by Edith Widder
At this point, I would like to go on record as saying that I think having a seawater inlet valve on a submersible is a bad idea. There’s a very good reason why Navy submarines don’t have portholes: It’s in recognition of the fact that anytime you violate the integrity of the hull, you are potentially allowing the pressure monster a point of ingress. Ironically, the seawater inlet valve on Deep Rover is one of its safety features. The idea is that if the sub ever becomes stuck on the bottom, there is enough life support for three days, but because of the limited payload, there is no drinking water reservoir. There is, however, a small desalinator, so you can open the valve, collect some seawater in a bottle, and then run it through the desalinator to remove the salt anytime you need a drink.
Peter agreed with Robi that the valve handle would be in the way and responded by saying, “No problem.” He quickly removed the handle and placed it in the toolbox behind the pilot’s seat. It all happened so fast that no one noticed that, in order to access the Allen screw that held the valve handle in place, he had turned the handle counterclockwise, opening the valve. When I emerged from the head, Peter failed to point out the reengineering that had occurred in my absence, and I climbed into the sub unaware of the open valve and its missing valve handle.
In this early version of Deep Rover, there was no hatch to climb through. Rather, the acrylic sphere was split into two hemispheres that were hinged at the top like a clamshell. You simply climbed through the gap at the bottom, then a crew member cranked the two halves together, sealing you inside. As with Wasp, there was no way to extract yourself, even at the surface. We joked about the need to have paper and markers inside so that if we ever came to the surface away from the ship, we could write instructions to our would-be rescuers about how to free us from our shell. This feature never bothered me when I was awake, but it occasionally plagued my dreams. Never before or since have I dreamed about being buried alive in a coffin, but I had that nightmare twice during this expedition, once so vividly that I woke up clawing at the bottom of the bunk above me. The lizard brain abhors entrapment.
As I flooded my ballast tanks, after I confirmed I had a seal, my focus was overhead, watching the water close in over the dome and then following the dancing trail of my ballast bubbles as they ascended in a shimmering stream. Each iridescent orb expanded with the lessening pressure as it rose upward, striving to rejoin its native sphere above the rolling ceiling of the sea. The scrubber fans, which were cleansing the air in my own personal bubble, whirred in the background, blending with and largely masking a faint, unfamiliar whine.
It was subtle, but once I convinced myself the sound was real, it seemed louder in my right ear than my left. Thinking it might be something electrical, I sniffed the air, but detected no hint of heated metal or burning insulation. Nonetheless, there was no denying that the noise was there, and growing louder. I was reporting my depth in fifty-foot increments over the through-water comms and had just announced passing 350 feet when my physical contortions aimed at locating the source of the noise caused my stockinged feet to slide down into the seawater that had been streaming in through the open valve.
The water was ankle deep. Its source was immediately obvious, but where the hell was the handle to turn it off? I blew ballast, jammed on the vertical thrusters, and then waited for what seemed like an eternity to see if I was already too late. Had I passed the tipping point? This was a classic example of a positive feedback loop, where the deeper I sank, the greater the pressure, and therefore the more water came in, making the sub heavier, causing it to sink faster, increasing the pressure, and so on, until I either sank below my operational depth limit and imploded or hit bottom and drowned.
The submersible seemed to shudder briefly, and then, slowly, it began to rise, but with water still streaming in. I called the surface and had a little WTF?! exchange with Peter. I told him there was water coming through the seawater inlet valve and the valve handle was missing, and he told me it was in the toolbox behind my seat. I dug around frantically, pucker factor*8 increasing from 8 to 9 as I attempted to locate the toolbox by feel. Once I did, I had to find the handle and its Allen wrench, then slide it over the valve stem and secure it with the set screw. When I had the handle in place, I tried turning it clockwise as hard as I could. It wouldn’t budge. The pressure monster had his finger in the valve and wasn’t giving up.
As the sub rose slowly through the water, the pressure decreased, allowing the air in the ballast tank to expand and gradually accelerating my rate of climb. Normally, I would have paused my ascent at fifty feet to make sure I wasn’t going to come up directly under the ship, but I blew through that protocol, my only concern being to get to the surface as fast as possible. As soon as I broke through the surface, the Zodiac appeared with divers who immediately attached lines that hauled me to the side of the ship so they could attach the crane hook.
The team recovered the sub and had me back on deck in record time. When they cranked the sphere open, gallons of water came rushing out in a whoosh. However, a quick inspection revealed that the water level had stopped short of the electronics in the seat base, so, after things were dry and the seawater inlet valve had been changed out, the sub was ready to dive again in less than an hour. It was a get-back-on-the-horse moment. I was rattled, but still game.
