- 22 minutes ago
Deep Ocean
Category
🐳
AnimalsTranscript
00:00Neptune, Neptune, control.
00:04Go ahead, control.
00:06Summer 2024.
00:08Neptune, you are all stopped if you choose to move upslope to 180 and follow transects to the north.
00:20Roger.
00:23An expedition is setting off in search of a little-known fish that lives in the deep sea.
00:38Its proselys skeletons had been found in rocks that are 400 million years old
00:44and suggest that these fish could be the ancestors of all backboned animals, including ourselves.
00:57But their fossils disappear at the same time as those of the dinosaurs, 66 million years ago.
01:06Then, in 1938, a trawler fishing off the coast of South Africa made an astonishing catch.
01:15It was undoubtedly the same kind of fish as Seelacanth, but an hour or so earlier, it had been alive.
01:24It was a sensation, a true living fossil.
01:29But little was known about how and where it lived.
01:35Now, a special expedition in a state-of-the-art research ship
01:39is setting off to try and discover more about this living fossil.
01:49And they hit lucky.
01:51Hey, what's that?
01:52What?
01:52That's Seelacan?
01:53Okay, Seelacanth.
01:55What's that?
01:56Is that Seelacanth?
01:56Seelacanth!
01:57Oh yeah, yeah, yeah!
01:58Seelacanth!
01:58Yeah, we found Seelacanth!
01:59There was a whole group of these ancient fish.
02:07Oh, but look, look how they're all moving.
02:10It's so crazy.
02:12And look at the white tummy.
02:16They even witnessed, for the first time,
02:19what appears to be its mating behaviour.
02:25And the video recordings they made shed light
02:28on how primitive fish like the coelacanth
02:31may have used their fins to walk on land.
02:36It's just gorgeous.
02:37And when we look at creatures like this,
02:39we see the evolutionary history we share with fish.
02:45Join us on a journey to discover more
02:48about this mysterious survivor from the very ancient past.
03:06The island of Sulawesi in Indonesia.
03:14It straddles the equator.
03:20And the waters around it
03:22contain some of the richest coral reefs in the world.
03:32This is Ocean Explorer,
03:35a vessel specially equipped for deep sea research.
03:39The team has special permission from the Indonesian government
03:43to spend two weeks looking for living coelacanths.
03:50The coelacanth is called Raja Laut in Indonesia,
03:54which means King of the Sea.
03:59They have a pair of powerful deep sea submersibles.
04:04Each has a transparent dome
04:07that will give it almost 360 degree visibility.
04:15And they are fitted with an 8K deep ocean camera system
04:20specially developed for this trip.
04:23The ultra-sensitive cameras are able to record clear pictures
04:28even in the darkest depths.
04:31They will also use a large unmanned ROV,
04:36a remotely operated vehicle.
04:42This ROV is equipped with additional cameras
04:46and can film in all directions.
04:51Iwata, I'm a coelacanth woman.
04:56Iwata, I'm a coelacanth woman.
04:57I'm clearly, I'm a coelacanth woman.
05:01These are the lead scientists on the expedition.
05:07Dr. Masamitsu Iwata has been carrying out research
05:11on coelacanths for over 20 years.
05:15It's big.
05:18It's more compact.
05:20It's more compact.
05:22Having worked and dived in the Indonesian waters
05:25for over 20 years,
05:27Iwata knows these seas very well.
05:32Wow.
05:33I'm Kerry.
05:35Lovely to be here.
05:36Dr. Kerry Sink first became fascinated by coelacanths
05:43when she was a child.
05:48To really see the seascape and the terrain
05:52is going to be an incredible experience.
05:55And I think what would be amazing
05:57is to see a coelacanth eyeball to eyeball.
06:04The team are planning to explore the waters
06:07off the northern shores of Sulawesi.
06:13The area is renowned for its active volcanoes,
06:16and frequent eruptions have created numerous caves
06:20and cavities on the sea floor.
06:24An earlier survey found a steep underwater cliff here,
06:29which the team are keen to investigate further.
06:35as the sun rises, they're ready for their first dive.
06:43Both subs will be used
06:45so they can cover as much ground as possible.
06:50Perfect.
06:51Just feet on there.
06:52Yep.
06:53Okay.
06:55Welcome.
06:57Pitching to the charge.
