Explorers of dark frontiers – submarine, Deep Rover, finds new species
An important thing to remember before diving in a small submarine: once you’re inside, there’s no getting out. This thought crosses my mind only after I’m sealed in the sphere of Deep Rover, a Volkswagen- sized submersible that’s sinking swiftly in the ocean off La Jolla, Calif. The sub hits the sandy bottom 70 feet down with a jolt. In my nervousness, I forgot to use its propellers to slow its descent.
Scuba divers hover anxiously around Deep Rover, like pilot fish about a shark. They peer inside; their underwater cameras flash. This must be how my goldfish feels. One diver makes a circle with thumb and forefinger and raises his eyebrows. O.K.? Fine, except that you guys are staring at me. I give the thumbs-up sign and they withdraw. The world becomes serene. Water moving past the sphere makes no sound; no color exists but blue.
Finally remembering the propellers, I use them to maneuver the sub off the bottom, and it glides forward with surprising grace. I can make it spin on its axis, or execute sweeping curves, or tip to one side; the sub rises and stops, then falls again; it hangs for a few seconds four feet above the ocean floor. We swoop, the sub and I, we twist and gambol over the sand, sometimes scraping the bottom clumsily and stirring up a cloud of silt.
The call to ascend comes too soon, after an hour, but I reach obediently for an overhead valve to fill the ballast chambers with air. As I rise, the surface shimmers and undulates like spilled quicksilver, until it’s rent by the sub bursting through. Divers splash noisily with their flippers as they guide me back to the mother ship. They hook a winch to a ring at the top of the sphere, clanging metal against metal, and the sub is hoisted on deck, where its hemispheres are unbuckled and opened by means of a hinge on the top. I squeeze out, a rumpled Venus emerging from her scallop shell.
On board the ship, people smile–knowing little smiles that say,we understand how you feel. It’s wonderful down there, isn’t it? It feels like fly ing, doesn’t it? ”You have post- dive euphoria,” says Sylvia Earle, one of the sub’s designers. And that was in barely 70 feet of murky water half a mile off the coast. Just imagine what it’s like to take Deep Rover to its maximum depth of 3,000 feet, where only a few stray photons of sunshine penetrate, where the brightest lights are those cast by bizarre and luminescent creatures.
The mid-water of the ocean, which ranges from just below the surface to 6,000 feet or more, constittes one of the largest unexplored regions on earth. It contains the greatest volume of organisms in the sea. Yet we know next to nothing about it, or its denizens, great numbers of which have never been seen.
Last August, Bruce Robi son, a blue-water oceanographer at the University of California at Santa Barbara, made a considerable dent in that ignorance by using Deep Rover to study mid-water life first hand. In a month of diving in Monterey Bay, south of San Francisco, he and half a dozen other biologists gathered reams of information. ”I thought I knew what was going on down there,” he says, ”but Deep Rover shattered my illusions. I’ve collected mid-water animals in thousands and thousands of net hauls around the world, and a lot of what we thought we knew was wrong.”
Our two-day cruise off La Jolla isn’t quite so scientific. WhileEarle, a biologist, will collect specimens in collaboration with the Hubbs Marine Research Institute, the cruise is also intended to test the submersible at its maximum depth, and to give it ”exposure.” A TV crew is there, as well as assorted distinguished onlookers, like astronaut Kathryn Sullivan. There’s a restaurateur who has won a dive in the sub at an auction, and a bunch of photographers. Tomorrow the ship will move farther offshore, where three people will each take Deep Rover down to 3,000 feet–deepair than eet has evair divven before, as Jacques Cousteau would say. The lucky three are Earle, Graham Hawkes, Deep Rover’s co-designer, and Phil Nuytten, president of Can- Dive Services, Ltd., which owns the sub and is Canada’s largest provider of diving services to salvage operators and offshore oil rigs. At the moment, scientists like Robison can lease Deep Rover, the on- ly vessel of its kind, from
Can-Dive. Earle, Hawkes, and Nuytten hope that orders for subs will come in from research institutions and commercial operations.
