So if we think of the deep ocean as being this dark, deep, horrifying place at the bottom of the Earth, it's easy to dismiss it as something which is out of sight and out of mind. But myself and colleagues have been there, and I think if we take some time to think about the deep ocean as part of our planet, we all might want to protect it as much as any other marine environment.
Let your imagination tell you what a deep-sea animal looks like. The one that immediately flashes into your head when you think deep sea. You're probably thinking something like this.
(Laughter)
And that is a real fish. That's a real animal from the deep sea. Now, that's the kind of image you are quite often presented with in the media when we talk about deep-water animals. But there's two things wrong with that photograph. First one, it's a little bit misleading in that those types of animals are generally quite shallowish in the grand scheme of things, maybe a few hundred meters, certainly top thousand meters. The second thing that's a little bit misleading is that they are normally about that big.
(Laughter)
Right? So they're hardly that scary.
(Laughter)
It's not going to come and get you, is it? But we are forever being told that there are "monsters of the deep" in a low voice, and aliens of the abyss. But when you take a moment to think about the technicalities of being an alien in the abyss, the only alien in the deep sea are the occasional human. Because everything else belongs there. So I am proud to say I am an alien of the abyss.
(Laughter)
And I've been studying the deepest parts of the ocean for 20 years, but more recently, we've been diving in a submarine.
One of the questions you quite often get asked when you tell someone, "Oh, Tuesday, I went to 10,000 meters," they say, "Ooh, isn't that scary?" And that is the important point, it's fear. It's that thing that we have in our heads that doesn't like being underwater. So if you think about what the deep sea represents, it's a physical, three-dimensional manifestation of two of the things we hate the most. And we have a phrase for that. We call it the deepest, darkest fears. Because we are air-breathing mammals. So we don't really want to be underwater, especially not super deep. And we're visually orientated animals, we like light. But 11 kilometers underwater is something that everyone goes, "Ah, that's really deep and horrible. That's just frightening." Take that 11 kilometers and turn it on its side. I reckon most people in the room have traveled 11 kilometers today.
And the other thing that we don't like is the unknown. And this is where we get into this whole relationship between reality and what we're told on the TV.
So on the TV, we're quite regularly told that we know more about the surface of the Moon than we know about the deep sea. For starters, that quote goes back before the Apollo missions and a time where we knew not very much about the Moon or the deep sea.
So if you're on the surface and you're looking out and you can see all these lovely whales and dolphins and squid and jellyfish, all that stuff has to die. All that material, all that lovely organic matter sinks. And where does it sink? It sinks down to deeper depths. It ends up in the place we call the abyss. And not "the abyss" like they say on TV. The abyssal zone technically are depths between 3,000 and 6,000 meters. OK, relatively shallow in my game. All that lovely organic material comes down and settles there. And it gets eaten by deep-sea animals. Those deep-sea animals are eating it, they're recycling it, they're burning it. They’re incorporating into the food chain, and they incorporate it into the sediments. So these animals are essentially gardening because if they didn't do that, these big, vast abyssal plains of the planet would become big, stagnant, horrible cesspits. So the deep-sea animals are basically irrigating a big chunk of the planet. And I say a big chunk. The abyssal zones account for about 70 percent of the planet.
Let's take a bit of a journey, a descent into the deep sea. How do we know where to dive? How do we know where we are ever? Because we're always being told ...
(Laughter)
No, it's true, we're always being told that we haven't mapped the oceans. A certain amount of seafloor has been seen with the naked eye. I took that with my phone.
(Laughter)
So I was seeing it at the same time. So it still counts. And there's a certain percentage which has been mapped or surveyed by remote systems. So this is about 2,000 meters deep. And about 20 percent of the planet has been mapped in pretty high resolution using acoustics. This is a huge, big trench running off north of New Zealand. Well, basically they have been mapped. It all depends on what resolution. OK so there's some places where we know where absolutely every little nook and cranny might be. There are no more Mariana Trenches to be found. Imagine we're in our submarine, this is us diving in the submarine, see, it's very spacious. It has all the latest mod cons, the sunlight diminishes very, very quickly in the top, maybe in the first two minutes. It goes that fast and you see that it does get dark very quickly. And as we descend down through the water column, we're always being told that the water is very, very cold. Very, very icy cold water. And yeah, it's cold. It's not anywhere near as cold as most, if not all of the winters I've ever endured until moving to Australia.
(Laughter)
It's about between one and two degrees at deepest point. It's not overly cold. But those water masses deep down are still moving, they're still ventilating, they're still full of oxygen and they're moving heat. They're pulling heat down from the atmosphere and the surface waters and dissipating it around the planet.
