Instant Genius - Why this tiny organism is essential for the health of the planet

Episode Date: June 11, 2026

Although it often goes unnoticed, plankton is the most abundant form of life in Earth’s oceans, making up 95 per cent of all oceanic biomass. These tiny organisms are responsible for generating around half of the planet’s oxygen, play a vital role in the oceans’ food chains and were around for millions of years before we humans came onto the scene. Simply put, without plankton, the world would be a very different place. As part of our Nature's Unsung Heroes miniseries, we’re joined by senior advisor to the United Nations on oceans Vincent Doumeizel to talk about his latest book, The Power of Plankton – How Plankton Made Life on Earth Possible and Why It’s Key to Our Future. He tells us how these often-ignored organisms played an essential part in the evolution of life on Earth, tells us the many ways plankton acts as the caretaker of the entire planet, and makes a passionate case for why we should be paying more attention to these fascinating, ancient organisms. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Hello and welcome to Instant Genius, a bite-sized masterclass in podcast form. Every Monday and Friday, you'll hear world-leading scientists and experts talking about the most fascinating ideas in science and technology today. I'm Jason Goodyear, commissioning editor at BBC Science Focus. Although it often goes unnoticed, plankton is the most abundant form of life in Earth's oceans, making up 95% of all oceanic biomass. These tiny organisms are responsible for generating around half of the planet's oxygen,

play a vital role in the ocean's food chains, and were around for millions of years before we humans came onto the scene. Simply put, without plankton, the world would be a very different place. In this episode, we're joined by Senior Advisor to the United Nations on Oceans, Vincent Domizel, to talk about its latest book, The Power of Plankton, how plankton made life on earth possible and why it's key to our future. He tells us how these often ignored organisms played an essential part in the evolution of all life on Earth. It tells us the many ways plankton acts as the caretaker of the entire planet

and makes a passionate case for why we should be paying more attention to these fascinating ancient organisms. So welcome to the podcast. Thanks so much for joining us. Thank you so much for inviting me. So today we're talking about your latest book, The Power of Plankton, how Plankton made life on earth possible and why it's key to our future. So I think really the obvious place to start then, a lot of people will have heard of plankton, but might not really know exactly what it is.

And as you talk about in the book, which we'll go into later, it's hugely diverse. So first off, broadly speaking, you know, what exactly are we talking about when we're talking about plankton? Well, first, that's the most important and probably the least understood ecosystem on the planet. So that's very important because it supports all the geochemical process we have on the planet. So it's like everywhere in our daily life. I mean, the oxygen we breathe, the rain we have, the carbon and the nutrients, everything is linked to plankton.

to this small organism drifting in the ocean. To come back to your question, what it is actually, I mean, it's a multitude of organisms that are drifting in the ocean. Planton is characterized by the fact that these organisms, they cannot go against the current. They cannot swim. They have no limbs to swim against the current. So they are drifting.

So as such, it gathers an incredibly wide range of organism, which will go from very, very tiny virus, which are like 50,000 times thinner than a hair to the longest animal on the planet, the Siphonofor, which is up to 100 meters long. So in terms of scale, if you compare this virus to the Siphonofor, it's in terms of size, I mean, a scale of size, it's like comparing an hunt or a needle

to the size of the gridbrose. So we are talking about an incredibly wide range of plankton. The most common, I mean the most known one are the jellyfish because they are visible because we experience them, but most of them are invisible and you have to imagine that 90% of the biomass in the ocean is made from plankton. So let's start by observing a droplet of water. You think it's empty because it's transparent, but actually it's an abundant ecosystem dimming with life and so important for everything we are.

on Earth and once again because it's invisible it's one of the least understood and that's where it's a fantastic opportunity to really work on a better future for all of us. Yeah absolutely so we'll get like right up to the modern day in a moment but like as you say in the title how plankton made life on earth possible going way back when I mean that that's like you know that's a huge statement so you know what can we say about the beginnings if this as you say, abundant and fascinating organism. Well, it all started in the ocean. Remember, we don't know how it started exactly,

but we know that life started in the ocean back four billion years ago. And actually, Plankton created this unique epic that is the story of life, the story of evolution. Because they are drifting, plankton are characterized by the fact that they can meet each other

and collaborate create symbiosis and cooperate. And that's what is evolution. It's about different organism meeting each other. If you are stuck on the land or in the benthic part of the sediment, then you cannot meet. But if you are drifting in the ocean, then you can meet and you can start evolution.

