- 5/30/2025
In February 2008, a team of the world’s leading marine scientists set out onboard the RV Tangaroa on a voyage like no other across the Great Southern Ocean to Antarctica. In the footsteps of Shackleton’s ill-fated expedition, their mission is to discover more about marine life in Antarctic waters. This is unchartered territory – as many scientists say… ‘less is known about the Antarctic seabed than the surface of Mars!’ Cooped up on a research vessel for 50 days they battle ferocious storms, some of the worst ice conditions ever encountered and personal tragedy. The stakes are high but this is science at the edge. If successful their findings could profoundly affect all our lives as the intrepid crew seek out clues about the future fate of our planet beneath the icy waters of one of the world’s most perilous yet most important oceans.
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00:00Antarctica. Unbelievable. Unbearable.
00:10And now, a 50-day sea expedition attempts to crack its mystery.
00:15Uncovering the improbable creatures that somehow thrive at this merciless alien edge of our planet.
00:30Day one. The government research vessel Tongaroa embarks from Wellington, New Zealand on a precarious 50-day, 6-million-dollar mission.
00:43Destination? Antarctica. A voyage of potential discovery and definite danger.
00:51Just getting to the Ross Sea will tax the ship and crew.
00:57Navigating the mighty southern ocean at 460 kilometers of crushing sea ice.
01:10In this international polar year, Tongaroa will join 17 other ships in a top-to-bottom census of Antarctic marine life.
01:22And Andrew Leachman is its captain.
01:27The telephone directory of everything that's down there. Because it's never really been done.
01:34But satellite charts show the worst icing condition in years.
01:38Even with Tongaroa's 70-meter-long reinforced hull, this could be a mission impossible.
01:46Though he can hardly wait to get his hands on the strange, scaly creatures from the sea floor.
01:51Marine biologist Andrew Stewart knows it'll be no dip in the ocean.
01:56The ocean is a very difficult environment to study.
02:00Down here in the southern ocean, everything is that much harder.
02:03You've got to kit up like the Michelin man to get out on deck. Everything takes so much more effort.
02:15Whatever happens, the 44 scientists and crew know they'd better play well together.
02:20Because there's no turning back.
02:23They certainly won't like toys.
02:27The team has new gadgets, new cameras, cutting-edge science to help them check the health of the ocean.
02:34Has overfishing caused harm?
02:38Is global warming forcing a sea change?
02:42The scientists aim to find out.
02:48Once they get past the seasickness.
02:51Ship's doctor, Jenny Visser, takes her job very seriously.
02:56Tongaroa will sail well beyond the reach of a helicopter rescue.
03:01If illness or injury strikes, help will come by slow boat.
03:07Or not at all.
03:09Dr. Jenny's skills could mean the difference between life and death.
03:16Right. How are we doing?
03:18Good. Perky bit. Just over here.
03:20Yep.
03:22Six days out, the team spots its first iceberg.
03:26See that? It's on the radar. That's good. That's good.
03:28A free-floating chunk of ice, calved off an ice shelf.
03:33This legendary menace of the high seas reveals only one-eighth of itself as it glides aimlessly and destructively through the water.
03:41Now you get up the port side, you'll see an iceberg.
03:47The team find it thrilling.
03:49An ominous hint of the hazards that lie ahead.
03:52Tongaroa is a fisheries research vessel. No icebreaker. And these small icebergs, called growlers, seem to be ganging up on the ship.
04:06Obviously, we're, um, there's icebergs around. It's Bergy water. There's a few growlers about.
04:13We're heading south, so I'm not certain exactly where I'm going to go. I want to go and have a look and just have a feel for the terrain and so which way we can work our way through the ice to the Ross Sea.
04:25Captain Leachman navigates these waters knowing others have attempted and failed.
04:32You're in the footsteps of Scott and Shackleton. It's a challenge. It's a real challenging thing for any ship's captain to take a ship down there.
04:40In 1914, Sir Ernest Shackleton's ship, Endurance, became trapped in sea ice.
04:52He and his crew spent a grueling winter battling the elements until the ice ultimately crushed and sunk the ship.
05:01It's an epic tale of Antarctic survival.
05:04And it replayed in 2007 when ice engulfed the tour ship Explorer in Antarctic waters.
