YT YouTube2Text

YouTube2Text → Transcripts → Why You'd Never Want To Meet A Greenland Shark

Why You'd Never Want To Meet A Greenland Shark — Transcript

by Depth Theory · 2,981 words · 451 segments · language en · Watch on YouTube

Open in transcriber Summarize with AI Download SRT/VTT

Full transcript

0:00Picture this.
0:01You're hanging 20 meters under the
0:03Arctic sea ice. Above you, a ceiling of
0:06ice two meters thick, and one small
0:09square of light where the hole is.
0:11The water is minus one and a half
0:13degrees. It's so cold it should be
0:16frozen, and it only isn't because it's
0:18salty.
0:20Your torch beam goes out a few meters
0:22and then just stops.
0:24And down there, at the very edge of it,
0:26something moves slowly.
0:29A gray shape longer than a car slides
0:32into the light, turns and starts to
0:34circle you.
0:36It doesn't hurry. It has never had to.
0:39Hanging off each of its eyes is a pale
0:41little worm, and those eyes are fixed on
0:44you.
0:45This is the Greenland shark, and it
0:47might be the oldest animal with a
0:49backbone alive on earth today.
0:51Some of the ones swimming right now were
0:53probably already swimming before the
0:55United States existed.
0:57It's also the slowest fish for its size
1:00that we've ever measured, and yet
1:02scientists have pulled whole seals out
1:04of its stomach, freshly swallowed, and
1:06they still can't fully explain how it
1:08caught them.
1:09And when divers finally went down to
1:11meet it, it did exactly what this one's
1:13doing. It circled them. It watched them,
1:17and it followed them all the way back
1:19up.
1:20It has all the time in the world. You
1:23don't. So let's talk about why you'd
1:25never want to meet one.
1:27First, the size. Most adults are
1:30somewhere between two and a half and
1:32four meters long.
1:34The biggest one anyone has properly
1:35measured was a female of five and a half
1:38meters. That's longer than most cars,
1:41and one shark that wasn't even fully
1:42grown yet weighed 700 kilos.
1:46The seven-meter monsters you'll read
1:47about online have never been verified,
1:50but even the real numbers make it one of
1:51the largest meat-eating fish on the
1:53planet.
1:54Its scientific name means small head,
1:57and that's fair. Everything else about
2:00is big. A thick, heavy body, the color
2:03of wet slate, tiny fins, and a mouth
2:07that, as we'll see, can take a seal in
2:09one go.
2:11the strange part. In 2012, researchers
2:14put tags on six of these sharks off
2:16Svalbard to see how they move. Their
2:18normal cruising speed was about 1.2 km
2:21an hour. You walk faster than that.
2:24Its tail swept once about every seven
2:26seconds. Its fastest burst was under 3
2:29km an hour.
2:31For its size, nothing with fins has ever
2:34been measured going slower.
2:36So you'd think this is the one shark you
2:38could just swim away from.
2:40Hold on to that thought because we're
2:42coming back to it.
2:43Because here's what turns up inside
2:45them. When scientists in Svalbard went
2:48through the stomachs of 45 of these
2:50sharks, a third of the ones with food in
2:52them had eaten seal. In Greenland, one
2:55shark of about 4.7 m had two harp seals
2:59inside it, whole and fresh, 14 and 19
3:04kilos, swallowed, not chewed. One had an
3:07entire reindeer in it. Others had parts
3:10of a horse. And in 2008, one off
3:13Svalbard had a piece of a young polar
3:16bear's jaw.
3:17Now that doesn't mean it hunts polar
3:19bears or reindeer or horses. Those
3:22almost certainly fell into the sea
3:24already dead. And this shark is very
3:27happy to eat anything that sinks. In
3:292013, two men in Newfoundland pulled a
3:32huge piece of moose hide out of one
3:34mouth while it choked on it. But the
3:36seals are different. Seals are fast.
3:40Most seals can swim about twice as fast
3:43as this shark's best burst. And the
3:45seals inside it were whole and fresh. So
3:48how does the slowest fish in the sea
3:51catch one of the fastest animals in it?
3:54The best guess right now is that it
3:56doesn't chase them at all. Up here,
3:58seals often sleep in the water to stay
4:01away from polar bears up on the ice, a
4:03sleeping seal floats still in the dark.
4:07And a shark that barely makes a ripple
4:09that moves like it's drifting could
4:11slide up underneath it and just open its
4:14mouth. One of the researchers who has
4:16dived with them said they could take a
4:18seal in zero visibility without the seal
4:21ever knowing. To be clear, nobody has
4:24ever filmed this happening. It's a
4:25hypothesis, but it would explain
4:28everything. This shark doesn't need to
4:31be faster than you. It just needs you to
4:33stop moving, and it can find you when
4:36you do. Its nose is packed with folds of