07:19The submersible Neptune, with Iwata on board,
07:23is the first to be launched.
07:25Ready for the water.
07:29Neptune.
07:30Neptune.
07:30Nadia.
07:31Boot stops.
07:32Come together.
07:33You are clearly ready when ready.
07:37Then they launch the Saturn submersible,
07:40Nadia,
07:42with Kerry on board.
07:44Boom.
07:52I'm still on astronauts.
07:53Are you visiting now?
07:55Roger.
07:56We'll stop attending now.
07:57Have a good day.
08:00Remember?
08:04Move the crew.
08:05It's ready to go pequeño.
08:08One day.
08:10Good day.
08:14Captain.
08:19I'm going to take a look at this.
08:27Leaving the creatures of the shadows behind, they head for deeper water.
08:34They're now at a depth of 200 meters.
08:38Deeper than this, it's pitch black.
08:44Control, control. This is Neptune. Depth 2 to 4 meters.
08:53They now plan to search an area roughly half a kilometer long.
09:01But in this darkness, that is not an easy thing to do.
09:26They're searching for bright spots that could be reflections from Masi-Lacanth's eyes.
09:41There are two bright specks in the darkness.
09:53It's a carpet shark, sitting motionless on the sea floor, waiting for prey.
10:06Meanwhile, Kerry's sub is scouring a different section of the cliff face.
10:17The fish.
10:19The fish.
10:19What is it?
10:19Jelly nose.
10:20Jelly noses.
10:22The crazy ones.
10:25It's a jelly nose.
10:27A rare kind of deep sea fish that, until recently, had never been seen alive.
10:37Its long ray-like fins are thought to be sensors that allow the fish to feel its way around in
10:45the darkness.
11:05The healthy fish.
11:08This is a secret shark.
11:08Shark?
11:10Shark?
11:11Shark?
11:12Yeah, fresher.
11:15It's the fresher shark with a distinctive long tail fin.
11:19It's at least three meters long.
11:27I'll slowly come up towards him.
11:30I'll just see how he reacts, okay?
11:32Yeah.
11:32Yeah.
11:36They appear to have entered the shark's territory,
11:39and it's slowly circling the submersible.
11:49Oh, no!
11:55Two smaller fish have sought shelter underneath the sub.
12:04They don't seem in the least fazed by such a strange contraption,
12:08and appear to be using it as a place to hide from the shark.
12:19But suddenly, there's a problem.
12:24See, it's different.
12:25See, it's shimmering.
12:30A strong underwater current has stirred up the sea floor,
12:35and the particles of sediment are obscuring the view.
12:41It's no longer safe to continue.
12:43They must return to the surface.
12:58The area is known for its strong and unpredictable ocean currents,
13:03which can make underwater exploration very dangerous.
13:07The team have to be prepared for setbacks like this,
13:10but it's frustrating when their time down here is so limited.
13:27So why are scientists so fascinated by the coelacanth?
13:33It seems that these primitive fish may have solved
13:37a long-standing evolutionary mystery.
13:42Coelacanths first appeared more than 400 million years ago,
13:47long before the dinosaurs,
13:49and they thrived in oceans around the world.
13:53It was thought that they became extinct at the same time
13:57as the dinosaurs, 66 million years ago.
14:10Then, in 1938,
14:12fishermen pulled up from the depths of the Indian Ocean
14:15a specimen of this ancient fish that was alive.
14:21Its discovery stunned the scientific world.
14:25The coelacanth was not extinct after all.
14:32Then, in the 1950s,
14:35another specimen was caught off the coast of Africa,
14:38and I had the privilege of examining it.
14:42Its fins have long, fleshy lobes at their base,
14:45which make them quite unlike the fins of any other living fish.
14:50In fact, the fins were so muscular
14:53that it was thought it might use them like simple legs
14:56in order to walk across the sea floor.
15:01Since those first discoveries,
15:04scientists around the world
15:05have been searching the deep sea for a living coelacanth.
15:13Then, in 1997,
15:16there was another surprising discovery.
15:19A coelacanth was caught far from Africa
15:22in Asian waters.
15:24The discovery reawoke interest in this strange fish.
15:39Three days into the expedition,
15:41and the team have decided to try a new strategy.
15:45find those points.
15:49The target depth is around 160.
