be like, it's a reef. It's a reef.

Starting point is 00:35:27 You can't disguise that. The fish know. They can tell when a moray eel is made of laminated plastic. Yeah. Just like throwing bottles in there. Look, it's a bottle. It's just a rock. It's basically a rock.

Starting point is 00:35:39 Yeah. Here you go, hermit crab. Here's your new butt shell. Thank you, Zeri. If you want to ask the science couch your question you can follow us on twitter at scishow tangents where we'll tweet out topics for upcoming episodes every week or you can join the scishow tangents patreon and get access to our discord and ask us there thank you to ike on discord at amanda728 and everybody else who asked us your questions for this episode if you like this show and you want to help us out it's real

Starting point is 00:36:04 easy to do that. First, you can go to patreon.com slash scishowtangents and become a patron. You get access to things like our newsletter. We got bonus episodes that we do. We got all kinds of weird stuff there. Second, you can leave us a review wherever you listen. That helps us know what you like about the show

Starting point is 00:36:17 and tell other people. People will see it and they'll be like, ah, I should watch that show. And finally, if you want to show your love for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. And I've been Sam Schultz.

Starting point is 00:36:32 SciShow Tangents is created by all of us and produced by Sam Schultz. Our editor is Seth Glicksman. Our story editor is Alex Billow. Our social media organizer is Julia Buzz Bizzio. Our editorial assistant is Deboki Chakravarti. Our sound design is by Joseph Tuna-Medish. Our executive producers are Caitlin Hoffmeister and me, Hank Green. And we couldn't make any of this without

Starting point is 00:36:51 our patrons on Patreon. Thank you, and remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. Most corals have what's known as a blind gut, where the polyps use one opening to both suck in food and poop out waste. But the species, Leptoceres fragilis, doesn't just have a mouth butt. It has a bunch of microscopic pores in its digestive system that help filter out food and squish out water from its body.

Starting point is 00:37:37 So, in a way, this reef-building coral is covered in secret buttholes. We just have to remember that their poop isn't as bad as ours. And they can't taste stuff. I feel like I've got to remind myself of that too, right? Because you can't be pooping and eating at the same mouth and be like a gourmet. No, and have like a strong palate. Yeah, you're right. Ratatouille could not have a mouth and a butt in the same space.

Starting point is 00:38:03 Ratatouille would never. That would be the most tragic Pixar movie of all. Like a jellyfish trying to be jelly-tooey? Gel-to-tooey. Oh, yeah. It's just like the guy with his hat on, and he's just constantly being stung. You can't even taste this, you monster.

Starting point is 00:38:21 Ow, ow, ow. This bargain is not worthwhile. Ow, ow, ow. This bargain is not worthwhile. But the food's delicious. Food is delicious.

SciShow Tangents - Coral Reefs

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