This time as I flooded my ballast tanks, I was not reveling in my bubble stream or thinking of anything except basic survival. So, as I approached three hundred feet again, adrenaline still pumping, I was on high alert when I heard a very different sound from the whine associated with the leak. This was a series of long, piercing whistles, each increasing in pitch and volume. I looked around frantically inside the sub, then quickly realized the sound was coming from outside. It was an orca, nearly twice as long as the sub. It seemed to be checking me out. The distinctive white-on-black markings, the tall, bladelike dorsal fin, the streamlined shape, and the ease and power with which it cruised in from behind me, then circled the sub in slow motion before leaving, all heralded its position as apex predator in these waters. What a sight, and what a reminder of how poorly adapted we are to probe these depths compared with these distant air-breathing cousins.
Despite our limitations, we were making progress, learning new things about life in the midwater with every dive. Etch returned to oversee the remainder of our dives, which made us all breathe a lot easier. Peter never again worked as a submersible operations coordinator. The light wand was still producing no results, but, based on the complexity of the bioluminescence I was seeing and the apparent extreme need for stealth, it was becoming clear that this was too simpleminded an attack on the problem. On the other hand, the video recordings I was making of stimulated bioluminescence using the transect screen, which we now referred to as the SPLAT screen,*9 were far exceeding my expectations. I was starting to develop a library of bioluminescent signatures—recognizable spatial and temporal patterns of different bioluminescent displays that allowed me to identify the emitters. And many of these fantastic light shows, especially those produced by fragile gelatinous life-forms, had never been seen before.
We were also finally able to share the thrill with people who had never been in a submersible—not just scientists but the public. Near the end of the expedition, both CBS and NBC sent news crews out to the ship to report on our explorations. In its national news coverage, CBS included a sequence of my video recordings of bioluminescence. There was also a documentary made about our adventure, produced for the BBC, called Dive to Midnight Waters. It, too, showed my bioluminescence recordings, along with what at the time was some of the highest-resolution video ever recorded of deep-sea life. Being able to take the public along on our dives gave us all a huge sense of accomplishment, and we had high hopes that it might help stimulate additional funding for deep-sea exploration. Alas, it’s just not that simple.
Seeing one news story about the deep sea or watching one or more documentarie
s is just a flash in the proverbial pan, with little lasting impact. Even when the public is transfixed by a subject, their interest does not translate to support. The space program arose not from public interest but from political interests. The perceived need to beat the Soviet Union into space resulted in NASA receiving a blank check in the 1960s, and it used some of that funding to create one of the best advertising and marketing campaigns ever seen for communicating science to the public. Public interest grew out of that campaign, which promoted space exploration as a fantastic frontier adventure tale complete with space-cowboy superheroes.
Funding for deep-sea exploration in general and bioluminescence in particular has always been a tiny fraction of that for space exploration. In fact, the only reason my interest in bioluminescence turned out to be fundable was that the Soviet Union was also interested in it. Had that not been the case, I doubt my adventures would have been possible.
Skip Notes
*1 The intensified silicon intensified target (ISIT) video camera used two stages of intensification to achieve a sensitivity nearly comparable to that of fully dark-adapted human eyes, although it took black-and-white images and had lower resolution.
*2 Although scientists describe marine snow as “raining down” from surface waters it’s a slow-motion rain, traveling only three to six inches per minute.
*3 Available for $99, because who wouldn’t want an overpriced nightlight guaranteed to scare the crap out of you at two a.m.?
*4 Or in some cases, like that first shrimp (Gnathophausia ingens) that I pulled from the trawl bucket, out of nozzles on either side of the mouth.
*5 An idea put forth by scientist Jim Morin.
*6 Strictly speaking there are “piddle packs,” but since these were clearly designed by men for men, I have made it a lifelong goal to never have to resort to using one.
*7 Ghost nets are fishing nets that have been lost at sea. They entangle and kill untold numbers of sea creatures every year, including whales, dolphins, sea turtles, sharks, and fish.
*8 Military slang referring to adrenaline-induced tightening of the anal sphincter. The scale is 1 to 10, with 10 generally reserved for explosions, extreme disfigurement, or death.
*9 Initially, splat was merely descriptive. It was many years later that my postdoc at the time, Sönke Johnsen, turned it into an acronym by coining a name for our process: the Spatial Plankton Analysis Technique.
Chapter 7
SEAS SOWED WITH FIRE
The ocean hides many secrets. But for those in the know, bioluminescence can reveal things otherwise unseen. It all boils down to being able to read the light.
Ancient navigators could read the sea in the same way that the Inuit people read snow.*1 Route finders drew on not just a lifetime of study but many lifetimes, passed on from one generation to the next. This knowledge was central to transforming the seas from hindrances into highways for exploration and opening up new frontiers for settlement and trade. Knowledge was power, which is why, in some ancient cultures, navigators were revered as priests and their knowledge was zealously guarded as state secrets.
