Scientists are finding clues about why water is so utterly weird

It turns out that similar coordinated maneuvers—with water molecules taking the places of the dancers—may be responsible for some of water's most puzzling features, an array of recent research findings suggest.

As liquids go, water is a radical nonconformist—differing from other liquids in dozens of ways . Most famous among water's peculiarities is its density at low temperatures. While other liquids contract and get denser as they cool toward their freezing points, water stops contracting and starts to expand. That's why ice floats and frozen pipes burst.

Water gets even weirder at colder temperatures, where it can exist as a liquid in a supercooled state well below its ordinary freezing point. Recent evidence suggests that supercooled water splits its personality into two distinct phases—another oddity unseen in other liquids. And last year, water surprised scientists yet again, when they found that at –63 degrees Celsius, supercooled water's weird behavior returns to "normal."

That discovery, scientists say, may help explain some aspects of water's peculiar personality, such as its ability to transition from gas to liquid to solid and back to liquid again. Findings from related experiments have important implications for understanding how water interacts with biological molecules, such as proteins, and may lead to better ways of freezing and storing biological tissues such as sperm and human oocytes.

Plunging ahead

Water's ability to exist in a liquid state well below its freezing point has been studied for centuries. What's new, scientists say, is growing evidence about what happens to water at superlow temperatures. Under these extraordinary conditions, there is not just one kind of water, but two.

This two-phase phenomenon was first predicted in 1992 by physicist H. Eugene Stanley of Boston University and his graduate student Peter Poole, now at St. Francis Xavier University in Antigonish, Nova Scotia. Using computer simulations to study the behavior of liquid water at very low temperatures, the scientists suggested that water could exist as either a high-density liquid or as a low-density liquid.

Stanley and Poole also proposed that the dividing line between these two liquid forms might end in a "critical point," where the two liquids would become indistinguishable, changing from one form to the other.

In a series of experiments in recent years, scientists have begun to close in on this critical point. These advances offer a glimpse of possible explanations for water's unusual behaviors, and suggest that Stanley and Poole may have been on to something.

Some of water's odd properties have traditionally been explained as consequences of the hydrogen bonds that form between water molecules (and sometimes other molecules). Each V-shaped molecule of water contains one oxygen atom centered between two hydrogen atoms. The chemical bonds holding the molecule together create a slightly negative charge on the oxygen atom and a small positive charge on each of the hydrogen atoms.

These unequal charges make water molecules extremely "sociable"—eager to bond with each other. Because hydrogen bonds are much weaker than normal chemical bonds, the water molecules move about freely, binding briefly with adjacent molecules before moving on to others. Stanley likens this fast-paced network to a square dance taking place in a large dance hall.

"In square dancing, you're always releasing one partner and grabbing another, and that is a hydrogen bond network, exactly," he says.

In the case of water, the square dance occurs among molecules that have four arms, instead of two. That's because each water molecule has the potential to form four hydrogen bonds. The result is a network of tetrahedrons, or pyramids with a triangular base.

This tetrahedral arrangement creates a peculiar tension, permitting structural changes in response to different temperatures and pressures. In liquid form, the tetrahedral structures allow unrestrained hydrogen bonding to occur as numerous molecules pack into and around the tetrahedron. (Imagine a swift square dance with dancers moving in and out of the center of the square and circling around it as well.) The result is a dense, fluid structure, such as that of everyday tap water.

As water approaches its freezing point (0°C), however, the tetrahedral structure becomes more open and begins to expand. Ordinary water reaches its maximum density at 4°C. As water continues to cool, falling to its freezing point and below, it continues to expand.

Here, the tetrahedral arrangement is more rigidly enforced, with molecules spaced an "arm's length" apart. The arrangement creates a more spacious, open structure, and water becomes lighter. If ice weren't lighter than cold water, ponds and lakes would freeze from the bottom, rather than form a floating layer of surface ice, and water would cease flowing in the dead of winter. Water's weirdness therefore allows fish to swim in the water beneath the ice and plants to survive the winter cold.

At temperatures below the freezing point, ice crystals form around defects, such as cracks or dust particles. By using extremely clean water samples—free from any such defects—scientists have found ways to defy freezing and obtain supercooled liquid-water that remains liquid below 0°C.