So Planton has created life back 4 billion years ago and created evolution all over the last 4 billion years. And it's incredible to think that if you look at this 4 billion years of life on the planet, I mean, 3 billion has been only plankton. Two billion years ago, one type of plantons, the cyanobacterias, they had an incredible stroke of genius. They made what is likely to be the most important innovation in the story of life, which is photosynthesis.

Two billion years ago, drifting bacteria invented this capacity to transform sunlight into living matter and while releasing oxygen. What we have to understand is that at this time, oxygen was a very toxic gas, so it destroyed almost all type of life on the planet. And everything that was existing has been destroyed by this very dangerous gas that is oxygen at this time. But some organism adapted and created what we call the breathing mechanism using oxygen, and then they are ancestors. And we are all there because of this cyanobacteria that invented photosynthesis and then oxygen.

And all plant on Earths, they have copied this capacity to do photosynthesis. That was the first work of Genus, the first big shift in the story of life. The second big shift in the story of life was when one billion years ago, plankton invented multicellularism. They had the capacity to get together, specialized, different type of plankton specialized, and they create organs, they create eyes, they create lung and hurt and skin, and then this complex organism. Back one billion years ago, the very very first basic one, and half a billion years ago only, I mean this plankton cooperated and was another big step forward was to invade the land. They conquered the land and they moved for the first time, 500 million years ago, life moved,

from ocean to the land through a cooperation of microalgae and fungi which are all plankton that was another big thing but if you think about it I mean all of this I mean over the four billion years of life 3.5 billion have been only and purely planktonic life so 90% of our history is a meaning of life history is made purely by plankton so 90% is purely planted so our earth is biologically and historically much more of a plankton planet than anything. And by the way, plankton and planet shares the same etymology. I mean, plankton is drifting in the ocean, just like planet is drifting in the universe. And that's why it's so important. And over these four billion of years,

plankton has created all the chemical processes that are characterizing our planet, like they have created the oxygen we breathe, they have created the carbon and sunk the carbon in the ocean to create our climate. They have created the clouds and the freshwater cycle by releasing gas to create clouds. They have created the nutrient circle for phosphate, for nitrogen, everything. So they are the base of everything and they have the key for the future of everything where we want to go. Yeah, so having said that, like as you say, they're enormously abundant. But what's the current health of plankton, you know, are they in good shape or not? Well, you know, plankton is here for 4 billion years, and I trust they will be there for the next billion years.

The question is not about plankton, it's about us. I mean, we are defined. I mean, the entire ecosystem we have right now is based on a foundation that is plankton. So it's like the basis of the pyramid. And we know that if the basis changes, the rest of the pyramid we crumble, and then a new pyramid will build up. But that will be a different one. And that's exactly what is happening right now.

Because of the anthropic activities, the human activities, typically because of global warming, because of pollution, plankton communities are changing. So they are not in better health or bad health. I mean, they are just very different. And then instead, I mean, right now, for the last 300 million years, the Earth is characterized by a community of plankton dominated by plankton that sequester carbon, release oxygen, and are not toxic for us. But right now it's changing. And we are getting to plankton that are toxic for us, that are not releasing good oxygen, and that are not sinking carbon and contribute to global warming. If that continue, then the ocean will release carbon instead of absorbing one-third of the carbon