05:13Read the history and you'll know I am very careful because I know the rules.
05:19The rules are simple. Never underestimate the ice. And never turn your back on it.
05:26Satellite ice charts and reports from other ships will help guide him to the thinnest parts of the pack ice.
05:32Head scientist, Stu Hanchett, worries about the encroaching ice barrier scuttling their plans.
05:39But he trusts the captain.
05:41There was quite a bit of a concern whether we would in fact be able to get into the Ross Sea and achieve some of our objectives.
05:48We envisage probably taking two, maybe three days to break through the pack ice into the open waters of the Ross Sea itself.
05:54The Tungaroa may not be an icebreaker, but the ice doesn't know it.
06:01The shark prowl makes short work of it, for now.
06:06The shark prowl makes short work of it, for now.
06:09Off the stern, the minky won a fine sanctuary, scarfing down a hearty meal of krill among the ice chunks.
06:29Minkies can grow nearly nine meters, positively puny compared to their blue whale cousins who can stretch to more than three times that size.
06:42And that means an awful lot of krill to sustain a healthy population of whales, penguins and seals.
06:53Especially the crab eater seals, who also make their home on the shifting ice, slurping down krill, not crabs.
07:00Each year, they eat about 25 times their body weight and krill, filtered through their interlocking, strainer-like teeth.
07:12And these ever-popular emperors of Antarctica will pass the dark and brutal winter by mating.
07:19They'll brave temperatures lower than minus 40 to lay eggs and raise their chicks.
07:24The work these scientists do down here could help all these animals survive an uncertain future.
07:32Each night, three hours of darkness brings new danger to the ice-clogged waters.
07:39Safety depends on constant vigilance.
07:44And this is only summer ice. In the winter, Tangaroa wouldn't stand a chance.
07:56Right, how are we doing? Let's look.
08:09At last, the ship breaks free.
08:19By now, Tangaroa has spent 10 days at sea, nearly four of them packed in ice.
08:27Wind and currents keep this part of the Ross Sea ice-free in summer.
08:31Voyage leader John Mitchell can breathe a little easier, but experience tells him he hasn't seen the last of it.
08:41It's always going to get in the way, regardless of what you do.
08:44Even on the best ice years, you still get ice. It's always where you want to be.
08:50While the sea stays calm and free of ice, the team prepares to plunge into an alien world.
08:55For the first time, sea scientists will get to see what's down there, courtesy of the deep-toed imaging system they call DITIS.
09:05Custom-made for this type of deep-sea exploration.
09:13Its high-definition video and stills cameras will access the team's eyes in this high-pressure, low-light environment.
09:20No one has actually field-tested the unit in such icy conditions before.
09:38Too late to think about that now.
09:40Like an explorer dispatched to a foreign world, the imaging system begins its fact-finding mission.
09:50The scientists hold their breath.
09:52Uh, yeah, this is the dry-legged rail on town 15, mate.
09:55Roger that, thank you.
09:59Nobody really knows what's down here.
10:01At last, the ocean floor.
10:04Andrew, could you just, uh, hold here for a moment, please?
10:11I'm recording now.
10:14To a marine biologist, this is big.
10:18Like the first moonwalk.
10:21As the live video images come up from the seabed, the scientists log what they see,
10:27and strain to find things they've never seen before.
10:36They will crawl for an hour, the length of a videotape,
10:40giving the team their first tantalizing image of polar marine life in perpetual nighttime.
10:46There's quite a lot of fragments of things here, isn't there?
10:56Now that they've seen the creatures on the video, they want to get their hands on them.
11:02For that, they'll need to trawl with nets, not cameras.
11:06They approach trawling systematically.
11:15First, they'll trawl the bottom of the ocean, sweeping across the floor to sample the bottom dwellers.
11:24Then, they'll trawl at mid-level, collecting samples of free-swimming fish.
11:29Then, skimming the surface for plankton.
11:33They'll also use specialized equipment to sample water and mud from directly beneath the ship
11:39to study its microbes and chemical makeup.
11:45As a commercial fishing practice, bottom trawling dredges up worldwide controversy
11:50because of damage to the seabed.
11:52Science, however, takes a gentler approach.
