Discovering new life at the bottom of the sea
Students in subs find sea floor alive with color

“The sea goes completely black at 800 feet,” said Stephanie Harbeson, a 22-year-old first-year U.Va. graduate student, who made two dives last November aboard the Johnson-Sea Link I (shown above). At right are tube worms, which Harbeson saw on the sea floor.

By Fariss Samarrai

Humans know more about the surface of the moon than the bottom of the sea. But there is no life on the moon. The sea is full of life, and scientists are redefining the meaning of life by the strange and fascinating life forms they find at the sea bottom.

And some of these scientists are U.Va. undergraduate and graduate students.

Through projects led by Steve Macko, professor of environmental sciences, U.Va. students have, during the past five years, made 31 ocean expeditions for the prospect of diving to the sea floor off the coast of the Carolinas and in the Gulf of Mexico. They have gone as deep as two miles below the surface and have found strange and fascinating creatures.

Such as 250-year-old mouthless tubeworms that eat bacteria. And worms that live and feed on toxic frozen methane. No such thing exists on the moon, or on any known planet. Until the discovery of these organisms only a couple of decades ago, scientists would have believed that life simply could not exist in such harsh and extreme conditions.
But there it is.

“The space program is looking for signs of strange life on Mars, but we have it right here on the sea bottom,” Macko said. “We’re possibly looking at the very origins of life, at the ways life developed in extreme conditions before photosynthesis.”

Most people have never heard of Green Canyon, Brine Pool or Bush Hill. Only a few hundred people have been to these locations, all far underwater in the Gulf of Mexico. But Stephanie Harbeson, a 22-year-old first-year graduate student has been there. Last November she made two dives aboard the Johnson-Sea Link I, a four-person submarine operated by the Harbor Branch Oceanographic Institute in Ft. Pierce, Fla.

“The sea goes completely black at 800 feet,” she said, describing the descent from blue surface to lightless bottom. But along the way there is bioluminescence, sparkles of light from billions of drifting microorganisms that glow in the dark.

She went down to 2,100 feet and 1,800 feet. At the sea bottom, with the sub’s external lamps turned on, she found the seafloor alive with color — vivid reds, brilliant blues and a countless assortment of blends in between. Bubbles of methane rose from the sediment. She observed writhing worms, huge clams and mussels, and an assortment of odd fish, all adapted to conditions so extreme, most other life forms would perish there in an instant.

On her second dive, she and the other scientists saw a creature that no human had ever seen: “A giant anemone, free swimming, with long tentacles like a man-of-war. We shot 15 minutes of video,” she said.
When they came to the surface and re-boarded the mother ship, everyone on board gathered to watch the video, seeing — second-hand — what the young graduate student had seen first-hand, pulsating just outside the bubble window of her sub.

Bill Gilhooly, a third-year geochemistry doctoral student with Macko, went on three research cruises before going on his first dive. Bad weather hampered his other opportunities, and his desire. But when he finally got a berth to the bottom, he saw huge tubeworm colonies.

Some of his dives were exploratory, simply traveling along the nearly featureless bottom in previously unexplored areas, looking for colonies of life. Generally they found a lot of sediment. Once, however, he did observe a Dumbo octopus, a rarely seen creature with giant flapping appendages that look like huge ears.

“The best thing is seeing these things with your own eyes, and knowing that very few people will have this opportunity,” he said. “It’s always a bit of a letdown when you come back to the surface.”

Most dives are three- to four-hours long.

During Harbeson’s cruise last fall, she spent nearly two weeks aboard the Seward Johnson II, a 168-foot research vessel, equipped with wet and dry labs and accommodations for 38 people. She loved her time at sea, living a dream it seemed, from the time she left the dock at Port Fourchon, La., through the too-brief time of her dives, to the moment she returned to shore at Gulfport, Miss.

“On ship you get to learn things hands on, first-hand,” she said. “I spent one 11-hour day dissecting tube worms that had been brought up. That is as fresh as it gets. Up until that moment I had only dissected a frog in ninth grade. ”

Gilhooly once spent 36 hours in the ship’s lab preparing samples fresh from the sea. “When the work comes, it’s pretty much non-stop,” he said. “And when samples are brought to the surface, everybody wants to see them.”

Gilhooly and Harbeson enjoy the collegiality of shipboard life. They meet and work with scientists from an assortment of disciplines — biologists, chemists, geologists and hybrids, such as biochemists and geochemists.

“It’s a great collaborative environment on the ship,” Harbeson said. “Everybody is interested in what everybody else is learning. We learn from each other; we share books and knowledge.”

In addition to study and lab work, the young scientists also find time to sit in the sun on deck, eat plenty of good food from the galley, look at the oil platforms in the Gulf, and gaze at the birds, the sea and their future. Both hope to continue studying the sea.

“This kind of hands-on research experience is the best way to get students into the field,” Macko said. “We’re training the creative young minds of this generation to make the discoveries that my generation missed.”

Right here on planet Earth.