This procedure works only to a certain point. At extremely cold temperatures, (–38°C and lower), it is nearly impossible to keep water from freezing. But under certain conditions, such as the ultrahigh pressures found deep undersea, water can remain liquid even at such low temperatures. Scientists have been unable to make water that cold in the laboratory, though, and so what Stanley calls a "no man's land" of conditions had been explored only in computer simulations.

But now, using a clever technique to confine water samples in nanoscopic pores, scientists are beginning to explore the structure and properties of deeply supercooled water.

As even a square-dancing novice knows, you can't hold a hoedown in a cramped, narrow hallway. Water's hydrogen-bonding network is a fast-moving, gregarious one. Cramming water molecules into a tiny space, with a diameter less than five water molecules wide, brings the molecular square dance to a standstill.

"If a room were very, very narrow, it would be hard to have a normal square dance because a lot of people would be up against the wall and there would be no partner to grab on to," Stanley says. "In a similar fashion, water molecules that are confined against a wall have only two or three arms, and the whole hydrogen-bond network is disrupted."

Because the hydrogen-bond network brings stability to water, the breakdown of this network changes water's properties, allowing it to remain liquid at a much lower temperature, he says.

Scientists began exploring ways to nanoconfine water molecules more than a decade ago, using a spongelike material that had holes of different sizes. While the experiments showed that nanoconfinement could be used to cool water well below its usual freezing temperature, the results were often hard to interpret because water in the larger holes would freeze, causing crystallization throughout the material.

In 2005, Sow-Hsin Chen of the Massachusetts Institute of Technology and his colleagues found a way to get around this problem, using a new material called MCM-41. Chung-Yuan Mou of National Taiwan University of Taipei had created MCM-41 by refining the fabrication of silica-nanotube assemblies. The material resembles a microscopic beehive with a hexagonal array of holes, all uniformly sized, just a few nanometers wide.

Curious to see how confined water might respond in MCM-41, Chen filled the hexagonal arrays with water. He then cooled the water to –73°C and bombarded the arrangement with neutrons. The microscopic cells of MCM-41 not only prevented ice crystals from forming but also allowed the scientists to probe water's molecular structure.

Building on this work, Chen and colleagues conducted a series of experiments to see how water's properties change as temperature drops at ordinary pressures.

In 2006, Chen showed that, when cooled below 225 kelvins (or –48°C), water's hydrogen-bonding structure undergoes a phase transition, changing from a disordered, fluid state to a more ordered, rigid state. Furthermore, this line of transition between a high-density liquid and low-density liquid, called the Widom line, occurred in a continuous fashion, as predicted by Stanley and Poole in 1992. This transition, called a fragile-to-strong dynamic crossover, helped explain why, at superlow temperatures, proteins and other biological molecules exist in a glassy state, losing all flexibility and biological function.

"This dynamical transition of protein at 225 K is triggered by its association with the hydration water, which shows a similar dynamic transition at that temperature," Chen says.

In addition, the study showed that water's phase change at 225 K—moving from a disordered state to a more ordered state—violates a well-known formula called the Stokes-Einstein relation. This formula, based on a picture of a disordered, fluid state, ties together liquid properties such as diffusion, viscosity, and temperature, and generally works for normal- and high-temperature liquids.

Because this formula breaks down in subzero conditions, the experiment suggests that supercooled water may be a mix of two liquid phases, rather than a single liquid. Chen's study, published in the Proceedings of the National Academy of Sciences (PNAS), provided the first experimental evidence of such "liquid polymorphism" and received the journal's 2006 prize for best paper.

Last year, Chen and his colleagues surprised the scientific community, and themselves, when they discovered that under supercold conditions, liquid water again begins to expand, returning to normal behavior. Using a neutron-scattering method and analysis to measure the density of subzero liquid water, they showed that water reaches a minimum density at 210 K, or –63°C.

In doing the experiments, the scientists used heavy water, or D₂O, because of its neutron-scattering properties. They then repeated the experiments using regular water and two light-scattering techniques and came up with the same results. The findings were reported last June in PNAS.

Though this kind of behavior had been predicted in computer simulations, it had never been observed. The findings add to the long list of experimental anomalies associated with supercooled water, and provide the strongest experimental evidence yet for a second "critical point" in liquid water, Chen says.

A critical point defines the set of pressures and temperatures at which a liquid changes from one form to the other. "It would be hard to explain a density minimum unless there was a second critical point," he says.

