April 22, 2013
Anyone who has read a Richard Preston book, such as The Hot Zone or Panic in Level 4, knows the danger of tampering with wildlife. The story usually goes something like this: Intrepid explorers venture into a dark, bat infested cave in the heart of East Africa, only to encounter something unseen and living, which takes up residence in their bodies. Unknowingly infected, the happy travelers jump on a plane back to Europe or the States, spreading their deadly pathogen willy-nilly to every human they encounter upon the way. Those people, in turn, bring the novel virus or bacterium back home to strangers and loved ones alike. Before the world knows it, a pandemic has arrived.
This scenario may sound like fiction, but it’s exactly what infectious disease experts fear most. Most emerging infectious diseases in humans have indeed arisen from animals–think swine and bird flu (poultry and wild birds), SARS (unknown animals in Chinese markets), Ebola (probably bats) and HIV (non-human primates). Therefore, experts prioritize the task of figuring out which animals in which regions of the world are most prone to delivering the latest novel pathogen to hapless humanity.
With this in mind, researchers at Harvard University, the University of Granada and the University of Valencia set out to develop a new strategy for predicting the risk and rise of new diseases transmitted from animals before they happen, describing their efforts in the journal Proceedings of the National Academy of Sciences.
To narrow the hypothetical disease search down, the team chose to focus on non-human primates. Because monkeys and great apes are so closely related to us, their potential for developing and transmitting a pathogen suited to the human body is greater than the equivalent risk from animals such as birds or pigs. As a general rule, the more related species are, the greater the chances they can share a disease. The researchers gathered data from 140 species of primates. They overlaid that information with more than 6,000 infection records from those various primate species, representing 300 different pathogens, including viruses, bacteria, parasitic worms, protozoa, insects and fungus. This way, they could visualize which pathogens infect which species and where.
Like mapping links between who-knows-who in a social network, primates that shared pathogens were connected. This meant that the more pathogens an animal shared with other species, the more centrally located it was on the tangled web of the disease diagram.
From studying these charts, a few commonalities emerged. Animals at the center of the diagram tended to be those that lived in dense social groups and also covered a wide geographic range (yes, similar to humans). These species also tended to harbor parasites that are known to infect humans, including more pathogens identified as emerging infectious diseases. In other words, those species that occurred in the center of the diagram are the best positioned to kick off the next pandemic or horrific infectious disease, and thus should be the ones that experts should keep the closest watch on.
Such animals could qualify as “superspreaders,” or those that receive and transmit pathogens very often to other species.”The identification of species that behave as superspreaders is crucial for developing surveillance protocols and interventions aimed at preventing future disease emergence in human populations,” the authors write.
Apes appeared in the heart of the disease diagram and are among the species we should be most worried about, which is not surprising considering that diseases such as malaria and HIV first emerged from these animals. On the other hand, some non-ape primates, including baboons and vervet monkeys, also popped up in the center of the diagram and turn out to harbor many human emerging disease parasites.
Currently, our ability to predict where, when and how new emerging infectious diseases might arise is “remarkably weak,” they continue, but if we can identify those sources before they become a problem we could prevent a potential health disaster on a regional or even global scale. This new approach for identifying animal risks, the authors write, could also be applied to other wildlife groups, such as rodents, bats, livestock and carnivores. “Our findings suggest that centrality may help to detect risks that might otherwise go unnoticed, and thus to predict disease emergence in advance of outbreaks—an important goal for stemming future zoonotic disease risks,” they conclude.
April 17, 2013
When Alexandra Cousteau, granddaughter of Jacques, recently went to Mexico to explore the southern terminus of the Colorado River, she found mud, sand and dust where water once raged. The expedition was videotaped for a short film (viewable below) produced in conjunction with Cousteau’s nonprofit, Blue Legacy, which raises awareness about water issues. The video was called Death of a River: The Colorado River Delta.
That title, it turns out, is an apt one: Today, the conservation organization American Rivers released its annual ranking of America’s most endangered rivers, and the Colorado topped the list.
The group cites outdated water management as the main malady attacking the Colorado’s health. “A century of water management policies and practices that have promoted wasteful water use have put the river at a critical crossroads,” a statement (PDF) released by the organization reads. “Demand on the river’s water now exceeds its supply, leaving the river so over-tapped that it no longer flows to the sea.”