emission we are having every year. And that's the end of the game for all of us and all our ecosystems. But other species will strive into that, and we will have evolution will come again. but that's the end of the human being. Sticking with the ocean and the creatures within that, plankton also play an absolutely vital role in the food chain in the ocean. Yeah, I mean, it's crazy because when you look at the Polynesian

who knows so well the ocean, but 2,000 years ago, they guessed that plankton there was some tiny and invisible organism in the ocean that we are feeding seafood, I mean, fishes and oysters and others. and that it was the base of everything, and that it was where life has started. 2000 years ago, 2000 years before Darwin and the theory of evolution,

these Polynesian people, they get that. And indeed, that's a source of everything we have in the ocean, and while we are all concerned about saving whales and dolphin and total, no one cares about what feeds them. If we really want to save them, I mean, the best is to take care and understand what has the dynamic in plankton communities at the moment. because the real danger for all these animals lies with the tiny part of the ocean,

the tiniest part of the ocean, which are this organism, because they get food out of them. That's the basis of everything. So we know that if the base is collapsed, then the rest of the building, they will collapse. And if you want to repair your house, you don't start by the roof,

you start by the foundation. And that's where we are. So we really want to change our mindset and change the way we look at life on Earth because we are missing the most important part. And the most important thing is that because of new technology, this part is becoming visible and understandable right now. And that was it's so exciting in this story.

Ah, yeah. So sort of coming after that. So you mentioned there that plankton in the book you write a lot about how it's largely understudied. So what do you think of some of the reasons for that? Is it because, like you say, it's invisible, it's hard to spot, it's difficult to study? Or is it like subtler things?

It's not as charismatic as, you know, say a panda or something like that. Well, yeah, it's not visible. They are beautiful. I mean, if you look at plankton, they are beautiful. They are some beautiful plantar, but they are invisible and they are in the water. I mean, two aspects that is kind of hard to handle for us. But they are more important. I keep being, I mean, bother than we keep talking to our kids at school about the dinosaur.

And dinosaurs, they are useless. They have disappeared 65 million years ago. we should stop talking about dinosaurs, the kid. We should talk about diatoms and cocolito-4 and dynophagulates and so forth, because they are what maintains life on this planet, you know? And why are they poorly studied? Because they are invisible and because we didn't have the tool to understand them. I mean, because to have the tools to understand them, you need to look them from the sky because

the planton gives the color to the ocean. So you can really study what are they doing by studying satellite images. And now we can do that. And you need to put your tools into the water. You need to measure what there is. It's easier in the soil and it is in the water, you know, because, I mean, you need to waterproof tools and waterproof device.

And now we have these remote sensors. We have all this capacity. And more importantly, this is the most by very, very far, because we are talking about four billion years of evolution. This is by very far the most complex ecosystem on the planet. So you need artificial intelligence to understand it because we cannot understand it. We cannot see it and we can understand the dynamic inside. It's one thing to understand what is there.

It's another thing to understand how they interact. And to do that, we need genomics, DNA sequencing to understand this very, very tiny organism, and we need artificial intelligence. Know it there. And over the last 10 years, we did an enormous amount of discovery, regarding plankton. We discover 150 million new genes in the ocean. I mean, we have 20,000 genes in our body. I mean, you imagine what 150 million new genes are. It's enormous. It's unlimited potential for innovation. I mean, just to give you another figure, back 10 years ago, we launched an

expedition in order to study virus. We knew about 40 virus in the ocean. 10 years after, we know half a million of virus in the ocean. That's this kind of the scale of innovation in the ocean. We know 10% of the species that live in the ocean. The best is yet to come and the ocean is the matrix and the source of life on the planet. If we fix the ocean, we can understand the planet biology and we can start to repair and cure our planet and fix our future. Yeah, so let's have a look at some of the sort of, I guess you call them novel, innovative uses of plankton and its unique properties and its abundance that you talk about in the book. So it's involved over, you know, as you say, hundreds of thousands and millions of years in the sort of warming and cooling cycles of the planet. And you talk about this thing that I'd never heard of called a biological pump.