Water already has one well-known critical point at 647 K, or 374°C, where, under ordinary pressures, the liquid and gas phases become identical.

"As water approaches this critical point, the difference between water and steam grows increasingly smaller," Stanley explains. "At the critical point, there is nothing distinguishing water from steam, there is just one, homogeneous fluid."

More important, he says, a critical point serves as a "tipping point," where water can exist in either of two states, and minor fluctuations can tip the balance in one direction or the other.

The hypersensitivity created by a critical point can have far-reaching effects upon a system, says Stanley. In predicting a critical point in supercooled water, he and Poole theorized that water's crazy low-temperature behavior might account for some of its unusual properties even at ordinary temperatures.

That's because changes at a critical point don't occur abruptly, Stanley says. The huge changes seen near the water-gas peak, for example, are often, if not always, foreshadowed by fluctuations over a large range of temperatures and pressures.

"It's like looking at the highest peak on a mountain range," Stanley says, gesturing toward a picture of Mount Everest in his office. "The critical point, or summit, doesn't rise out of nowhere, but rises in a gradual manner and distorts the terrain all around it."

That means that a critical point at –63°C might account for water's bizarre behavior at much higher temperatures, such as its ability to expand as it cools.

Though findings from recent studies point to the predicted second critical point, it is still too soon to know whether such a point exists for sure. Further evidence is needed.

This year, Chen and his group will seek some of that evidence by performing another, more far-reaching set of experiments on supercooled water in MCM-41. Using a specially designed pressure cell for low temperatures, the scientists will analyze changes in liquid water as it moves from its maximum density point at 4°C to its minimum density at –63°C and beyond under various pressures. By studying how density changes with temperature and pressure, the researchers hope to locate the liquid-liquid critical point precisely.

"The critical point is at a high pressure, and no one knows exactly what it is, but we believe it's probably above 1,000 atmospheres," Stanley says.

Other scientists are raising questions about the extent to which supercooled water in confined volumes, no matter what the pressure, actually behaves like cold, bulk water.

"When you put water into confinement, it changes the way in which water molecules are arranged with respect to each other," says C. Austen Angell, a chemist at Arizona State University in Tempe, who studies liquid phases in supercooled water. "The question is, how much does it change it?"

Angell notes that despite recent progress, much remains uncertain and many of the explanations are built on simulations that can give different results, depending on the model and tools used in the study.

"There are other possibilities, related to the second critical point scenario, in which the low-pressure supercooling of uncrystallized bulk water is terminated by a first-order [sharp] transition to a second 'low-density' liquid phase," he says. Angell's take on supercooled water will appear in an upcoming issue of Science.

Confirming the predicted second critical point could have an impact beyond the study of water's molecular mysteries for their own sake.

Biologists, for example, are looking at how this transition in liquid states, and the accompanying rigidity it brings, affects living structures such as proteins and DNA.

Other practical benefits could flow from the new water knowledge. For example, scientists at Cornell University have found that high-pressure cooling of protein crystals causes them to diffract better than they would if flash frozen, and has allowed scientists to improve methods for crystallizing and studying proteins and other biological tissues.

The scientists are now pursuing ways to use high-pressure techniques to improve methods for freezing sperm and human oocytes. The studies may lead to better ways of freezing and storing sperm for livestock production and allow women to freeze their eggs and use them at a later time to conceive a child.

The studies may also help explain some more ordinary, everyday occurrences related to water's mysterious behavior. Chen recalls hiking in New Hampshire's White Mountains, a site known for its frigid temperatures and long months of ice, and noticing that the trees stopped abruptly at 4,400 feet, nearly 2,000 feet below the summit of Mount Washington. Soon after he published his findings on a minimum density, he received a phone call from a Canadian biologist who was interested in the work.

"It turns out that this tree line stops where the windchill temperatures reach 220 degrees K," Chen says, noting that this is the temperature at which water's hydrogen-bonding structure undergoes a phase transition, changing from a fluid state to a more rigid state.

At this point water becomes very, very slow, and no longer supports biological functions. Or, to put it another way, the square dance of water comes to an end.