Late in the evening, after the first day’s shallow dives, the sub’s creators and a few others sit around the teak table in the ship’s galley, eating kil- ler chili from paper plates. Hawkes and Earle’s company, Deep Ocean Engineering, has leased the Egabrag III, a 140- foot research vessel, Guamanian cook included. The ship’s name, for those not palindrom- ically minded, is ”garbage” spelled backwards, after the first Egabrag, a converted Navy garbage scow.
”I wanted to be an airplane designer but ended up doing submarines for the Navy,” says Hawkes. ”I was just as happy with subs once I realized I wouldn’t have been able to design a new wing and try it out, as in the early days at
Kitty Hawk.” The British- born Hawkes is an engineer and a true tinkerer. He constantly scribbles designs on any available scrap of paper.
A number of his other sub- mersibles and remotely operated vehicles (or ROVs, as they’re known in the biz) are used by companies throughout the world, particularly in the North Sea oilfields.
Hawkes and Earle worked out the rough design for Deep Rover on apaper napkin over dinner five years ago. ”In those days we were dreaming of going to thirty-five thousand feet,” she says. It was Earle, a marine botanist by training, who urged Hawkes to make Deep Rover a tool for biolo- gists as well as a repair sub. ”The idea has always been that scientists couldn’t be trusted to drive a submersible by themselves because they’d get so involved in their work they’d run into things,” she says.
Earle is an accomplished diver, with 5,000 hours logged under water and years of experience experimenting with all manner of submarine contraptions. Like Cousteau’s, her enthusiasm for the ocean has gone beyond scientific research into the realm of commerce and promotion, which has earned her the nickname Her Deepness among some of her more academic colleagues. Yet no one else, says one admirer, can wax quite so purple about the wonders of the ocean and still hold your attention.
After dinner we go back on deck to make sure that the sub is tied down securely. It consists essentially of two acrylic hemispheres, each five feet in diameter and five inches thick. They are sealed by means of an O-ring, a rubber gasket between the anodized aluminum bands that rim each one. Near the bottom of the hemispheres are two coffin-sized boxes containing 120-volt batteries. Above the batteries are the two ballast tanks and four aluminum housings for the propellers, or thrusters.
A green tank on the outside of the sub bleeds a measured flow ofoxygen to the inside, while two canisters in the bubble filter carbon dioxide. The air pressure doesn’t change appreciably, even at 3,000 feet. The sub carries a week’s sup- ply of oxygen and carbon dioxide filtrate.
Although at first glance it seems as if the sphere holds about five million switches and gauges, you can get away with using just a few on a first dive. There are only two truly life- threatening emergencies a pilot might have to contend with, short of a puncture in the sphere. If the sub gets hung up on the bottom or the ballast tanks won’t fill with air, the batteries and a clump weight can be released from the craft, which would then shoot up to the surface like a missile ejected from a Trident submarine. In case of fire, pulling a single pin on the fire extinguisher releases a chemical flame retardant. There’s an oxygen mask for breathing until the smoke dies down. Lesser emergencies are also provided for. Full bottles of drinking water are wedged behind the seat, and pee bags, each labeled as such in felt-tip pen, are stuffed inside the emergency radio kit. For a woman, the bags look pretty useless.
The only piece of computerized equipment in the thing, says Earle, is ”between the ears of the operator.” At least in submersibles, computers have an annoying tendency to break more often than mechanical devices. Hawkes had to replace a fancy computerized clock that reminded the pilot to call topside every 15 minutes with an ordinary plastic kitchen timer.
The next morning at dawn the Egabrag’s diesel engines spew blackexhaust as the vessel heads toward San Clemente Island, 60 miles out to sea. Near dusk, the ship finds calm water in the lee of the island.
A few of yesterday’s onlook- ers, including the TV crew, arrive on another boat just as Hawkes, the day’s first diver, begins going through the pre- dive checklist. Power? On. Lights? Working. Radio? On. Oxygen per cent? Twenty-one point five. The indigo water is very, very deep here, half a mile from the cliffs of San Clemente: the sloping island shelf, 100 fathoms below, falls off into a 6,000-foot abyss. This evening Hawkes will descend to 3,000 feet, where the pressure per square inch is 100 times atmospheric pressure, and where it’s so dark it doesn’t matter whether he dives during the day or at night.