Yeah. In the ocean, in fact, you have two different. and pump, you have one is that is biological, typically, which is that the organism, when they die at the surface, they go at the surface, I mean, all these small, tiny organisms, they go at the surface of the ocean to get the light in order to create their biomass, and then they die, and because they have a shell, they will think in the ocean. We call that marine snow, this constant organism that are falling down in the ocean when they die. And doing that, they will sequester a huge amount of carbon, because once again, we're

We are talking about billion and billions of organisms dying every second and sequestering a lot of carbon in the sediment. And once in the sediment, this carbon is captured there for thousand, if not millions of years. So we are talking about very long-term sequestration, which is why plankton define the climate and the Earth's temperature. It has been the case for the last four billion years and nothing will change. And just why biological pump? because we see that this is a pump of carbon that is linked to the biology. And then it triggers another pump in the ocean, which is a more complex mechanical pump

that is due to the current of the ocean and triggered by this biological pump. But to make it simple, let's say that plankton accounts for about 30% of the carbon absorption on the planet and sequester most of it. So it's like huge... it's so important to mitigate climate. change and to maintain the climate we have.

So when we're talking about the oceans and sort of environmental issues that we're facing at the moment, one thing that will come to a lot of people's minds is the problem with plastic waste. So sort of two questions. How is that affecting plankton? And also, how can plankton come to the rescue? Well, I will start with the first one. Plankton can come to the rescue by degrading plastic. And some plankton know how to do that.

I mean, fungi and some bacteria, they know how to degrade plastic. So that's a bit of like, once again, when we start to understand how they work and what they can do and what the kind of genes they have and what type of protein they are cutting. Then we can start to work on the biology of our planet and fix the cycle. I mean, it's all a question of cycle. Plastic is nothing but dead plankton, remember? I mean, everything that is oil-based, oil is dead plankton. Our old consumption today is that every year we use for oil, and have oil,

one million years of sedimented plankton. Oil is sedimented plankton that has gone through the earth and that gave birth to this oil. So we are burning one million years of sedimented plankton every year. And plastic is nothing but this. So there's two side to your question. One, we could degrade plastic with plankton. And there's other plantin bacteria, plantin bacteria, that produce PHA, which is the type of plastic,

and that can be used in order to replace plastics through a living organism, which will be, as such, biodegradable and compostable and possibly edible as well. So there's multiple solutions. And to answer your question about how plastic is impacting plankton, It does, of course. It does impact some of the plankton that we are very familiar with and that we need to survive, like diatoms. It does not help them. It does provide a lot of problems to plankton.

But once again, it will depend from which plankton. And it's the same for any human activities. There are some plankton that are striving into everything we are doing, notably plastic pollution. I mean, take a quick example about the jellyfish, the very well-known jellyfish. Jellyfish are striving into anything with everything we are doing to them. They love climate change because they can adapt easily to changes. They love warm water. They love overfishing because overfishing get rid of their predator and their competitors for food.

They love acidification because it prevents some plant on to create a shell so they can eat them easily. They love microplastic because they can spawn their hands. eggs on microplastic and the flotability of microplastic will spread the eggs around the world very easily for them. And remember some jellyfish, they can spawn 19,000 eggs a day. So we are talking about a massive. They love plastic bags as well because plastic bags tends to kill turtles because tortoise because tortoise think that plastic bags are jellyfish, they eat them and they thawked and then they die. And the turtles, it's 300 jellyfish a day. So each time we kill a total with a plastic bag, it's really cool for jellyfish.

So once again, and pollution as well, they love it because it will boost the proliferation of some planton that they eat. So everything we do in the end, they like it. And maybe tomorrow will not be the planet of the ape, but the planet of the jellyfish, and they will dominate the planet as they did some 100 million years ago. And maybe they are the next species to survive and to strive into everything we are doing. So it will, once again, just to come back to your question, plastic, just like any other human activity pollution and activities,

they will have a direct impact on plankton on modifying the communities which will tend to be detrimental to all of us. So you touched on something there that I'd like to ask you about a little bit more. And that's that some plankton's edible to humans. So can you tell us about that? Most of the plantain are edible. There are a few toxic plantons, notably microalgae, dynophagulate. I mean, there are really not a lot of them.