Great Apes endangered by human viruses

A new study published in the journal Current Biology by researchers of the Robert Koch Institute (Berlin), the Max Planck Institute for Evolutionary Anthropology (Leipzig) and the Centre Suisse des Recherches Scientifiques (Ivory Coast) confirms the disease threat, finding the first direct evidence of virus transmission from humans to wild apes. The study also showed however that research and tourism projects strongly suppressed the poaching of chimpanzees. This protective effect outweighed the substantial chimpanzee mortality caused by human disease introduction.
Respiratory disease introduction by humans has long been suspected at sites where apes in the wild have been in close contact to humans but this is the first study to diagnose the disease agent and quantify the population impact. "We need to be much more proactive about instituting strict hygiene precautions at all ape tourism and research sites", says Fabian Leendertz, senior author of the paper and a wildlife disease epidemiologist at the Robert Koch Institute in Berlin. "One possibility for promoting compliance is a certification process similar to the green labelling system now used in the timber industry."

The study used a multidisciplinary approach involving behavioural ecology, veterinary medicine, virology and population biology to track human disease introduction into two chimpanzee communities at Taï National Park in Côte d’Ivoire, where researchers first began to habituate chimpanzees to human presence in 1982. Tissue samples taken from chimpanzees that had died in a series of outbreaks dating back to 1999 tested positive for two human respiratory viruses that are major sources of human infant mortality in the developing world, namely human respiratory syncytial virus and human metapneumovirus. Viral strains sampled from the chimpanzees were closely related to pandemic strains concurrently circulating in human populations as far away as China and Argentina, suggesting recent introduction from humans into the chimpanzees. The authors also used clinical observations and demographic analyses to infer that similar respiratory outbreaks could date as far back as 1986.

The research project has however also had strongly positive effects. Longitudinal surveys showed that the presence of researchers had suppressed poaching activities in the surrounding area. Consequently, chimpanzee densities at both the research study site and a nearby chimpanzee tourism site were much higher than would be expected given their accessibility to poachers. "Researcher presence is confirmed to have a major positive impact on the protection of an area," says co-author Christophe Boesch of the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Leipzig, who directs the research project at Taï. "However, it comes with some hygienic problems which need to be addressed".

"The study confirms that multidisciplinary research is needed to investigate different issues involved in ape conservation", said Paul N’Goran, a researcher at the Centre Suisse de Recherches Scientifiques en Côte d’Ivoire. "Our study shows the critical role that scientific research can play in monitoring the impact and effectiveness of conservation strategies".

Earth's soils bear unmistakable footprints of humans

The dirt under our feet is being so changed by humans that it is now appropriate to call this the "Anthropocene (or man-made) Age," says a new worldwide overview by Duke University soil scientist Daniel Richter.

“With more than half of all soils on Earth now being cultivated for food crops, grazed, or periodically logged for wood, how to sustain Earth’s soils is becoming a major scientific and policy issue,” Richter said. His paper appears in the December issue of the research journal Soil Science.

“Society’s most important scientific questions include the future of Earth’s soil,” Richter added. "Can soils double food production in the next few decades? Is soil exacerbating the global carbon cycle and climatic warming? How can land management improve soil’s processing of carbon, nutrients, wastes, toxics and water, all to minimize adverse effects on the environment?"

“Each of these questions require long-term observation and analysis, and we know far too little about how to answer them in much detail," he said. "We need to work to sustain soils with a greater sense of urgency.”

As an example of the challenges, Richter said leading scientists are concerned that agriculture in Africa has so degraded regional soil fertility that the economic development of whole nations will be diminished without drastic improvements of soil management.

"This is an old story writ large of widespread cropping without nutrient recycling, with the result being soil infertility," he said. "And agriculture is only part of the reason why soils are so rapidly changing. Expanding cities, industries, mining and transportation systems all impact soil in ways that are far more permanent than cultivation."

"If humanity is to succeed in the coming decades, we must interact much more positively with the great diversity of Earth's soils," his Soil Science report said. The research was funded by the National Science Foundation, the United States Department of Agriculture, the Andrew W. Mellon Foundation and Duke's Center on Global Change.

A professor of soils and ecology at Duke's Nicholas School of the Environment and Earth Sciences, Richter and his international colleagues have recently established what is described as the first global network of long-term soil experiments, a network with an extensive web site <http://ltse.env.duke.edu>.

The network has two objectives, he said. "The first is to bring more attention to how fundamental soil is to environmental quality, the global carbon cycle, and climate change, all in addition to soil being the basis for food and fiber production."

