In March of this year, filmmaker, explorer, and high-profile tinkerer James Cameron etched his name in the record books when he became the first man to pilot a solo submarine to the world’s deepest ocean trench.
During a full-house presentation to the American Geophysical Union’s annual conference in San Francisco on Tuesday, Cameron and his team of scientists presented some initial results from the expedition.
Previous reports from the Challenger Deep (10,913 meters beneath the surface of the ocean) weren’t very encouraging: the only sample returned from Cameron’s piloted journey was a 50-mililiter scoop of mud. A hydraulic leak occurred immediately after arrival on the seafloor, rendering the sediment coring machinery ineffectual and turning a sample collection expedition into an observational one.
But while the haul on that March morning wasn’t exactly the mother lode the team had hoped for, other aspects of Cameron’s exploratory initiative yielded more promising results. Cameron’s Challenger Deep descent may have garnered the headlines and set records, but other manned dives and robot-assisted maneuvers to equally unexplored ocean depths – most notably the New Britain Trench – returned more compelling data.
All told, there were four submersible dives to the New Britain Trench (reaching 1, 3.8, and 8.2 kilometers), two at Challenger Deep (one of which reached the deepest point), and 20 supporting lander dives. The lander platform acquired thousands of high definition photographs, but had no mobility and limited sample collection capability.
Cameron seemed most excited by the engineering challenges of building a deep-sea submersible, showing off his engineering fluency with unstilted references to “the bulk modulus,” “syntactic foam,” “hydroplating,” and “the PBUF magnet.” He also relished the opportunity to do things differently. By assembling a diverse team from varied backgrounds – including the engineers that designed the animatronic orca whale in Free Willy – Cameron claims he was able to construct his vessel faster and cheaper than a comparable government-sponsored program. (He neglected to divulge the cost of the venture.)
Doug Bartlett, a Professor of Marine Microbial Genetics at the Scripps Institution of Oceanography and an expert on the effects of pressure on living organisms, was brought on as a scientific advisor. Given Cameron’s penchant for visuals, Bartlett showed off gorgeous images of pelagic sea cucumbers, foraminifera, and worms. In terms of both macrofauna and microbial populations, the New Britain Trench is more diverse than Challenger Deep, due its closer proximity to land an organic nutrient-rich runoff.
The team also discovered enormous amphipods crustaceans – “maybe a new species,” according to Bartlett – that exhibit deep-sea gigantism, ballooning from the size of a thumbnail in surface waters to 30 centimeters long in the New Britain Trench. Other organisms, like crabs, squid, and fish show similar trends of larger body size with greater depth. Biologists believe this link may have to do with lower rates of metabolism leading to larger cells and longer lifespans, though the details remain murky.
At the molecular level, Bartlett was most intrigued by the ecosystem’s complement of osmolytes – molecules that shuttle water in and out of pressure-stressed cells and help maintain water balance. One organism possesses scyllo-inositol, an osmolyte that has shown promise in mouse trials for its ability to degrade beta amyloid plaques associated with Alzheimer’s Disease. Scyllo-inositol is found in land-based plants as well, but this discovery from the ocean depths could open the door to a new frontier of bioprospecting.
Cameron seems eager to remain involved with such work by continuing to expand the possibilities of deep-sea exploration. “I go replenish the treasury every few years and make a Hollywood movie,” Cameron said, referring to blockbusters on his resume like Avatar and Titanic, “and then come back and do this kind of work.”