WHOI  WHOI People  

News Tip Sheet

May 2008

Santelli with rock sample
Enlarge image

Biogeochemist Cara Santelli examines a rock sample recovered from the East Pacific Rise by the Alvin submersible. (Courtesy of Cara Santelli, Woods Hole Oceanographic Institution and Harvard University)

Scientists Find Bacteria Thriving on a Feast of Seafloor Rock

May 28, 2008

On the deep ocean floor, microbial life is feeding on fresh volcanic rock and flourishing with greater abundance than even the most optimistic scientists thought possible. According to a study published May 28 in the journal Nature, scientists have found bacteria growing on oceanic crust in concentrations that are thousands- to ten-thousand times (three to four orders of magnitude) greater than what is found in the overlying waters.

Researchers collected and examined rock and water samples from the East Pacific Rise, the Nankai Trough, the Mid-Atlantic Ridge, the Sargasso Sea, and the seafloor near Hawaii. The research team—which included scientists from the Woods Hole Oceanographic Institution (WHOI), the University of Southern California (USC), the University of Bremen, Western Washington University, the Marine Biological Laboratory, and the Scripps Institution of Oceanography—used various molecular and genetic analysis tools (such as quantitative polymerase chain reaction and clone libraries) to quantify the abundance, richness, and diversity of communities of bacteria living on young ocean crust.

What they found was a community of microbes—growing without light and eating rocks—that is as fertile and prodigious as what can be found in terrestrial farm soil. Such seafloor microbes have been detected before, but this is the first time that they have been quantified.

"We were truly shocked to find microbial life thriving at the levels we observed,” said Cara Santelli, a recent graduate of the MIT/WHOI Joint Program in Oceanography and now a postdoctoral scholar at Harvard University. Santelli conducted the research with geochemists Katrina Edwards and Wolfgang Bach while all three were in Woods Hole. Edwards is now at USC, while Bach has moved to the University of Bremen.

“Theoretical research by Edwards and Bach had suggested that life could exist in such a dark, cold, and rocky environment,” said Santelli, lead author on the Nature paper. “The objective of our project was to provide tangible evidence. Not only was the biomass in seafloor lava greater than in the overlying seawater, but the bacterial diversity was significantly greater than we could have imagined.”

The findings open up new questions about the evolution of Earth and of seafloor life.

“We are just beginning to scratch the surface,” Santelli said. “What role does this microbial community play in global ocean chemistry? What sort of metabolism is needed to live in and dominate this environment? And what exactly are these microbes doing down there?”

The research by Santelli and Edwards, et al, was funded by the National Science Foundation’s Ridge 2000 program, the NASA Astrobiology Institute, and Western Washington University.

Related Links
» Nature magazine: Abundance and diversity of microbial life in ocean crust
» NSF: Bacteria Feed on Ocean Bottom's Crust
» Living Large in Microscopic Nooks
» Who is Cara Santelli?
» Who is Katrina Edwards?
» Formation of Lava Bubbles Offers New Insight into Seafloor Formation

Chris Reddy sampling in SF Bay
Enlarge image

Marine chemist Chris Reddy samples oiled rocks from the edge of San Francisco Bay in December 2007. (Photo courtesy of Bryce Reddy)

Marine Chemist Says "Not So Fast" to Quick Oil Detection Method

May 28, 2008

A new method for assessing environmental contamination after oil spills is in danger of being applied in situations where it doesn't work and might produce false conclusions, a scientist at Woods Hole Oceanographic Institution (WHOI) has warned.

Private firms and government agencies have recently started using long strands of absorbent polypropylene snares, also called “pom-poms,” as a means to check for contamination of the seafloor in the wake of an oil spill. The method is becoming popular because it is rapid and low-cost.

But according to WHOI marine chemist Christopher Reddy, the approach may give a false sense of security. In a recently published letter to the Marine Pollution Bulletin, Reddy notes that while the pom-pom method is effective in locating areas where excessive amounts of oil have sunk to the bottom, it does not necessarily identify the fractions and compounds of oil that can linger in sediments and have long-term impacts on ecosystems and public health.

Following a 2004 oil spill in the Delaware River, emergency response crews employed the new pom-pom method to quickly determine the locations of large oil patches on the river floor. The information was invaluable for the emergency response and cleanup.

After the M/V Cosco Busan oil spill in San Francisco Bay in November 2007, the pom-pom method was used again. But this time, the goal was to determine if sediments near the Port of Oakland were safe to be dredged and re-used in restoration projects.

“This approach is flawed,” Reddy wrote. “It relies on the assumption that the lack of visible oil on the snares…indicates a total lack of oil contamination in the sediment…While testing of sediments with snares delivers rapid, low-cost data, it is only an indicator of gross contamination.”

“Before this approach becomes standard practice for determining whether sediments have been contaminated at levels that may impact ecosystems,” Reddy added, “prudence dictates much more rigorous testing of the test itself.”

Funding for this research was provided by the Richard and Rhoda Goldman Fund and the WHOI Coastal Ocean Institute.

Related Links
» Marine Pollution Bulletin: A cautionary tale about evaluating analytical methods to assess contamination after oil spills
» Oceanus: Popular Way to Assess Oil Spills Can Be Misused
» Comparing the San Francisco Oil Spill to East Coast Analogs
» Oceanus: Still Toxic After All These Years

Mark Johnson tagging a whale
Enlarge image

Mark Johnson, a WHOI bioengineer, stands poised to attach a D-tag to a pilot whale off the island of El Hierro in the Canary Islands. Johnson developed the non-invasive tag to record whale movements and sounds in the deep. (Courtesy of Mark Johnson, Woods Hole Oceanographic Institution)

Cheetahs of the Deep

May 28, 2008

A new study has revealed that pilot whales are “the cheetahs of the deep sea,” making high-speed, all-or-nothing dives to chase and catch large prey before surfacing to catch their breath. Such sprinter-like dives stand in stark contrast to the longer, slower, and more conservative dives of other whale species that have been studied.

Marine mammal researchers working off the Canary Islands attached non-invasive, temporary tags--known as D-tags--to 23 whales to digitally record movements during their 15-minute dives, as well as the sounds that they make and hear. Researchers analyzed the recorded “clicks,” “buzzes,” and other whale sounds--together with the whales’ recorded speeds, orientations, and depths--to reconstruct a picture of the whales’ hunts.

That picture shows pilot whales diving down to about 1,640 feet (500 meters) and then leveling out to select a target; large squid are believed to be a favorite. Once they have picked their prey, a chase starts that can take the whales to 3,000 feet (1,000 meters) depth and speeds up to 20 miles per hour (9 meters per second).

Most of the deep-diving whales studied to date swim at only 1 to 2 meters per second, allowing them to conserve energy and oxygen and to maximize hunting time in the depths. "The sprints of these short-finned pilot whales open a new perspective into optimal foraging theories of deep-diving, breath-holding mammals," said Natacha Aguilar de Soto of the University of La Laguna, lead author of the study.

