Nature | John Clarke Online

Battle of Titans: Orcas vs Gray Whales

It is an ageless story, mothers banding together to protect their young from instinctive killers. The fact that it was a battle between behemoth Gray Whales and Killer Whales (Orcas) made it all the more epic in scope, and worthy of the telling.

A fellow scientist and I had driven south early one springtime morning from Anchorage, Alaska to Seward. At 11 AM our glacier view cruise boat left the docks at Seward and headed for the glacier fields at the Kenai Fjords National Park where the glaciers sliding slowly down from the mountains calved into the Gulf of Alaska.

Out of Seward — Heading south from Seward.

From there we motored on until we were attracted to a near-shore area by the blowing of water and foam from a group of migrating Gray Whales. The rapid pace of their exhalation was a sure sign that something was wrong. We had stumbled upon a battle involving another type of calf just as the combatants were taking their positions on the battlefield.

A female Gray whale weighing between 30 to 40 tons had birthed her baby during the winter in Baja California and now the mother, quickly growing baby, and two female caretakers (often called “aunties”) were almost through with their migration to the Bering Sea. But as they swam beyond Prince William Sound, not far from their final destination, they were attacked by two adolescent transient Orcas who wanted that baby whale.

Our boat stopped far enough from the battle to not hinder the fight, but close enough for us to witness the events. Our biologist guide warned us that if we had a weak stomach we might not want to watch because often times the Orcas succeed in killing the baby Gray.

I don’t think anyone on the boat averted their eyes as the three massive females arranged themselves head to tail into a triangular defensive formation, with the baby in the middle. There was no way for the Orcas to get past the females on or near the surface, so they made repeated dives trying to enter the center of the triangle from underneath and attack the baby. But with each dive, the wily Grays maneuvered to block the Orcas.

The Orcas were nothing if not persistent. Perhaps sensing that, the whales started moving closer to a rock cliff face, and then they did something clever, but potentially risky. There was an opening in the rock wall and the baby whale had been nudged into that opening. One whale, probably the mother, was completely blocking that opening with her body. The Orcas tried repeatedly to find a way past her to the baby, but between the blocking action of the other two Grays and the blubbery plug of the cave entrance by the mother, there was nothing the Orcas could do.

We of course saw the riskiness of that defense. It looked to us like the baby was trapped underwater. Even a whale has to breathe sometime.

Whale cave — The other boat was too close to the action, but provides scale for the "cave".

But as I look at the photo I realize now that the cave was tall enough and just deep enough to allow the baby to breathe even with water access cut off. Obviously, the Gray Whale mother had made good use of her 4.3 kg brain. Nevertheless, from our elevated vantage point we could see over the mother whale, and we saw that the baby remained submerged. I’m guessing it was wedging itself in as tightly as it could. The anxiety on our boat grew perceptively as the minutes ticked down with us knowing the baby was holding its breath.

The tactic worked, for the Orcas eventually tired of the game, and after making one or two leaps out of the water they moved away from the whales and headed north toward seal colonies we passed on the way south. The seals would be easier pickings than those highly protective Gray Whales.

There was jubilation on our boat. I think we’d all been holding our breath like the baby, at least a little.

When the coast was clear, literally, the Grays moved back into the open water near where the battle had begun and caught their breath, heaving great geysers of watery air as they panted. They had obviously been very stressed, but their cleverness and strategic cooperation saved the day, or at least the moment.

: Two Orcas. Copyright by Rolf Hicker. Used under fair use.

Things could have been different, both better and worse. Local Orcas were so-called residents who don’t attack Gray Whales. Residents tend to be fish eaters. Fortunately for the Gray baby, the more lethal transients were not as experienced with the local geography. They were also adolescents, not as experienced as adults, and there were only two of them. A pack of them, with adolescents being guided by adults, might have been more succesful. Transient Orcas, genetically different from Residents are reported to kill a third of the baby Gray Whale population each year.