At one time, the river emptied into the Gulf of California, between mainland Mexico and the Baja Peninsula. In fact, this river mouth can still be found on maps, including Google’s, because it’s supposed to be there. But a recent study (PDF) conducted by the Bureau of Reclamation (a division of the U.S. Department of Interior) determined that the entire river and its tributaries are siphoned off to meet the drinking, bathing and toilet-flushing needs of 40 million Americans throughout seven states, including Arizona, California, Colorado, New Mexico, Nevada, Utah, and Wyoming. It also irrigates 5.5 million acres of land and helps meet the electrical-power appetite of much of the West through hydro-power facilities. Nearly two dozen Native American tribes depend on it, and it’s the centerpiece of 11 national parks,
most famously the Grand Canyon.
“Growing demands on the Colorado River system, coupled with the potential for reduced supplies due to climate change may put water users and resources relying on the river at risk of prolonged water shortages in the future,” the study authors write. “Ultimately,” they add, “the Study [sic] is a call to action.”
But what action is needed? Water conservation, water reuse and water augmentation–replacing water drawn from wells–the authors say. Specifically, landowners and municipalities must boost their agricultural, municipal and industrial water conservation agendas, as well as improve their energy water-use efficiency. Solutions for the most challenging regions include finding ways to import water, reuse waste water and desalinize ocean and brackish water.
Scientists acknowledge some solutions they’ve looked into are easier said than done and that not all are viable in every region. For instance, options like importing water to Southern California via submarine pipelines, water bags and icebergs (PDF), along with watershed management techniques like weather modification (aka cloud-seeding) are a bit pie-in-the-sky.
The Colorado isn’t the only endangered river, by far. Georgia’s Flint River, the San Saba River in Texas, Wisconsin’s Little Plover River, the Catawba River in the Carolinas and Minnesota’s Boundary Waters were all also red-flagged by American Rivers this year.
The challenge for all of these rivers, including the Colorado, only grows in the future. Climate-change-induced drought is working against them. American Rivers notes (PDF) that changes to climate are expected to reduce the Colorado River’s flow by as much as 10 to 30 percent by the year 2050. It could leave yet more sand and mud behind, making parts of the American West and Southwest even more parched.
April 5, 2013
In the aftermath of Superstorm Sandy last fall, New York Governor Andrew Cuomo joked to President Barack Obama that New York “has a 100-year flood every two years now.” On the heels of flooding from 2011′s Hurricane Irene and Tropical Storm Lee, it certainly seemed that way. Given that climate change has sparked multiple major storms and raised sea levels, and that urban and agricultural development have impeded our natural flood-management systems, chronic flooding could be here to stay.
Wetlands, which include swamps, lagoons, marshes and mangroves, help mitigate the problem by trapping floodwaters. “Historically, wetlands in Indiana and other Midwestern states were great at intercepting large runoff events and slowing down the flows,” environmental engineer Meghna Babbar-Sebens of Oregon State University said in a recent statement. ”With increases in runoff, what was once thought to be a 100-year flood event is now happening more often.”
One key problem is that most of our wetlands no longer exist. By the time the North American Wetlands Conservation Act (PDF) was passed in 1989, more than half of the wetlands in the United States had been paved over or filled in. In some states, the losses are much greater: California has lost 91 percent of its wetlands, and Indiana, 85 percent. In recent years, scientists have been honing the art of wetlands restoration, and now a recent study published in the journal Ecological Engineering by scientists at Oregon State University is helping to make new wetlands easier to plan and design.
The research focused on Eagle Creek Watershed, ten miles north of Indianapolis, and identified nearly 3,000 potential sites where wetlands could be restored or created to capture runoff. Through modeling, the scientists discovered that a little wetland goes a long way. “These potential wetlands cover only 1.5% of the entire watershed area, but capture runoff from 29% (almost a third) of the watershed area,” the study authors wrote.
Their next step was to begin developing a web-based design system to allow farmers, agencies and others to identify areas optimal for new or restored wetlands and to collaborate in designing them. The recently launched system, called Wrestore, uses Eagle Creek as a test-piece.
The tool has a variety of functions: It helps identify a region’s rivers and streams, divides watersheds into smaller sub-watersheds and shows where runoff is likely to collect—places conducive to building wetlands. If a city wants to reduce flooding in its watershed, the site’s interactive visualization engine displays various conservation options and allows groups of city planners to collaborate on the design of new wetlands.