11:55You know, we have limited our trawls to about 15 or 20 minutes bottom time.
11:59The actual percentage of the total seabed area impacted by the bottom trawl is very small.
12:07Woo! It's chilly cold!
12:10But the bottom trawl doesn't even last 15 minutes before the rough seabed forces the crew to pull the net.
12:18That's the cue for American marine biologist Christopher Jones to grab his gear.
12:24This will be exciting.
12:27The anticipation makes the scientists forget all about the minus 10 degrees Celsius conditions.
12:34And Andrew Stewart thinks all of his Christmases have come at once.
12:38It's going to be a bit like Santa Claus coming up the stern ramp there.
12:43We don't know what's going to be in that sack.
12:45It could be a pair of socks, or it could be a new bike, who knows.
12:53Now, this is good. We've got all sorts of things in here.
12:55Santa must be pleased with Christopher Jones.
12:59There's a big desosticus, a big, beautiful desosticus mossini.
13:04That's what we're looking for. We've got a good one here.
13:06Desosticus mossini, the Antarctic toothfish, one of the giants of the marine ecosystem.
13:12On the menu, it goes by Chilean sea bass, and it's harvested by the thousands.
13:17If it disappears from the ocean, more than dinner's at stake.
13:23A nice, diverse catch here.
13:26It could mean an ecosystem on the brink of collapse.
13:30This is the fish that is probably the most economically important species that's being caught by the commercial fishery in the Southern Ocean.
13:39This is a fine specimen here of an Antarctic toothfish.
13:42This big guy tells the crew that all's well down below.
13:49The undersea camera built up the team's expectations about what they might collect.
13:56The bottom trawl net delivers on its promise.
14:00Sponges, among the most primitive sea animals, have no nervous or digestive systems.
14:06They feed by filtering water through their pores.
14:08The trawl brought up an exotic specimen that weaves its body out of silica.
14:15That's a hexactonellid sponge, which is also known as a glass sponge.
14:20And a very slow growing, very irritating if you get any of the spicules on you.
14:26And Santa's sack has delivered a special gift for Andrew.
14:29Snail fish. Fantastic.
14:31Snail fish are poorly understood.
14:33And Andrew may have found a new species.
14:35Some of these beauties down to the lab.
14:37Get a ball.
14:39This is why I came to Antarctica.
14:41Seeing things like this, it's just beyond words.
14:43We now have whole families of fishers that are found nowhere else in the world except in the Southern Ocean.
15:02And these are fascinating animals.
15:04These are the ice fishes.
15:06Temperatures above 5 degrees Celsius are too hot for them and in fact are lethal for them.
15:10The sea holds a dizzying variety of fish to baffle and thrill marine biologists.
15:17Nature even saw fit to make about 115 species of Andrews snailfish.
15:23You have to look at such features as the shape of the teeth, the jaws, the shape of the gill rakers, as well as counts of the vertebrae, counts of the dorsal and anal fin rays.
15:33And then along comes the kind of discovery that blows biologists out of the water.
15:40Now I have no idea which species this is at the moment.
15:45That color pattern on the fins is like nothing I've ever seen before.
15:49Most scientists hope to find something truly new, but only a few actually accomplish it.
15:54Andrew might have discovered yet another new species.
16:00Making him the first human to lay eyes on this creature that's evolved over millions of years.
16:09Though cut short, this first trawl offers something for everyone.
16:13I'm very happy with the first trawl.
16:16Yeah, we only had 10 minutes on the bottom.
16:18And it was still quite rough ground so we had to haul early.
16:22But yeah, it looks very good for the first one.
16:25Scientists have catalogued about 135 species of fish from the largely unexplored Moss Sea.
16:33On this expedition, the team intends to add a new chapter to this Antarctic fish story.
16:46In the depths of the ship, the team studies the fish finder to locate schools of small fish and krill,
16:52the foundation of the elaborate food chain.
16:55Since big fish depend on little fish, the scientists want to check their health.
17:00That means another fishing expedition.
17:04Yeah, hi, Andrew. It's Richard here down in the acoustics lab.
17:09We're seeing a bit of a mark on our sounder down here.
17:11We're quite interested in doing a mid-water trawl.
17:16The target's spotted. The net's deployed.