This secretiveness and a dependence on oral tradition mean that most of the ancient knowledge is lost forever. A notable exception was made possible by sailor and Polynesian scholar David Henry Lewis, who tapped into the oral tradition of Pacific Islanders while it was still extant, interviewing and sailing with South Seas navigators to garner their secrets. His research, published in 1972 in a book called We, the Navigators: The Ancient Art of Landfinding in the Pacific, sheds light on a puzzle that had mystified many early European explorers: How was it possible that these “primitives” in their outrigger canoes routinely crisscrossed a vast blue expanse that encompasses nearly a third of the Earth’s surface area, managing to locate tiny specks of land without the benefit of such seemingly indispensable navigation tools as compasses, sextants, or maps?
Based on Lewis’s findings, it appears that many factors were brought into play to achieve such remarkable maritime feats. Pacific Islanders steered by the stars, by the sun, and by the prevailing winds and swells. They followed the migration routes of tropical seabirds, tracking long-tailed cuckoos from Tahiti to New Zealand and golden plovers from Tahiti to Hawaii. They also expanded their target search, not depending on spotting a nearly invisible dot of land on the horizon but instead looking for clouds massing over islands and training dogs called kuri that barked when they smelled land.
Yet another extraordinary technique involved learning to read bioluminescence in the form of a phenomenon they called te lapa. Unlike ordinary bioluminescence, or te poura, which was seen at or near the surface, te lapa was deep luminescence, described as underwater lightning darting to and fro as streaks and flashes seen anywhere from a foot to six feet below the surface. The best navigators could gauge the distance to land from the patterns of the displays. Far from land, the motion of the “lightning” was slower than it was close to the land, where it was more rapid and jerky. It was most visible eighty to a hundred miles out and essentially disappeared eight to nine miles offshore. Navigators also claimed to be able to distinguish reef lapa from land lapa because the light from reefs was slower-moving than that from equally distant islands. Lewis personally observed both reef lapa and land lapa and claimed that they were readily distinguishable.
Te lapa, which Lewis first learned about from Polynesians in the Santa Cruz–Reef Islands, was described almost identically by Micronesians in the Gilbert Islands, who called it te mata, and by Polynesians in Tonga, who called it ulo aetahi, which translates as the “glory of the seas.” The fact that this unusual method of land finding was shared by remote indigenous peoples suggests that it may have been a common part of the South Seas navigators’ tradecraft. But what was it, exactly?
Lewis suggested that swells and backwash waves reflected off islands might play a part. Just like sound waves, ocean waves bend (refract) and reflect off solid objects, and in the presence of multiple islands they can create distinctive swell interference patterns. Although South Sea Islanders did not have charts in the traditional sense, they did create stick charts, constructed of palm ribs tied together with coconut fibers and with cowrie shells used to represent islands. These charts were not created to represent true distances, but rather were intended as mnemonic devices to remind the user which swell patterns were associated with which specific island groups.
The bending of waves around solid objects doesn’t happen only at the surface. It can also occur in deep water because of the presence of what are known as internal waves. You can visualize such waves in a full bottle of salad dressing, where lower-density oil sits atop higher-density vinegar. Tilt the bottle back and forth and you can create an internal wave where the oil and water meet. In the ocean, such layers occur when warm water overlays colder, denser deep water. In places where reefs or other projections protrude into these layers, it’s even possible to have internal breaking waves that create turbulence at the interface. Whether or not this helps explain te lapa remains to be shown.
Being able to see te lapa for myself and, better yet, film it, is on my bioluminescence bucket list. The closest I have come to anything comparable was once when David and I were on a camping/kayaking trip in the Sea of Cortez. We were night paddling under a full moon. The water was so clear and calm that it seemed to disappear beneath our boat, and I felt a sense of vertigo looking down at the moonlit bottom many feet below, where flashing dinoflagellates swirled and danced in an unseen current. It did not look like underwater lightning, but evidently it was the result of mechanical stimulation created by the turbulence of a bottom current interacting with the rock-littered seafloor.
It seems unlikely that te lapa involved prolonged interaction with the seafloor, since that would have been evident and therefore mentioned. Studies done by former fellow grad student Mike Latz and h
is colleagues have demonstrated that the conditions needed to stimulate bioluminescence in dinoflagellates are found under three common circumstances. The first is at the boundaries of moving objects, like boats or swimming animals; the second is when there is lots of turbulence, as in breaking waves; and the third results from flow at ocean boundaries, such as a current dragging water along the seafloor. The nature of the stimulus field responsible for te lapa doesn’t fall easily under any of these headings and remains a mystery, but my money is on internal waves.
Although there have been quite a few experiments designed to pinpoint the nature and strength of the stimulus needed to excite bioluminescence in dinoflagellates, there is still controversy on this front. Rather than get embroiled in hydrodynamicists’ nerd rants, however, I prefer to revert to my physiologist roots and think in terms of what I observed back in my graduate student days, when I was using a glass probe to jab single cells of Pyrocystis fusiformis. Under those circumstances, the most effective stimulus was one that caused a rapid deflection of the membrane. The question is, what kinds of disturbances are occurring with te lapa that might generate similar membrane distortions?