Most of them are edible because, remember, they are the source of everything. So life, as we know, it has been built around it. So, I mean, they are, of course, very good and healthy. And you for sure know the healthiest food on the planet, which is pirulina. It means pirulina is the basis of the most nutritional food you can get. it's so good for your body, for your brain, for everything. I mean, spirulina is a bacteria, is a cyanobacteria. Chlorala is another microalgae that you can eat.

And plankton can be a revolution in the food system as well because their production rate is so high that you can produce a lot of them and they are up to 70% protein if you look at spirulina and others. Very high in lipids, very high of all type of vitamin. EPA, DHA, of course, vitamin B12. you cannot find this anywhere else.

I mean, if you're vegetarian, but in plankton. So there can be functional food to many of us. Of course, it's not particularly appetizing. You don't like, you don't enjoy eating spirulina much, but it's so healthy that it can be used as a way to feed people on the planet. And some are delicious. I mean, there's a story of a three-star Michelin chef that made his reputation out of Plankton Marino

in the South of Payne, the guy made of a sauce based on Planton that is delicious, and people love it so much, and the guy got Twister and the Michelin Guide and so forth. And he's very famous now. So it can be very good, but everything, once again, same here. Everything has to be done. We are at the very, very, very beginning of a very exciting story. So sort of sticking with the food sauce idea then, is it possible to farm Plankton? Of course it is.

But we don't know yet. Not really. I mean, we know how to farm some microalgies. We know how to farm spirulina. And it's interesting because basically spirulina is very easy. You need water and sun. Some pioneers, some entrepreneurs, they already put some vats on the roof in some emerging cities like Bangkok and so forth which are very polluted and very sunny.

And then the pollution will feed the plankton and the sun will feed the spirulina and then the spirulina will proliferate without any effort almost. So there's something very easy to do, I mean, once we know the process. So we have to understand how to cultivate plankton. Same here, we don't know yet. I mean, we are in the very, very early stage of cultivating plankton. We know how to cultivate a few microalgae, but we are not very efficient at it. We do it mostly in photobioreactor, which is on land, in lighted by leads, you will produce

plant on there, or in pounds, in some pounds. We'll do it very, very rarely in open sea. because it's very hard to cultivate them. So once again, the best is yet to come here. We need to innovate. We don't know yet how to farm the next level of plankton, which are the most important one, because the lowest part, you need a layer in between

in order to convert them into something edible for fish. And those who are feeding the fish, it's very hard to what we call the zooplankton. It's very hard for us to cultivate them, first and foremost, because we cannot cultivate what feeds them very, well. So it's even more complicated to feel the next layer. But there are some progress about this over the last five years. So we should be very optimistic for the future. And Kriel, for instance,

that is feeding a wells would be a very interesting source of food for us as well and feed very, very rich, very, very healthy. And if we could produce them or cobopods, that would be so interesting to create a very, very sustainable aquaculture system. Because there's a very, very important. Because The big problem we have with aquaculture and the sustainable aspect of it is that we don't manage the lowest trophic level in aquaculture. So how can you produce something sustainably if you don't, if you're not able to produce what feeds this level? So it's kind of, let's start same with the foundation and then the rest will come naturally.

So another sort of fascinating property of plankton that we haven't talked about, which you write about in the book, that can have potential uses for us as well. It's bioluminescence. So, yeah, what can you tell us about that? Yeah, most of the living organism in the ocean are bioluminescent, meaning that they can produce some light. And you can see them. I mean, there are some amazing touristic attraction in some places of the world

where you can look at this bioluminescent plankton and you have such, you have waves colored by very, very powerful lights, and you feel really weird, and it's so amazing. And it has been known for centuries, I mean, because, of course, fishermen, they knew about them. And that was very interesting because when you see a lot of plantons, you know that there will be a lot of fish around them. So when you have a lot of lights, then you need to get to the light. So that has been known for a while. So, yeah, plankton can be bioluminescent.