17:23But as the net closes in on the fish, the weather closes in on the ship.
17:31Unlike the previous trawl, this monster mid-water net will trawl between surface and the sea bottom, scooping up the free-swimming fish.
17:42This is the bit that's going into the trawl, and all these little red tick marks through here, that tells us we're catching fish.
17:49So everything's looking good, isn't it, Andrew?
17:51It is indeed.
17:53Menacing clouds gather on the horizon.
17:57A sudden turn into polar weather can endanger equipment and anyone caught on deck.
18:02Okay.
18:04We'll pull it down. There, Annie.
18:06Coming up. There she comes.
18:07The wind from the approaching front hits suddenly.
18:13Before they can get the net on board, a full gale sends its fury.
18:17All the way down. All the way down.
18:18All the way down. All the way down.
18:19All the way down.
18:20All the way down.
18:21All the way down.
18:22With the stern ramp open, the angry scene floods the deck.
18:23,
18:25.
18:35.
18:47.
18:51Crashing over the stern can easily sweep a crew member into the icy churning sea, where
18:56the cold shot can kill in three minutes.
19:00But the crew won't abandon the catch.
19:06The net overflows with silverfish, a very healthy sign.
19:16It's one of the most abandoned species in the Ross Sea.
19:20It's eaten by quite a lot of species, so it's important in the food chain.
19:26Among the massive silverfish, Andrew spies a lethal predator most likely feeding when snared.
19:33What's the name of that again, Andrew?
19:34Daggertooth.
19:35A daggertooth.
19:36I wonder what was called that.
19:38Pick your finger in his mouth.
19:39This striking find wields a mean set of choppers.
19:43It's a pretty fish.
19:45It's just up underneath like that.
19:46Lights down, chop, reverses, and it severs the spinal cord.
19:52It's paralyzing that fish.
19:54It turns around.
19:56The ferocious storm puts a halt to the science program.
20:01The ship slows down to ride it out.
20:06Nature runs the showdown, and the team battens down the hatches.
20:13This isn't fun, you know.
20:15Despite the boats pitching and rolling, life goes on.
20:21A well-stocked galley serves those who could still manage to keep the food down.
20:28Whatever the sea throws at them, the team takes in stride.
20:34Though striding in heavy swell does take some practice.
20:38At last, the storm passes, costing the crew a day and a half's sampling.
21:07Microbiologist Julie Hall's work involves checking the health of the Southern Ocean's
21:12tiniest residents.
21:17This device collects her water samples.
21:22She can remotely open and close the sampling bottles at various depths from the seabed to
21:27the surface.
21:29Okay, we're ready to go.
21:32Once the samples break the surface, the team rushes to retrieve them without spilling a drop.
21:37There we go.
21:38Get ready.
21:39Get up, boy.
21:40Get up.
21:41As you can see, it's a difficult and dangerous operation, and the deck crew have to be really
21:51careful bringing it on board in such rough and slippery conditions.
21:55So we're going to pull it round into the garage so that we're out of the wind with the sampling,
21:59and then we'll start taking the samples off the bottles.
22:04She wants to see if increased greenhouse gases in the ocean have any effect on life down here.
22:09She'll measure chemicals, water temperature, and bacteria in the sea.
22:16We've got the water from that coming out and going in about ten different directions for
22:21analysis of nutrients in the water, chlorophyll, phytoplankton.
22:26We're also looking at viruses, the micro zooplankton, those very, very tiny zooplankton.
22:35Her work in this far off sea may have global implications, but Julie's about to feel the
22:41full weight of her isolation from the world back home.
22:45Just two weeks into the mission, Captain Leachman receives an urgent satellite phone call from
22:55the New Zealand police.
22:57Early morning, I was called to the bridge, and the sergeant in Matamata said, look, we've
23:08got some bad news.
23:09Have you got a Dr. Julie Hall aboard?
23:11And I said yes, and he said, well, unfortunately her husband's been killed in a gliding accident.
23:24Anyway, what I did do is got Julie up and sat her down.
23:30It was my duty to inform her, and it's a very, very difficult thing to do, so I'm awfully sorry.
23:40I've got some bad news, and your husband's been killed.
23:45Julie's husband, Dr. Trevor Adkins, was also a scientist.