The second objective, emphasized in the Soil Science report, "is to strengthen and renew the world’s long-term soils research sites, because those provide our best direct observations of how soils are changing on time scales of decades," he said.

“One problem is that such studies have not worked together in the past. Study sites have never been comprehensively inventoried, and many operate without stable institutional support. Several highly productive long-term experiments have even been abandoned in recent years, including important studies in Africa and South America.”

Despite those problems, “long-term soil studies are clearly demonstrating the susceptibility of soils to change in response to land management," Richter said. "They also provide important data to model climate warming and the global carbon cycle.”

New radar satellite technique sheds light on ocean current dynamics

Ocean surface currents have long been the focus of research due to the role they play in weather, climate and transportation of pollutants, yet essential aspects of these currents remain unknown.

By employing a new technique – based on the same principle as police speed-measuring radar guns – to satellite radar data, scientists can now obtain information necessary to understand better the strength and variability of surface current regimes and their relevance for climate change.

Scientists at the SeaSAR 2008 workshop held this week in ESRIN, ESA's European Centre for Earth Observation in Frascati, Italy, demonstrated how this new method on data from the Advanced Synthetic Aperture Radar (ASAR) instrument aboard ESA’s Envisat, enabled measurements of the speed of the moving ocean surface.

Synthetic Aperture Radar (SAR) instruments, such as ASAR, record microwave radar backscatter in order to identify roughness patterns, which are linked to varying surface winds, waves and currents of the ocean surface. However, interpreting radar images to identify and quantify surface currents had proven very difficult.

By using the new information embedded in the radar signal – the Doppler shift of the electromagnetic waves reflected from the water surface – Dr Bertrand Chapron of the French Research Institute for Exploitation of the Sea (IFREMER), Dr Johnny Johannessen of Norway’s Nansen Environmental and Remote Sensing Centre (NERSC) and Dr Fabrice Collard of France's BOOST Technologies were able to determine how surface winds and currents contribute to the Doppler shift.

The Doppler shift occurs due to changing relative velocities, experienced in everyday life in the way the pitch of a siren on a passing ambulance goes up as it approaches, then goes down as the vehicle recedes away.

The shift is introduced by the relative motion between the satellite platform, the rotation of the Earth and the velocity of the particular facets of the sea surface from which the SAR signal scatters back to orbit. The initial two values are well known – particularly for Envisat, with its very stable satellite orbit and attitude – and can be simply subtracted to extract the useful sea surface velocity information.

Chapron first demonstrated the concept in 2005 with initial tests carried out over the Gulf Stream. Although the results were promising, repeat acquisitions and careful validation were not possible. However, based on these conclusions ESA upgraded its ASAR ground segment in July 2007 to systematically process and disseminate a Doppler grid product, a regularly spaced collection of individual Doppler information, for all Wide Swath acquired images.

The Doppler grid, embedded in ESA standard products, is now regularly tested on a number of so-called super-sites, including regions of the Gulf Stream and the greater Agulhas Current, both among the strongest western boundary currents of the world’s oceans.

"These measurements are very useful for advancing the understanding of surface current dynamics and mesoscale variability, as well as for determining surface drift, important for oil dispersion and pollution transport and for wave-current interaction, probably influencing the existence of extreme waves," Johannessen said.

"The method at this very high resolution could also complement the use of additional information sources to improve 3-D ocean models. Its use for sensor synergy with radiometry, spectrometry and altimetry is very promising," Chapron added.

The ground segment upgrade is also allowing the scientists to examine the anticipated Doppler shift signal of the river outflow at the mouth of the Amazon delta to monitor river runoff and improve our understanding of hydrological processes.

Chapron and Collard also presented their Near Real Time global swell wave observations to the workshop, attended by 150 participants from 25 countries. Using standard processed SAR ESA wave mode products, the team produces three hourly animations every morning for the Atlantic, Pacific and Indian Oceans and makes them available online.

Tracking swell waves from space is very important because they are generally preceded by calm water, making it impossible to detect their arrival from shore. Envisat’s Wave Mode acquires 10 by 5 km small images, or 'imagettes', of the sea surface every 100 km along the satellite orbit. These small images, which depict the wave groups, are then mathematically transformed into wave energy and direction, called ocean-wave spectra.