Interestingly, the Grays seem to know where transient Orca populations are the most active, and in those regions they tend to stay close to shore. In this case that strategy paid off by allowing the baby to be protected by a rock wall and its mother.

On the boat we celebrated all the way back to Seward; we had witnessed a frightening conflict with, for us and the whales, a happy ending.

To learn more about Orcas attacking mother Gray Whales and their calves, see the excellent photos and story at the following website. http://creagrus.home.montereybay.com/MtyBayOrcaattack.html

Scalloping – What If the Tide Turned?

It’s scallop season in the fertile waters of the Florida Panhandle. Almost completely surrounded by a peninsula called Cape San Blas sits a shallow body of clear water and sandy bottom that is an ideal location for bay scallops. Unfortunately for the scallops, the shallow water makes a yearly harvest of scallops by boaters and waders almost too easy.

Recently my extended family of eight descended on the unsuspecting bivalves as if our lives depended upon them. We spent most of a day in a hunter-gatherer mode, reaping the benefit of a bountiful crop, imagining an earlier day when local tribes did in fact depend on the local scallops and oysters for their survival.

I had been scalloping in Saint Joseph’s Bay once before, but this year the scallops were larger, and seemingly more bountiful. They attempted to hide in the sea grass, and I suppose those that hid well were passed over. But fortunately for us, many could not hide from the practiced eyes of determined snorkelers.

Usually scallops react to being picked up by snapping their shells together in an attempt to protect their vulnerable innards. However, one large scallop which had apparently lived long enough to be the equivalent of a wise scallop, or perhaps simply an inquisitive scallop, started to close his shell, and then stopped. We remained locked in a gaze, me with my green eyes staring through a diving mask, and it staring at me with its multiplicity of luminous, iridescent blue eyes.

scallopeyes-wide-big — Photo credit: Bill Capman, 2002.

I know this is blatant anthropomorphism, but it seemed like it was saying, “Well, hello. What’s this? Are you a deity? I’ve heard about you, but you’re not at all what I was expecting.”

I must admit I stared back quizzically, surprised by this little fellow’s bravado. He truly seemed to be checking me out.

It was bad luck for him that his telepathic powers of communication didn’t make a dent in my determination to eat him, or at least to eat his adductor muscle after discarding the rest. So into the bag he went with the growing collection of other scallops. In the end, his bravado did him no good at all.

It was somewhat of a pitiful sight as the captives were poured in a heap on a wooden platform just above the water of the bay. I bet they could smell it, the safety of water so close, and as the cliché says, so far away. They all tried to escape, to jet away, sounding like a chorus of castanets. Of course, in air, jetting just doesn’t work for them. They were stranded. I could almost sense their collective panic.

I suspect the mechanics of scallop butchery came as quite a shock to this little guy. I’m just glad that this year I didn’t have to do it — my son took my place at the sacrificial altar. After all, shucking is, at its best, tiring and a little bit gross. Beer helps of course.

In the unlikely event that now jaded scallop had seen me, had watched me with its sixty or more eyes as I began to take a shucking knife to it, could I really do what my family was expecting of me? Probably, but I don’t know for sure.

Well, I didn’t have to face that, and I will confess, I felt only pleasure, no guilt, as I finished off the last of those pure white scallop muscles, sautéed with butter, garlic and a dollop of lemon juice.

It was about 48-hours later, when the delicate flavor of those fresh scallops began to fade from my memory, that I had a sobering thought. Could those bivalves in fact be more sentient than we assume? After all, I’ve been mistaken before about the intelligence of invertebrates.

I’ve heard that scallop eyes can’t really see shapes, only shades of light, and movement. Arguably there is not enough neural matter for them to generate anything like a thought — at least in human terms.

But what if we’re wrong? Even worse, what if a highly advanced alien species, hungry after traveling interstellar distances, encounters humans? Would they consider us with the same lack of respect that we consider scallops? Could we be considered to have too little cerebral grey matter to create an organized thought — at least in alien terms? Would we be considered insentient and therefore unworthy of pity as we’re “shucked” and sautéed for dinner?

