A Conversation with WHOI's Caroline Ummenhofer
Scientists search for aquifers trapped under the ocean
Geological marvels are gold mines for climate history
Stealing parts from their prey, these hunters turn into farmers
From the nebulous roots and trunk on the tree of life, the three known fundamental domains of life branched out billions of years ago: bacteria, eukaryotes, and archaea. Exactly when that monumental evolutionary divergence occurred has also remained unknown, but a team of scientists has now pinpointed that the three domains were well separated and evolving independently by 2.7 billion years ago. Gregory Ventura (in red suit), now a postdoctoral student at Woods Hole Oceanographic Institution, analyzed ancient shales found in a deep gold mine in Canada. Using a sophisticated, multidimensional gas chromatography device, the researchers could distinguish individual archaea-produced chemical compounds within the complex mixture of molecular fossils. The team reported its findings Sept. 4, 2007, in the Proceedings of the National Academy of Sciences. It included Fabien Kenig, Ventura’s Ph.D. advisor at the University of Illinois, Christopher Reddy (WHOI), Glenn Frysinger (U.S. Coast Guard Academy), and Juergen Schieber (Indiana University). (Image courtesy of University of Illinois at Chicago).
They are thousands of times thinner than a single human hair, but stronger than steel, more durable than diamonds, and can efficiently conduct heat and electricity. No wonder carbon nanotubes have been hailed as a wunderkind material that will provide the building blocks for multibillion-dollar industries in the 21st century. But MIT/WHOI graduate student Desirée Plata issued an attention-grabbing warning at the American Chemical Society meeting in August 2007. With her advisors, chemists Christopher Reddy of WHOI and Phil Gschwend of MIT, she analyzed the emissions formed in the carbon nanotube manufacturing process and reported finding several cancer-causing compounds and substances that trigger ozone formation and cause respiratory ailments. The researchers seek to work proactively with industry, before carbon nanotube production ramps up, to develop safe and sustainable manufacturing methods that avoid large-scale health and environmental problems. (Photo by Dr. A. John Hart, University of Michigan)
When the National Oceanic and Atmospheric Administration asked WHOI biologist Michael Moore to help investigate mysterious and alarming whale deaths in October 2007, he hastened to the tip of South America with whale expert colleagues Katie Touhey (Cape Cod Stranding Network/International Fund for Animal Welfare) and Bill McLellan (University of North Carolina Wilmington). Southern right whales congregate around the Valdés Peninsula on the remote Patagonian coast of Argentina to calve. This year, reported deaths of young whales ballooned to 83, the highest number since 1971. Samples from dead whales collected and now being tested by scientists may identify the causes. Suspected causes include: toxins from dense algal blooms (the shiny green material in the aerial photo at left by Mariano Sironi, science director of the Instituto de Conservación de Ballenas in Buenos Aires, Argentina); infections in wounds from seagulls, which peck through the whales’ blubber; or other causespossibly in combination.
Scientists usually use large corers to penetrate seafloor sediments and extract samples used to decipher ocean changes far back in Earth’s history. But a particularly hard-packed area off the New Jersey coast required something biggerand tougher. In the summer of 2007, University of Texas geophysicist Jamie Austin and colleagues traveled on the research ship Knorr with a vibracorer (left), a tool designed to shimmy into even the toughest seafloor sediments. "It essentially functions like a pile driver," Austin said, adding that any other corer used in that location "would just bounce right off this tough sediment." Austin earned his Ph.D. from the MIT/WHOI Joint Program in 1979. For 20 years, he has been going to the New Jersey shelf to learn about past sea level changes in this region. "We now are beginning to understand how the geology of the shelf responds as sea level falls and then rises," Austin said. The research, he added, is "very relevant to preparing for sea level rise to come, as a response to global warming." (Photo courtesy of Jamie Austin and John Goff, University of Texas Institute for Geophysics.)
After four years of design and construction, WHOI’s new deep-sea exploration vehicle Nereus took its first plunge in deeper waters during a test cruise in December 2007 off the Waianae coast of Oahu, Hawaii (left). Nereus is the first underwater vehicle designed with dual capabilities. It can operate as an autonomous, free-swimming vehicle to fly on pre-programmed missions over wide areas, mapping the seafloor, gathering data on the oceans, and searching for specific research targets. But then engineers can convert it within a few hours into a tethered vehicle connected via a hair-thin, 25-mile long cable, which enables scientists on the surface ship to receive real-time video images and send instant commands to maneuver the vehicle and its mechanical arm for close-up investigations and sample gathering. Nereus can also work in the deepest parts of the ocean, from 6,500 meters to 11,000 meters (21,500 feet to 36,000 feet), a depth currently unreachable for routine ocean research. After more testing and development, the goal is to aim Nereus to explore the deepest known waters on the planetChallenger Deep, a trench in the Pacific Ocean southwest of Guam. The trench is deeper than Mount Everest is high, extending almost 11,000 meters (36,000 feet) beneath the sea surface. (Photo by Tim Shank, Woods Hole Oceanographic Institution)