“Users can look at various scenarios of implementing practices in their fields or watershed, test their effectiveness via the underlying hydrologic and water quality models, and then give feedback to an ‘interactive optimization’ tool for creating better designs,” Babbar-Sebens, lead author of the study and the lead scientist on the web tool, told Surprising Science.
It provides an easy way for landowners to tackle such environmental challenges. “The reason we used a web-based design system is because it gives people the flexibility to try and solve their problems of flooding or water quality from their homes,” Babbar-Sebens said.
As the spring flood season approaches and environmental degradation continues throughout the nation, a new tool for mitigating wetland loss with targeted, minimal wetland gain is certainly a timely innovation. Babbar-Sebens and her team have been testing it out on Eagle Creek Watershed and will be fine-tuning it throughout the spring. ”There is a lot of interest in the watershed community for something like this,” she said.
March 27, 2013
Imagine a 100-million-ton mass of rock, soil, mud and trees sliding off a mountain 30 miles from a major city, and no one knowing that it happened until days later.
Such was the case after Typhoon Morakot hit Taiwan in 2009, dumping around 100 inches of rain in the southern regions of the island over the course of 24 hours. Known as the Xiaolin landslide, named for the village it hit and obliterated, the thick carpet of debris it left behind smothered 400 people and clogged a nearby river. Though only an hour’s drive outside of the crowded city of Tainan, officials didn’t know about the landslide for two days.
“To be that close and not know that something catastrophic had happened is just amazing,” notes Colin Stark, a geomorphologist at the Lamont-Doherty Earth Observatory (LDEO). But now, “seismology allows us to report on such events in real time.” Research published last week in Science by Stark and lead author Göran Ekström, an LDEO seismologist, show that scientists armed with data from the Global Seismographic Network can not only pinpoint where a large landslide occurred, but also can reveal how fast the churning mass traveled, how long it ran out, its orientation within the landscape and how much material moved.
All this can be done remotely, without visiting the landslide. Moreover, it can be done quickly, in stark contrast to the more tedious methods typically used to estimate characteristics of a landslide. In the past, scientists had to wait for reports of a landslide to filter back to them, and once alerted they searched for photos and satellite images of the slide. If they could, they coordinated trips to the landslide tongue—well after the event—to estimate the mass of disturbed rock.
But the new method puts landslide detection and characterization in line with how scientists currently track earthquakes from afar. Just as seismometers tremble when energy from a strong quake hits their locations, allowing seismologists to determine the precise location, depth and direction of rupture as well as the amount of energy released during the quake and the type of fault tectonic plates slid along, these same seismometers move during a landslide. The shaking isn’t the frenetic twitches typically seen in seismographs of earthquakes or explosions—the signatures are long and sinuous.
Ekström and colleagues have spent many years combing through reams of seismic data in search of unusual signatures that can’t be traced to typical earthquakes. Previously, their work on seismic signatures in tectonically dead Greenland classified a new type of shaking, called “glacial earthquakes.” But the genesis of the recent research on landslides can be traced back to Typhoon Morakot.
After the storm hit Taiwan, Ekström noticed something strange on global seismic charts—their wiggles indicated that a cluster of events, each with shaking exceeding a magnitude 5 earthquake, had occurred somewhere on the island. “Initially, no other agency had detected or located the four events that we had found, so it seemed very likely that we had detected something special,” Ekström explained. A few days later, news reports of landslides—including the monster that swept through Xiaolin—began to pour in, confirming what the scientists hypothesized about the events’ source.
Equipped with seismic data from the Xiaolin landslide, the authors developed a computer algorithm to search for telltale seismic signatures of large landslides in past records and as they happened. After collecting information from the 29 largest landslides that occurred around the world between 1980 and 2012, Ekström and Stark began to deconstruct seismic wave energies and amplitudes to learn more about each.
The guiding principles behind their method can be traced to Newton’s third law of motion: for every action, there is an equal and opposite reaction. “For instance, when rock falls off a mountainside, the peak is suddenly lighter,” explains Sid Perkins of ScienceNOW. The mountain “springs upward and away from the falling rock, generating initial ground motions that reveal the size of the landslide as well as its direction of travel.”