ESA has provided SAR data to some 500 oceanography projects since 1998 and remains committed to providing continuity to its SAR missions. As part of its Global Monitoring for Environment and Security (GMES) programme, the agency will launch the Sentinels – the first series of operational satellites responding to the Earth Observation needs of GMES, a joint initiative of the European Commission and ESA.

Sentinel-1, expected to be launched in 2011, will ensure the continuity of C-band SAR data with ESA's ERS-2 and Envisat satellites. Important applications driving the mission concept include marine - vessel detection, oil spill mapping and sea ice mapping. With these new findings, Sentinel-1 is expected to provide additional information, such as consistent wind, wave and current products.

Hot springs microbes hold key to dating sedimentary rocks

Scientists studying microbial communities and the growth of sedimentary rock at Mammoth Hot Springs in Yellowstone National Park have made a surprising discovery about the geological record of life and the environment.

Their discovery could affect how certain sequences of sedimentary rock are dated, and how scientists might search for evidence of life on other planets.

“We found microbes change the rate at which calcium carbonate precipitates, and that rate controls the chemistry and shape of calcium carbonate crystals,” said Bruce Fouke, a professor of geology and of molecular and cellular biology at the University of Illinois.

In fact, the precipitation rate can more than double when microbes are present, Fouke and his colleagues report in a paper accepted for publication in the Geological Society of America Bulletin.

The researchers’ findings imply changes in calcium carbonate mineralization rates in the rock record may have resulted from changes in local microbial biomass concentrations throughout geologic history.

A form of sedimentary rock, calcium carbonate is the most abundant mineral precipitated on the surface of Earth, and a great recorder of life.

“As calcium carbonate is deposited, it leaves a chemical fingerprint of the animals and environment, the plants and bacteria that were there,” said Fouke, who also is affiliated with the university’s Institute for Genomic Biology.

The extent to which microorganisms influence calcium carbonate precipitation has been one of the most controversial issues in the field of carbonate sedimentology and geochemistry. Separating biologically precipitated calcium carbonate from non-biologically precipitated calcium carbonate is difficult.

Fouke’s research team has spent 10 years quantifying the physical, chemical and biological aspects of the hot springs environment. The last step in deciphering the calcium carbonate record was performing an elaborate field experiment, which drew water from a hot springs vent and compared deposition rates with and without microbes being present.

“Angel Terrace at Mammoth Hot Springs in Yellowstone National Park is an ideal, natural laboratory because of the high precipitation rates and the abundance of microbes,” Fouke said. “Calcium carbonate grows so fast – millimeters per day – we can examine the interaction between microorganisms and the calcium-carbonate precipitation process.”

The researchers found that the rate of precipitation drops drastically – sometimes by more than half – when microbes are not present.

“So one of the fingerprints of calcium carbonate deposition that will tell us for sure if there were microbes present at the time it formed is the rate at which it formed,” Fouke said. “And, within the environmental and ecological context of the rock being studied, we can now use chemistry to fingerprint the precipitation rate.”

In a second paper, to appear in the Journal of Sedimentary Research, Fouke and colleagues show how the calcium carbonate record in a spring’s primary flow path can be used to reconstruct the pH, temperature and flux of ancient hot springs environments. The researchers also show how patterns in calcium carbonate crystallization can be used to differentiate signatures of life from those caused by environmental change.

“This means we can go into the rock record, on Earth or other planets, and determine if calcium carbonate deposits were associated with microbial life,” Fouke said.

Crop Varieties from Four Corners of the World Depart for Arctic Seed Vault

At the end of January, more than 200,000 crop varieties from Asia, Africa, Latin America and the Middle East—drawn from vast seed collections maintained by the Consultative Group on International Agricultural Research (CGIAR)—will be shipped to a remote island near the Arctic Circle, where they will be stored in the Svalbard Global Seed Vault (SGSV), a facility capable of preserving their vitality for thousands of years.

The cornucopia of rice, wheat, beans, sorghum, sweet potatoes, lentils, chick peas and a host of other food, forage and agroforestry plants is to be safeguarded in the facility, which was created as a repository of last resort for humanity’s agricultural heritage. The seeds will be shipped to the village of Longyearbyen on Norway’s Svalbard archipelago, where the vault has been constructed on a mountain deep inside the Arctic permafrost.

The vault was built by the Norwegian government as a service to the global community, and a Rome-based international NGO, the Global Crop Diversity Trust, will fund its operation. The vault will open on February 26, 2008.

