Telling Our Way to the Sea: A Voyage of Discovery in the Sea of Cortez - Hardcover

Aaron Hirsh is chair of the Vermilion Sea Institute. He is a research associate in the Department of Ecology and Evolutionary Biology at the University of Colorado-Boulder, and his essays have appeared in literary journals, The New York Times, and The Best American Science Writing. Hirsh cofounded the biotechnology company InterCell and serves on the board of Roberts and Company Publishers. He lives in Boulder, Colorado.

PART I
 
Isostichopus fuscus
LEARNING TO SEE
 
 
1
A school of needlefish parts to stream around me, and I find myself momentarily among the silver traces of a comet shower. I move to join them, but they accelerate and dissolve into open water, leaving me to stare at the luminous, molten mirror that is the underside of the ocean’s surface. Veronica taps my arm—a signal that says both look at that and be right back—as she slips from the roiled layer of silver and descends swiftly, like a being born underwater. Her skindiver’s fins form a single broad fluke, which propels her neoprene form sinuously toward the rocky bottom. Bright bubbles, escaping her snorkel, wobble urgently back to the air above. A thousand times I have seen her descend like this, yet still I find myself wondering if, this time, she might go too deep, or stay too long.
Here, mercifully, the seafloor is only twenty feet down—a depth at which the plunging chutes of sunlight are just converging to their vanishing point. As she approaches the rocks, Veronica twists, glides to a supine and weightless pause, and gazes up at the students who float beside me here at the surface. She seems to be pointing at something on the seafloor.
Allie, the student to my right, turns to look at me. Inside the partial shade of her dive mask, her eyes are hard to read: They look puzzled, a little concerned. She is probably just wondering why Veronica wants them to notice what appears to be a mud-brown lump of sea muck. Though it also seems possible that Allie has already perceived Veronica’s tendencies underwater—the strange private gravity that seems to draw her to depth—and she is now asking, in her gentle way, whether something should perhaps be done to bring Veronica back to the surface. I take several long breaths, saturating my blood with oxygen and preparing to dive, but just as I draw my last, deep dose of air, Veronica finally relents. She places her hand gently around the nondescript mound and pulls it from the rocks, holding it as one might hold a soft loaf of bread.
Arriving among us, Veronica holds out her hand, upon which rests her inert quarry. What was mud-colored below is now—in this bright, shallow water—more of a yellow ocher, and it is studded with pale tubercles that are almost the color of lemon drops. The skin, stretched taut over the knobby body, appears thin and mucosal, making the thing look terribly exposed, like a bodily organ drawn by the hand of a surgeon into the sudden brightness of the operating theater. The students—there are five of them here—draw in around Veronica’s palm, peering intently through their panes of tempered glass. They seem transfixed, certain that Veronica’s plunge must have been for something thrilling, and yet I know their patience can be short, especially this early in the trip, when everything around them feels new. And so, as the thing on Veronica’s palm waits us out, stolid as a piece of earth, I begin to worry that the students will soon lose interest, and miss what Veronica wants them to see.
Just when I think they may be eyeing one another through their personal portholes—wondering, perhaps, if it would be rude to resume their search for colorful fish—the lump trembles, inches forward along Veronica’s palm. Suddenly it is less vegetable than animal, and the students pull back apprehensively. But as the circle of masks starts to widen, Veronica’s free hand catches Allie by the wrist.
Veronica is wise, I think, to choose Allie, because there are others who might not be so trusting. Carefully, she opens Allie’s palm and holds it beside her own. As the knobby creature slides from one hand to the other, Allie’s eyes widen and she speaks into her snorkel—an incomprehensible but richly expressive string of syllables. For a moment, she seems frozen. But even in her astonishment, she looks to the other students. She takes the hand of the young man floating beside her, opens his palm, and holds it next to her own. The animal slides over obligingly, and as it does, Cameron explores the creature’s back with his other hand.
Cameron’s hands look muscular, well-worn, and they sometimes move in unusual ways: the fingers seem to explore independently, executing many minor adjustments, as if they were navigating the neck of a string instrument. These hands have learned to perceive more than other hands, because Cameron cannot see. He is blind. And as his fingers creep across the animal’s back, investigating, it becomes clear that they are following a pattern: the yellow warts, which at first seemed to be scattered more or less randomly, are in fact arranged—loosely, but nonetheless perceptibly—into two rows.