23:50He died while competing in a gliding competition.
23:53He was competing in the New Zealand championships, and he'd had an accident very close to the airfield, and had been killed instantly on impact at the site.
24:03I explained that I would do everything in my power to get her home, but the difficulty, of course, of being isolated where we were, there's no guarantee we could get her off.
24:18Fickle weather and enormous distances have conspired against Julie.
24:31By now, Tangaroa has sailed well beyond reach of any helicopter, and too far out to turn around.
24:42If Julie has any hope of getting home, Captain Leachman must find a nearby ship able to make the journey.
24:48I had to think about my own situation, how I felt about things, how any decision impacted on others back in New Zealand, but also the impact me leaving would have on the science and the people around me.
25:00With the weather deteriorating, and the nearest ship at least three days away, Julie has to make an immediate decision.
25:11Stay with the mission, or return home to her family.
25:17And as it turned out, I'd made the decision not to leave.
25:23She decided that really, she was going home to an empty house, and that she didn't want to go home.
25:28She was happy where she was.
25:31The strongest reaction of why aren't you coming home came from people who really didn't understand the isolation,
25:36and also not really the situation on the ship in terms of being surrounded by close colleagues who were very supportive.
25:49As they edge their way along the Ross Ice Shelf, the wind kicks up an icy spray.
25:54Just another summer day in the Antarctic.
26:00The temperature plunges to minus 14 Celsius, and spray freezes on contact.
26:08The next deep-toed imaging deployment gets put on hold, much to the crew's relief.
26:14Such is the life of a sailor. Everything's frozen, including us.
26:23And the forecast gets even more chilling.
26:26Okay, it's a satellite image that just came in this morning to show us the current state of play.
26:31The southern Ross Sea is refreezing faster than expected, already covering several of their planned sampling stations.
26:39It could be arduous. If the southerly wind continues, the whole thing's going to freeze up, and it'll be like operating in fresh-legged concrete.
26:49So it's not good. We won't really do much sampling if those conditions prevail.
26:53With the water temperature down to minus 1.8 Celsius, the sea starts to freeze in a spectacular, if alarming, display.
27:06It stretches to the horizon in every direction, and can potentially strand the ship.
27:11I don't like it when it's really thick. I really don't. I'm always fat and I'll do a Shackleton.
27:28The pancake ice has begun.
27:31Heralding one of the planet's greatest annual displays, the freezing of seas around Antarctica.
27:36Over winter, the event effectively doubles the size of the continent.
27:54The science leaders call an emergency strategy meeting.
27:59Morning. How are you?
28:00Morning all.
28:01I think the general consensus is now that we don't go much further east than here, which is probably a good idea, because looking out the window.
28:11They agreed to continue their work here as long as they can, before the ocean freezes solid.
28:18Because of the southernmost extremity of our activities, we're going to do Adidas tow, and then we will proceed north-west.
28:24It's like fishing in a margarita.
28:44The slushy turmoil on the surface hides the calm waters below.
29:02As Antarctica began its deep freeze over 30 million years ago, life here evolved and flourished.
29:09Now comes a new challenge.
29:14Despite the pristine nature of this remote ocean, the imaging system shows human intruders.
29:20The stills camera snaps a beer bottle.
29:23And commercial fishing activity leaves its mark in the form of a trawler's longline.
29:30When the weather allows, commercial trawlers drop their deadly longlines here to catch toothfish, the so-called sea bass.
29:40This healthy specimen means more than tonight's dinner special.
29:51It's the poster child for good fishing management.
29:55Elsewhere in the southern seas, indiscriminate practices have dangerously depleted its relative, the Patagonian toothfish.
30:02But stricter Antarctic regulations allow us to have our fish and eat it too.
30:10Christopher Jones hopes it stays that way.
30:14It's the one fish that human beings are having the greatest impact on.
30:19We're okay now, but we have to be very, very cautious if we decide to increase the catch.
30:25This whopper weighs an incredible 56.8 kilograms.
30:30And still only half the size these mighty fish can grow.
30:35In one recent summer, the longliners relieved the raw sea of 3,000 tons of them.
30:41While Tangaroa has only caught five for research.
30:46There may still be plenty of fish in the sea, but these scientists are always chasing the one that got away.