And as such, that's one of the biomimicking innovation that we could have. I mean, like some companies have already worked on using plankton as a source of light. for the cities, for house, and this source of light is very, very good for us. It creates peace in mind and it's much less aggressive than the electric lights. Of course, same. I mean, there's a lot to be done to monitor the entire process. But we can think about cities where the light will come from living organisms, from plankton and so forth in the future. That is technically possible.

And there are same here in terms of industrial application, unlimited potential for innovation. We could think about plankton cleaning waters. I mean, that's already the case. I mean, most of the cleaning water organism are planktonic one in cleaning water systems. We could think about plankton producing glass, for instance. I mean, the most abundant plankton of the planet, the diatoms, they are producing a shell of glass around them, and they do that at four degrees at natural temperature. Well, we need 1,500 degrees to produce glass. So let's consider this energy savings we could have by producing glass.

at natural temperature. So the same. I mean, they have an unlimited potential. You can produce hydrogen out of plankton. You can produce many, many things. You can control rains. You can, once again, once we will know about it, things will be way, way easier for all of us.

So sort of looking forward in the next five, ten years, what is someone listening who you've piqued their interest and they think, oh, this is something I'd like to learn more about. You know, what can they look out for that you think is going to be some of the key innovations? Well, I think we need more funding. I mean, that's one thing. We need to start to have this discussion at the highest level. I mean, I started this journey because I realized that attending COP climate and COP biodiversity,

there was never any mention on plant on there. I mean, as the ocean absorbed 30% of the global emission on the planet. And the first mention of the ocean was at COP21. So we waited 20 different COP climates to mention what's absorbing one third of the ocean. Up to last year, when I gave my first presentation of Planton, there was not any mention of Planton at COP. And the same with biodiversity. The biodiversity on Earth is all descending from plankton. Most of it is made from planton, but there was never any mention of plankton organism in the COP biodiversity process.

And same at, I mean, with all the big NGO programs, no one care about Planton. So I think the first thing is to start to talk about it, to raise awareness, which is why I wrote a book, because, I mean, initially I did a document with the UN, which was called the Plankton manifesto gathering the 40 best specialist on Plankton worldwide and telling the story about why it's so important and what we can do out of it from a science-based, from science-based evidence, you know, know, not like an opinion on paper. And then that was used by the big policy makers on the planet to get an understanding about what is plankton. And then I realized that there was too much to say for 20 pages. And we can write a book. And with a book, you speak to the public, you speak to everyone, you speak to the kids.

We need more marine biologies. We need more people studying what's happening in the ocean. We need more people telling stories about the ocean. We need plankton to be present in education. We need to plant on to be present in our food. We need to learn how to eat plant on or to cultivate. We need finances and investors to be interested in investing in this. I mean, if you look at the SDGs, life below water is 0.05 of the investment.

If you look at all the 17 SDGs. So one of the most important one is 0.05% of the investment, financial investment. So there's a lack of funding there. There's a lack of education. No one talks about them, we all ignore even what is Plankton. When you talk to people, they will think like it's krill or it's some heavy character in SpongeBob Square Prince and this kind of thing, you know, and that's about it. So or tiny thing that doesn't matter.

That's what they will think of. So we need to raise awareness. We need to talk, we need to spread the stories where the Plankton goes spell around us because Plankton is the greatest unsung hero we have on the Blankton. it. Thank you for listening to this episode of Instant Genius brought you from the team behind BBC Science Focus. That was Vansom Domizal. To discover more about the topics we've just discussed, check out his book, The Power of Plankton, how plankton made life on earth possible and why it's key to our future. If you liked what you just heard, then please do consider

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