Transcriber: Lidia Anthony Reviewer: David DeRuwe
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 a 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.
Though, that’s the kind of image you’re quite often presented with
in the media when we talk about deep-water animals.
But there are two things wrong with that photograph:
First one is a little bit misleading in that those types of animals
are generally quite shallow-ish 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 are 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 is 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 a good 20 years,
but more recently, we’ve been diving in our submarine.
One of the questions you’re often asked when you say:
“Oh, Tuesday I went down 10,000 meters”,
they say: “Ooh, isn’t that scary?”
And that’s the important point. It’s fear.
It’s that thing 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 superdeep.
And we’re visually orientated animals - we like light.
OK, 11 km underwater is something that everyone goes:
“Ah, that’s really deep and horrible. That’s just frightening.”
Take that 11 km and turn it on its side, right?
I reckon most people in this room have travelled 11 km 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 65 years,
about 15 years before the Apollo missions,
in a time where we knew not very much about the Moon or the deep sea.
If you’re on the surface and 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 is or are depths between 3,000-6,000 meters,
relatively shallow in my game, but ...
all that lovely organic material comes down,
settles there and it gets eaten by deep sea animals.
Those deep sea animals are eating it, recycling it, burying it,
they’re incorporating it 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% of the planet.
Most of Earth is abyssal plane.
If you take an average
from the highest altitude of Mount Everest to the deepest depth of Mariana Trench,
an average is 4,000 meters underwater on planet Earth,
which puts this planet as an abyssal 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)
That’s true - we’ve always been told that we haven’t mapped the oceans.
A certain amount of seafloor has been seen with the naked eye.
I took that on my phone.
So it wasn’t too bad. I was seeing it at the same time, so it still counts.
And it’s a certain percentage which has been mapped or surveyed by remote systems.
So this is about 2,000 meters deep,
and about 20% of the planet has been mapped
at 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, 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 a submarine. This is us diving.
And the submarine feels very spacious. It has all 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’ve always been told that the water was 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 1° or 2° at deepest points,
it’s not overly cold.
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,
the surface waters and dissipating around the planet.
As we go down to the bottom of the Mariana Trench, we now have
one tonne per square centimeter of pressure,
squeezing down on that titanium ball we’re sat in.
It takes a person of a certain disposition to do this,
but you can’t feel it on the inside.
It’s fine; it’s cold outside, and we’re moving around.
If you look out the window, we’re looking mostly at mud.
Imagine all that stuff that’s come down from the surface,
all that lovely organic matter.
It’s carbon; it’s taking carbon from the atmosphere.
It’s been absorbed into the ocean, the surfaces of the ocean.
It basically comes down; it sinks into the mud.
What happens to the carbon?
The bottom of the trenches, why the trenches are so deep,
the reason why they are 11 km in some places
is because two tectonic plates have hit each other.
Sometimes they get pulled apart; sometimes it slides 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 we’re looking out the window, what does it look like?
(Laughter)
If you switch the lights on, right, it looks like that.
You have a lot of places are very flat.
Lovely, luscious, golden-brown. That’s a good healthy sea floor. OK.
Sometimes you see some rocks and some rocky outcrops, cobbles and rocks
and boulders and all the rest of it.
Sometimes it’s a bit crazy, but none of these images look that weird.
They look like something you would expect to see scuba diving at night.
The actual visual landscape of the deepest place 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.
Right, imagine this thing coming up from the deep sea.
You’re probably thinking something a bit like that:
(Laughter)
That’s also a picture I took on my phone recently,
(Laughter)
but it's been a funny old week.
But that’s the kind of image your imagination puts into your head.
You think “Deep Sea Tentacles R’Us”; the reality of the matter is,
and I can proudly say that I discovered the deepest octopus in the world,
(Exclamation of awe)
It’s the size of a puppy too.
(Laughter)
Right? It gets better.
Its real name is Grimpoteuthis, which is a bit “aargh”,
but its common name is “Dumbo Octopus”, because it has big Dumbo-like ears,
and this lives at close to 7,000 meters 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 darkness coming to get you.
The deepest fish in the world is 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 looking for stuff and they’ve got little eyes.
They’re actually gelatinous. That’s his liver you see on the side of its body.
They’re very soft-bodied.
And what I really love about the deepest fish in the world:
they’re not really deep sea fish.
They’re a shallow-water family that 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 a snailfish, you know?
(Laughter)
So another animal, a couple more.
We like our 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 meters.
And that wouldn’t look that out of place in a fish market, right?
Nothing weird about that 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 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.
Done it!
(Laughter)
(Applause)
Thank you!
(Applause)
I’m not doing it again. 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 start in thinking about the oceans as just one big ocean,
from surface to the bottom,
but the ocean doesn’t recognise 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.”
(Laughter)
Right? And that’s actually what we do.
You wouldn’t turn up in the Amazon and say: “All right, everyone,
we’re going catalogue 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% of the planet.
And that's what I find quite frustrating.
Another question I get asked sometimes as well, 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 honestly actually find it a genuinely difficult question to answer,
because it’s quite exciting, afterwards, you’re like: “Oh, that’s really exciting”
but at the time it is quite humbling,
because I think you’re kind of aware of the fact you’re seven miles under water
and one tonne per square centimeter and all that.
You do feel quite remote,
but I just think it feels kind of majestic.
I think it’s certainly the exact polar opposite
of what you’re told it should feel 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’re 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 onboard,
will we ever truly, truly protect and live alongside our oceans.
Thank you.
(Applause)