4:39scent-detecting tissue. And like other
4:42sharks, it can sense the tiny electrical
4:45fields that living bodies give off. Now,
4:48about those eyes. That little worm is a
4:51parasite, a crustacean that clamps onto
4:54the eye and hangs there for life. Around
4:56Greenland and the eastern Canadian
4:58Arctic, roughly nine in 10 of these
5:01sharks have one. It scars the eye. And
5:04for years, a lot of people assumed that
5:06meant these sharks were blind. Then, in
5:09January 2026, a team published a study
5:12of their eyes. They're not blind. Their
5:15retinas are built only from the cells
5:17for seeing in dim light, tuned to deep
5:20blue, which is the last color left down
5:22there. And in sharks estimated at more
5:24than 130 years old, those retinas showed
5:28no obvious signs of wearing out. So in
5:30the dark, it smells you, it feels you,
5:34and it sees you. And you see a few
5:37meters of torch beam.
5:39So what happens when people actually
5:41meet one? In 2003, a team of divers in
5:44the St. Lawrence River in Canada, near a
5:46town called Baie-Comeau, started running
5:49into Greenland sharks in shallow water
5:51between 10 [music] and 28 m down. And it
5:54kept happening. Over a few years, they
5:57saw 85 of them, up to 11 on a single
6:00dive. The behavior was always weirdly
6:03similar. The shark would come in on a
6:06course that crossed the diver's path.
6:08Then it would circle. The divers
6:10described continuous eye contact. One of
6:13the researchers said, their eyes swivel
6:16and follow you. When the divers got too
6:18close, the shark gave a kind of warning
6:20display with its fins and then slid
6:23away. And when the divers headed up, the
6:25sharks often followed them all the way
6:27to the surface. The scientists wrote
6:30that these sharks could outpace a diver
6:32in a straight line, and they advised
6:34caution in low visibility. Remember the
6:37shark you could just swim away from? You
6:39can't. Here's the part that might
6:41surprise you though. There is no
6:43confirmed case of a Greenland shark
6:45attacking a person ever. The only
6:48reported one is from around 1859 when a
6:51shark caught in the Canadian Arctic
6:53supposedly had a human leg in its
6:56stomach. Nobody ever checked it, and
6:58even the registry that lists it suspects
7:00the person was already dead. So this
7:03isn't a story about a man-eater. It's a
7:06story about an animal that's patient,
7:08that's curious about you, and that lives
7:10in a place where you're already in
7:12trouble.
7:14So let's put you back under that ice and
7:16make it real. What would you actually
7:19do?
7:20You're 20 m down off Baffin Island.
7:22You're in a dry suit with two separate
7:25regulators on your tank because up here
7:27one of them freezing is not a matter of
7:29if.
7:31A line runs from your harness back to
7:32the only hole for 100 m in any
7:35direction, and a tender up top is
7:38holding the other end.
7:39Your buddy is next to you.
7:41You're 25 minutes into the dive. You've
7:44got 120 bar of air left, and your hands
7:47are already stiff.
7:49And now there's a 4 m [snorts] shark
7:51circling you, about 5 m away, and it's
7:54coming in tighter.
7:56So first move.
7:58Do you bolt for the hole, press yourself
8:00flat against the ice and keep still, or
8:03turn and face it?
8:05Pick one before I tell you.
8:07If you picked bolt, that's what almost
8:09everyone would do, and it's the most
8:11dangerous thing on the list.
8:13First, you can't swim straight up.
8:16There's a ceiling.
8:17The only way out is the hole, and you're
8:20not under it.
8:21Second, if you shoot up from 20 m
8:24holding your breath, the air in your
8:26lungs tries to expand to three times its
8:28size.
8:30Divers have been hurt by a held breath
8:32over an ascent of less than 2 m.
8:35Third, panic breathing.
8:37Pulling air hard and fast through a
8:39regulator in water this cold is exactly
8:42what makes it ice up and jam open. A
8:45free-flowing regulator can empty a tank
8:47in minutes. And even if it doesn't
8:50freeze, a panicking diver can burn
8:52through air three times faster.
8:55That 120 bar, calm, it would last you
8:58around 27 minutes at this depth.
9:00Panicking, maybe eight.
9:03And the shark you're trying to outrun is
9:04faster than you over a straight line
9:06anyway. Running turns you into prey.
9:10If you picked keep still against the
9:11ice, you've just turned yourself into
9:13the thing it's best at catching,
9:16something quiet, motionless, and in the
9:18dark.
9:19The right answer is the third one, and
9:22it's what dive safety organizations
9:24actually teach.
9:25Divers Alert Network puts it simply,
9:28continually face the shark. Don't bolt
9:31for the surface. Get something at your
