Dispatches

Abstract

On January 20, the President of the Republic of Congo fulfilled a promise made more than a decade ago by officially expanding the Nouabalé-Ndoki National Park to include a unique ecosystem known as the Goualougo Triangle. “With the stroke of a pen, President Denis Sassou-Nguesso made a significant and lasting step toward the conservation and protection of biodiversity in his country by granting protected status to the Goualougo Triangle, a key conservation area and stronghold of great ape research in the Congo Basin”, says Crickette Sanz – who, along with David Morgan, heads the Goualougo Triangle Ape Project (Nouabalé-Ndoki National Park, Republic of Congo). Home to a diverse ape population first discovered in 1989 by Wildlife Conservation Society (WCS) scientists, the Goualougo Triangle is a dense, lowland forest that – according to WCS – is a pristine area teeming with gorillas and forest elephants, as well as “naïve” chimpanzees, so-called because of their lack of contact with humans. “In spite of some selective logging, the area remains one of the most important, intact, and spectacular forests and wildlife habitats in Africa”, says James Deutsch, WCS Executive Director for Africa Programs (New York, NY). “Within Ndoki, this is really the fragile Eden.” Goualougo chimpanzees are unafraid of humans. The recent move expands the Nouabalé-Ndoki National Park by more than 8%, from 1492 to 1636 square miles (386 426 to 423 722 ha). “To put this in perspective”, explains Morgan, “the [newly protected] area (144 square miles [37 295 ha]) is more than seven times larger than the Gombe Stream National Park in Tanzania (20 square miles [5179 ha]), where scientists have studied chimpanzees for the past 50 years. This provides one of the last opportunities to study wild chimpanzees in a vast, intact landscape.” WCS partners with researchers and the Congolese Government to deploy ecoguards and educate local communities. The local timber company Congolaise Industrielle du Bois also cooperated by surrendering its legal right to harvest timber from the area. Deutsch concludes, “We all need to recognize that – when the government and a logging company agree not to exploit a place like Goualougo, and when local communities agree not to hunt there but instead to protect the wildlife – a real sacrifice is being made for the sake of biodiversity, a common good that benefits all of us on Earth. We, the global community, need to repay this debt, and at the very least provide the resources necessary to manage and protect this jewel.” Every year, millions of shorebirds flock to the world's river deltas and tidal mudflats to gobble up worms, clams, crustaceans, and insects. However, previous research on intertidal food webs has suggested that such prey do not represent the complete diet of shorebirds; now, a new study shows that the mud itself contains a critical nutritional link – biofilm – on which shorebirds depend (Ecol Lett 2012; doi:10.1111/j.1461-0248.2012.01744.x). As bacteria and diatoms settle out of seawater in intertidal zones, they secrete mucus that binds them to mud, creating a layer of paper-thin biofilm. Robert Elner, an Emeritus Scientist with Environment Canada (Vancouver), discovered previously that migrating western sandpipers feed on biofilm at Roberts Banks, south of Vancouver, in an area devoid of invertebrate prey. In the current study, Elner and his colleagues examined the feeding habits of three widely distributed species – western sandpipers, dunlins, and red-necked stints – at six intertidal sites in Japan and Canada. Using high-speed video cameras, the team observed the birds scraping biofilm off of the mud using their tongues, which are covered in fine hairs. Analysis of the birds' droppings revealed that energy-rich biofilm made up a large part of their nutritional intake. To determine the prevalence of this behavior among shorebirds, the team microscopically examined the mouth-parts of 30 different species, finding that nearly three-quarters had feeding apparatus that resemble those of the sandpipers. “It's not just western sandpipers, it's all small shorebirds worldwide that are doing this”, explains Elner. The importance of biofilm in a shorebird's diet depends on availability, environmental conditions, and the bird's body size; small shorebirds may at times feed exclusively on biofilm – which overall may account for more than two-thirds of their diet, according to the researchers – while larger birds probably ingest smaller amounts but also feed on invertebrates that consume it. The connection between shore-birds and biofilm reveals a long-sought missing link in intertidal food webs – one that raises serious conservation concerns. Development projects, such as the construction of port facilities, decimate biofilm-rich habitat and thus may have detrimental impacts on shore-birds. “Worldwide declines in shore-bird populations raise an alarm for far-reaching effects on the stability of whole ecosystems”, the researchers warn. In the midst of skyrocketing automobile ownership in China, a new study assesses the environmental and health risks and finds that, surprisingly, electric cars (e-cars) recharged by energy derived from coal-fired power plants contribute higher levels of fine particulate matter (PM2.5, emissions <2.5 microns in diameter) pollution than do conventional vehicles (CVs; gasoline and diesel cars and buses; Environ Sci Technol 2012; doi:10.1021/es202347q). In the past decade, the popularity of electric vehicles (EVs; both e-cars and electric bikes [e-bikes]) in China has risen sharply, paralleling rising personal income levels. While other studies focus on greenhouse-gas emissions, this research seeks to fill a knowledge gap by examining primary PM2.5 pollution, which presents a threat to human health due to the particles' small size. As Christopher Cherry, a professor of Civil and Environmental Engineering at the University of Tennessee (Knoxville), reports, “E-cars use