“The D-tag was the first instrument to capture an echo from prey in the wild, one of the great challenges in studying echolocation,” said Peter Madsen, a professor at the University of Aarhus (Denmark) and one of the study’s authors. “It is a really unprecedented chance to study how whales find and capture their dinner.”

"What’s cool is to ‘see’ how whales hunt at depth using their own sounds—without the intrusion of lights and a camera,” said Mark Johnson, a bio-engineer at the Woods Hole Oceanographic Institution and inventor of the D-tag.

The study by Aguilar de Soto, Johnson, and colleagues was published online in the Journal of Animal Ecology.

The new observations should help scientists reinterpret thinking about the whales’ behavior. Pilot whales often congregate in groups at the surface and have a reputation for being calm, approachable, and not bothered by boat activity. Instead, they may just be too tired to react. The new understanding about whale diving and feeding behaviors should also inform policies to better manage whale-watching and shipping movements in areas with whales.

Support for this research was provided by the U.S. Department of Defense, the U.S. National Oceanographic Partnership Program, and the Canary Islands Government-Spanish Ministry of Defense.

Related Links

» Journal of Animal Ecology: Cheetahs of the deep sea: deep foraging sprints in short-finned pilot whales off Tenerife
» Oceanus: Pilot Whales—the Cheetahs of the Deep Sea
» WHOI Marine Mammal Center
» Oceanus: Playing Tag with Whales
» Oceanus: The Deepest Divers

April 2008

Carbon nanotubes

Carbon nanotubes have been hailed as a new ?wonder material? whose remarkable strength, durability, and ability to conduct electricity and heat can be exploited for a wide variety of industrial uses (Illustration by E. Paul Oberlander, Woods Hole Oceanographic Institution.)

Making Sure the Wonder Materials Don’t Become the Wonder Pollutant

April 1, 2008

Carbon nanotubes are 10,000 times thinner than a human hair, yet stronger than steel and more durable than diamonds. They conduct heat and electricity with efficiency that rivals copper wires and silicon chips, with possible uses in everything from concrete and clothes to bicycle parts and electronics. They have been hailed as the next “wonder material” for what could become a multi-billion dollar manufacturing industry in the 21st century. But as useful as nanotubes may be, the process of making them may have unintentional and potentially harmful impacts on the environment. MIT/WHOI graduate student Desirée Plata and her mentors—chemists Phil Gschwend of the Massachusetts Institute of Technology and Chris Reddy of the Woods Hole Oceanographic Institution—recently analyzed ten commercially made carbon nanotubes to identify the chemical byproducts of the manufacturing process and to help track them in the environment. Plata found that the ten different carbon nanotubes had vastly different compositions; most previous toxicity studies have generally assumed that all nanotubes are the same. This diversity of chemical signatures will make it harder to trace the impacts of carbon nanotubes in the environment. In previous work (first presented last fall), Plata and colleagues found that the process of nanotube manufacturing produced emissions of at least 15 aromatic hydrocarbons, including four different kinds of toxic polycyclic aromatic hydrocarbons (PAHs) similar to those found in cigarette smoke and automobile tailpipe emissions. They also found that the process was largely inefficient: much of the raw carbon went unconsumed and was vented into the atmosphere. The new research by Plata et al was published April 3 on the web site of the journal Nanotechnology. In the next phase of Plata’s work, she will collect real-time data from a European nanotube manufacturing facility that is poised to let her set up the same monitors she used in the MIT lab. “It is the indiscriminant use of poorly understood chemicals that causes environmental and public health costs,” Plata said. “We want to work proactively with the carbon nanotube industry to avoid repeating environmental mistakes of the past. Instead of reacting to problems, we hope to preclude them altogether. Plata was honored in February for her nanotube work by the Division of Environmental Chemistry of the American Chemical Society, which selected her as a winner of one of its 2008 Graduate Student Paper Awards.

Related Links
» Making Nanotubes Without Harming the Environment
» Diversity among carbon nanotubes may enable environmental detection for risk assessment
» Protecting Public Healthy By Preventing Pollution
» Industrially synthesized single-walled carbon nanotubes: compositional data for users, environmental risk assessments, and source apportionment
» Helping the Carbon Nanotube Industry Avoid Mega-Mistakes of the Past
» Who is Phil Gschwend?
» Who is Chris Reddy?
Ice survey

A native Alaskan (Inupiat) guide armed with a rifle stands watch while WHOI technicians gather data on a recent survey mission. A polar bear approximately 11 feet tall approached the tent, but quickly turned away after being confronted by the guide. (Sean Whelan, Woods Hole Oceanographic Institution)

Scientists Prepare for a Risky Mission Under the Arctic Ice

April 1, 2008

Bone-chilling temperatures, biting winds, and rapidly changing sea ice conditions make the Chukchi Sea off Point Barrow, Alaska, a particularly challenging place to work. And then there are the curious neighbors – towering polar bears that periodically stop by camp unannounced.
These are just a few of the challenges researchers from the Woods Hole Oceanographic Institution (WHOI) faced as they performed sea ice and underwater acoustic surveys last month in preparation for a return trip in March 2009 to better understand the flow of water to the Arctic from the Pacific Ocean. “The inflow of Pacific water plays an important role in maintaining the Arctic ice cap,” said Al Plueddemann, a WHOI physical oceanographer who will lead the 2009 mission. “Interaction with the Pacific is a critical component of the Arctic system that has not been given as much attention as interactions with the Atlantic.” This region north of Alaska is where huge volumes of sea ice are formed and ocean water is transformed in ways that help shield and protect the polar ice cap.  Since the process occurs beneath sea ice in winter, it is difficult to observe. To overcome that obstacle the research team plans to use an Autonomous Underwater Vehicle (AUV) to help them gather data beneath the ice. The AUV will navigate with the assistance of a few strategically placed acoustic transponders. If things go as planned, the AUV will do much of its work out of transponder range, using only internal navigation to find its way back home to an ice hole. On the recent reconnaissance trip, WHOI engineers Jeff Lord and Sean Whelan documented the performance of under-ice communications equipment and evaluated logistic support equipment, such as snowmobiles, sleds, ice-augers, tents and heaters, necessary for winter operations. They also gathered data regarding currents and salinity of the waters off the coast of Barrow, which will all be factored into the mission next winter. “This is a well-suited mission for an AUV because of the water depths, which range from 10 to 150 meters, and the relatively short distances that need to be covered,” Plueddemann said. “But it’s risky because if the vehicle malfunctions during the mission, hits an ice keel, or can’t find its way home to the ice hole it was deployed from, it may be impossible to retrieve it. Not to mention the risks to the field personnel from harsh weather and changing ice conditions.” These are risks the team is willing to take to gain a better understanding of this critical “choke point” of the Arctic circulation system and the first direct measurement of Pacific water transport into the western Arctic in winter.