Maintenance men scurry around the sub in orange coveralls that make them look like overgrown bees tending their queen. Someone binds five Rolex watches to the wrist of one of the sub’s external manipulators. (Rolex donated money to the cruise; it gets to have its watches tested in return.)
Someone else gives Hawkes the thumbs-up sign; he smiles, shakes his head, and points his thumb down. The winch shrieks horribly and gives off an acrid whiff of hot hydraulic fluid as it lowers the sub.
As Hawkesdescends, the sub’s lights cast a wide corona in the water. Everybody aboard ship clambers up to the bridge to listen to his report over the underwater telephone. Far too many people have crowded into this six-by-twelve-foot space, and the heavy metal door keeps clanging shut, cutting off any breeze. The air reverberates with the syncopation of the ”ping ping ping” of the ship’s echo sounder and the slower beat of the sub’s audio locator beacon. Both sound like the hollow ring of sonar in submarine warfare movies.
After 28 minutes Hawkes says, ”This is Deep Rover. I’ve reachedbottom, at depth thirteen forty-three.” Scat tered cheers go up, and then guffaws when he says, ”Which way do I head for deeper water?” The sound of the sub’s locator beacon is picked up by hydrophones, which makes possible a calculation of its position relative to the ship. A brief discussion ensues between the chief engineer of the Egabrag and the Can-Dive crew: Should Hawkes steer 350 degrees, or 35? Finally they agree on a northeasterly direction and soon Hawkes resumes his descent.
Earle asks him if he sees any animals. ”There’s some fish down here,” he replies.
”What kind of fish?”
”Oh, some long green fish. And a flounder sort of thing.” Spoken like a true engineer.
As he passes 2,000 feet the tension mounts and the bridge fills with even more bodies.
At 2,700 Hawkes pauses to review his checklist. The transducers pick up the unmis- takable clicking sounds of a school of dolphins, which must be swimming near the ship. Intensity radiates outward from Earle, and the only sound on the bridge for minutes is the sonar’s insistent ping. Hawkes, having resumed his descent, calmly calls out his depth, ”Twenty-eight five zero.” Nine minutes later Earle pounds the table in glee at the announcement ”I’ve arrived.”
”What is your depth, Deep Rover?”
”You’re a bit short,” says Earle. ”Tell him to get out his shovel,” says a bystander. A television reporter asks if he can talk to Hawkes. Everyone’s attention focuses on the reporter. What cosmic question will he ask?
”Graham,” he intones, ”tell us, what does it mean to be at three thousand feet?”
What does it mean? To be the first person ever to descend to that depth alone? Others on the bridge roll their eyes. Hawkes pauses before answering. Finally he says, ”It means that after three years of work, I didn’t make any mistakes.”
”Whaddya think it means?” somebody mutters. ”It means my machine works. It means that I’m still three-dimensional, that I’m not squashed as flat as a tapeworm.”
Hawkes returns to the ship more ebullient than he has been during the entire cruise. His sub worked beautifully, except for a couple of details; for instance, the oxygen level dropped precipitously. During the next 24 hours Nuytten and Earle also make successful dives. Earle, the biologist, is the only one to return with reports of exotic creatures: a red octopus, two blue sharks, starfish, lantern fish, a translucent octopus with delicately dangling tentacles, and hundreds of unidentified glowing things.
Sometimes, at the beginning of their careers, young biologists get the idea that all the good questions have already been asked, that all the good ecological systems have already been described. But all they need to do is get on a ship and look down. A vast ecosystem awaits them: the average depth of the ocean is nearly two and a half miles; the seas cover 70.8 per cent of the planet. That’s a lot of unexplored territory, where most of the ecological interactions remain unexplained. They are just waiting for a small submersible to penetrate these mysteries. Almost every biologist who has driven it hopes that Deep Rover or a similar sub will be his vehicle into the unknown.
For Bruce Robison, the chance to observe mid-water organisms from Deep Rover was what he’d been waiting for all his professional life. ”Imagine you’re an ecologist and you’ve always had to study the forest from a blimp and the forest is in a dense fog,” he says. ”That’s what it’s been
like to study the mid-water.” Last summer Robison spent every penny of a $250,000
National Science Foundation grant to lease Deep Rover for a month’s worth of dives in Monterey Canyon, a deep gash in the floor of Monterey Bay, where the water teems with life as the bottom drops to several thousand feet within ten miles of shore. ”Deep Rover is like suddenly being given the chance to walk in the forest,” he says. ”The change in the scope of your perspective
is revolutionary. Right now we’re overwhelmed by all that we’ve seen.”