Looking across all their analyses, Ekström and Stark find that, regardless of whether the landslide was triggered by an erupting volcano or a scarp saturated with rainwater, landslide characteristics are governed by the length of the mountainside that broke off to start the landslide. This consistency hints at hitherto elusive broad principles that guide landslide behavior, which will help scientists to better assess future hazards and risk from failing slopes.
For those who study landslides, the paper is seminal for another reason. David Petley, a professor at the U.K.’s Durham University, writes in his blog that “we now have a technique that allows large landslides to be automatically detected. Given that these tend to occur in very remote areas, they often go unreported.”
Petley, who studies landslide dynamics, wrote a companion piece to Ekström’s and Stark’s paper, also published in Science, that provides a bit of perspective to the new results. He notes that “the technique currently overdetects large, fast landslides by an order of magnitude, requiring considerable work, for example, with satellite imagery to filter out the false-positive events. Nevertheless, it opens the way to a true global catalog of rock avalanches that will advance understanding of the dynamics of high mountain areas. It may also enable the real-time detection of large, valley-blocking landslides, providing a warning system for vulnerable communities downstream.”
The insight gained by Ekström’s and Stark’s method is readily seen in a striking example of a landslide that occurred in northern Pakistan in 2010. Satellite images of debris flow, which is spread on the flanks of the Siachen Glacier, suggest that the event was triggered by one, maybe two episodes of slope failure. However, Ekström and Stark show that the debris slid from seven large landslides over the course of a few days.
“People rarely see large landslides happen; they typically only see the aftereffects,” Ekström notes. But thanks to him and his co-author, scientists around the world can now quickly get a first glance.
March 6, 2013
Locusts have plagued farmers for millennia. According to the Book of Exodus, around 1400 B.C. the Egyptians experienced an exceptionally unfortunate encounter with these ravenous pests when they struck as the eighth Biblical plague. As Exodus describes, “They covered the face of the whole land, so that the land was darkened, and they ate all the plants in the land and all the fruit of the trees that the hail had left. Not a green thing remained, neither tree nor plant of the field, through all the land of Egypt.”
Locusts attacks still occur today, as farmers in Sudan and Egypt well know. Now, farmers in Israel can also join this unfortunate group. Earlier today, a swarm of locusts arrived in Israel from Egypt, just in time for the Jewish Passover holiday which commemorates Jews’ escape from Egyptian slavery following the ten Biblical plagues. “The correlation with the Bible is interesting in terms of timing, since the eighth plague happened sometime before the Exodus,” said Hendrik Bruins, a researcher in the Department of Man in the Desert at Ben-Gurion University of the Negev in Israel. “Now we need to wait for the plague of darkness,” he joked.
While the timing is uncanny, researchers point out that–at least in this case–locust plagues are a normal ecological phenomenon rather than a form of divine punishment. “Hate to break it to you, but I don’t think there’s any religious significance at all to insects in the desert, even a lot of them, and even if it seems reminiscent of a certain Biblically described incident,” said Jeremy Benstein, deputy director of the Heschel Center for Sustainability in Tel Aviv.
In this region of the world, locusts swarm every 10 to 15 years. No one knows why they stick to that particular cycle, and predicting the phenomena remains challenging for researchers. In this case, an unusually rainy winter led to excessive vegetation, supporting a boom in locust populations along the Egyptian-Sudanese border. As in past swarms, once the insect population devours all of the local vegetation, the hungry herbivores take flight in search of new feeding grounds. Locusts–which is just a term for the 10 to 15 species of grasshoppers that swarm–can travel over 90 miles in a single day, carried by the wind. In the plagues of 1987 and 1988 (PDF)–a notoriously bad period for locusts–some of the befuddled insects even managed to wash up on Caribbean shores after an epic flight from West Africa.
When grasshoppers switch from a sedentary, solo lifestyle to a swarming lifestyle, they undergo a series of physical, behavioral and neurological changes. According to Amir Ayali, chair of the Department of Zoology at Tel Aviv University, this shift is one of the most extreme cases of behavioral plasticity found in nature. Before swarming, locusts morph from their normal tan or green coloring to a bright black, yellow or red exoskeleton. Females begin laying eggs in unison which then hatch in synch and fuel the swarm. In this way, a collection of 1 million insects can increase by orders of magnitude to 1 billion in a matter of months.
