Digital Extra: Mountains in the Sea

NOAA

These two samples of black corals were gathered during last year's expedition: Bathypathes sp. black coral is the larger branched specimen and Tanacetipathes, or bottle brush black coral, is the smaller brush-shaped specimen.

Six thousand feet may not seem like a long way, if you're strolling a pleasant path on a sunny afternoon. It's easily done in twenty minutes or less. You can climb or fly 6,000 feet straight up, and still feel comfortable. The air up there is a little thinner, maybe a little chillier, but it will do you no harm.

But travel six thousand feet straight down from the surface of the sea, and you've entered a foreign and hostile land with pressures and problems beyond what our bodies can tolerate.

So when Hercules spends all night on the seamount slope, 6,000 feet down, and brings up a watertight box packed full with biological specimens, they are subjected for the first time to an alien world that many of them can't bear. Some of the creatures drip with mucous when exposed to our warm, thin atmosphere, or they turn to mush, or they die and deteriorate almost immediately.

But most of what was collected today seems to have made it intact to the surface. Whether they made it dead or alive is often hard to tell. The specimens are still, quiet, and inert, but that's their normal state.

These animals are born into a black, silent world, far beyond where the sunlight ever reaches. They live and die in darkness. This raises some questions among the scientists on board.

"The colors of the brittle stars seem to match the colors of their hosts [the coral stalks]," scientist Lauren Mullineaux observed, looking into a plastic bucket holding some of today's collection. "Why should that be, when there's no light down there?"

Les Watling, principle investigator, has no answer beyond, "I wish I knew."

The bright colors of many of the corals and urchins shown on the video feed is a nagging mystery to biologists. What is the point of all that color, when nobody can see it?

All afternoon, the scientists labor to process their samples. Tiny branches from fragile corals are snipped, dunked into tubes filled with ethanol, sealed and labeled. They will be used for genetic tests. Another sample prompts detailed discussion about the "weirdness" of its polyps.

Scott France calls us into the freezer room for a quick show: A long bamboo coral, nearly an inch thick, lies tangled in a five-gallon bucket. France turns off the lights, gently taps the coral a few times with a plastic ruler, and it sends off rays of pure white light. Why it does that is yet another mystery. Does it frighten off predators? What kind of predator would it be?

Science knows very little about these deep-sea animals. Trying to learn about them, now that we have the technology to reach them, is a race against time. Once we have the means to get to a place and explore it, it's never long before we also have the urge to exploit it.

"We need to understand how these corals reproduce, and if they migrate, how far they can go," says France. "Are the corals on Bear Seamount the same species as those on Manning? Or have they been isolated and evolved into separate species, like Darwin's finches on the Galapagos? How critical are the coral colonies to the fish populations? If we understand these things, we can try to predict how these communities could recover -- or not -- once they're disturbed."