Related links

» Flying Blind in the Ice Factory
Scientists test innovative technology to navigate vehicles under Arctic ice
» Is Global Warming Changing the Arctic?
And will polar changes trigger climate shifts beyond the Arctic?
» The Flywheel of the Arctic Climate Engine
Remote Beaufort Gyre expeditions reveal clues to climate change
» A Sentry at the Atlantic Gateway
Experimental mooring monitors water flow through Hudson Strait
» Under-ice Floats Offer a ‘Breakthrough’
New instrument proves its mettle in an icy ocean
David Ralston

(Tom Kleindinst, Woods Hole Oceanographic Institution)

David Ralston Receives Young Investigator Award

April 1, 2008

The Office of Naval Research (ONR) has selected David Ralston, an assistant scientist at the Woods Hole Oceanographic Institution (WHOI), as one of the recipients of the U.S. Navy’s 2008 Young Investigator Awards. Ralston, who works in the WHOI Applied Ocean Physics and Engineering department, is among 27 researchers honored nationwide in the highly competitive Young Investigator Program. Typically, about 10 percent of the submitted proposals are chosen for funding. This year the ONR received 208 proposals.Ralston will receive up to $100,000 a year for a period of three years to fund his project, “Sediment Transport at Density Fronts in Shallow Water.” Specifically, Ralston will be examining how fresh and salt water mixes and spreads in intertidal regions – salt marshes and mud/sand flats – at the mouth of the Skagit River in Puget Sound, WA. “From a transport perspective, this frontal region is important because flow convergence traps sediment and other material there,” Ralston said. “The trapping can impact whether material stays in the intertidal zone or gets carried offshore.” Ralston will also collaborate with participants in a larger ONR-funded project to study hydrodynamics and morphology on tidal flats near rivers. The Young Investigator program supports basic research by exceptional faculty at U.S. universities and research institutions who received doctorate or equivalent degree within the preceding five years, according to ONR. Ralston earned a doctorate in civil and environmental engineering from the University of California in 2005. Young Investigators are considered among the best and brightest young academic researchers in the country. The awards recognize research achievements, potential for continued outstanding research efforts, and strong support and commitment from their respective universities and research institutions. Past WHOI recipients of the Young Investigator Award include Ryan Eustice (2007), Steve Jayne and Chris Reddy (2003), Simon R. Thorrold (2002), Peter Traykovski (2001), Britt Raubenheimer (2000), Heidi Sosik (1997), and Deborah Smith (1987).  

Related Links

» Who is David Ralston?
» ONR Young Investigator Program
» 2008 Young Investigators Awardees

January 2008

Shrinking sea ice cover in the Arctic is making it harder for polar bear mothers to find food for themselves and their cubs.
Enlarge image

Shrinking sea ice cover in the Arctic is making it harder for polar bear mothers to find food for themselves and their cubs. (Chris Linder, Woods Hole Oceanographic Institution)

Polar Bear Population Likely to Become Extinct

January 1, 2008

Within the month, the U.S. government must decide whether to list the polar bear as an endangered species. The question is: will such a declaration be too late because of climate change? A 2007 study by biologists, including Hal Caswell of the Woods Hole Oceanographic Institution (WHOI), concludes that the declining habitat of the bears—namely, the shrinking ice cover of the Arctic Ocean—makes it likely that they will become extinct in the southern Beaufort Sea, near the coast of Alaska and western Canada. The population of bears worldwide is expected to shrink by at least two-thirds of current levels. Using data from an intensive U.S. Geological Survey (USGS) study, Caswell and former WHOI postdoctoral investigator Christine Hunter (now at University of Alaska-Fairbanks) determined that climate change is dramatically hindering the polar bears’ ability to find food and to reproduce. Polar bears need ice as a platform to hunt for seals. As the Arctic Ocean lost more ice cover for more days in 2004 and 2005, polar bear breeding and cub survival declined below the point needed to maintain the population. With sea ice dramatically receding over the past decade, and projections of ice-free summers by 2050, it is hard to see a positive outcome for the ice bears. Caswell and Hunter collaborated on their reports with Erich Regher, Steven Amstrup, and Michael Rundge of USGS and Ian Sterling of the Canadian Wildlife Service. In September 2007, they presented their work to administrators of USGS, the Fish and Wildlife Service, and to Secretary of the Interior Dirk Kempthorne.


Related Links
» Oceanus magazine: Melting Ice Threatens Polar Bears' Survival
» Polar Bears in the Southern Beaufort Sea: Demography and Population Growth in Relation to Sea Ice Conditions
» Polar Bears in the Southern Beaufort Sea I: Survival and Breeding in Relation to Sea Ice Conditions
» Who is Hal Caswell?
» Future Retreat of Arctic Sea Ice Will Lower Polar Bear Populations and Limit Their Distribution
» New Polar Bear Findings

Seals entangled in fishing lines and gear may strand on beaches, where they are noticed by people.
Enlarge image

Seals entangled in fishing lines and gear may strand on beaches, where they are noticed by people. Local stranding networks around the country send workers to evaluate the animals' condition and make difficult decisions about how to care for them. Here, a worker wraps and prepares to examine a badly entangled grey seal. (Courtesy of Cape Cod Stranding Network)

Should Every Stranded Dolphin or Seal Be Saved?

January 1, 2008

A sick or injured seal or dolphin is found stranded on a beach. Should limited marine mammal protection funds be spent to rehabilitate the animal, or would they be better used to increase public education, law enforcement, or research activities? Six marine mammal specialists—spanning the research, conservation, veterinary, education, and stranding network communities—have taken on that heart-wrenching question in a paper published in the journal Marine Mammal Science.  The authors, led by Michael Moore of the Biology Department at the Woods Hole Oceanographic Institution, have proposed an innovative “decision tree” to sort out the conflicting priorities and issues that arise in the United States when a distressed animal comes into human contact. The authors state: “Rehabilitation efforts should be evaluated on whether the likely benefits to science, nature, or knowledge outweigh the potential harm to individuals or populations.”
The systematic framework assesses the risks, benefits, costs, and probabilities that branch out from various choices to euthanize, rehabilitate, and release stranded animals. For decades, stranded animals have been treated and placed in zoos and aquariums, but today there are more rehabilitated creatures than permanent homes for them. In some regions, there are also public sentiments that creatures should be released back into the wild, sometimes exposing healthy populations to sick animals. Emotion-charged decisions to rehabilitate can lead organizations to care for animals they have no assurance of funds to support or treat. “Marine mammal rehabilitation is an effort that currently lacks a coherent central set of core values, ethics, or goals...The effort remains inconsistent, poorly supported, and fractious.”