In Stephen Hawking’s opinion, that is a real possibility. http://www.timesonline.co.uk/tol/news/science/space/article7107207.ece

So, maybe we shouldn’t be trying so hard to attract the attention of extraterrestrials. If they show up hungry, maybe our communication, telepathic or otherwise, would do us no more good than it did that inquisitive scallop.

He sure was tasty.

How to Teach Ice Diving When the Arctic Is Melting

In 2007 Michael Lang of the Smithsonian Institution’s Scientific Diving Program sponsored a spring-time ice diving course in the high Arctic at Ny-Ålesund, Svalbard, in an area generally called Spitzbergen.

Ny-Ålesund, an international Arctic research town situated at 78°56’N, 11°56’E, is the most northern continuously operated community. It sits on the shore of a fjord called Kongsfjorden. In the springtime, the sea ice on the Kongsfjorden is usually several feet thick, providing an inviting platform for ice-diving operations.

DSCN1501 — North Pole Hotel, Ny-Ålesund, Svalbard

However, during the last decade the sea ice has been becoming thinner and sparser. By the time we arrived, there was virtually no ice on the fjord. The closest ice source was a glacier over two miles away. With no ice, polar bears could not capture their ringed seal prey, and were thus hungry, leading undoubtedly to the polar bear encounter described in an earlier posting (April 12).

It also left the course instructors, and I was once of them, in a quandary. It was expensive transporting diving scientists to the high Arctic to learn ice diving operations, and there was no ice to be seen. It appeared to us that the Arctic really was melting, surprisingly early in this case.

Although we had a few frigid days during our week-long stay, frigid enough to remind us we were close to the North Pole, one memorable day was almost balmy, reaching 0° C (32° F). Looking out over the fjord I saw mini-icebergs, recently calved by the rapidly melting glacier a few miles away.

Mini-icebergs, born on an unusually warm day

The word went out to launch all divers.

Dry land and underwater cameras, and high-definition video were working overtime to record the encounters between divers and ice. The result was some striking photos of delicately scalloped floating ice, with divers getting into the frames — just to prove they were indeed “ice-divers.” Unfortunately, that was not the type of experience that had been planned for those scientists.

As you might imagine, the water in the fjord was still bitterly cold, so the part of the course designed to teach about human and equipment survival in cold water was fully accomplished.

However, due to the growing sparseness and unreliability of the Arctic sea ice cover, the Smithsonian Diving Program has now moved its training and testing operations to McMurdo Station, Antarctica (see April 11 and May 26th posting). There, at least for the time being, lies plenty of thick sea ice covering the Ross Sea during the austral springtime.

I had not been impressed by the global warming rhetoric before I traveled to the Arctic. However, having seen the consequences first hand, at least in the far North, I get the strong impression that there are undeniable local climate changes occurring. Whether it is a truly global change, and whether man is somehow responsible, is an area of speculation that I will not venture into.

Only time will tell.

Outsmarted by an Octopus

Jim Duran and I started a night dive in about sixty to seventy feet of water several miles off the beaches of Panama City, FL. I was wearing double 80 tanks, held a collecting bag and lights, and fully intended to capture an octopus, alive.

At the time I was working in an invertebrate physiology laboratory at Florida State University, under the mentorship of Dr. Michael Greenberg. I had been impressed by the reputed high intelligence of the octopus and was also interested in the effects of high pressure. The Navy base at Panama City had a new high pressure chamber, capable of simulating deep-sea pressures. Since I was in training in the combined Navy and NOAA program called the Scientist in the Sea, it seemed logical to me to catch an octopus and study it to see if it would be a suitable candidate for testing in the Navy’s giant hyperbaric chamber.