The idea of using a submarine to study the mid-water isn’t a newone. In 1934 the indefatigable and intrepid naturalist William Beebe, accompanied by his financial backer, Otis Barton, dived to 3,028 feet off Nonsuch Island, in Bermuda. They went down in a device of Barton’s design: the bathy- sphere, a crude steel ball with quartz windows, suspended on a cable from a ship. The bathysphere was a miserable machine. It was cold, cramped, leaky, and dangerous. It had no means of propulsion and was entirely dependent upon the cable connecting it to its mother ship. Beebe returned from the depths with lyrical descriptions of creatures that had never been seen before, but after thirty or so dives he abandoned the bathysphere and went back to studying birds.
Since then there have been a number of subs built for non- military uses, but each has been designed for a purpose not particularly well suited to studying the mid-water. There was the U.S. Navy research vessel Trieste, for example, which went to the bottom of the Marianas Trench, nearly seven miles down–but only once: after that it was restricted to shallower waters. Then there are the Johnson Sea- Links, dumbbell-shaped gizmos the size of a Lincoln Continental that require a professional pilot. And there’s the research submersible Alvin, one of the greatest scientific tools ever built–the underwater equivalent of the telescope. But Alvin isn’t useful to everyone. It can’t make a move without a specially designed mother ship; it costs about $20,000 a day to operate; it requires a pilot to drive its scientists around; and it’s designed to work just above the sea floor in depths around 10,000 feet.
Deep Rover is primarily a mid-water machine. It has neutral buoyancy, which means you can trim it at any depth by adjusting the amount of air or water in the ballast tanks. (The bathysphere was negatively buoyant, which means it sank like a stone.) Thus Deep Rover can operate easily anywhere between the surface and 3,000 feet down. (Lloyd’s of London has certified the sub to that depth, although it’s engineered to go four times that deep.) Furthermore, it costs only $5,000 a day, and as this novice pilot can attest, just about anybody can learn to use it.
Robison’s enthusiasm for Deep Rover is overwhelming. ”We’ve been aware of deep sea animals for a hundred years, ever since the British ship Challenger sailed around the world,” he says. Before then the deep ocean had been considered too dark and too cold, and its pressure too great to support life. Naturalists aboard Challenger brought animals up in nets, proving conclusively there was deep- sea fauna in all the wrld’s oceans. What’s astonishing, says Robison, is that the means biologists have at their disposal to sample the mid-water fauna hasn’t changed much since those times. ”You still stand on the deck of a ship, cranking out a forty-foot-long net on the end of a cable, dragging it through the water, hauling it back to the surface, and getting excited about what you haul up.”
A century of trawls has shown that the mid-water encompasses oneof the richest communities of organisms on earth. But to think of it as a uniform blanket containing a homogenized mix of creatures would be a mistake. ”It’s partitioned,” says Robison. ”Along the coast of North America there are different kinds of communities, each associated with different kinds of hydro- graphic regimes. Off Santa Barbara, for example, there’s a tiny pocket of deep water where the bottom drops off. It’s deep enough to support oceanic organisms, but it’s limited to a small area. Yet there it is, a happy little deep- water community out there surrounded by a completely different one.”
Biologists have only the roughest notions of which animals are found where in the mid-water. During his dives in Monterey Bay, Robison was astonished to see gangs of three-inch octopuses–until then thought to be strictly solitary animals. However, one of the few things in the mid-water that biologists are familiar with is an assemblage of creatures that form the deep scattering layer (DSL), so named because it deflects, or scatters, the sound waves of a ship’s sonar. It appears on a sonar screen as a broken sheet of objects, which rises to the surface dur- ing the night and falls back into the depths before dawn. Biologists now know that the DSL consists of different species in different parts of the ocean. In places it contains, during the day, such animals as euphasid shrimp, or krill, microscopic crustaceans, squid, and lantern fish; at night some of these animals rise to feed on plankton at the surface.