Related Links
» Oceanus magazine: A New Look at Stranded Marine Mammals
» Rehabilitation and Release of Marine Mammals in the United States: Risks and Benefits
» Who is Michael Moore?
» Oceanus magazine: Doing the Right Thing for the Right Whale

Ken Buesseler examines a neutrally buoyant sediment trap (NBST), while engineer Jim Valdes looks on.
Enlarge image

Ken Buesseler examines a neutrally buoyant sediment trap (NBST), while engineer Jim Valdes looks on. NBSTs are swept along with the currents for several days, collecting dying plankton, fecal pellets, and other organic (ie, carbon-based) particles that sink out of the upper ocean. (Tom Kleindinst, Woods Hole Oceanographic Institution)

WHOI Scientists Offering Timely Global Change Talks at Science Meeting

January 1, 2008

Three senior scientists from the Woods Hole Oceanographic Institution will offer cautionary looks at the past and future of global climate change at the upcoming annual meeting of the American Association for the Advancement of Science (AAAS) in Boston. Lloyd Keigwin, a geologist who specializes in the ocean’s role in past climate changes, will discuss “The Arctic's Role in Abrupt Climate Change Since About 12,000 Years Ago” on February 15. Keigwin’s research has led him to gather sedimentary evidence for past climate from the floors of the Atlantic, Pacific, and Arctic oceans. Biogeochemist Scott Doney has conducted extensive research on the effects of excess carbon dioxide on the global oceans. At the AAAS meeting, he will describe how CO2 and acid rain impact the seas in a talk entitled “Surface Ocean Acidification and Carbon Cycling.” Doney’s presentation is part of the session “Strange Days on Planet Ocean,” which will be held on February 17. On February 18, WHOI marine chemist Ken Buesseler will discuss “Advances in Our Understanding of Iron Fertilization in the Oceans: What Comes Next?” Buesseler has participated in several iron fertilization experiments and recently convened an international, interdisciplinary colloquium on the subject. Environmental engineers have proposed spreading slurries of dissolved iron into the oceans in order to promote the growth of marine plants and combat rising concentrations of greenhouse gases in Earth’s atmosphere. AAAS is the world’s largest general scientific society, and its meeting usually attracts about 10,000 participants to share science across disciplines and to promote effective communication between policymakers, researchers, and the public. The theme of this year’s AAAS meeting is “Science and Technology from a Global Perspective.”

Related Links
» AAAS Meeting
» Who is Lloyd Keigwin?
» Oceanus magazine: Ocean Circulation and a Clam Far from Home
» Who is Scott Doney?
» Acid Rain Has a Disproportionate Impact on Coastal Waters
» Ken Buesseler’s Café Thorium
» Oceanus magazine: Fertilizing the Ocean with Iron

December 2007

The remotely operated vehicle Hercules (University of Rhode Island and Institute for Exploration) collects corals from the Corner Rise seamounts and takes pictures of them during a 2005 expedition.
Enlarge image

The remotely operated vehicle Hercules (University of Rhode Island and Institute for Exploration) collects corals from the Corner Rise seamounts and takes pictures of them during a 2005 expedition. Deep-sea coral communities—which provide lush habitats for fish and other marine life—were extensively damaged, most likely by deep-sea fishing trawlers. (DASS05 URI IFE IAO NOAA)

Trawling Leaves Lasting Scars on Deep Ocean Coral Habitat

December 1, 2007

More than a decade after fishing stopped near the Corner Rise Seamounts in the North Atlantic, researchers have found that the seafloor still has patches that are almost completely devoid of life. During an expedition to study deep-sea corals, Woods Hole Oceanographic Institution (WHOI) biologist Rhian Waller and colleagues found that several coral communities were extensively damaged, with evidence that the scars were caused by fishing trawlers. Corner Rise is a cluster of ancient volcanoes at least a half-mile below the sea surface and 1,200 miles from shore. Using a remotely operated vehicle to survey the volcanic slopes, the research team found broken branches of bubble gum corals, which usually grow in abundance atop seamounts. The entire top of Kükenthal Peak was wiped clean; on Yakutat Seamount, the number of live corals was negligible. Though fishing stopped many years ago, the summits “no longer support habitat-forming corals in any significant numbers,” the biologists wrote in the Journal of the Marine Biological Association of the United Kingdom. As fishing grounds close to shore become over-fished and increasingly regulated, deep-sea habitats have become more appealing for fishing fleets. At the same time, deep-sea corals grow very slowly—perhaps an eighth of an inch per year—and some can live for thousands of years. The combination of a stressed fishing industry and slow-growing corals, the biologists note, adds up to trouble.
Related Links

» Oceanus Magazine: Coral Catastrophe on the Corner Rise Seamounts
» Anthropogenic impacts on the Corner Rise seamounts, north-west Atlantic Ocean
» Slideshow of Destroyed Corals on Corner Seamounts
» Oceanus Magazine: Coral Gardens in the Dark Depths
» Molecular Ecology and Evolution Laboratory
The Jaguar AUV is lowered into the Arctic Ocean from the icebreaker Oden during a June 2007 engineering test.
Enlarge image

The Jaguar AUV is lowered into the Arctic Ocean from the icebreaker Oden during a June 2007 engineering test. (Clayton Kunz, Woods Hole Oceanographic Institution)

Robotic Tag-Team is Headed for the Seafloor

December 1, 2007

In the summer of 2007, engineers from WHOI’s Deep Submergence Laboratory proved they could operate an autonomous underwater vehicle (AUV) beneath Arctic ice. Six months later, the team will now attempt to operate two AUVs simultaneously in deep ocean waters. The first-of-its-kind engineering trial will be the highlight of WHOI’s next Dive and Discover online expedition. For years, scientists have dreamt of sending small fleets of robots to explore the depths, but the ocean presents formidable obstacles to navigating and communicating in the deep. On an 18-day expedition to the South Atlantic aboard the research vessel Knorr, researchers will unleash Puma and Jaguar at the same time; the AUVs will be unpiloted and unattached to the ship. Puma is designed to use sonar, lasers, and chemical sensors to sniff out signals of hot, mineral-rich fluids venting from the ocean floor. A twin AUV, Jaguar, carries cameras and bottom-mapping sonar to collect photographs and bathymetry maps. Both vehicles are designed to hover like a helicopter over the seafloor. As these underwater “cats” prowl a little-explored stretch of the Mid-Atlantic Ridge, researchers will test navigation and communication technologies that will enable the AUVs to talk to each other and to scientists aboard Knorr in real time.

Related Links
» Dive and Discover: Expedition 12
» Underwater Vehicles at WHOI
» Media Resources for the 2007 Arctic Gakkel Vents Expedition
» WHOI Online Expeditions

Maps depict the model-estimated atmospheric deposition rates of carbon, nitrogen, and sulfur; alkalinity; and potential alkalinity to the ocean caused by human activity relative to conditions before the Industrial Age began.
Enlarge image

Maps depict the model-estimated atmospheric deposition rates of carbon, nitrogen, and sulfur; alkalinity; and potential alkalinity to the ocean caused by human activity relative to conditions before the Industrial Age began. (Scott Doney et al, from Proceedings of the National Academy of Sciences)

Magazine Recognizes WHOI-Led Global Change Research

December 1, 2007

In selecting its “100 Top Science Stories of 2007,” the editors of Discover magazine recognized WHOI marine chemist Scott Doney and his colleagues for research on the effect of acid rain in coastal waters. The paper “Impact of anthropogenic atmospheric nitrogen and sulfur deposition on ocean acidification and the inorganic carbon system”—published in the Proceedings of the National Academy of Sciences by Doney and six colleagues from four institutions—was listed as top story #23 in Discover’s year-end roundup. In their September 2007 journal article, Doney et al noted that the release of sulfur and nitrogen into the atmosphere by power plants and agricultural activities is altering the chemistry of coastal surface waters, making seawater more acidic. The strongest effects are downwind of major pollution regions in eastern North America, western Europe, and southern and southeast Asia. Ocean “acidification” occurs when chemical compounds such as carbon dioxide, sulfur, or nitrogen mix with seawater, a process which lowers the pH and reduces the storage of carbon. It hampers the ability of marine organisms—such as sea urchins, corals, and certain types of plankton—to harness calcium carbonate for making hard outer shells or “exoskeletons.” These organisms provide essential food and habitat to other species, so their demise could affect entire ocean ecosystems.