Navy Experimental Dive Unit, Panama City, Florida

It sounded like a reasonable plan to me, and Jim Duran was willing to follow along as my assistant critter catcher. And to begin with, the plan worked. We spied our quarry only a few minutes into the dive. The gray-brown octopus was crawling over the sandy bottom and initially seemed unaware of our intentions. But as the two of us closed in on him, specimen bag flapping in our self-generated current, he sprang off the bottom and squirted away.

But we were strong swimmers, and our quarry was in the open, maybe eight feet off the bottom. He had nowhere to hide – silly thing. Keeping our lights on him, and stroking like mad, I began gaining on him, at which time he let loose with his ink. I was prepared for that, and continuing to kick I soon caught up with him and got my hands on him, trying to stuff him into my bag. But he would have none of that.

Off we went again. What we didn’t realize was that the clever invertebrate was constantly turning to our right. We of course were too intent on capturing him to notice his strategy. And besides, invertebrates were incapable of strategic planning – or so we thought.

Apparently, the octopus was determined not to be touched again, or else we were tiring, for we never quite caught up with him. So close, and yet so far away.

And then a curious thing happened. He collapsed his tentacles upon themselves, streamlining his body shape, and shot like a rocket from our depth to the sandy bottom. Once on firm ground again, he spread his tentacles as wide as he could, and his entire body turned white. I froze in shock.

In another instant, before I could recover my senses, he collapsed his body down to the width of an apple and slithered into his hole in the sea floor.

He was gone.

It didn’t take long for us to realize that the chase had started near his home, and he had led us at a furious pace in a large circle, which ended precisely where it had begun. He had maneuvered us to within striking distance of safety.

Humbled, and now growing low on air, and embarrassingly empty-handed, we headed back to the off-shore platform where our dive had begun.

It had seemed like such a good idea. Who knew that two graduate students would be outsmarted by an invertebrate.

Below is a link to a video showing an octopus’ ability to disguise itself, and some of the defensive behavior we witnessed.

Purple octopus photo by Diane Picchiottino on Unsplash

Broken Sparrow – Everyone Loves a Fighter

What on earth could make a blog posting on a sparrow worth reading?

Well, people love stories of near tragedy, survival, and salvation, and this has some elements of them all.

A nesting pair of House Sparrows showed up at work this Spring, hidden in the metal framework of a second-story bridge connecting two brick buildings of typical government construction. Their nest lay only a foot from the heads of passers-by. No one paid them much attention until the hatchlings started calling incessantly for food. Then the nest became both busy and noisy.

The real story began after a wind storm struck one weekend, leaving behind an injured male sparrow. It was obvious that one of his wings had been damaged for we found him on a Monday morning walking up and down the concrete walkway, trying to dodge the frequent pedestrians, and not flying away to safety. In fact, it looked almost as if a wing had been torn off.

But what got everyone’s attention was the sight of him hopping down 12 feet of metal stairs to get to the ground, search for some food, then hopping all the way back up those stairs to defend his nest site, the best he could by being there, injured. Considering he was only about 3 inches high, those hops would be equivalent to us hopping up and down 232 feet of stairs, repeatedly.

I was probably not the first to test his flying ability, and indeed, when frightened he would fly a short distance to a palm tree trunk not far from the bridge. But then he would climb to a secure spot on top of the palm tree, rather than fly straight to the top. Flying for him had become a last result. It was difficult and seemingly painful for him, although he never cried out in pain or alarm, as I’ve heard sparrows can do.

The next day I borrowed some birdseed from a bird lover and set out a small pan of water, so the injured bird would not risk being eaten by the feral cats that roam our buildings at odd times of the day. When that seed was quickly eaten, a warrior friend of mine came asking for some seed so he could feed his bird.

His bird? So, I was not the only one taking an interest in this brave little male and his struggle for survival.

Unfortunately for the female, her mate was not able to forage for the young, and she had to work double-time. That could be why, as soon as the babies had fledged, the nest was emptied, and the female never returned to her mate for another breeding cycle. She could do better, I suppose.

