Fish Pee: The Coral Reef Superfood

Fish Pee: The Coral Reef Superfood


The ocean is full of mysterious deep-sea life,
sunken historical artifacts … and a whole lot of pee. I’m not just talking about those of you
who think the ocean is his personal port-a-potty. There are millions of animals that live, eat,
and make lots of waste in there. It might sound kind of gross, but a recent
study in Nature Communications showed just how much the nutrients in fish pee help keep
coral reefs healthy. Coral reefs get plenty of energy from the
sun, but nutrients – like compounds rich in nitrogen and phosphorus – are harder
to come by. Fish are like mobile nutrient reservoirs – storing
them in their bodies, or spreading them around. See, fish excrete waste through their gills,
pee, and poop, creating a delicious nitrogen and phosphorous bath for the reef! So a team, led by a researcher from the University
of Washington, wanted to study how fishing affects the nutrients in 43 Caribbean reefs. Specifically, they analyzed around 73,000
fish, representing 143 species, to learn how the fish excretions changed the chemistry
of a sample of ocean water. Using statistical models, they estimated that
heavily-fished coral reefs had around half the measured nutrients of well-protected areas. And the key to a healthy cycle of nutrients? Balance. Just like a company needs the right mix of
employees, a coral reef needs the right mix of fish, because different fish excrete different
amounts and kinds of waste. Some smaller fish, for example, have higher
metabolisms and excrete nitrogen faster. Hungry predators like groupers and barracuda,
on the other hand, store more nutrients and pee out more phosphorus thanks to the food
they eat. Unfortunately, these big fish also happen
to be very popular with fishermen. That’s bad news for coral ecosystems, because
they’re losing a lot of nutritious waste. Conservation efforts usually focus on maintaining
numbers of different species – and that’s still important. But these reefs also need the right balance
of fish: big fish, small fish, predators, and prey. According to these researchers, if we really
want to protect coral reefs, we need to consider how all these organisms interact and share
nutrients. Even – and especially – through their
pee. But, you know what else is in seawater, and
soil, and your body? Viruses! There might be more viruses on Earth than
there are stars in the observable universe, and we think they can infect every known lifeform. Bacteria … humans … nothing is safe. We know a lot about a few viruses, mostly
the ones that infect humans. But, now, thanks to some powerful computing
and a tool called CRISPR, the global scope of viruses is becoming clearer than ever before. A research team at the US Department of Energy
analyzed over five trillion DNA bases – that’s five terabases – looking for new viral genes. They took 3000 DNA samples from around the
world: from seawater to soil, and hot springs to the human body. And they combed through those samples using
software that recognized viral DNA sequences. Viral genes could be anywhere in those terabases
– usually embedded in the DNA of some infected organism. After years of searching and improving their
software, we now know of around 16 times more viral genes than we used to! Using those genes, the researchers wanted
to figure out which viruses infect which species – mostly focusing on bacteria hosts. So, they used CRISPR. Recently, CRISPR’s been hitting the headlines
as a revolutionary gene-editing tool. But in the wild, bacteria use CRISPR to defend
themselves against their viral enemies: bacteriophages. Whenever they defeat a virus, the bacteria
snip out a gene fragment and store it in a special part of their DNA called a CRISPR
locus. Like a row of “most-wanted” posters, CRISPR
helps them find and destroy bacteriophages if they return. The team of researchers compared these “most-wanted”
posters to their viral database, and found nearly 10,000 new matches. But what’s the point of knowing which viruses
can affect which bacteria? Turns out, we have our own uses for bacteriophages. A couple types are used in FDA-approved treatments
for meat and cheese, keeping bacteria at bay so the food is safe to eat. Others can screen for bacterial infections
like the deadly MRSA. Or these bacteriophages could eventually be
used as phage therapy, instead of antibiotics: to target, infect, and kill certain harmful
bacteria without destroying our friendly microbes. Not to mention, with a huge viral database,
it might be easier to fight off a new virus that infects humans – especially if we’ve
seen something like it infecting other species. Thinking beyond human health, bacteria are
really important for global nutrient cycles – kind of like the fish pee in coral reefs,
but everywhere! And viruses that infect these bacteria could
have a major influence on these cycles, but we barely know anything about them right now. So these researchers are working on expanding
their database, and creating an open resource for scientists worldwide. With a catalogue of genes that encode nearly
3 million new viral proteins, they’ve made a strong head start! Thanks for watching this episode of SciShow
News, which was brought to you by our patrons on Patreon. Thank you if you are one of those people. If you want to help support this show so we
can keep make stuff like this, you can go to patreon.com/scishow. And if you just wanna keep getting smarter
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100 thoughts on “Fish Pee: The Coral Reef Superfood

  1. "over five trillion bases – that's five terabases"
    I like the mild implication that "trillion" is more obscure than "tera"

  2. But are there viruses that kill viruses? And I know they're categorically not actually living things due to a couple technicalities, but are there?