The DSL is central to the food web in oceanic waters. Many of the pelagic species that people are familiar with, such as whales, dolphins, and tuna, feed on it. Yet its exact composition is unknown, because only a certain proportion of the organisms down there are going to get caught in a net. ”There’s a bias in any sampling technique,” says Robison.
Like any terrestrial ecologist, Robison is interested in the relationships between or- ganisms–who’s eating whom, for example, and how–which is something trawls can’t readily tell him. What comes up in a net is a jumble of fish, shrimp, eels, sharks, squids, octopuses, crabs, and the tattered shreds of soft-bodied gelatinous creatures known in the business as jellies. ”You’d be picking through a trawl catch, saying here’s this fish, and this fish, and this fish–and here’s this gob of goo,” says Robison. ”There was no way you could consider that bunch of organisms as evidence of a biological association.”
Only by using mid-water submersibles have biologists begun to gain an inkling of how important these gelatinous creatures are. Richard Harbison, a jelly ecologist at the Woods Hole Oceano- graphic Institution in Massachusetts, dived in the mid- water in the Bahamas in a Johnson Sea-Link in 1984. ”Right now all I’m doing is being a taxonomist,” he says, ”just trying to name them. I got twenty different species of one group, fifteen of them unde- scribed. It’s like being a natu- ralist at the beginning of the nineteenth century.”
Aboard Deep Rover in Monterey Bay, Robison was able to see that those gobs of goo from his nets were far more important than anybody had realized, not only in number but also in the roles they play in the system. Marine animals encounter very different difficulties from those faced by terres- trial ones. Where, for example, are you supposed to hide in the open ocean? How can you anchor yourself in one spot in a such a shifting, dimensionless environment?
One solution for mid-water animals is to use each other. Robisonobserved such an association between a peculiar type of jelly, called a sipho- nophore, and two species of fish. A siphonophore resembles nothing that exists on land. It looks a little like a bunch of jellyfish strung together in a chain that can stretch to forty feet. The chain acts as a single organism, with numerous mouths, swimmer ets, and tentacles for stinging prey. But it’s actually a cooperative colony. The siphonophore is made up of hundreds of individuals, some of them acting as stomachs while others do the swimming or deploying of tentacles.
”A siphonophore is this big thing that goes around sucking up food,” says Robison. The two species of fish accompany it only at certain times. One, a kind of lantern fish, hangs in the water a few feet away. The other, a kind of smelt, snug- gles among the siphonophore’s tentacles, which spread out when it’s feeding. Robison thinks that the fish stay close
to eat scraps and to hide.When a siphonophore’s tentacles are retracted–which means that it isn’t feeding–the fish are nowhere to be found. As further proof of the association, the siphonophore inhabits a region between 1,600 and 1,900 feet, and while the fish species have a much broader range, they’re certainly most common at depths where siphonophores live. Says Robison, ”Both those fish are hanging around because the siphonophore is a swell food source and cover.”
Another clue to the behavior of mid-water creatures is provided by University of California at Santa Barbara biologist Edie Widder, a slight, energetic woman whose specialty is the study of bioluminescence, one of the most beau- tiful phenomena in the sea. Aboard Deep Rover, she made the first film footage of mid- water organisms lighting up in their own environment.
Widder leads the way into her darkened lab, illuminated only by dim light from under the door. She takes down from a shelf one of four jumbo-sized Erlenmeyer flasks with about three inches of water in it. She swirls the flask, causing thousands of pinpoints of blue light to flash inside. The lights are produced by dinoflagellates, microscopic animals that live amid other planktonic organisms at the surface of the ocean. The longer Widder swirls, the dimmer the lights become. She puts the flask back and says, ”They’re getting tired.”
Dinoflagellates are among the hundreds, or possibly thousands, of species of oceanic animals that can produce light chemically, the way a firefly can. Probably 80 per cent or more of mid-water organisms have this ability but, says Widder, ”we know very little about it. For one thing, it’s difficult to study.”
Like other experts on bioluminescence, Widder has had to be content with dangling light-measuring devices from ships or dragging her organisms to the surface to study them, or looking at shallow- water species. Some, like dinoflagellates, can be grown in a lab, but the glow of many other animals has been observed only fleetingly, while they lay on the deck of a ship, giving off their last flickers before dying.