15:56They have decided to concentrate their search
15:59to depths of around 160 metres,
16:03which are rich in underwater caves
16:04and where water currents are relatively stable.
16:15Today is the day we're going to find the fish.
16:2650 minutes into the search,
16:29and Iwata notices some interesting-looking rocks.
16:37Clumps of them stand on the otherwise even sea floor.
16:51The sub approaches cautiously.
16:57The cameraman has noticed something
17:00between the two clumps of rock.
17:05Oh, there is something.
17:06There is a fish.
17:09What's that?
17:10Oh, that's a fish?
17:11Yes, a fish?
17:12Yeah, maybe.
17:13Maybe.
17:16A closer look reveals a creature
17:18hiding in the cracks.
17:24What's that?
17:25Is that coelacanth?
17:26Oh, yeah, yeah.
17:27We found coelacanth.
17:28Yeah, we found coelacanth.
17:31The team are thrilled.
17:33It's their first glimpse of a live coelacanth.
17:36Unlike the dead specimens,
17:38the living coelacanth is a steely blue colour
17:42with light flecks.
17:47I can get us a little closer,
17:49but if we just do a bit of filming here
17:51so we don't scare it off, right?
17:53Yeah, yeah, yeah.
17:57You have coelacanth.
17:58Understood.
17:59Market location.
18:01Coelacanth?
18:02Yeah.
18:02Coelacanth?
18:03Yeah.
18:04Control, control.
18:05This is Neptune.
18:07Confirm that coelacanth's over.
18:09Wait for it.
18:14After half an hour,
18:15the coelacanth emerges,
18:17giving them a better view.
18:19It's over a metre long.
18:39There he is in the cave.
18:40Got it.
18:41Yeah.
18:42The other team have found yet another coelacanth.
18:45Great.
18:47That is pretty spectacular.
18:56This is the first time
18:58that anyone has recorded such a high quality 8K image
19:03of a coelacanth in its natural habitat.
19:14Its large eyes are adaptations to the poor light down here.
19:22The fish are extremely sensitive,
19:25and can see quite well even in darkness.
19:43Most animal species continue to evolve in some way over time.
19:48But astonishingly, the coelacanth has remained almost unchanged
19:52for over 400 million years.
20:02It has scales that shimmer in the light,
20:05a characteristic that doesn't fossilize.
20:13its fleshy fins are far more versatile than those of most fish.
20:21They move in a coordinated way,
20:24keeping its large body steady.
20:40One of its oddest features is its tail fin.
20:44Like that of fossil coelacanths,
20:47it has a little tuft at the end,
20:49which it can move independently.
20:53What function this could have still baffles scientists today.
20:58Perhaps it acts as a small rudder
21:00and helps the fish to make tight turns.
21:04Or maybe it's an electrosensor
21:07that helps it navigate in the eternal darkness.
21:11Much about this ancient creature is still a mystery.
21:42How the Coelacanth survives at great depths
21:46This still remains largely unknown, despite efforts of scientists across the world.
21:54Deep sea exploration is not only challenging, but costly, so every day is precious.
22:03To maximize their chances of observing more behavior, the team have decided to deploy
22:09all of their equipment simultaneously.
22:11We are launching number two before we are recovering number one.
22:19Yes, that was the request, yes.
22:21Always an overlap?
22:22Yes.
22:24Okay.
22:25Okay.
22:29The aim is to carry out continuous observations for 72 hours.
22:36It's an ambitious plan and requires the crew to run the subs in shifts, day and night.
22:45This is a first even for the crew of Ocean Explorer.
22:53The scientists are now sure that coelacanths stay dormant throughout the day.
23:00They suspect that the fish is nocturnal, so they start their daily shift in the early evening.
23:19This coelacanth is still in exactly the same spot as it was when they found it the previous
23:28day.
23:30But the team must be ready to respond if and when it does move.
23:39They know perfectly well that the coelacanth, to sustain its massive body, must come out to
23:45feed sometime.
23:49But it doesn't move, even at night, as the team proves by speeding up their video recording.
23:57It remains in exactly the same spot.
24:02At midnight, the second sub with carry-on board sets off.
24:13She now takes over from Iwata, in keeping watch.
24:32But even after 10 hours, the coelacanth has still not shifted and shows no sign of wanting
24:40to look for food.