9:33back. Under here, that means your buddy.
9:36So you go back to back, upright, and you
9:39turn with it so it never gets behind
9:41either of you. You keep looking at it.
9:44One study of reef sharks found they came
9:46significantly closer whenever divers
9:48broke eye contact. So now you're in a
9:51staring contest with something that
9:53might be 300 years old, and you are not
9:56allowed to blink first.
9:58Then you leave, but slowly. You give the
10:01line four pulls, which means haul me in,
10:04and you move along it together, hand
10:06over hand, still facing the shark.
10:09Polar diving guidelines are blunt about
10:11this. At no time should divers swim
10:14quickly away.
10:15And this is where the cold starts to
10:17cost you. With badly protected hands,
10:20divers can lose the ability to work
10:21their gear in 5 to 10 minutes. Feeling
10:24the line pulls, working your clips,
10:27gripping the rope, all of it gets worse
10:29with every minute. When you reach the
10:31hole, you still can't just go up. You
10:34rise slowly, about 9 m a minute, and
10:37then you stop at 5 m for 3 minutes so
10:40your body can get rid of the nitrogen. 3
10:43minutes hanging still in a column of
10:45light, which is exactly when your hands
10:48are at their coldest. And dive guides
10:50warn that sharks often rise with divers.
10:53So you point your fins at it and you
10:55wait. And then comes the most dangerous
10:58moment of the whole dive, getting out.
11:01For a minute or two, your head is up in
11:03the air and your body is hanging in the
11:05water underneath you while your tender
11:07helps you out of your gear. Something
11:09still at the surface, at a hole in the
11:12ice. To anything looking up from below,
11:15that's what a seal at its breathing hole
11:17looks like. Polar dive manuals say
11:19divers are most vulnerable going in and
11:22coming out. So the safest diver is the
11:24one who gets out of the water fast and
11:26doesn't hang around in it. You did
11:28everything right and it never touched
11:31you. It didn't need to. It has all the
11:33time in the world.
11:35Because time is the real story of this
11:38animal. Sharks are almost impossible to
11:41age, but in 2016, a team led by Julius
11:44Nielsen found a way using the lens of
11:47the eye. The center of the lens forms
11:49before birth and never changes after. So
11:52they carbon dated it. And to check their
11:54clock, they use something you wouldn't
11:56expect. The nuclear bomb tests of the
11:581950s and '60s left a spike of carbon in
12:02the oceans. And only the three smallest
12:05sharks had that spike in their eyes.
12:07Everything older than that had been born
12:09before the bombs. They put the biggest
12:12shark at just over 5 m at around 390
12:16years old.
12:18But the uncertainty is huge.
12:20It could have been as young as 270
12:23or as old as 512.
12:26That's where the famous 512-year-old
12:28shark headline comes from, and it's
12:30misleading because that's just the top
12:32of the range.
12:34Some scientists also think the whole
12:36method needs more testing, but even the
12:38lowest number means that a big shark
12:40alive today was probably born before
12:421776.
12:45The middle of the range puts it around
12:47the time the Mayflower sailed, and they
12:49grow incredibly slowly. One shark tagged
12:52in 1936 and caught again 16 years later
12:56had grown about half a centimeter a
12:58year.
12:59Your fingernails grow several times
13:01faster than that.
13:03And here's what that does to them.
13:05A female isn't ready to have pups until
13:07she's at least about 150 years old.
13:11In 2022, a 4 m female washed up in
13:14Cornwall in England.
13:16She was estimated at around 100 years
13:18old, and she was still a juvenile, a
13:21teenager basically, at an age most
13:24people never reach.
13:26So how does anything live that long?
13:28The cold slows everything down, but
13:30that's not the whole answer.
13:32In May 2026, a team in Japan published
13:35its full genome.
13:37It has around 5.9 billion letters of
13:40DNA, nearly twice as many as yours, with
13:43extra copies of genes linked to
13:45repairing DNA and fighting cancer. And a
13:482026 study of its heart found something
13:51weird.
13:52The heart muscle was full of scarring
13:54and old damage, the kind you'd expect
13:56from great age, and it was still working
13:59fine. So it doesn't avoid getting old,
14:02it just doesn't let getting old stop
14:04[snorts] it. Now, say you met one and
14:07somehow came out on top, could you at
14:09least eat it?
14:11Please don't. Its flesh is loaded with a
14:13chemical called TMAO,
14:16which helps it cope with the cold and
14:17the pressure. When your gut breaks that
14:20down, it turns into something toxic.