In spite of his troubles, and probable pain, he remained the strong sounding male, calling, announcing his prime nesting site. Never mind that no other bird wanted it. If they had, they could easily have taken it from him since he was defenseless. But still, he thought, he had a job to do. It was a man-thing.

For weeks we would see that male, starting to hop down the stairs, to look for food, and if he happened to see my warrior friend or I bring food, he would turn around and hop back up the stairs to eat, rather than risk foraging on the barren ground. He became used to us caring for him. Of course, he always kept a safe distance from us.

One morning my warrior friend was visibly upset. Three female sparrows and a ringneck dove started mooching off the birdseed. He chased them off, as I did when I saw them, but they were persistent.

“How dare they steal food from my bird,” my friend said. “I’m gonna bring a BB gun and stack their little corpses up like cordwood.”

We both laughed at the irony of it.

And then he said, pensively, “I wonder how many birds I’ll have to kill to save this one?”

Others got into the protection business when three females, perhaps his offspring, ganged up on him when he was on the ground and started pouncing and pecking on him mercilessly. One of our female employees became angered by the attack on the injured male and chased the females away. After that, the male flew best he could back up to the relative safety of the second-story walkway.

And that was a good sign. He was growing stronger. A week later, I saw the sparrow flying instead of walking or hopping, and calling loudly to attract a female back to his nest, without success.

But I think the story is now complete, for today he left, fully healed, perhaps in search of more desirable real estate.

When I told my warrior friend the bird was gone, and that we had apparently saved him long enough for him to heal, he said, “You know, I go bird hunting a lot, but there was something about this guy that made me want to save him. It must be something psychological.”

“He was a brave soldier,” I said, “and you don’t leave an injured man to die on the battlefield without trying to save him.”

He smiled and nodded his head. He knew exactly what I meant.

The Puerto Rico Trench and Denizens of the Deep

(Public domain - from U.S. Geological Survey) — Puerto Rico Trench. (Click once or twice for full image) U.S. Geological Survey

The Puerto Rico Trench is the deepest part of the Atlantic Ocean, and is only surpassed in its depth by the Marianas Trench in the Pacific Ocean. It is 500 miles long, and at its deepest plummets 28,232 feet down.

After receiving my doctorate with a special interest in deep-sea physiology, I was invited on board the oceanographic Research Vessel (RV) Gilliss for an expedition to the Puerto Rico Trench. I was accompanied on that research cruise by Dr. Robert Y. George, a deep-sea biological oceanographer from Florida State University.

I had been studying the effect of very high pressure on invertebrate hearts. As luck would have it, the largest population of deep-sea creatures indigenous to the deepest places in the ocean are invertebrates (animals lacking vertebrae, backbones.) But on the way down to the deepest reaches of the trench, you encounter some very strange creatures indeed, such as the Humpback Angler Fish.

ocean-layers-diagram — Click for a larger image

These bizarre and frightening looking fish inhabit the abyssal pelagic zone (or the Abyss) between 13,000 and 20,000 feet. But below the water containing these abyssal fish lies the zone of the deep trenches, the hadalpelagic zone between 20,000 and 36,000 feet, the deepest point in any ocean.

“Denizens of the Deep” are known in merfolk tradition as the beasts that swallow up the sun at the end of the day, which is somewhat ironic since sunlight never reaches down to the abyssal and hadal zones. Whatever light is there, is produced by bioluminescence. Down there, light means either a meal, or a trap. And since meals are uncommon in the sparsely populated ocean depths, predators seem designed to ensure they miss no opportunities to feed. Their jaws, fangs, and other anatomical structures seem especially designed to snag a hapless passer-by, and provide no chance of escape for those caught. Fortunately for us, animals adapted to the high pressure, low oxygen environment of the deep ocean cannot survive in shallow waters.

But imagine for a moment that something perturbed that natural order. Time has separated us from man-eating dinosaurs, but the only thing separating us from deep-sea monsters, ferocious predators that make piranhas look playful, is something as simple as pressure and oxygen. Could things change?