Related Links
» WHOI News Release: Acid Rain Has a Disproportionate Impact on Coastal Waters
» Impact of anthropogenic atmospheric nitrogen and sulfur deposition on ocean acidification and the inorganic carbon system
» Who is Scott Doney?
» Discover Magazine
» WHOI News Release: Marine Organisms Threatened By Increasingly Acidic Ocean

November 2007

WHOI environmental chemist Chris Reddy examines an oil-smudged rock following a spill off the coast of Massachusetts. (Tom Kleindinst, Woods Hole Oceanographic Institution)
Enlarge image

WHOI environmental chemist Chris Reddy examines an oil-smudged rock following a spill off the coast of Massachusetts. (Tom Kleindinst, Woods Hole Oceanographic Institution)

Comparing the San Francisco Oil Spill with East Coast Analogs

November 1, 2007

In the wake of the November 7 spill of 58,000 gallons of fuel oil into San Francisco Bay, environmental chemist Chris Reddy of the Woods Hole Oceanographic Institution (WHOI) has collected and analyzed oil samples to help assess the long-term impact on the environment. With support from WHOI’s Coastal Ocean Institute and the environmental group Baykeeper, Reddy and colleagues collected oil-covered rocks from beaches around the Bay and used two-dimensional gas chromatography to delineate the precise chemical composition of the mixture. The “bunker oil” that spilled from the Cosco Busan and fouled at least 40 miles of California coastline is very similar to the oil that was spilled into Buzzards Bay (along the Massachusetts coast) in April 2003. Both contained polycyclic aromatic hydrocarbons (PAHs), which are known to be toxic and carcinogenic. Reddy, who specializes in examining the breakdown and longevity of oil compounds in the marine environment, collected this initial oil sample because long-term studies of impacts require an understanding of which oil compounds have weathered or degraded and which ones linger in the water and sediments. Reddy has forwarded his results to environmental groups in the Bay area, as well as the National Oceanic and Atmospheric Administration. He hopes to compare his samples with an original batch of oil directly from the ship to see how much the composition has already changed, and to have a baseline for assessing how nature breaks down the oil in the future.

Related Links
» Still Toxic After All These Years
» Oil in Our Coastal Back Yard
» Buried, Residual Oil is Still Affecting Wildlife Decades after a Spill
» SF Baykeeper
» Chris Reddy’s research

Enlarge image

Images from the WHOI TowCam show where fresh lava covered up sediment-covered seafloor following a 2006 eruption along the East Pacific Rise. (Adam Soule, Dan Fornari, et al, Woods Hole Oceanographic Institution)

Researchers Compile Most Detailed Map of an Underwater Eruption

November 1, 2007

Examining more than 50,000 seafloor images, geologists have created the most detailed map ever assembled for a volcanic eruption along a fast-spreading mid-ocean ridge. Researchers from the Woods Hole Oceanographic Institution, University of Florida, and University of Hawaii mapped where fresh new lava had paved over sediment-covered seafloor, while also identifying eruptive fissures and channels where lava had flowed. Scientists’ understanding of deep ocean volcanic eruptions has been limited by the ability to observe them. In April 2006, researchers got an unprecedented opportunity to investigate the dynamics of eruptions after discovering a recent lava flow along the East Pacific Rise (EPR) between 9° 46’ N and 9° 56’ N (900 km southwest of Acapulco, Mexico). Lead author Adam Soule and colleagues used support from the National Science Foundation’s RIDGE2000 program to conduct 37 surveys of the site with WHOI’s digital deep-sea towed camera system, plus another 10 dives in the submersible Alvin. In analyzing the imagery, they identified 186 sites where new lava met old. They documented that the eruption covered an area of 14.6 square kilometers with lava averaging 1.5 meters deep. More than 22 x 106 meters of lava were estimated to flow out of the Earth, yet it was only about 15 percent of what was stored in the magma chamber below the surface. The team observed that areas with the largest lava output coincided with the greatest concentrations of previously known hydrothermal vents. The map and findings were published online on November 26, with a printed version coming in the December issue of the journal Geology.

Related Links
» Geology (journal) — New insights into mid-ocean ridge volcanic processes from the 2005-2006 eruption of the East Pacific Rise
» Adam Soule’s research
» Scientists See New Ocean Floor Just Before and After It Is Created
» East Pacific Rise Photo Galleries
» WHOI TowCam website

» Ridge2000 website

WHOI photographer and research technician Chris Linder is leading a public outreach effort to allow the public to follow the daily travels and travails of polar scientists. (Mike Carlowicz, Woods Hole Oceanographic Institution)
Enlarge image

Photographer Chris Linder is sending photos back daily from Antarctica to allow the public to follow the travels and travails of polar scientists. (Mike Carlowicz, Woods Hole Oceanographic Institution)

Walking in a Real Winter Wonderland

November 1, 2007

Penguins sing, are you listening? Lava flows, snow is glistening. Through the use of the Web and satellite technology, researchers and communicators from Woods Hole Oceanographic Institution are bringing the sights, sounds, and smells of the season—that is, the summer season in Antarctica—to students and museum-goers across America. In the third installment of WHOI’s Polar Discovery project, photographer Chris Linder and science writer Hugh Powell will accompany researchers who are continuing a 55-year-long study of Adélie penguins in the Ross Sea. They will then hitch a helicopter ride to the interior of the continent, camping with WHOI geologists and chemists on Mount Morning to study how ice and rock shape and carve each other over time. They will send photos, audio clips, and daily dispatches from the field to the Polar Discovery Website from November 26 to December 23, while also talking to students and museum visitors via satellite phone during a series of “Live from the Poles” events. Funded by the National Science Foundation as part of the International Polar Year (March 2007 to March 2009), Polar Discovery takes the public on a virtual expedition to observe how polar exploration is conducted and to learn what real scientists are like—what excites them, how they cope with their environment, and what challenges they face as they try to gain a better understanding of our planet.

