UNDERWORLD: The deepest trenches of the world's oceans have largely been out of reach to researchers searching for novel compounds from which to develop new drugs. Image: Courtesy of National Oceanic and Atmospheric Administration (NOAA)/National Geophysical Data Center (NGDS)
Blockbuster-moviemaker-turned-aquanaut James Cameron's solo dive in the Pacific to the Mariana Trench's Challenger Deep site last month opens up a vast, under-explored region of the world's oceans to researchers. There, scientists hope to discover, retrieve and study a host of previously unknown organisms and chemical compounds that may someday help solve decades-old medical mysteries.
"What better place to look for adaptations and unusual compounds that have unusual characteristics than in the most extreme environments we can go to on this planet," says Richard Lutz, a professor of marine ecology and biology of deep-sea hydrothermal vents at Rutgers University and director of the school's Institute of Marine and Coastal Sciences.
In the April 12 issue of the journal Science, Lutz and co-author Paul Falkowski, a professor in Rutgers's departments of Geological Sciences and Marine and Coastal Sciences, point out that the handful of samples taken thus far from the ocean's depths have introduced scientists to new strains of an anaerobic bacteria known as actinomycetes, which Lutz calls "fascinating organisms with profound medical possibilities." Lutz and Falkowski cite one study where unique chemical compounds isolated from an actinomycete strain inhabiting deep-sea sediments about 3.3 kilometers down in the South China Sea have shown potent activities against three cancerous tumor cell lines and also showed antibacterial activities. Several different types of actinomycetes found in much-easier-to-reach terrestrial soils are already used to produce antibiotics such as streptomycin.
The success of Cameron's DEEPSEA CHALLENGER submersible, which dove to 11 kilometers and spent about three hours there, means more biological samples can be collected from the deepest spots on the planet. Three other vessels have been to Challenger Deep, but two of those were robotic. The only other humans to see the Challenger Deep were U.S. Navy Lt. Don Walsh and Swiss oceanographer Jacques Piccard on board the bus-size bathyscaph Trieste in 1960. Japan's Kaiko robotic sub in March of 1995 and the Nereus, an autonomous sub built by Woods Hole Oceanographic Institution engineers, made the trip in May 2009.
The DEEPSEA CHALLENGER's ability to linger at the ocean bottom for an extended period of time means scientists on future dives might be able to study microbes such as actinomycetes in their natural environments. "We've never had the luxury of bringing back microbes that are what you call strict barophiles, microorganisms that can survive under great pressures," Lutz says. Typically, such organisms live at depths of greater than 5,000 meters. "If you take them to lower pressures, most likely they won't live due to the change in pressure, so you literally don't have a way of studying these organisms." With specially pressurized containers, a DEEPSEA CHALLENGER aquanaut might even be able to bring living deep-sea microbes to the surface for study.
Lutz compares Walsh and Piccard's 1960 journey to the Challenger Deep to Sir Edmund Hillary's ascent of Mount Everest in 1953 and the 1969 Apollo 11 moon landing—all manned, monumental accomplishments to extreme locations that could not easily be repeated at the time. Cameron's accomplishment re-ignites excitement for exploration in part because he is a hugely successful filmmaker, but also because he made the trip to the deepest part of the ocean himself in a well-designed vehicle expected to make many subsequent trips to Challenger Deep. Lutz is acquainted with the moviemaker, having worked as science director on the iMAX film Volcanoes of the Deep Sea, which Cameron co-produced.