2017 is a big year for hydrothermal vents, marking the 40th anniversary of the discovery of life in darkest depths of the ocean. It was an astonishing find. Entire ecosystems supported by chemicals rather than sun, like something out of a Ray Bradbury novella. The discovery of vent ecosystems is so new that its pioneers are still working. And so, my first dive in Alvin is with pilot Pat Hickey and senior scientist Horst Felbeck, two such pioneers. Horst has been on about 30 dives, an impressive number for a scientist. This is Pat’s 681st dive, a record by a landslide. Both have been visiting vents since their discovery or close to it. In contrast, I was born into a world where vent ecosystems were known, though still very new and astonishing. They still seem new and astonishing to me, as the bottom comes into view and we transit to the first stop on our undersea itinerary, a burst of life in a cold, volcanic world.
It feels strangely intimate to peek into the lives of these creatures. Most are blind, and some are eyeless; like animals from deep caves, eyes are useless in a dark world. This means that, diving, Alvin’s lights don’t bother them. They’ll shy from movement in the water, but if the sub is still, they just go about their day as usual. It’s an unusual feeling, being able to watch animals so closely without disturbing them. Pale, wrinkled, worm-like fish dart back and forth in front of our windows. Tubeworms sway gently and suddenly retreat when hungry crabs come by, pulling extravagantly red plumes into the safety of translucent white tubes. A squat lobster, curious, perches on Alvin’s robotic arm and rides along with us for a few minutes before jetting off backwards to more pressing lobster business. It’s surreal to watch this marine scene play out just beyond my fingertips, knowing that it’s happening under enough pressure to crush a car.
We are, of course, not just here to sight-see. There is work to be done, samples to be collected for a wide-ranging team on the ship one and a half miles above. Pat, our pilot, does most of the work. He is astonishingly good, and he makes a fine undersea fisherman. My work is first on the list, retrieving a crab trap from the side of an undersea pillar and replacing it with a new one. I got skunked: the trap is empty. (Sardines in oil are apparently not the exotic delicacy I was hoping they’d be.) Pat is undeterred. He uses Alvin’s port arm, the more agile of the two, to crush a few large mussels and put them in the insulated biobox on the front of the sub. The crabs smell food, and greedily move in to check out this unexpected windfall. As they approach the rim of the biobox, Pat gently nudges them in with Alvin’s arm, so that they land unharmed in the bottom of the box to gorge themselves on a last meal.
Fishing expedition complete, we move on to the main event, collecting samples of water and microbes for most of the rest of the science party. (Horst and I are unusual on this cruise in that we study things you don’t need a microscope to see.) We stop at a shaggy white mound, ripples of hot water rising visibly from a few openings. This is an accumulation of sulfide from the water, covered with the tubes of small heat-loving bristleworms named Alvinella after our vehicle. The Alvinella are handsome creatures, squat and red and with little gray pelts of bacterial growth on their backs. They’re much cuter than they sound, and look about as jolly as it’s possible for a worm to look. They’re one of many biological marvels down here, thriving in extraordinarily hot and chemical-laden water. We take a sample of the mound and the worms, collect some hot outflowing water, and place a bacterial colonizer in the area hoping to attract microbes previously unknown to science.
Next stop: black smokers. On land, these might be hot springs or geysers. At 2,500 meters depth, they’re knobbly spires of accumulated minerals, sending up constant pillars of superheated black “smoke”. They are perhaps the more surreal part of an already-alien landscape, transient cathedrals looming above the bustle of life in neighboring, lower-temperature areas. We measure 360°C in one smoky outflow, using a temperature probe designed to handle the volcanic heat, and take a water sample for the geochemists.
The last item on the dive plan is collecting tube worms for Horst’s team. We visit one mound covered with an extravagant tangle of worm tubes and crawling with associated life. It is beautiful, but it won’t do. The worms are nearly six feet long. They won’t fit in the insulated biobox for the trip to the surface, and, Goldilocks-like, Horst declares them too big. We zip back to a younger community, which is deemed just right, and Pat plucks worms like flowers, placing the resulting bouquet carefully into the biobox.
With that, we are done with sampling. The basket in front of Alvin is full, but we still have some battery charge left. “Let’s have some fun,” says Pat, and takes us away from the crags and valleys of the central volcanic area to the relatively flat and lifeless surrounding lava fields. “OK, who wants to drive?”, he asks. I do. It’s a surprisingly delicate operation, a smooth ride, with the buoyancy of the sub making it feel entirely unlike driving a car. “You can go a little faster or we’ll never get there,” Pat prompts. I speed up a little, carefully. The bottom glides by, volcanic undulations dotted here and there with a long-legged red shrimp, glass-clear sea cucumber, or, once, a starfish the size of a dinner plate. Away from the heat and the energy of the vent field, life is sparse, but present.
I return the helm to Pat, so we can head back into the canyon and look for Flea Vent, a feature Horst named on a prior trip. We find it, maybe. It can be a little hard to tell. This is a transient landscape. Vents form at active volcanic sites. Spires fall; vents erupt or go dead; lava flows; biological communities rise and fall in concert with geological shifts. Flea Vent (we think) is an isolated tower with a delicate, almost lacy collection of spikes on top. It must not be too active now, since the only life seems to be a few anemones and a small cave writhing with half a dozen blind white fish.
With this, our battery is nearly spent, and it’s time to head back. Pat drops some weights and the sub starts to lift. Soon the bottom is no longer visible, and Pat turns off the lights. We rise in darkness, broken by flashes and blinks of blue-green bioluminescence out the windows. It takes about an hour and a half to get to the surface. As we wait, I watch the jelly creatures flicker and we all eat our packed lunches, peanut butter sandwiches and Hershey bars. A fine meal for the grade school cafeteria and a voyage to the bottom of the sea alike.
Back on board Atlantis, the dive is over for Pat and Horst, but not for me. There’s a tradition surrounding first dives, and mine is no exception. Stefan hugs me, then steps away as Sean and Francois swoop in and give me crab claw gloves and a tubeworm tube to pretend to nibble, crab-like. Thus adorned, I’m baptized with a couple of buckets of ice-filled seawater. My first dive ends this way, dripping and grinning, dreaming of future cruises and future dives and forty more years of astonishment.