  3. Heyg scishow, is our poo good for plants? Or does it just spread desiases? e.g.: could you take a scoop of your septic tank and pour it on plants?

  4. This is why people need to go vegetarian or vegan so the world can get back into balance. I feel so bad for Mother Nature .

  5. You know what I want to see? I want to know different voices to re say what someone said. Like if you repeat someone who was being annoying you use a high pitched voice where as dumb is deeper and laughing while talking almost.

  6. there are a lot of people that think that the world is getting heavier. my mother is one of those people. i have reason to believe that the world is either not changing in weight or is in fact losing weight. could you please do a video on this subject so my mom can stop thinking that the world will get to heavy and fall out of the solar system.

  7. Coral reefs are dying.. We can totally blame this on fish now, they're not peeing enough!

    Now, how do you get a fish to drink more water? The Coral depends on this solution

  8. "Reefs need all the right fish:
    big fish, small fish, predators and prey.
    Quit eating dishes of big fish.
    Save a coral reef today." ?

  9. I find it funny how "a company needs a balanced mix of employees" is an understandable analogy for the balance in nature. I'm sure it used to be the other way around, where concepts from nature – which everybody knew about – was used to explain things in commerce and industry.

  10. That makes me wonder if it's possible to identify the kind of fish to expect to find in a location from the coral. Maybe a small table for divers to refer to when trying to identify if potentially dangerous predatory fish are in their location.

  11. "Statistical Models"?

    Sounds like a theory is being supported by sophisticated conjecture. That isn't science, that's pseudo science.

    I'm not saying the "conclusions" are wrong, I'm just saying this isn't proper science.

  12. Thank you for getting rid of that awful female host. Awesome Scishow, you listen to the vast majority of your subscribers.

  13. I'm no public speaker, and I'm sure the producers know what they're doing with this show, but isn't the number one rule of giving a presentation "DO NOT read your slides out loud word for word"?

  14. Could you do a video about why parts of our body get like a shocking feeling after laying pressure against them? I get this and it's so sensitive.

  15. Whales shit about 2 tons of crap ( the size of a moving van) and pee about 500 gallons per day……..You don't want to be around when they do……

  16. "…like groupers and barracuda…" just filled with tech, Hank. Grouper is a model of Nexus 7 (the 2012 edition with only Wi-Fi; I own one) and Seagate is famous for their Barracuda brand hard disks.

    Just sayin'

  17. ….this was basically my undergrad research project…except with urchins instead of fish, and algae instead of coral….ok

  18. When you're saying there might be more viruses on Earth than stars in the observable universe you are talking about single virus… "particles" or w/e you want to call it, right? Because if that's virus species I'm outta here…

  19. what are the characteristics of viral DNA that allows us to differentiate from other DNA samples? Is it the fact that they encode viral proteins? What if those proteins have been embedded in other organisms through millions of years of evolution and are not sitting as inactive genes without a promoter , do they account for that?

  20. I think that it'd be a cool idea to keep track of all the SciShow videos that reference CRISPR over the next or two and put them in a playlist so we can see all the different experiments and/or breakthroughs it's been used in.

  21. I wonder if a fish would ever intentionally hold its pee/poo, in favor of going or not going in a specific area. I don't mean as defense or because of some magical thing that is in it from a specific species. I just mean simply like how humans will delay going to the bathroom, ONLY because they have to go TO a bathroom, where as a fish can just go instantly since their entire living environment is also their bathroom and they don't have to clean up after words because the water washes everything away.

    This isn't really a serious inquiry, it's more of a funny thing to imagine if fish held their waste in, as pure inconvenience to themselves. I don't think it would even be possible to really test this, since you would have to know if the fish was consciously choosing to delay going to the restroom, because it was worried about what went on that day or that they may scare off their friends by going in front of them publicly. Hahaha.

  22. Phage therapy sounds like more "Let's release this organism in the ecosystem to it'll do x. Oh no! It's not doing x and now it's ruining everything and we can't fix it!" That old man-fixes-wild scenario.

  23. Corals actually cannot use nitrogen and phosphorus, they actually react negatively to it and it is highly toxic to corals. Corals are not pants they are animals that rely on their zooxanthellae, the zooxanthellae photosynthesis the sun into energy and give some energy to the coral polyp itself as trade for giving in its tissue, the zooxanthellae will die in concentrations of phosphorus above 1 ppm and nitrogen which is usually in nitrate above 80ppm, Corals need calcium, magnesium, alk, and a handful of trace elements to create their skeletons and expand/grow.

  24. Now that the tiny little (relatively speaking) Human Genome Project is complete let's stop playing at being genetic researchers and begin the real (again relatively speaking) Terran Species Catalogue Census and Genome Project, let's see just how deep the rabbit hole is.

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