A few mid-water fish have one or more glowing ”organs,” pockets on their bodies packed with bioluminescent bacteria. The fish are able to stimulate the bacteria with nerve impulses or chemicals–in effect, to turn them on and off. Most fish, as well a many of the jellies, such as the siphonophores and jellyfish, produce their own light chemically, without bacteria.
While biochemists have been uncovering the process by which animals can produce light, biologists have barely begun to understand why these creatures glow. Can all luminescent animals switch their lights on and off? Do they use them to signal members of their own kind, the way fire- flies do?
It was questions like these that led Widder to accept Robison’s offer to join the Monterey Canyon project. Her dives in Deep Rover paid off immediately. ”My major discovery has to do with background luminescence,” she says. A significant unknown for biologists has been whether there’s some constant level of light produced by ani- mals living in the mid-water. Creatures brought to the surface will luminesce if they’re touched, or if the bucket they’re in is shaken. But in their own environment, do the animals leave their lights on all the time?
”What I discovered was that there was zero background luminescence,” says Widder. Nearly 2,000 feet down, when she turned off the lights and allowed the sub to drift, it was completely dark. ”I saw nothing,” she says. ”I think that’s a really exciting finding.”
In fact, the only way Widder could get the animals in the mid-water to light up was to stimulate them physically. She put a fine mesh screen on a frame and attached it in front of a video camera, which was mounted on the sub. As Deep Rover moved slowly through the water with all its lights out, the mesh net gently struck the animals in its path. The result was the first movies of bioluminescence in deep water.
Widder pops a video tape into a cassette player and turns on thetelevision. The scene is unearthly–like something you’d see from the starship Enterprise. A jellyfish brushes the mesh, and a brilliant nebula spins against a velvety sky; a siphonophore sends chain lightning streaking. In two minutes of tape, perhaps a hun- dred organisms, some of them stretching for three feet across the mesh, flare for Widder’s camera.
Yet none of the creatures would luminesce when she kept Deep Rover still. ”I think that indicates an important strategy for a lot of the fish,” she says. ”It’s known that fish tend to hang in the water column and not move around, and the speculation was that this was for metabolic reasons– they didn’t want to expend the energy to move. That may be true, but it’s also true that if they move, they’re going to light themselves up like an all- night diner.”
While some organisms remain dark in order to hide, others use their lights judiciously to catch food or to escape. The angler fish, for example, waggles a lighted appendage that hangs like a fishing lure directly in front of its wide-open and toothy jaws. Mid-water squid and shrimp squirt luminescent clouds to distract predators. Colobone- ma, a species of jellyfish that’s Robison’s favorite animal, employs a complicated set of il- luminated escape maneuvers. When first approached, it turns on little white lights at the ends of its tentacles and turns off the lights in its bell, as its body is called. It then stretches the bell as far away from the glowing tentacles as it can, and finally douses the tentacle lights and shoots off.
If a predator continues its pursuit, the jellyfish switches to Plan B, turning on both the tentacles and a blue light in the bell. When its attacker is quite close, it darkens the bell and scrams, leaving behind a writhing mass of still-bright tentacles, like a lizard’s jettisoned tail.
Widder’s film reminds me of Beebe’s descriptions of what he saw fifty years ago from the pitifully small windows of the bathysphere. In his book Half Mile Down, he wrote: ”The only other place comparable to these marvelous nether regions must surely be naked space itself, out far beyond atmosphere, between the stars, where sunlight has no grip upon the dust and rubbish of planetary air, where the blackness of space, the shining planets, comets, suns, and stars must really be closely akin to the world of life as it appears to the eyes of an awed human being, in the open ocean, one half mile down.”
Like Beebe, Earle sees the parallel between inner and outer space, but it’s clear which one holds her interest. At night on the deck of the Egabrag III she stretches her arms wide to point simultaneously at the stars above and the sea below. People are so busy looking into outer space, she laments, looking up. Billions of dollars are being shot out there, while most of the planet still begs to be seen. ”Hey, everybody,” she says, shaking a finger at the water, ”take a look down here!”
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