And as we go down the bottom of the Mariana Trench, we now have one ton per square centimeter of pressure squeezing down on that titanium ball we’re sat in. Again, it takes a certain person of a certain disposition to do this stuff, but you can’t feel it on the inside, it’s fine, it’s cold outside. And we’re moving around, and if you look out the window, we're looking mostly at mud. Imagine all that stuff that has come down from the surface. All that lovely organic matter. It's carbon, it's taking carbon from the atmosphere, it's being absorbed into the ocean. The surface of oceans basically comes down and sinks into the mud. What happens to the carbon? The bottom of the trenches, the reason why the trenches are so deep, the reason why they're 11 kilometers in some places is because two tectonic plates hit each other. Sometimes they get pulled apart, sometimes they slide side by side. But the trenches are formed when one tectonic plate hits another one and drives it down into the Earth’s mantle. Hence you end up with something like Mariana Trench. Now all that carbon trapped in the sediment is now being pushed back into the Earth’s mantle. The deepest points on the planet are one of the few places where we're actually disposing of carbon. So they're again, performing a service to the planet.
So when looking out the window, what's it look like?
(Laughter)
If you switch your lights on, right, it looks like mud. You have a lot of places that are very flat. Lovely, luscious, golden-brown. That's a good, healthy sea floor, OK. Sometimes you see some rocks and some rocky outcrops. You see cobbles and rocks and boulders. Sometimes it's a bit crazy. But none of these images look that weird. They look like something you would expect to see if you were scuba diving at night. So the actual visual landscape of the deepest places isn't that strange either, it's certainly not something you should fear.
So let's get back to the monsters of the deep. What do you reckon the deepest tentacled animal is in the world? Bear in mind, it's the tentacles that have been putting the fear of God into sailors since I don't know when. Imagine “The Thing” coming up from the deep sea. So you're probably thinking something a little bit like that.
(Laughter)
That's also a picture I took on my phone recently.
(Laughter)
It's been a funny old week. That's ... That’s the kind of image your imagination puts into your head when you think deep sea, tentacles and the rest of it. The reality of the matter is -- and I can proudly say that I discovered the deepest octopus in the world --
Audience: Aw.
AJ: It’s the size of a puppy, too.
(Laughter)
It gets better. Its real name is Grimpoteuthis, which is a bit “rurr.” But its common name is Dumbo Octopus because it has big Dumbo-like ears. And this lives at close to 7,000 metres in the Indian Ocean. That is your big, scary octopus that's coming to get you.
So then we think about what's the deepest fish look like. Because they've got big, horrible fangs, right? And they're lurking in the darkness, coming to get you. Deepest fish in the world is actually what we call a snailfish. If anything, it's a bit goofy-looking. It's not really that threatening. It's not something you should fear. They're snuffling around, they're looking for stuff and they've got little eyes, they're actually gelatinous, that's its liver you can see on the side of its body. They're very soft-bodied. And what I really love about the deepest fish in the world is they’re not really deep-sea fish. They're actually a shallow water family that has just radiated. Most snailfish are actually really shallow, you even get some in estuaries. It's just a fish that doesn't care, you can't pigeonhole the snailfish.
So ... Another animal ... that we like are prawns, right? Everyone loves to eat a prawn. That there is the last, the deepest of the big crustaceans. That's a prawn, and those are down to nearly 8,000 metres. And that wouldn't look that out of place in a fish market. There's nothing weird about it either.
And one of my personal favorites from the very, very, deepest points, and we see these bizarrely at the very deepest points in multiple trenches, we very rarely see them anywhere else except for the most extreme places. And it's a type of anemone. And they just kind of look like white flowers floating in the wind. They’re actually really beautiful animals, and they’re living in, unbelievably, what we would class as being extreme environments. They have an unpronounceable Latin name, which I maybe shouldn't try, but it's Galatheanthemum. I've done it.
(Laughter and applause)
Thank you.
(Applause)
I'm not doing it again, though, I got away with it once.
So if you start to rethink the visual imagery and the way in which the deep sea is in reality and not the way we're told, it's time that we started thinking about the oceans generally as just one big ocean, from its surface to the bottom. The ocean doesn't recognize imaginary lines that we've drawn and said that's sea, that's deep sea. So we care, don't care. Care, don't care, right? And that's actually what we do. You wouldn't turn up in the Amazon, and say, "Right, everyone, We're going to catalog every known species for the first 200 meters, everything after that are monsters of the trees."
(Laughter)
"Because it's just dark and horrible in there, so let's not do that." But that is exactly what we do right now to 70 percent of the planet. And that's what I find quite frustrating.
Another question I get asked sometimes as well is -- other than the fear stuff, and the claustrophobia and the toilet question and stuff like that -- is, you know, what’s it like being in the bottom of the sea, looking out the window and seeing stuff? And I actually find it a genuinely difficult question to answer. Because it’s quite exciting. Afterwards, you’re like, “Ooh, that was really exciting.” But at the time, it’s quite humbling. Because I think you’re kind of aware of the fact you’re seven miles underwater and one ton per square centimeter and all that kind of, you do feel quite remote. But I just think it looks kind of majestic.
I think it's certainly the exact polar opposite of what you're told it should be like. It’s not scary, it’s peaceful, and it’s nice, and there’s beauty there. And I think we need to challenge the narratives that we are given and change the story and start to think of the deep sea as a place which is fascinating, it's wonderful, it's interesting, and it's really, really important. And only at that point, if we take all that on board will we ever truly, truly protect and live alongside our oceans.
Thank you.
(Applause)