This first installment from the CGIAR collections will contain duplicates from international agricultural research centers based in Benin, Colombia, Ethiopia, India, Kenya, Mexico, Nigeria, Peru, the Philippines and Syria. Collectively, the CGIAR centers maintain 600,000 plant varieties in crop genebanks, which are widely viewed as the foundation of global efforts to conserve agricultural biodiversity.

“Our ability to endow this facility with such an impressive array of diversity is a powerful testament to the incredible work of scientists at our centers, who have been so dedicated to ensuring the survival of the world’s most important crop species,” said Emile Frison, Director General of Rome-based Bioversity International, which coordinates CGIAR crop diversity initiatives.

“The CGIAR collections are the ‘crown jewels’ of international agriculture,” said Cary Fowler, Executive Director of the Global Crop Diversity Trust, which will cover the costs of preparing, packaging and transporting CGIAR seeds to the Arctic. “They include the world’s largest and most diverse collections of rice, wheat, maize and beans. Many traditional landraces of these crops would have been lost had they not been collected and stored in the genebanks.”

For example, the wheat collection held just outside Mexico City by the CGIAR-supported International Maize and Wheat Improvement Center (CIMMYT) contains 150,000 unique samples of wheat and its relatives from more than 100 countries. It is the largest unified collection in the world for a single crop. Overall, the maize collection represents nearly 90 percent of maize diversity in the Americas, where the crop originated. CIMMYT will continue to send yearly shipments of regenerated seed until the entire collection of maize and wheat has been backed up at Svalbard.

Storage of these and all the other seeds at Svalbard is intended to ensure that they will be available for bolstering food security should a manmade or natural disaster threaten agricultural systems, or even the genebanks themselves, at any point in the future.

“We need to understand that genebanks are not seed museums but the repositories of vital, living resources that are used almost every day in the never-ending battle against major threats to food production,” Bioversity International’s Frison said. “We’re going to need this diversity to breed new varieties that can adapt to climate change, new diseases and other rapidly emerging threats.”

Why are genebanks important?

The CGIAR collections are famous in plant breeding circles as a treasure trove for plant breeders searching for traits to help them combat destructive crop diseases and pests, such as the black sigatoka fungus, which is devastating banana production in East Africa, and grain borer beetle, which is destroying maize in Kenya.

Just from January to August of 2007, CGIAR centers distributed almost 100,000 samples. The materials mainly go to researchers and plant breeders seeking genetic traits to create new crop varieties that offer such benefits as higher yields, improved nutritional value, resistance to pests and diseases, and the ability to survive changing climatic conditions, which are expected to make floods and drought more frequent.

In addition, these collections have often been used to help restore agricultural systems after conflicts and natural disasters.

For example, among the 135,000 food and forage seeds maintained at the CGIAR-supported International Center for Agricultural Research in the Dry Areas (ICARDA) in Aleppo, Syria, 3,000 varieties are native to Afghanistan, and 1,000 are from Iraq. The seeds preserved have been used to help revitalize crop diversity in these war-torn regions.

“Svalbard will be able to help replenish genebanks if they’re hit,” said Cary Fowler. Iraq’s genebank in the town of Abu Ghraib was ransacked by looters in 2003. Fortunately there was a safety duplicate at the CGIAR center in Syria. Typhoon Xangsane seriously damaged the genebank of the Philippines national rice genebank in 2006. “Unfortunately, these kinds of national genebank horror stories are fairly common place,” said Fowler. “The Svalbard Global Seed Vault makes the CGIAR’s genebank collections safer than ever.”

After the Asian tsunami disaster of 2004, the CGIAR-supported International Rice Research Institute (IRRI) used its collections to provide farmers with rice varieties suitable for growing in fields that had been inundated with salt water. The genebank at the CGIAR-supported International Center for Tropical Agriculture (CIAT) in Palmira, Colombia was instrumental in providing bean varieties to farmers in Honduras and Nicaragua in the aftermath of Hurricane Mitch in 1998.

According to Geoff Hawtin, Acting Director General of CIAT and former executive director of the Rome-based Global Crop Diversity Trust, “The shipments going to Svalbard from the CGIAR genebanks are a vital measure for further safeguarding the world’s crop collections. With coming climatic changes, higher food prices, and expanding markets for biofuels, our best available options for progress, if not survival, will be in what we have conserved and studied against all thinkable predictions.”