Related Links
» Polar Discovery
» Students, Museum Visitors, and Web Surfers Can Join First Search for Life on the Arctic Ocean Floor
» Polar Research at WHOI

October 2007

Researchers detected invisible residues of olive oil, oregano, and mastic inside these two amphoras that were retrieved from a 2,400-year-old shipwreck off of Greece.
Enlarge image

Researchers detected invisible residues of olive oil, oregano, and mastic inside these two amphoras that were retrieved from a 2,400-year-old shipwreck off of Greece. (Courtesy of the Hellenic Ministry of Culture, Ephorate of Underwater Antiquities)

CSI Deep Water: Finding Invisible Clues to Ancient Greek Culture

October 1, 2007

Like forensic investigators hunting for strands of DNA at a crime scene, Maria Hansson and Brendan Foley have found a way to detect archaeological clues that are invisible to the naked eye. Hansson, a molecular biologist from Lund University (and former postdoctoral scholar at the Woods Hole Oceanographic Institution), and Foley, a deep-sea archaeologist with joint appointments at WHOI and the Massachusetts Institute of Technology, have developed a genetic technique to determine the original contents of amphoras, the ceramic vessels often used for transporting and storing goods in the ancient world.

Foley was co-leader of a 2005 expedition with the Hellenic Ministry of Culture and the Hellenic Centre for Marine Research to survey a 2,400-year-old shipwreck off the Greek island of Chios. Foley’s Greek colleagues recovered two amphoras from the wreck, each of which appeared to be empty—cleaned out by seafloor creatures and microbes over the centuries. But Hansson suggested that perhaps modern DNA sampling techniques could be used to detect residues of the original contents. They scraped the insides of the amphoras, performed DNA analysis, and found genetic traces of olive oil, oregano, and mastic (an ancient wine preservative). The technique promises to teach researchers more about what crops and foodstuffs were traded in the ancient Mediterranean, as well as when, where, and to whom they were traded. The findings have been published on the web site of the Journal of Archeological Science, with a printed version expected in the coming months.

Foley and Hansson are now proposing to examine as many as 40 amphoras in the Greek collection. Foley is also working with colleagues at MIT and WHOI’s Applied Ocean Physics and Engineering Department to develop technologies that could allow marine archaeologists to detect the chemical composition of seafloor remains without having to raise them out of the water or disturb the sites.

Related Links
» Ancient DNA fragments inside classical Greek amphoras reveal cargo of 2400-year-old shipwreck (subscription required)
» Autonomous Underwater Vehicle Maps Ancient Greek Shipwreck
» Cask from the Past
» 2005 AUV survey of Classical Greek wreck at Chios
» Who is Brendan Foley?
» MIT Deepwater Archaeology Research Group
An artist's conceptions shows how an Argo float sinks to the depths, drifts with ocean currents (taking measurements along the way), rises to the surface, and transmits data back to shore via satellite.
Enlarge image

An artist's conception shows how an Argo float sinks to the depths (as much as 2000 meters), drifts with ocean currents (taking measurements along the way), rises to the surface, and then transmits data back to shore via satellite. (Jack Cook, Woods Hole Oceanographic Institution)

Fleet of Ocean Observers Grows to 3,000 Strong

October 1, 2007

The oldest method for studying ocean circulation is to drop something into the water and let it float wherever it may go. For the past decade, oceanographers have given that approach a high-tech boost with the Argo global array of profiling floats. On November 1, researchers from WHOI, the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration, and the University of Washington—as well as collaborators from 22 other nations—will celebrate the deployment of the 3,000th operational float and the completion of the Argo armada.

Argo floats are built to rise and fall vertically through the top 2,000 meters of the water column, using simple mechanical pumps, bladders, and other devices to change their buoyancy. These instrumented cylinders measure water temperature, depth, and salinity as they also move horizontally with ocean currents, traveling long distances without the need of a ship, person, or propeller. Floats are programmed to rise to the surface periodically in order to note their position (via the Global Positioning System) and send data via satellite antenna to scientists on shore.

Discussions of a global Argo array started in November 1997, and the first instruments went into the water in 2000. These simple, floating observatories play a critical role in measuring the fine details of ocean dynamics—from the direction and speed of currents and eddies to the characteristics of parcels of water within the ocean. Data from the floats are helping scientists examine parts of the ocean that have scarcely been sampled in the past, while adding great depth and breadth to models that previously relied on a handful of data points.

Related Links
» Argo
» Under-Ice Floats Offer a Breakthrough
» Unprecedented Global Measurement Network Achieves Full Coverage of Oceans
» International Argo Information Centre
» Float 312, Where Are You?

Enlarge image

Researchers hope digital tags, or D-tags, will provide insights into the behavior of manatees so that conservation managers can do more to prevent vessel strikes. (Tom Hurst, Woods Hole Oceanographic Institution)

Novel digital device is used to help prevent boat collisions with manatees

October 1, 2007

Despite regulations designed to prevent collisions, dozens of manatees are injured or killed each year by boats in the waters around Florida. Searching for better ways to protect this endangered species, a team of researchers from Florida turned to the Woods Hole Oceanographic Institution for help in understanding how the animals behave underwater.

Douglas Nowacek, a biological oceanographer from Florida State University and graduate of theMIT/WHOI graduate program, called on some of his Woods Hole colleagues to adapt their digital acoustic recording tags (D-tags) for tracking the slow-moving “sea cows.” Developed for use on whales, the D-tag is designed to temporarily stick to an animal’s skin and record its movements—along with the sounds they make and hear underwater. WHOI engineers Tom Hurst and Mark Johnson had to customize new tags, which would not adhere to the manatees’ whisker-covered skin, so that they could be belted harmlessly around the mammal’s tail. Through the use of the D-tags, researchers were able to observe how the manatees react—or don’t react—to oncoming boats, while also learning about how and when they dive, communicate, and feed.

Ten manatees in Lemon Bay were tracked with D-tags this year, with more studies planned for 2008. Johnson and Hurst are also working to adapt their instruments for use with dolphins, harbor porpoises, and larger whales.

Related Links
» Put the D-tag on the Manatee
» Douglas Nowacek Labratory at Florida State University
» Florida Fish and Wildlife Conservation Commission Manatee Program
» Playing Tag with Whales

May 2007

Ilya Buynevich
Enlarge image

Using ground-penetrating radar, geologists can find old, buried scarps -- beach sand formations that indicate when severe hurricanes or Nor'easters struck the coast. (Photo by Donatas Pupienis)

Beach Sand Formations Tell Tales of Past Storms

May 1, 2007

Geologists have recently devised a new method for reconstructing the history of severe storms along the coast: examine the steep slopes and cliffs left behind when severe wind and water erode the beach. After hurricanes and Nor’easters make landfall, they move and sculpt the sands into “scarps” while leaving behind a distinct signature of different-sized sand grains. Intense winds blow away the lightest and smallest grains—such as quartz, feldspar, and muscovite—and leave a surface enriched with heavier minerals such as garnet, magnetite, and ilmenite. WHOI geologist Ilya Buynevich, working with colleagues from Boston University and the University of Nebraska, recently used ground-penetrating radar to find these enriched scarps buried along the coast of Maine. They also collected sediment cores and used a novel technique known as optically stimulated luminescence—which uses the crystal structure of the sand, along with a zap of radiation, to figure out when the scarps were last exposed to sunlight at the surface. In the June issue of the journal Geology, Buynevich and colleagues describe how they reconstructed a record of intense storm activity in the Gulf of Maine. The scarps indicate there was a massive storm about 1,600 years ago, followed by long quiet period, and then a rise in storm activity in the past 400 years.

