A narrower passage to the sea bottom
Ask Janet Voight about diving in a research sub, and her initial scientific detachment gives way to a tinge of awe at marine biology's light show.Skip to next paragraph
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"You're sitting in a bubble," she says of the plexiglass dive chamber. "The bioluminescence on the way up makes everything worthwhile. You just see the density of life in the water column."
This diversity of life, most of which remains undiscovered, has fascinated scientists like Dr. Voight, associate curator at the Field Museum of Natural History in Chicago, for at least seven decades. Ever since 1934, when scientist William Beebe first peered into the deep ocean from a hollow ball of steel 923 meters below the surface, manned and unmanned deep-sea submersibles have been resurfacing with one stunning discovery after another.
But the underwater craft have proved so useful that these days there aren't enough to go around. Some researchers warn that today's deficit could become a dearth if scientists move ahead with plans for increased ocean exploration as well as the development of permanent undersea observatories.
It's a resource dilemma that has confronted many scientific disciplines as they have moved into the era of "big science."
Two major independent reports have proposed expanding ocean exploration and observatories in the past 18 months. Both objectives would require ready access to the deep ocean. Will the pace of discovery slow without more deep-sea research vehicles?
Some researchers are worried. The sub shortage is hitting just as nations are beginning to realize the oceans' importance and their role as global grocery store, potential pharmacy, and a storage "sink" for industrially produced carbon dioxide, widely seen as a key factor in global warming.
"We are at an important decision point," says Bruce Robison, a senior scientist at the Monterey Bay Aquarium Research Institute (MBARI) at Moss Landing, Calif.
Over the past 40 years, researchers have "confirmed the scientific value of having both human presence and telepresence available for conducting research in the deep sea," he notes. But progress has been hampered by a shrinking number of submersibles available to the broadest cross section of marine researchers. The gap "has been slowing things down for years," he says.
One solution sits in a binder on Robert Brown's conference table here at the National Deep Submergence Facility at the Woods Hole Oceanographic Institution, in Woods Hole, Mass. Mr. Brown is the project manager for a replacement for the venerable deep-sea submersible Alvin. When completed in 2008, the $21.6 million sub will dive deeper than Alvin while giving researchers increased flexibility at shallower depths to stop and take samples on the way up or down. While Alvin can reach depths that in principle allow researchers to study upwards of 63 percent of the ocean floor, Alvin's replacement would boost that proportion to 99 percent.
The design is the result of roughly a decade's worth of discussion in the marine-science community about a new human-occupied vehicle (HOV). Researchers had considered other options, including the use of mothballed US Navy deep submersibles. But they were too big and cumbersome to be of much use around fragile, tightly packed vents and valleys along mid-ocean ridges.
"A new vehicle was the best way to regain the depth capabilities" the Navy's subs represented, says Mr. Brown, a former Navy submariner.
The new research sub will boast improvements in capacity, sub-to-ship communications, speed, endurance, and other features that will make her the most capable research sub available. And then, there are the creature-comforts - relatively speaking - like a larger dive chamber, where the pilot and two scientists operate.