24:48Finally, at 8 in the morning, the team decide to bring out the unmanned ROV.
25:01Terry is exhausted.
25:05They've now been watching the coelacanth continuously for 24 hours.
25:11But it still has shown no sign of moving.
25:17Perhaps the sub's lights are making it nervous.
25:23So they switch to infrared lights that are virtually undetectable by any fish.
25:29Okay, darkness.
25:31Darkness.
25:33Darkness.
25:36And still the coelacanth does not move.
25:48At 7am the following day, 39 hours later, it finally does something.
26:08The coelacanth, at last, is on the move.
26:23It swims slowly, but in a way that our scientists have not seen before.
26:39It propels itself forward by moving its fins rhythmically from left to right.
26:48The two fins appear to provide forward propulsion.
27:05You're in steep there.
27:10The head is a vertical cliff face.
27:22It's really interesting to see if she goes up, there's a crack here.
27:29She's going along the crack.
27:34The coelacanth makes its way purposefully along the steep cliff.
27:44So this is a good...
27:46Then it comes to an overhang in the rocks.
28:07She's near?
28:08Yeah, she's near.
28:09That's perfect.
28:11Yeah, we want to leave her somewhere where she can maybe stay.
28:15We don't want her going.
28:17Mark, there's a waypoint.
28:21The bag of mama's new hips.
28:25Death 160.
28:29The fish has disappeared into the crevice.
28:43The place where the coelacanthus chosen to hide is one the scientists had not expected.
28:50It's a large overhang in the cliff.
28:53Effectively, an underwater cave.
28:59Tracking the fish's movements has led them to a new hideout.
29:03This is a real reward for the 72-hour vigil.
29:14Then Terry spots something else.
29:18Oh, I think I see another one.
29:20What?
29:20On the left.
29:22On the left.
29:25Oh, three.
29:27There.
29:27There you go.
29:28Is it?
29:35There appear to be more coelacanths hiding in the cave.
29:39It's an extraordinary sight.
29:44One, two, three, four, five, six, seven, eight.
29:49Eight.
29:50Eight.
29:51Eight.
29:52Eight.
29:52Eight.
29:53What is happening?
29:56There are definitely eight individuals and the team are astounded.
30:02What could be the reason for such a gathering?
30:14Spawning aggregation.
30:18It's hard to know why these coelacanths have assembled in such a tight space, but they seem to be resting
30:26peacefully side by side.
30:37Suddenly, the thresher shark reappears.
30:48The coelacanths retreat further into the crevice.
31:02The arched overhang provides good cover, allowing even a large fish like a coelacanth to hide unnoticed.
31:16The cave also provides protection from ocean currents, so there is little danger of being swept away.
31:28It's a fortress in the kingdom of the coelacanths.
31:50To help them get a better view beneath the ledge, the crew use another piece of equipment.
32:01To help them get a better view beneath the ledge, the crew use another piece of equipment.
32:04It's a tiny underwater camera that they maneuver into position and attach to the rock face.
32:13Despite its small size, it gives a surprisingly detailed image.
32:21They can just distinguish a coelacanth huddling underneath the ledge.
32:27They can just distinguish a coelacanth huddling underneath the ledge.
32:32Within minutes, swarms of tiny fish appear.
32:38They are lantern fish attracted by the camera's bright light.
32:51Once the swarm has dissipated, the coelacanth comes into view again.
33:02And then...
33:07Slowed down, we can see what happened.
33:10Faster than the blink of an eye, it lunges for a passing morsel of food.
33:20This is very different from the slow-moving languid creature the team had seen until now.
33:29The footage clearly shows the coelacanth feeding in a manner only known to be used by prehistoric fish.
33:37Until now.
33:39Recent research has shown that this way of feeding is only possible because of the unique shape of their skull.
33:48It is in fact split into two halves, which are connected by a special hinged joint.
33:57This allows the fish to widen its mouth to more than 30 degrees,
34:02enabling it to bite with the force needed to feed on hard, scaly animals or to swallow particularly large prey.
34:14Many ancient sea creatures once had this kind of a hinged joint,
34:19but the coelacanth is the only known living fish to still possess one.
34:27So, at last, we're starting to unravel some of the mysteries that surround this ancient creature.
34:34It uses its fleshy fins to propel itself slowly through the water and into narrow crevices.