I have never noticed this rough regularity, but now that I see it, I suspect it might be meaningful: I suspect, in fact, that those two haphazard rows are clues to a deep connection—an invisible but very real thread that links the ugly animal on Cameron’s hand to far more beautiful creatures we’ve seen this morning. Just moments before her plunge, Veronica pointed us to a sun star, Heliaster kubiniji, a pink-and-green starfish in the unmistakable shape of a sunflower. And before that, we all hovered in admiration over the crown sea urchin, Centrostephanus coronatus, which is a sphere of long and slender spines, each one perfectly black but for the occasional sharp wave of blue light that races from tip to base. To describe these scattered pulses to Cameron, Allie said it looked “like an alien’s brain.”
After Heliaster kubiniji and Centrostephanus coronatus, even the name of the animal now sliding across Cameron’s hand rings a little prosaic. It is Isostichopus fuscus, the brown sea cucumber, and one would not readily assume that it has much in common with those other, much lovelier animals. Yet that is precisely what Cameron’s subtle touch has just revealed: those messy lines of tubercles, I now realize, are among the attributes that place the brown cucumber firmly in the broad alliance of animals known as phylum Echinodermata. And who else should number among the echinoderms but the sea stars and urchins. All of these creatures, from ugly I. fuscus to brilliant C. coronatus, are the descendants of a single ancient species: an ur-echinoderm that inhabited the ocean 520 million years ago. And because that ur-echinoderm, in its own time on earth, underwent several extraordinary modifications—we could even call them innovations—we now find mementos of those changes in every single one of the creature’s descendants. In fact, those vague rows of bumps just now detected by Cameron’s hands are but a faint reminder of the ur-echinoderm’s most fundamental innovation. But exactly what that innovation was, and how it later became a trace so obscure it took Cameron’s touch to disclose—these are questions I should raise later, when we’re back at the field station. Because right now, Veronica seems to have a plan of her own; she has just lifted her head from the water, letting her snorkel dangle by her face, and the rest of us now follow her lead.
“Cameron,” she says, “do you feel it attaching to your hand?”
“Yeah, totally,” he responds. Cameron grew up in a small town outside of Santa Barbara, California, and he talks like a surfer. “It’s got those wicked little suckers,” he continues, “just like the starfish.”
“ Exactly,” Veronica says, clearly pleased with his suggestion. “Sea stars and cucumbers both have tube feet.”
As Veronica begins to explain how these ingenious little devices operate, Cameron allows the cucumber to creep back to Allie, who then takes the hand of another student. It’s Chris, a quietly confident young man who may already know much of what Veronica is explaining. Chris has spent a semester at a marine biological laboratory, a month on an oceanographic research vessel, and, judging from his comfort in the water, a lot of time diving. As I talked with him during our long drive down the Baja Peninsula, Chris seemed strangely familiar, as if I knew him from somewhere. But it wasn’t until we arrived at our destination, the small town of Bahía de los Ángeles, that I finally understood: the only people I’d ever met who possessed this calm composure—not arrogance, really, but equanimity—were the more formidable patriarchs here in Bahía. That Chris shares this trait is perhaps not entirely coincidence. His father is Mexican, and Chris spent part of his childhood in a picturesque village not far from Mexico City.
The student floating beside Chris, Anoop Prakash, appears less comfortable in the water. In fact, he seems to be expending a tremendous amount of energy just to remain upright, and occasionally his fin flails out and whacks Chris in the legs. Despite these occasional assaults, the transfer of the cucumber from Allie to Chris goes smoothly, and Chris is now placing one hand in front of the other to make a kind of treadmill for the animal. Even with our faces above water, and the cucumber just below the surface, we can see that as it slides forward, its front seems to dab back and forth laterally, as if it were exploring the curious new terrain. The end of this treadmill ride, I’m afraid, will be Anoop’s hand, and the thought of that unsteady platform makes me more than a little anxious—for the animal and Anoop alike.
I assume Veronica too is monitoring Anoop’s buoyancy, because his safety in the Vermilion Sea was the subject of some debate when we first reviewed applications for our field course. Anoop had approached us after the Baja info session, an informal presentation that Veronica and I offer for prospective students. As soon as the presentation had ended, he unfolded himself from his writing desk—he is tall for a South Indian, about six foot one—and in three gangly steps, he arrived at the front of the room. With a black goatee and wire-rimmed glasses that gleamed silver against his chestnut skin, he looked quite scholarly. And because the lenses over his eyes appeared somewhat too small—as though they could possibly clarify only what lay straight ahead, leaving the periphery in a blur—he also looked intensely focused. Fixing his narrowly tunneled view on Veronica, he said, “Dr. Volny, I’d like to ask what endemic species of salt-tolerant plants are found around the research station.”