14:23Sled dogs fed fresh shark meat have
14:25staggered around, had convulsions, and
14:27even died.
14:29Inuit stories explain it differently.
14:32One says the first Greenland shark was a
14:34cloth used to dry an old woman's hair
14:36after she'd washed it in urine and that
14:38it blew into the sea.
14:41In Iceland, they found a fix. You bury
14:43the shark under gravel and stones for 6
14:46to 12 weeks, dig it up, and hang it to
14:48dry for months. That makes hákarl,
14:51Iceland's famous fermented shark.
14:54Anthony Bourdain called it probably the
14:56single worst thing he'd ever eaten.
14:59Gordon Ramsay threw it up into a bucket.
15:02It's a national dish.
15:04And for an animal this famous, we know
15:06almost nothing about how it starts life.
15:09Only one pregnant female has ever been
15:11properly confirmed back in 1957, and she
15:15was carrying 10 pups, each about the
15:17length of your forearm. Nobody knows how
15:20long the pregnancy lasts, and in a 2025
15:23study, researchers looked at more than
15:251,600 sharks caught in fjords and on the
15:28shelf around Greenland, and not one of
15:30them was a newborn. The few newborns
15:33ever found turned up far out in the
15:35North Atlantic, near the middle of the
15:37ocean. So somewhere out there, in deep
15:40water, there's a nursery for this animal
15:42that nobody has ever seen. And they
15:45don't stay in the Arctic. Tagged sharks
15:47have dived past 1,800 m, and one was
15:51caught in the Gulf of Mexico.
15:53So here's the thing. After all of that,
15:55you'd think this animal is invincible.
15:58It isn't, and people are the reason why.
16:01A century ago, Greenland and Iceland
16:04hunted them for the oil in their livers.
16:06In the early 1900s, Greenland took the
16:09livers of around 44,000 sharks a year.
16:12The oil lit lamps in Copenhagen.
16:15Norway caught close to 60,000 in a
16:17single year in 1948.
16:20Later, fishermen were even paid bounties
16:23for shark hearts as proof of the kill.
16:25Today, nobody really hunts them, but at
16:28least 3 and a 1/2 thousand a year still
16:30get caught by accident in nets and on
16:33lines set for other fish. And even when
16:35they're released, about a third of the
16:37ones caught in trawls die within a
16:39month. They're so slow and so calm that
16:43one scientist said they're good at
16:44playing dead, so crews often assume they
16:47already are.
16:49Now think about what that means for an
16:50animal that can't have pups until it's
16:52150.
16:54A shark that dies in a net today might
16:56have been swimming since before your
16:58great great great great grandparents
17:00were born, and replacing her takes a
17:03century and a half. In 2020, it was
17:06listed as vulnerable. In 2022, the
17:09international body that manages fishing
17:11in that part of the Atlantic banned
17:13keeping them. And in Canada, any
17:15Greenland shark that's caught now has to
17:17be released alive.
17:19So that's why you'd never want to meet
17:21one. Not because it's a monster. There's
17:24no confirmed attack on a person ever.
17:26It's because of everything around it.
17:29The cold that takes your hands in
17:30minutes, a ceiling of ice with one way
17:33out, a shark that can find you in the
17:36dark, that circles, watches, and follows
17:39you up, and it seems to have one rule.
17:42It doesn't need to be faster than you.
17:44It just needs you to stop moving. You'll
17:47get maybe an hour down there. It's had
17:50400 years. It has all the time in the
17:53world. You don't.
17:56Anyway, thanks for watching this one. If
17:58there's another animal you'd like us to
17:59put you in the water with, let me know
18:01in the comments. And if you want to see
18:02another video like this one, check it
18:04out here.

About this transcript

This page contains the full transcript of Why You'd Never Want To Meet A Greenland Shark by Depth Theory, generated from the public captions YouTube serves with the video. The transcript has 2,981 words across 451 segments, with the original timestamps preserved so you can click any line to jump to that moment in the embedded player.

What you can do with it

Use the transcript to take notes, quote the speaker, build a study guide, generate a summary with ChatGPT or Claude via the YouTube Summary tool, or export it as a timed subtitle file with YouTube to SRT. You can also re-open it in the transcriber to choose a caption track available on the video.

Free YouTube transcript tool

YouTube2Text is a free YouTube transcript generator — no signup, no daily limit. Paste any YouTube link and get the full transcript instantly, with timestamps, click-to-jump, caption language selection, AI prompts for ChatGPT, Claude, and Gemini, and exports to TXT, SRT, VTT, or Markdown.