34:42But when necessary, it can move surprisingly quickly.
34:50And the unique joint in its skull allows it to open its mouth wider than most modern-day fish are
34:58able to do.
35:02These ancient features have clearly served the coelacanth well for millions of years.
35:10Recently, scientists have discovered that coelacanths can live to be a hundred years old.
35:17In the deep, it seems that it's the slow and the steady that wins the race.
35:29The scientific team are keen to take a closer look at the footage to solve a particular puzzle.
35:35What?
35:38Oh, there it is.
35:41Oh, beautiful.
35:43Yeah.
35:50Its fins have a thick, fleshy base, a characteristic feature of an ancient group called the lobe-finned fish.
36:02The fins of most modern-day fish are connected to the body in a way that enables them to flap,
36:09but little more.
36:17The coelacanth's fins, however, are much larger and have a row of bones attached to thick muscles,
36:24which gives the fins much greater strength.
36:28This arrangement is also found in the limbs of most land animals today,
36:32and suggests they share a common ancestor.
36:38Scientists have long puzzled over how animals first haul themselves out of the water and onto land.
36:46The coelacanth may provide the answer.
36:52Their fleshy fins may have led to limbs with an upper arm, a forearm, and fingers and toes.
37:04And that enabled the first back-boned animals to crawl out onto land.
37:19Whilst the evidence from the fossil record is compelling,
37:23it can't show us exactly how these ancient creatures moved.
37:30At the University of Chicago,
37:33evolutionary biologist Dr. Neil Shubin has been trying to solve this puzzle for years,
37:39and is very excited by the team's discoveries.
37:45It's like it's a fish with arms.
37:47That's what's amazing.
37:48So the way they swim is with movements of an arm.
37:54They're doing this.
37:56It's not just a little paddle.
37:58It has bones inside that can move much like our own arm bones.
38:02Look at that turn around.
38:06A closer look at the footage reveals some important details
38:10of how the coelacanth uses its frontal or pectoral fins.
38:16It appears to rotate each fin as if it were trying to stroke its own head.
38:30Slowed down, we can see the movement more clearly.
38:37By superimposing the bone structure onto the fin,
38:40we can see that the bone bends at each joint,
38:44allowing for this wide range of movement.
38:57Even the scientists themselves are surprised by this revelation.
39:04I haven't seen it like this, no.
39:06I can make guesses, hypotheses, about how those bones actually moved.
39:13But I don't really have the creature to look at.
39:15I'm inferring it from a skeleton.
39:18But when I see a video like this,
39:20I begin to see a living creature and how those bones are used.
39:25So it allows us to interpret those fossils in whole new ways.
39:31As we study these fish, we understand something about ourselves.
39:36I find that very powerful and very beautiful.
39:39And when we look at creatures like this,
39:41we see the evolutionary history we share with fish.
39:46On land, these bony and flexible structures supporting the body would have then gradually evolved into well-mossed legs.
39:59Over time, those early limbs evolved into many different forms.
40:06Sturdy legs for walking on land.
40:10Light wing bones for taking to the sky.
40:15And dexterous hands capable of grasping.
40:22They evolved to meet the needs of different habitats.
40:26And as a result, life on land became rich and varied.
40:33The coelacanth's fins led to limbs suited to movement on land,
40:37and so paved the way for all terrestrial life and our own evolutionary history.
40:49Whilst the coelacanth has shed important light on evolutionary questions,
40:54we still know very little about how the species lives.
40:58Dr. Kerry Sink is hoping to answer some of these questions.
41:04One of her main aims is to find out more about the fish's reproductive behaviour.
41:12Cedacanths have white speckles all over their bodies.
41:17Each fish has its own unique pattern and looks slightly different.
41:28Kerry has used these differences to identify individuals.
41:36I want to be paying attention to what's happening from fish to fish,
41:42so I've been taking careful notes about which fish is which
41:46and how they might be interacting.
41:48On this expedition, one particular individual has attracted Kerry's interest.
41:58It's the female that she had followed to the group under a ledge.
42:02Kerry recognises it by a unique feature.
42:07So the W mark is one of the most distinctive marks
42:11on the right flank of the big female.
42:15Kerry knows it's a female because of its size.
42:19Females are larger than males.
42:23She's keen to follow this female to see if she can discover
42:27any evidence of breeding activity.