Related Links
» A 1,500 yr record of North Atlantic storm activity based on optically dated relict beach scarps
» Who is Ilya Buynevich?
» WHOI Coastal Systems Group
Related Links
» Rising Sea Levels and Moving Shorelines
» A 1,500 yr record of North Atlantic storm activity based on optically dated relict beach scarps
» Who is Ilya Buynevich?
» Sediments Shed Light on Past Coastal Events
» WHOI Coastal Systems Group

Enlarge image

WHOI geologists and chemists cut holes through the ice on top of several lakes in Canada's Mackenzie River Delta in order to sample the soil-rich sediments on the bottom for clues to past climate change. (Photo by Angela Dickens, Woods Hole Oceanographic Institution)

Ice-Covered Arctic Lakes May Harbor Signs of Climate Change

May 1, 2007

Arctic coastal environments are some of the most vulnerable to climate change. A team of WHOI researchers visited Canada’s Mackenzie River Delta in April 2007 to find out just how vulnerable. Marine geochemists Tim Eglinton, Daniel Montluçon, and Angie Dickens, and geologist Liviu Giosan trekked into the frozen wilderness to drill through ice and water and into the sediments on the bottoms of lakes within the delta. Each spring, as the Canadian interior thaws and snow melts, a sediment-laden pulse of melt water surges down the streams and rivers, inundating the delta, flooding river banks, and filling the numerous low-lying lakes. The sediments that settle to the bottom comprise old carbon (derived from plants, microbes, and animals) that has been sequestered for many years in Arctic soils within the watershed. These sediments can tell the history of past river flows and floods up to the globally warming present. This spring, Eglinton and colleagues collected sediment cores stretching back for at least 1,000 years, and they hope to decipher how the discharge of the river has changed. The increasing flow into the ice-capped lakes of the Mackenzie Delta is a clear sign of increased melting in the Arctic; it may also suggest that more organic carbon will be released from the Arctic permafrost soils and back into the ocean and atmosphere. This year’s expedition was launched to prove that researchers could recover useful data from the delta. Eglinton is now planning to return in 2008 for more extensive sampling.

Related Links
» Links between Climate Change, Permafrost Stability, and Terrestrial Organic Carbon Export from the Mackenzie River
» Follow the Carbon Trail from Oceanus magazine
» The Once and Future Danube Delta from Oceanus magazine

Related Links
» Follow the Carbon Trail from Oceanus magazine
» The Once and Future Danube Delta from Oceanus magazine
» Links between Climate Change, Permafrost Stability, and Terrestrial Organic Carbon Export from the Mackenzie River

Enlarge image

An eruption that covered 9 square miles of seafloor with lava at the East Pacific Rise trapped three ocean-bottom seismometers. Scientsts attempted to recover them with the remotely operated vehicle Jason in April 2007. They successfully recovered two and will learn in the weeks ahead if the data they contain are still viable. (Photo courtesy of the National Deep Submergence Facility, ROV Jason, Woods Hole Oceanographic Institution, and the National Science Foundation.)

Robotic Vehicle Recovers Instruments and Data Locked in a Lava Flow

May 1, 2007

A lot of ocean science equipment goes into the water and never comes back. Some of it was intended to stay; other times, the sea claims it by force. Recently researchers used the WHOI-operated underwater vehicle Jason to take back some instruments—and hopefully some scientific secrets—that had been claimed by a seafloor volcanic eruption. In April 2007, scientists and technicians on the research vessel Atlantis returned to a patch of seafloor on the East Pacific Rise with Jason to find and rescue a trio of ocean-bottom seismometers (OBSs). The earthquake-monitoring instruments had been glued to the ocean bottom (1.6 miles/2,500 meters deep) by erupting lava that had flowed and hardened around them. Scientists were particularly interested in getting the OBSs back because they may have recorded the moments when the undersea volcano erupted, a phenomenon that has rarely been observed in progress. Marine geologists have been debating whether this particular eruption happened all at once or over several months. The 1,200-pound, robotically armed Jason successfully plucked two of the OBSs and their data out of the hardened rock (click here for video), so now the researchers may have a chance to settle the argument.

Related Links
» Rescue Mission on the Seafloor from Oceanus magazine
» Scientists "See" New Ocean Floor Just Before and After It Is Created
» 9 North OSC Expedition
» Remotely Operated Vehicle Jason

Related Links
» Rescue Mission on the Seafloor from Oceanus magazine
» Scientists "See" New Ocean Floor Just Before and After It Is Created
» 9 North OSC Expedition
» Remotely Operated Vehicle Jason

Rebecca Gast
Enlarge image

Biologist Rebecca Gast examines a gel used to sort and examine fragments of DNA from microorganisms found in water and sediment samples, which helps determine the types and abundances of microbes present. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)

Hurricane Katrina’s Flood Legacy Does Not Include Disease

May 1, 2007

When the levees broke in New Orleans after Hurricane Katrina, officials feared that Lake Pontchartrain might be infiltrated with disease-causing microbes from a “toxic gumbo” of water, polluted sediments, and sewage. In the weeks after the flood, scientists from several U.S. Centers for Oceans and Human Health, including WHOI biologist Rebecca Gast, mobilized to sample the mud and waters around the lake. After several months of study, the research team found the influence of contaminated floodwaters on Lake Pontchartrain was relatively short-lived, limited to coastal areas, and did not leave a lasting contamination or disease problem. For her part, Gast and her Woods Hole colleagues looked for the presence and persistence of microbes and certain pathogens. In addition, Gast organized a workshop and colloquium in Woods Hole in November 2006 that allowed scientists to compare their findings and assemble them into a publication that appeared in May 2007 in the Proceedings of the National Academy of Sciences.

Related Links
» Impacts of Hurricanes Katrina and Rita on the Microbial Landscape of the New Orleans Area
» Woods Hole Center for Oceans and Human Health
» Who is Rebecca Gast?
» The Impact of Hurricane Katrina on Human Pathogens in Lake Pontchartrain
» Legions of Legionella Bacteria from Oceanus magazine
Related Links
» Impacts of Hurricanes Katrina and Rita on the Microbial Landscape of the New Orleans Area
» Woods Hole Center for Oceans and Human Health
» Who is Rebecca Gast?
» The Impact of Hurricane Katrina on Human Pathogens in Lake Pontchartrain
» Legions of Legionella Bacteria from Oceanus magazine

March 2007

Enlarge image

Will iron fertilization promote healthy marine life and the consumption and sinking of carbon dioxide out of the atmosphere (left), or will it acidify the ocean or promote nuisance species without helping the atmospheric greenhouse problem? (Illustration by Jack Cook, Woods Hole Oceanographic Institution)

Should We Pump Iron to Slow Climate Change?