Well, not to scare you, but until 1983 or so, the Puerto Rico Trench was a huge pharmaceutical dumping ground. Massive quantities of steroids and antibiotics, and chemicals capable of causing genetic mutations, came to rest on the sea floor, or were dispersed in the waters above and around the trench.

You don’t need to take just one person’s word for it. Professor R.Y. George himself commented on the issue in his resumé.

July 5 – July 30, 1977. Revisited Puerto Rico Trench (now Pharmaceutical Dump Site) aboard R/V GILLISS of the University of Miami to study Barophylic (pressure-loving)bacteria (Dr. Jody Demming’s Ph. D. work from Dr. Rita Colwell’s Lab. in the University of Maryland), and to study meiofauna, macrofauna and megafauna (in collaboration with Dr. Robert Higgins of the Smithsonian Institution).

Frankly, if I was visiting Puerto Rico, and signed up for a deep-sea fishing trip, I’d ask the boat captain just how deep we’d be fishing. I really wouldn’t want to bring up a Humpback Angler Fish large enough to eat the boat. After all, Angler Fish are fishermen too.

For a NOAA sponsored animated tour of the Trench, play the following high resolution video.

[youtube id=”v1OnsuyFdaM” w=”700″ h=”600″]

Polar Bear in Town

In some places, the food chain gets down-right personal. In the high Arctic, a careless human is not a top predator; he is a meal. Polar Bears are methodical hunters, showing no fear of humans. When hungry, they are white death on paws.

In 2007 the U.S. Navy and I were helping the Smithsonian Institution Scientific Diving Program teach a course on under-ice diving in Ny-Alesund, Svalbard, an international research town a relatively short distance from the North Pole. Ny-Alesund is the most-northern continuously occupied settlement, and is occupied year-round by scientists and support personnel.

The fjord adjacent to Ny-Alesund is normally covered in 4-5 feet of sea ice in the springtime, making it an ideal location for training in under-ice diving. To gain access to the water, ringed seals travel some distance from land to find holes penetrating the ice, through which they enter and exit the water beneath the ice. And polar bears walk out on the ice to patiently wait for the seals to reappear, and be gobbled up.

In 2007, the sea ice was gone. The polar bears’ food was not concentrated around breathing holes, and thus the bears were not catching many seals. They were hungry.

By law, the resident and visiting scientists had to carry rifles with them when they ventured away from the icy town to do research in the surrounding hills. But in town, no weapons were required. Polar Bears simply didn’t come into town.

Until one night.

There is only one bar in Ny-Alesund, and it specialized in serving Jesus Drinks during parties. A Jesus Drink is any alcoholic mixture served with glacial ice that is roughly two thousand years old. Get it?

On the night of the bear sighting, a petite Australian doctor friend of mine was walking back from the bar alone, and as she approached the dormitories, she saw a polar bear passing along the side of the dorm I was in. As it disappeared around a corner of the building she was left wondering if she was hallucinating. To make sure of what she saw, she ran across the end of the building just in time to see the white bear reemerge, calmly walking down a snowy road. Since she was close by, I clearly heard her yell the alarm, “Polar Bear in Town!”

The bear was headed towards the area where about a dozen Greenland Huskies, used for pulling sleds, were tied down for the night. So the deathly calm of the Arctic night was shattered by a female doctor yelling at the top of her lungs, while the vulnerable dogs were barking to save their lives — literally.

Of course I hopped out of bed, threw on my multiple layers of Long Johns, slipped into my Arctic parka and gloves and headed out the door to see the bear.

As luck would have it, our experienced dive team leader from the Smithsonian was walking in as I was headed out.

“John, you’re heading outside, in the dark, with a bear close by, and you have no gun.”

“Hmm… I see what you mean.” I hadn’t looked at it from the perspective of a hungry bear. I turned around and went back to bed.

The next morning we found bear tracks a plenty. The dogs had scared off the bear apparently, since he didn’t claim any animals. Lucky dogs.