30:53Besides catching a mammoth toothfish, the team has also collected some of its favorite food, including the glacial squid.
31:02That's a lovely specimen of the glacial squid.
31:06Very nice condition indeed for a very delicate squid.
31:11Squid and octopus, fragile members of the rich and diverse cephalopod family, live in every climate and at every depth.
31:17They may look bizarre, but they boast the biggest brains among the invertebrates.
31:24Like any spineless creature, a squid's first instinct is to hide.
31:29But a cornered one has some potent weapons in its armory.
31:33Like this parrot-like beat that can deliver a nasty peck.
31:37Or these lethal hooks used for snaring prey.
31:40But right now, Darren Stevens has snared his catch of the day.
31:47An incredibly rare, deep-water octopus.
31:51This is a lovely specimen of Storotuthis.
31:55It's another one of the Dumbo octopus and a very gelatinous individual.
32:02Only a handful of these octopuses have ever been found anywhere.
32:06And this is the first intact one caught in the Ross Sea.
32:10The fact that it came out of the net 100% intact makes it even more remarkable.
32:14So far, Darren has collected 26 species of squid and octopus.
32:25But he yearns for the big one.
32:30This baby colossal squid, found only in Antarctic waters, can grow up to an amazing 4 meters long.
32:37Darren hopes to meet its mother.
32:39Overnight, the imaging system shows the seabed too rocky for the bottom trawl net.
32:48The situation calls for the smaller, more robust beam trawl.
32:56Instead of the steel doors, a large wooden beam props open the mouth of the net.
33:01Here we go.
33:03As the net pulls in, the team eagerly awaits its catch.
33:08From 1600 meters down, it feels like they've hooked the big one.
33:13Perhaps it's Darren's colossal squid.
33:19Well, yeah, I heard something go whomp right there.
33:23Not a squid, but colossal all the same.
33:27Well, it looks like we might have done a little bit more geologic sampling.
33:31Oh dear!
33:37The deckhands get left with the heavy lifting.
33:47Studying the latest satellite charts, Captain Leachman finds a pathway through the ice barrier.
33:52If they leave right away.
33:53At some stage, we'll need to escape from this area, through this ice bridge, and away to the north.
34:01The way to deal with encroaching ice is to head for warmer waters.
34:04And, in the southern hemisphere, that only means one thing.
34:12Go north, young man. Go north.
34:17Bring her up and drop those.
34:19As Tangaroa steams north into deeper water, Julie deploys the multiple opening and closing net, or mockness.
34:32Each tentacle of this mockness monster has snatched plankton and krill from various depths.
34:37This is a very important mockness sample for us.
34:41It's come from 3,400 meters. It's the deepest one we've ever done.
34:47Along with the microscopic animals, known as zoo plankton, Lisa spies a tiny deep sea squid.
34:53A little gift for Darren, the squid guy.
34:56Is Darren up there?
34:58Darren?
34:59Darren, yeah.
35:00He says he is.
35:02Tell him we've got a present for him in the plankton lab.
35:07Isn't he beautiful? He's in very good condition.
35:10You know, we've found some fascinating things, and quite often they're bright red, which is really cool.
35:16He's great and very much still alive.
35:21What have you got for me?
35:23Here we go.
35:24That is gorgeous.
35:27Vathytosis of bisicola.
35:29You've done very, very well.
35:39As Tangaroa nudges north into the sea ice, the work in the plankton lab goes on.
35:48In the mockness net, we collect some of the larger phytoplankton in there, and sometimes it's come up literally looking like pea soup.
35:54With those larger phytoplankton that get caught in the net.
35:58I'm amazed at the amount of life in here.
36:00It certainly looks quite productive, a lot more productive than I'd imagine for Antarctic waters.
36:07But I guess something's got to be there to feed the krill, which live down here.
36:11The mid-troll net hold up plenty of krill, and Chris gets the smelly job of weighing and measuring every last one of them.
36:18It's the only way to calculate how many of these crucial crustaceans inhabit the Ross Sea.
36:25Krill really drives most of the ecosystem.
36:29That is all the land-based predators, the penguins, the seals, the birds, most of the fish species, whales, they're all highly dependent on krill.
36:42The arrival of two humpbacks delights the team.
