Digital Extra: Mountains in the Sea

NOAA file photo, courtesy of J. Weirich

The Hercules ROV was specially designed to conduct underwater archaeological surveys. It is on its first expedition since being modified to reach greater depths.

Out at sea, there is no Home Depot. No corner hardware store or Walmart. So when technician Dave Wright figured out what had gone wrong with the ROV Hercules, and what it would take to fix it, he sent a helper round the ship in search of the proper tool. He needed something small, kind of bristly, with a long skinny handle, to clear the carbon from some critical wires.

To the rescue: A set of watercolor brushes, brought on board by Lance Arnold, a high school teacher from Connecticut.

Hercules and Argus are complex and unique machines. Every structure and wire and cable has been figured out by engineers and craftsmen and fitted together piece by piece. Every system -- for propulsion, for video, for manuevering, for manipulation, for lights, for communication -- has been meticulously fabricated and interfaced and trial-and-errored.

Originally designed for underwater archeology, this is the ROVs' first time on a biology expedition. It's also their first mission since they were modified to reach greater depths, so a few glitches and tweaks were expected.

Tuesday morning, Hercules reached a slope on the north side of Bear Seamount, and began to explore. The science crew and the ROV crew were working together for the first time, so it was a learning experience on both sides. "We had to learn what the ROV can do, and they had to learn what we need," said Scott France, one of the science watch leaders. "It all went kind of slowly, but that's to be expected at first."

The work was cut short about 9:30 Tuesday morning, when a burned-out circuit tripped a safety feature that shut down both machines. In the control van, screens went dark and all telemetry was lost. There was no choice but to start the two machines on their long upward haul to the surface. Only a few samples had been collected before the blackout.

About noontime, while many us were gathered on deck to watch a pod of pilot whales romp nearby, Hercules was winched back on to the deck, and the science team pounced to extract their samples from the bio-box.

Out came a branching bamboo coral, a bright orange sea star, a beautiful two-foot-long strand of frilly orange stuff called Chrysogorgia that looked like a delicate bonsai creation. A tiny creature called a brittle star wrapped its long skinny arms around a stalk of coral and wouldn't let go, so they came to the surface together. Each one was dunked immediately into a bucket of cold seawater and taken to a cold room near the science lab. And each one was treated by the scientists like a precious artifact exiled from the sea.

In the lab, the samples were divided up, bits snipped off and preserved for DNA analysis, while other bits were examined under microscopes. Some of the scopes were hooked to video displays so everyone could watch. Each specimen was poked and prodded, in search of eggs, parasites, clues. The orange sea star, under the scope, was found to have a mouthful of coral skeletons.

Les Watling, the lead scientist on this cruise, called everyone over to share his find. Apparently the sea star had been captured mid-meal, before it had time to expel the waste. "It's got a mouthful of pooey," Watling said. "It's as if you put a whole chicken leg into your mouth, and then spit out the bones. This shows that the sea star was feeding on the deep-water corals. It's the first known predator."

Meanwhile, Wright, with his tiny paintbrush, some alcohol, and electrical tape, patiently cleaned and wrapped each troublesome wire on Argus. By sunset, the two vehicles were ready to go for dive number three. With the pilot whales cruising off the starboard side, the round red sun slowly sinking, and an osprey circling overhead, Hercules was lifted overboard. It trailed behind the ship and surfed with its top level with the waves, its bright lights reflecting in the dark water.

Next, Argus was lowered off the stern, and the two sank into the darkness.