Well, the next evening we happened to have a party, with plenty of glowing blue Jesus ice. Although the walk to the bar, down a snowy road with no protection from the elements had not seemed daunting in the fading polar daylight, things were different when I returned to the dorm about midnight, by myself.

There was no moon so the sky was pitch black, but everything else was white, except for me. My parka was brown, and in retrospect made me look a bit like a muffin. And of course I knew that out there in the whiteness, somewhere, was a brazen, hungry bear looking for a snack.

I had never thought of myself as a potential meal, until then.

My head was on a swivel, and my not-yet dark adapted eyes were peering towards the most distant snow and ice, in all directions, looking for a movement that might warn me of a bear. And then the huskies started yelping again, in obvious alarm. That was when I realized that by the time I saw the white on white predator, he would have me. They’re fast, and I had nowhere to run for safety. I was in the open.

That is a curious feeling, knowing that you could be taken like a hunter takes a deer.

I wondered how badly it would hurt.

Well, with that Jesus ice coursing through my veins, I felt safe. That is, I felt safe once I was back in the dorm, snug in my bed.

As I lay there trying to fall asleep, I couldn’t help but reflect on how primal a fear it is, that fear of being eaten.

Diving Under Antarctic Ice

You are 100 feet down using scuba, with your dive light spotlighting the most exotic looking Sea Hare you’ve ever seen.

It’s noon at McMurdo Station, Antarctica but it’s dark at your depth because between you and the surface of the Ross Sea lies19 feet of snow-covered ice. Your dive buddy has drifted about 100 feet away, but you can see him without hindrance in the gin clear water of the early Antarctic springtime.

The 800 foot water visibility also means you can easily see the strobe light hanging on the down line 200 feet away, the line leading to the three and a half foot diameter hole bored through the ice.

Under these conditions, you should not have to worry about your regulator, but you do, because you know that any scuba regulator can fail in 28° F water, given enough opportunity. You also know that some regulators tolerate these polar conditions better than others, and you are using untested regulators, so yours might free-flow massively at any moment.

Should that happen, you have a back-up plan; you will shut off the free flow of air from your failed regulator with an isolation valve, remove the failed second stage from your numb and stiff lips and switch to a separate first and second stage regulator on your bottle’s Y-shaped slingshot manifold, after first reaching back and opening the manifold valve. Of course, that backup regulator could also free-flow as soon as you start breathing on it – as has already happened to one of your fellow test divers.

In that situation you would have no choice except to continue breathing from what feels like a torrent of liquid nitrogen, teeth aching from the frigid air chilled to almost intolerable temperatures by unbridled adiabatic expansion, until you reach your dive buddy and convince him that you need to borrow his backup regulator. Once he understands the gravity of the situation, that two of your regulators have failed, then the two of you would buddy-breathe from his single 95 cu ft bottle as you head slowly towards the strobe marking the ascent line. And of course he will be praying that his own primary regulator doesn’t fail during that transit.

Once you reach the ascent line you are still not out of difficulty. The two of you cannot surface together through the narrow 19-foot long borehole. So you would remove your regulator once again and start breathing off a pony bottle secured to the down line. Once it is released from the line, you can then make your ascent to the surface; but only if a 1300-pound Weddell seal has not appropriated the hole. In a contest for air, the seal is far more desperate following an 80 minute breath-hold dive, and certainly much more massive than you. Weddells are like icebergs – their cute small face sits atop a massive body that is a daunting obstacle for any diver.

But you even have a plan for that — you’ve heard that Weddell seals don’t like bubbles, and they get skittish about having their fins tugged on, and will thus relinquish the hole to you. … At least, that’s what you’ve been told. You certainly hope he would leave before you consume the meager amount of air in your pony bottle.

The text above was taken from a U.S. Navy Faceplate article I wrote concerning a 2009 Smithsonian Institution sponsored diving expedition to Antarctica in which I participated. On and under-the-ice photos were taken by expedition members Drs. Martin Sayer and Sergio Angelini.