36:48Whales!
36:49Can I just drop it down?
36:50Whales!
36:54Oh, nice.
36:55Whales!
36:57They've come for the krill, of course, gorging themselves before migrating back to the breeding grounds in the Pacific.
37:03This is great, it couldn't be any better. The sun is shining and it's just a beautiful day. The ice is right behind those whales.
37:23Emperor penguins also come for the all-you-can-eat buffet.
37:26After laying their eggs in the dead of winter, the females complete an arduous trek from open water to feed the chicks.
37:34And krill, one of the lowest links in the food chain, becomes a meal fit for an emperor.
37:39Thirty-three days into the expedition, Tungaroa breaks into open water again.
37:59On the horizon looms Scott Island and Hagate's Pillar.
38:02These insignificant-looking rocks are actually the top of a seamount.
38:10A volcanic undersea mountain thrust from the bottom of the ocean, 4,000 meters below.
38:17A deep region known as the abyssal seabed.
38:21Yeah, these ones were more dispersed.
38:24That second set.
38:26Malcolm Clark studies these bedrock communities that thrive on dramatically steep slopes.
38:30Some creatures prefer a bed with more support.
38:36They opt to live on the rocky seamount instead of the posh seabed.
38:43So animals that need to attach to something really hard, like corals, sponges,
38:49they're able to latch on and again survive where the soft sediment of the abyssal plains doesn't enable them to survive.
38:56The team decides to drop in on the seamount community using the beam trawl.
39:04But the seamount is not accepting visitors.
39:07Up comes nothing but the tangled cables of the broken trawl.
39:22The wooden beam is smashed in two.
39:23From the, the data's have looked pretty good.
39:24So, uh, worth a go and it's just one of the risks we take.
39:25They need to repair it or they're dead in the water.
39:40The crew is optimistic.
39:43It's not a problem.
39:44It's not going to take long.
39:45I mean, if you give us an air or something, we're done.
39:47They cut out the tangled wire and splice it back together.
39:55And where would a sailor be without his knots?
40:00Practicing the crocheting.
40:01Yeah.
40:02Before long, they're back in business.
40:07Having braved ice storms, broken equipment and rough seas for almost two months,
40:16the team braces itself for the most high-pressure assignment of all.
40:21They will delve 3,500 meters into the abyssal plain, a depth almost as high as the Swiss Alps.
40:32To prepare for the mission, team members perform an exacting scientific endeavor, decorating polystyrene cups.
40:40Because they've been made and compressed with air, when we put them down to the deep,
40:44they'll hopefully compress and get smaller and smaller and smaller.
40:47And eventually, we hope they'll turn out basically like symbols.
40:55It will endure 300 times more pressure than we experience every day.
41:09Suddenly, the abyssal plain reveals itself.
41:12It looks barren, like the surface of Mars.
41:18But a closer look reveals life.
41:22No one has ever witnessed sites like these in Antarctica before.
41:27Then, something goes horribly wrong.
41:39We've just lost the video.
41:41Yeah, we just noticed that.
41:42We're just going to see what happens.
41:44We're wondering what's going on.
41:46It could be a minor malfunction or a catastrophic failure.
41:49It just concerns me when you get to that depth that it suddenly goes.
41:52You sort of think, oh God, the pressure has broken a seal or something.
41:58They haul the apparatus back up.
42:01And see the problem right away.
42:03Oh dear.
42:04Dropping water up.
42:05That's not supposed to happen.
42:06Yeah, what's happened is the pressure has been too great for the glass in the bottom.
42:18And it's got a hairline crack across it.
42:20Remarkably, the camera continued to operate, allowing Chas Marriott to replay its destruction.
42:26You can see a crack started to form across the glass lens on the front of the housing.
42:34And as we scroll through the frames, you can see water starting to seep into the housing.
42:41It's these blurry bits here, and slowly filling up the bottom of the housing.
42:47And the lens of water evens out across the glass.
42:51You can still see all the photos quite clearly again.
42:56For the rest of the team, the experiment is a crushing success.
43:05300 atmospheres of pressure bearing down equally on all sides have miniaturized them without damage.
43:12Oh, they're great.
43:15Even the illustrations and lettering remain in perfect miniature.