42:33The sub prepares for another dive.
42:48They have headed to the rock face where they last saw the female coelacanth.
42:55I haven't seen the W. Have you seen the W?
43:00After 30 minutes, the female with the W mark appears.
43:10She is over a metre long.
43:13And because she's larger than the others,
43:16Kerry hasn't exclaimed her Big Mama.
43:20And she continues to keep a close watch on her.
43:28Five hours later, the coelacanths begin to do something
43:32that the scientists have never seen before.
43:40Some of the fish begin to hang vertically in the water.
43:47Oh, good luck.
43:48Look how they're all moving.
43:50So crazy.
43:53Kerry believes that this may be coelacanth courtship behaviour.
44:00I think we're promoting coelacanths.
44:09The coelacanths.
44:10And look at the white tummy.
44:14They don't normally look like that, right?
44:20Very interesting behavior.
44:25The coelacanths have turned their undersides white.
44:29Many fish change colour in order to attract a mate.
44:34And Kerry suspects that coelacanths may also do so
44:37to appeal to the opposite sex.
44:47The team in the other sub are also witnessing some interesting activity.
44:54One of the coelacanths is heading away from the rest of the group.
45:04It's heading straight for another fish approaching from the other side.
45:23The two fish begin to circle each other.
45:27Perhaps their rival males competing for a female.
45:35The two fish begin to circle each other.
45:41Back at Kerry's sub, Big Mama, with her distinctive W mark,
45:47is also being approached by a male.
45:52He is clearly smaller than she is.
46:00As he sidles up to her, he appears to rub his head on her underside.
46:08The researchers think that she might also be producing some kind of a theramone
46:14that attracts males.
46:23He continues with this curious mating dance for over three minutes.
46:29He continues with this curious mating dance for over three minutes.
46:46It's an exciting discovery that brings us one step closer to understanding their breeding behaviour.
46:57For Kerry, this is a career highlight.
47:02Just like deep gratitude and something I've wanted for a long, long time.
47:0924 years.
47:10I told the coelacanps, thank you.
47:13Thank you, thank you, thank you.
47:17Big hugs.
47:20Congratulations.
47:21It's so cool.
47:23Of course.
47:31Although coelacanps have managed to survive for 400 million years,
47:36they now face a new threat.
47:44Oh, what's this?
47:50Oh, what's this?
47:51There is something drifting in the water.
47:55Trash, I guess, maybe?
47:57Yeah, I think so.
47:59The team are shocked to discover plastic waste, even at these depths.
48:07Throughout the expedition, they found evidence of human waste products, littering the ocean floor.
48:23The ancient fish now face a deep-sea home full of our rubbish.
48:31And a dead coelacanth has even been found with plastic bags in its stomach.
48:42The coelacanth's home is often close to human habitation.
48:50Strong storms and typhoons carry rubbish deep into areas where the coelacanths live.
49:03Today, our activities threaten the home of this ancient creature in all of the world's oceans.
49:19The two-week expedition has come to an end.
49:28The coelacanth has come.
49:33The coelacanth has come up.
49:35To be present in this ancient creature, the coelacanth has come up.
49:43Here we have some Scanthus.
49:49The Coelacanthus is really a very special animal that has this window into the past, that
49:56has these really unique features that inspire incredible curiosity.
50:04For me, the Coelacanthus is also the ultimate survivor, and I was just experiencing amazement
50:11and awe and gratitude.
50:16The expedition recorded many important aspects of the Coelacanthus life for the first time.
50:23Its discoveries have helped us understand a creature that looks very similar to those
50:29that lived 400 million years ago.
50:35Hiding beside underwater cliffs, it now has a slow and energy efficient lifestyle.
50:49And breathes unobtrusively.
51:01As a species, Coelacanths have survived all the environmental upheavals that have transformed
51:10the planet.
51:12Watching them has brought to life one of the most crucial episodes in the history of life,
51:19when fish with stout, fleshy limbs emerged onto the land for the first time and became the
51:26ancestors of all land living backbone animals, including us.
51:32the wind lives of the sea whose life is the main levels of the beetle!
51:53But today, we go to the next generation.
51:53If you were to see you!
51:53I know your ancestors, my ancestors!
51:53I know your ancestors!
51:57You
Comments