A brine pool is an accumulation of very
salty water at the bottom of the ocean. And the water is so salty, or we'd call it saline,
that it sits as a pool beneath the seawater. It gives us a window into how oceans are born. And indeed we know this from a hundred
million years ago when the Atlantic formed, when it was a baby sea just starting
to open up like the Red Sea is today. But the processes that were going on in the early Atlantic a hundred million years
ago are very poorly understood. But with the Red Sea, we can
watch it in process today. So it's an incredibly powerful analog to
the formation of all of the oceans on Earth. Quite recently, a brine pool was found,
not at the spreading axis of the Red Sea where there's a lot of volcanic activity,
but slightly off it in shallower water and that gave an indication that maybe
they exist in other environments. They've certainly never been found
outside the Red Sea in the Gulf of Aqaba and they've certainly never been found
on the coast, which is where we found it. Yes, it might be long along the wall. It kind of seems surprising, unless
it's ginormous, that we'd just stumble across it, right? Unless it ran the whole length of the bottom here. So freaking cool. It's the first one in the
Northern Red Sea in the Aqaba. Wow. Woah. We'd been driving for eight and
a half hours across this barren, abyssal plain and I felt incredibly guilty because
all of the effort had gone into finding nothing. And something changed in the far
distance. It looked a little bit murky and I remember the sea floor was getting darker. And we were starting to approach the wall from
the coastline at that point and I've thought, "Oh, we must now be at the end
of the dive and we've failed." But the image got slightly darker and then as
we got closer there was little bits of seaweed, which have washed down from the
shallows, but they were floating just above the seafloor in a really weird way. And then the lights from the ROV cast
down and you could see the bow wave from the ROV propagating ours across the brine
pool and it was the most beautiful thing. And I remember the first thing I felt was relief. Look at the waves. Woah. Wow. Oh my goodness. That's huge. Wow. That's awesome. Anything that goes in there doesn't move. (Indistinguishable Chatter) The CTD was the only way that we could get
samples of the water back to the surface and also measure the chemical properties
of the brine and we had to have the CTD and the ROV down at the same time because we
were using the ROV to see what was going on. And there was a lot of trepidation
because they're both tethered to the ship by cables nearly a mile
and a half beneath the ship. And there's an incredibly high chance
that they're going to get tangled and cause the loss of the ROV,
the loss of the CTD, or both. So what we did is we lowered the ROV down and rested it on the
brine because the brine is so dense. And once we got that positioned, we could give the signal visually
of when to trigger the water sample. So the first sigh of relief is when the
CTD appeared in the video coming from the ROV cause we knew then it made it
down that far without getting tangled. But then to guide it down literally centimeter
by centimeter very slowly to make this very precise point and then
actually seeing the bottle snap close with the water
inside it, it was a huge relief. It was very exciting because I don't think this
has ever been done before in such a precise way. There's a lot of life around the brine pool and even within it, and it doesn't
seem to be coincidence. It seems the organisms have learned about the brine
and they're using it to their advantage. So there were these huge armies of shrimp, which
live on the rocks looking down into the brine, and it seems that when anything
goes into the brine by accident, before the organism dies and sinks to the bottom
of the brine pool where it's inaccessible, the shrimp rush in and snatch it from the brine
surface and they're using the brine as a trap. The reason why this is so special is that
to get this sort of environment, you need hydrothermal activity. And if you're going to get
hydrothermal activity, you need plate tectonics. And if Earth is one of the rare planets
which has plate tectonics and that can produce such environments, it's conceivable
that life in the universe is very rare indeed. Perhaps we're the only ones. And if we're going to go out in the universe
and look for life elsewhere we're going to be targeting planets or moons like Europa around
Jupiter where we understand there's a hydrothermal circulation and you might have brine pools
very similar to what we're seeing right now. We nearly missed it. I mean
we were close to giving up. And it just goes to show that
if you're at the bottom of the sea and you've got fifteen minutes
left, push on. It's a privilege. Take every single minute and
every singe second you've got cause you never know what's around the corner.