Usually, students ask if we might really see a whale shark, or if the dolphin are there every year, or if it’s truly so hot as we say it is. They do not, in general, ask about endemic salt-tolerant plants, and it took Veronica a moment to gather her answer. Later, when Veronica and I were laughing about the question, she seemed charmed by it, but she was also earnestly concerned that Anoop’s sheer focus might compromise a more general awareness of his surroundings. “He’ll step on a scorpion,” she said.
The students’ written applications arrived two weeks later, and Anoop’s was fabulously impressive. As I read certain sections to Veronica, she said, “You’re making this up!” and grabbed the page from my hands. But I hadn’t made it up. Besides the independent research in yeast genetics and a concentration in philosophy of science, there were graduate seminars on Marcel Proust and Ludwig Feuerbach, in which Anoop, a sophomore undergraduate, had earned perfect grades. But there were also a few sentences that Veronica referred to as “warning signs.” In response to the simple question Can you swim? Anoop had written, Last time I checked, I was competent in breast stroke, Australian crawl, back stroke, and side stroke—a response that Veronica deemed suspicious for its very thoroughness. “He won’t step on a scorpion,” she said. “Because he’ll sink first.”
In the end, I argued we simply had to take Anoop; his academic record—not to mention his devotion to salt-tolerant plants—left us no choice. Veronica consented, but added, “He’s on your watch.” And now I do watch—quite closely—as Anoop’s hands rise and open to form the animal’s next platform. Without his arms for paddling, he drops slightly: his chin lowers into the water, and he tilts his head back to keep his mouth above the wavelets.
Tube feet, Veronica’s been explaining, are the only outward sign of an internal system possessed by all echinoderms—sea cucumbers, urchins, sea lilies, sand dollars, brittlestars, and, as Cameron sensed, sea stars. The bodies of these animals are piped with a network of tubes, and when an echinoderm decides to move, water flows to the appropriate plumbing, creating hydraulic pressure. Each one of those hundreds of tube feet on an echinoderm’s underside is the continuation of an internal pipe. When a foot needs to take a step, a small ampule inside the animal contracts, driving water into the tube and extending it until it touches the surface below—in this case, a student’s palm. What feels like a miniature suction cup—or, as Cameron put it, a wicked little sucker—is in fact something stranger: As the little foot makes contact with the surface, it secretes a kind of quick-dry superglue, fastening it to its substrate. And when it is ready to let go, the foot secretes a fast-acting antidote to its own adhesive.
Having crept from Allie to Cameron, back to Allie, and on to Chris and Anoop, the cucumber now seems to have reached something of a cul de sac, and I wonder whether any of the other students are growing impatient with Anoop. I don’t think he intends to monopolize the sensation of tube feet on the palm; it’s just that he’s fully absorbed in keeping his head above water and his hands relatively steady. Rafe, the only student in our floating circle who has not yet handled the animal, seems to be sidling closer to Anoop, awaiting the transfer, though he is held at bay by Anoop’s erratic kicks.
Ever since he introduced himself at the Baja info session, Rafe has made me uneasy, because his self-assurance sometimes verges on blithe overconfidence. Veronica had asked everyone at the meeting to say a word about themselves, and most students seemed to blush and hurry through rather self-effacingly. But Rafe spoke slowly, with striking nonchalance. In his thick Australian accent, he said, “My name is Kurtis Rafe, but you can call me Rafe. My major is chemistry, but I’m taking a lot of theoretical physics as well.” And when he said, serenely, “I’m applying ’cause I think it’d be ace to swim with sharks,” the room broke into laughter, expelling its awkward tension, and Rafe sat back, smiling slightly. Even here in Baja, he keeps his long blond hair nicely combed, pulled back in a tidy ponytail, and he wears a small but thick gold hoop in one ear.
Evidently, Veronica is not as concerned as I am about Rafe’s looming encroachment; ignoring him, she says she wants to show the students something very strange about the echinoderms. And just from the way she says “very strange”—as if she were some sort of haruspex, preparing to astonish her small audience—I suddenly know what’s coming, though I can hardly believe she’s really going to do it with the creature resting on Anoop’s hands.
The first time Veronica took me diving in these waters, seven years ago, she found a brown cucumber. She placed the animal on my open palm, and when it began to creep forward, she gently pressed a finger against its knobby back. Almost instantly, the animal contracted, like a biceps balling up in tension. I pressed it with my own finger—it was as hard as a billiard ball—and I widened my eyes and shook my head in underwater communication of astonishment. But Veronica held up a finger, as if to say, “Just wait, there’s more.” She began to rub the animal’s back, as though she were polishing its hardened surface. At first nothing happened; the billiard ball rested hard and c...