March 23, 2007

One of the solutions offered for the global greenhouse gas problem is the fertilization of the ocean; that is, spreading iron into the open ocean to promote the growth of floating microscopic plants. In at least 12 experiments over the past 14 years, researchers have shown that the presence of dissolved iron is critical to blooms of phytoplankton, which draw large amounts of carbon dioxide out of Earth’s atmosphere and deposit a fraction of it in the deep ocean. Some researchers have speculated that we might reduce greenhouse gases by coaxing more marine plants to grow—selling it as the oceanic equivalent of planting more trees. However, the value and viability of such iron-enrichment activities, says WHOI marine chemist Ken Buesseler and 22 international colleagues in a recent issue of Science magazine, remains questionable because the artificial addition of iron has provoked very different results in different parts of the world. Iron fertilization on a large scale might promote healthy, useful growth, but it might just as well promote a harvest of oceanic “weeds”—such as harmful algal blooms, nutrient pollution, and other unforeseen problems. In a new project funded by the WHOI Ocean and Climate Change Institute, Buesseler and colleagues are planning to deploy instruments off the coast of Cape Verde in late 2007 to measure just how much carbon is sinking from the surface to the seafloor in a part of the ocean that is naturally seeded with iron by dust from the Sahara.
Related Links
» Why Dump Iron into the Ocean?
» "Mesoscale Iron Enrichment Experiments 1993-2005" (Science magazine subscription required)
» WHOI Ocean and Climate Change Institute
» Postcards from the Bottom of the Earth
» "The Effects of Iron Fertilization on Carbon Sequestration in the Southern Ocean" (Science magazine subscription required)

Enlarge image

Scientists have discovered that the endosymbiotic bacteria living inside tubeworms are capable of using two fundamentally different means to generate organic carbon--both the "Calvin" cycle and the reductive tricarboxylic acid (rTCA) cycle. (Photo by Woods Hole Oceanographic Institution)

Seafloor bacteria are multi-tasking with the carbon cycle

March 22, 2007

Scientists have long known that microorganisms can use one of two different methods to convert carbon dioxide into a form that living things can use for energy. What they didn’t know until recently is that at least one form of bacteria can switch between these two “carbon fixation” pathways or use them both at the same time—a fundamental discovery for scientists who believe such bacteria played a role in the evolution of life on Earth. Past research has shown that symbiotic bacteria live inside tubeworms and provide energy to their hosts in exchange for a safe place to live. Biologists knew this marriage was a good one, as the tubeworm is the fastest-growing marine invertebrate known to exist. But they did not know the details of how the bacteria make the energy because they could not culture the bacteria successfully in the lab. WHOI microbiologist Stefan Sievert was part of a research team—led by Thomas Schweder and Stephanie Markert of the Institute of Marine Biotechnology in Germany—that studied the bacteria’s genome to discover how these microbes switch back and forth between both carbon-fixing methods—the “Calvin cycle” and the reductive tricarboxyclic (rTCA) cycle—to adapt to fast-changing environmental conditions on the deep seafloor.

Related Links
» "Deep-sea Tubeworms Get Versatile 'Inside' Help"
» Stefan Sievert's Lab
» "Physiological Proteomics of the Uncultured Endosymbiont of Riftia pachyptila" -- PDF download of the Science paper

Enlarge image

In the real world, harmful algal blooms are caused by species of tiny plants?-phytoplankton?-that produce potent chemical toxins. In the virtual world of Whyville, these plant cells are a ticket to marine education. (Photo by Don Anderson, Woods Hole Oceanographic Institution)

Going Virtual in Marine Biology Education

March 8, 2007

Whyvillians have a problem: harmful algae are threatening their beaches and coastal ecosystem. In order to investigate, understand, and mitigate the problem, citizens are turning to the Whyville Oceanographic Institution (WhOI), with its boats, its underwater laboratories, and other resources for exploring the ocean. This interactive experience is part of a new partnership between the developers of Whyville.net, a leading educational Web site for youth, and the Woods Hole Oceanographic Institution (WHOI). To learn more about how nutrients can fuel plankton blooms, Whyvillians must collect samples from the virtual ocean, use the laboratory to identify the species and nutrient at the root of the problem, trace the nutrient to its source, and stem the nutrient flow by restoring a virtual wetland. “One of our biggest challenges as a research institution is conveying our work to the public," said WHOI Associate Scientist Sonya Dyhrman, who helped create the new feature. "Whyville.net is an excellent tool for communicating information about the oceans, and their significance to our everyday lives, in a unique and entertaining format.”
Related Links
» Sonya Dyhrman's Phytoplankton and Marine Biogeochemistry Laboratory
» Whyville
» Center for Ocean Sciences Education Excellence - New England

Enlarge image

Jeff Donnelly and colleagues sink metal coring tubes into lake bottoms to collect plugs of sediment that are analyzed and dated to reconstruct a record of past climate conditions. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)

Climate Change in the Bottom of a Lake

March 20, 2007

Climate is often discussed in global terms, but it is the regional and local effects that will matter most to everyday people. WHOI geologist Jeff Donnelly and colleagues are looking closely at the regional effects of a past period of climate change, and it’s not all about rising temperatures. Between 5,400 and 3,000 years ago, the distribution and circulation of fresh water in New England fundamentally changed. Droughts persisted for hundreds of years; tree, plant, animal, and insect populations changed; and water levels in lakes dropped from Cape Cod to New York. The research group led by Donnelly has been working to reconstruct water-level histories to see what the rise and fall of these inland waters can tell us about regional climate in the past. Using ground-penetrating radar and traditional coring techniques, the researchers are examining sedimentary patterns within small lakes and ponds to track shifts in moisture over time. Such reconstructions may offer essential clues for understanding the causes and potential impacts of future climate change in the region.
Related Links
» Oceanus magazine -- Lakes and Climates Have Their Ups and Downs
» Jeff Donnelly?s research
» WHOI Coastal Systems Group

Enlarge image

Hauke Kite-Powell of the WHOI Marine Policy Center is one of several Institution scientists who have examined the economics and practical issues affecting shellfish farming and other forms of marine aquaculture. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)

Is U.S. Marine Aquaculture Economically Sustainable?

March 19, 2007

With growing global populations and ever-increasing demands for seafood, fish farms are expected to expand significantly over the next few decades. But is aquaculture economically sustainable? Do the benefits outweigh the costs when all of the relevant environmental factors are considered? A team of social scientists from WHOI’s Marine Policy Center produced an analysis of the economics of marine aquaculture in the U.S., identifying major challenges on the path to large-scale aquaculture such as: disease transmission from farmed fish to wild stocks; the effects of interbreeding in farmed fish and of escapes into the wild population; and the availability of forage fish stocks for feeding carnivorous finfish in farms. The team also discusses some of the significant conceptual issues that arise when attempting to characterize the "economic sustainability" of a specific activity like marine aquaculture in a single country.
Related Links
» Economic Sustainability of Marine Aquaculture -- A report from the WHOI Marine Policy Center to the Marine Aquaculture Task Force (1.8 MB PDF download)
» WHOI News Release -- Report of the Marine Aquaculture Task Force
» WHOI Marine Policy Center
» Aquaculture Information from WHOI's Coastal Ocean Institute

Related Files
» Economic Sustainability of Marine Aquaculture