From there, they take flight, though the exact trigger remains unknown. Labs in Israel and beyond are working on understanding the mathematics of locust swarming and the neurological shifts behind the behaviors that make swarming possible. ”If we could identify some key factors that are responsible for this change, we could maybe find an antidote or something that could prevent the factors that transform innocent grasshoppers from Mr. Hyde to Dr. Jekyll,” Ayali said. “We’re revealing the secrets one by one, but there’s still so much more to find out.”
A swarm of locusts will consume any green vegetation in its path–even toxic plants–and can decimate a farmer’s field almost as soon as it descends. In one day, the mass of insects can munch its way through the equivalent amount of food as 15 million people consume in the same time period, with billions of insects covering an area up to the size of Cairo, Africa’s largest city. As such, at their worst locust swarms can impact some 20 percent of the planet’s human population through both direct and indirect damages they cause. In North Africa, the last so-called mega-swarm invaded in 2004, while this current swarm consists of a measly 30 to 120 million insects.
Estimating the costs exacted by locusts swarms remains a challenge. While locust swarms reportedly cause more monetary damage than any other pest, it’s hard to put an exact figure on the problem. Totaling the true crost depends on the size of the swarm and where the winds carry it. To be as accurate as possible, costs of pesticides, food provided to local populations in lieu of wrecked crops, monitoring costs and other indirect effects must be taken into account. No one has yet estimated the cost of this current swarm, though the United Nation’s Food and Agriculture Organization (FAO) allots $10 million per year solely to maintain and expand current monitoring operations.
This morning, the Israeli Ministry of Agriculture sprayed pesticides on an area of around 1,000 hectares near the Egyptian border. To quell a plague of locusts, pest managers have to hit the insects while they’re still settled on the ground for the night and before they take flight at dawn. So far, pesticide spraying is the only option for defeating the bugs, but this exacts environmental tolls. Other invertebrates, some of them beneficial, will also shrivel under the pesticide’s deadly effects, and there’s a chance that birds and other insectivores may eat the poisoned insect corpses and become ill themselves. Researchers are working on ways to develop fungus or viruses that specifically attack locusts, but many of those efforts are still in initial investigative stages. However, the company Green Muscle developed a commercially available fungus that affects only locusts.
Even better, however, would be a way to stop a swarm from taking flight from the very beginning. But this requires constant monitoring of locust-prone areas in remote corners of the desert, which is not always possible. And since the insects typically originate from Egypt or Sudan, politics sometimes get in the way of quashing the swarm before it takes flight. “We really want to find them before they swarm, as wingless nymphs on the ground,” Ayali said. “Once you miss that window, your chances of combating them are poor and you’re obliged to spray around like crazy and hope you catch them on the ground.”
In this case, Egypt and Israel reportedly did not manage to coordinate locust-fighting efforts to the best of their abilities. “If you ask me, this is a trans-boundary story,” said Alon Tal, a professor of public policy at Ben-Gurion University. “This is not a significant enemy–with an arial approach you can nip locusts in the bud–but the Egyptian government didn’t take advantage of the fact that they have quite a sophisticated air force and scientific community just to the north.”
Ayali agrees that the situation could have been handled better. He also sees locusts as a chance to foster regional collaboration. Birders and ornithologists from Israel, Jordan and Palestine often cooperate in monitoring migratory avian species, for example, so theoretically locusts could likewise foster efforts. “Maybe scientists should work to bridge the gaps in the region,” Ayali said. “We could take the chance of this little locust plague and together make sure we’re better prepared for the next.”
For now, the Israelis have smote the swarm, but Keith Cressman, a senior locust forecasting office at the FAO’s office in Rome warns that there is still a moderate risk that a few more small populations of young adults may be hiding out in the desert. This means new swarms could potentially form later this week in northeast Egypt and Israel’s Negev region. His organization warned Israel, Egypt and Jordan this morning of the threat, and Jordan mobilized its own locust team, just in case.
For those who do come across the insects (but only the non-pesticide covered ones!), Israeli chefs suggest trying them out for taste. Locusts, it turns out, are the only insects that are kosher to eat. According to the news organization Haaretz, they taste like “tiny chicken wings,” though they make an equally mean stew. “You could actually run out very early before they started spraying and collect your breakfast,” Ayali said. “I’m told they’re very tasty fried in a skillet, but I’ve never tried them myself.”
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