43:18The team also take the opportunity to trawl the bottom.
43:26Having fed up more than 5,000 meters of the repaired table into the seat.
43:35The beam trawl finally comes aboard at 2 a.m.
43:38And after six hours of waiting, the team gets its reward.
43:47Twelve buckets of mud and one single fish.
43:53But in this mud lies many delectable delights.
43:58Like this sea cucumber.
43:59It's hard to see where's the front of them.
44:00That would be, I guess, another oral appendage.
44:06He's wagging his tail, though.
44:09Now, if this doesn't demonstrate all the glamour of marine biology, nothing does.
44:13Carine has cleaned up her sea cucumber for a better look.
44:28This is the back side of it, and the front of it is clearly the other side, which has got these aural tentacles.
44:36Then, Carine finds an even more curious specimen.
44:47It has something quite interesting at the front, which sort of likened it a little bit to as a hippopotamus.
44:55We don't know how many are down there.
44:58We don't know how common this is.
44:59I have never seen anything like this before.
45:02Sea cucumbers are the ocean's vacuum cleaners.
45:05Walking along the bottom, sucking nutrients out of the mud they eat.
45:10The video enables the scientists to observe them in all their sluggish action.
45:17Scientists recognize about 1,200 species of sea cucumbers, none of them very attractive.
45:24Except, maybe, to a marine biologist.
45:27But as the expedition winds down, they'll encounter creatures strange by any standard.
45:3544 days into the voyage, and the last day of sampling has arrived.
45:42It's also Andrew's 50th birthday.
45:45The team has stayed up late to prepare a surprise.
45:49They've conducted 312 sampling deployments at 39 different stations.
46:04Yet still, a sense of expectation grips them.
46:07This is the last bottom trawl of the cruise.
46:12The video shows parasites attached to deep sea rat tail fish.
46:18The scientists hope the trawl snares one.
46:21After a long day's wait, Andrew and the others get to see the last net come in.
46:26With deep trawls, they've come to expect some strange specimens.
46:33They are not disappointed.
46:36These abyssal fish have evolved to cope with the crushing pressure down below.
46:41But when they're pulled to the surface, their guts blow up like a balloon.
46:44As they've come up, the pressure has caused their swim ladders to expand and blow out their mouths.
46:52Unfortunately, it doesn't do them much good.
46:56And the fish with its horrifying host has turned up in the net.
47:01One of these big parasites right here on the rat tail.
47:05You can see that thing. It's got a tube. Part of it goes in well down into the body cavity.
47:17Today, Andrew receives a birthday gift only a biologist could love.
47:22An ambush predator with a mouth of needle-sharp teeth.
47:26And the scientific name for this one is Kali, named after the Hindu goddess of destruction.
47:30These fish have a remarkable ability to swallow prey much, much larger than themselves.
47:36And the whole stomach area just unzips and expands.
47:40This is just a great find. It's the first find for this expedition.
47:43First record of this family in the Ross Sea.
47:47As the mission winds down, the scientists log the last of the specimens.
47:51This snapshot of Antarctic biodiversity will be compared with the results of expeditions to come.
48:10As they head back to New Zealand, Captain Leachman reflects on Tangaroa's 7,000 nautical mile journey
48:16through one of the most challenging oceans on Earth.
48:22Once you've had a touch of it and seen the visibility, see 200 miles.
48:27See Mount Melbourne, pink in the midnight sun.
48:30Oh, I mean, there's no, words can't describe just the beauty of it. It's wonderful.
48:35And would he go again?
48:37Of course.
48:38For Julie Hall, the life she's coming back to is not the one she left.
48:51But she has no doubt that the painful choice she made was the right one.
48:55I felt that he would have wanted me to stay and finish the program that I've put so much time and energy into developing.
49:04I've been planning this for over two years, so to walk away would have been very difficult.
49:10Andrew Stewart and the fish team scored 88 different fish species.
49:15At least five are thought to be new to science.
49:18But only a small fraction of what scientists believe is still out there.
49:22I think that what we have already retrieved from the Southern Ocean has been incredible.
49:29I think in many ways we've barely scratched the surface.
49:32As these scientists return home, they're proud that their 50 days aboard Tongaroa have made this unfathomable world a little more knowable.
49:42.
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