a lot of energy, and in many regions of China, [energy comes from] the unregulated, lower-quality coal power plants. On average, e-cars emit ~19 times more primary PM2.5 per kilometer than gasoline cars”. Pollution from e-cars comes predominantly from coal-fired power plant emissions, whereas CV-based pollution originates primarily from tailpipe emissions. This presents a spatial discrepancy, where CV emissions are typically closer to urban centers than e-car emissions. According to Cherry, this “distance advantage” of e-car emissions reduces the health impacts of e-cars in urban areas, although the overall impacts are still higher than those of CVs. The location of EV emissions away from urban centers may result in a general decline in health impacts because they reach fewer people; however, health risks may be transferred to rural, low-income populations that do not benefit from urban EVs, adding to the complexity of the problem. Among all vehicle types tested, e-bikes showed the lowest associated environmental and health risks. As China and other industrializing nations increase regulation of power plants, the emissions trends are likely to shift. Explains Cherry, “In the longer term, the power sector will clean up and [EVs] will be cleaner, which is a huge advantage over [CVs] – in other words, clean up one power plant instead of thousands of cars”. A new deep-sea internet cable stretching from Australia to Los Angeles will be embedded with seismographs and other sensors, in order to fill enormous gaps in the knowledge of this remote part of the Earth. “Most seismographs are on land, even though most of the planet is covered by ocean”, points out geophysicist John Orcutt of the Scripps Institution of Oceanography (La Jolla, CA). Ports on the 13 000-km cable will also accommodate climate instruments to assess ocean warming as well as hydrophones to capture sounds from whales and other marine mammals. This is the first such partnership between ocean researchers and a commercial telecommunications company (TE SubCom; Morristown, NJ). “They came to us, which was a bit of a surprise. Companies have always been reluctant to outfit commercial cables with scientific instruments because of service disruptions”, Orcutt explains. The team, which includes researchers at the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory (Seattle, WA), will minimize this risk by separating the cable's commercial and scientific components. Testing of a prototype is expected to be underway within a year. Timely seismic data will help more people survive tsunamis. One advantage of the fiber-optic cable is that it will power the sensors. “Right now we rely on batteries, which limits the instruments you can use”, notes Orcutt. Another benefit is that the cable will transmit information in seconds. Near-real-time seismic data are key to tracking the size and direction of tsunamis in the Pacific Ocean, which will help provide earlier and more accurate coastal alerts. In contrast, current seafloor seismographs do not transmit the data they collect. “We bring them up after about a year, which is not timely for warnings”, observes Orcutt, who chaired a 2011 National Research Council report concluding that the US is ill-prepared for tsunamis. The seismic sensors will also yield a better understanding of the inner workings of the planet, from the crust to the core. Says Orcutt, “Data from the Earth's movements give us something like a CAT scan. We can see tectonic plates that dove under each other millions of years ago, which lets us track the Earth's evolution”. Data from the cable will be open access and thus available to researchers worldwide, and TE Sub-Com ultimately plans to install sensor-embedded cables across all of the world's major oceans. “This will mean a huge leap in the quantity and quality of deep-sea data, which will improve our images of the Earth”, Orcutt concludes. New research that compares ancient and modern DNA sequences suggests that king penguins (Aptenodytes patagonicus) on Macquarie Island in the sub-Antarctic have regained their past levels of genetic variation after intense human exploitation in the 19th and early 20th centuries. “These penguins recovered their genetic diversity surprisingly quickly”, explains researcher Tim Heupink (Griffith University, Nathan, Australia). This quick recovery, he suggests, “may be because the major threat the penguins faced – human exploitation – was completely removed”. When Macquarie Island was discovered in 1810, hundreds of thousands of king penguins were living there, in two large colonies. By 1894, one colony was gone and the other had been reduced to about 3400 birds. “Early human settlers boiled the birds to death”, explains Heupink, “chucking thousands of them into steam digesters to extract their blubber oil”. They may look the same, but these king penguins are genetically diverse. Blubber extraction on Macquarie Island ended in 1920, the island was declared a wildlife sanctuary in 1933, and penguin numbers are now back to pre-exploitation levels. But what about genetic diversity? Heupink and his colleagues sequenced part of the mitochondrial hypervariable region of 18 ancient DNA samples extracted from 1000-year-old king penguin bones excavated on the island and 17 DNA samples from modern carcasses. The ancient and modern populations, the researchers report, are closely related and show a similar degree of genetic variance (Biol Lett 2012; doi:10.1098/rsbl.2012.0053). “This study shows how genetic methods that rely on ancient DNA can be used to give us a glimpse into the recent past”, comments Craig Millar (University of Auckland, New Zealand), who studies molecular ecology and evolution. “The speed of recovery of pre-exploitation levels of genetic variation is likely due to the penguin population only being in a ‘population bottleneck’ for a short time”, he adds. Indeed, suggests Mark Hauber (City University of New York, NY), who studies the evolution of bird behavior, “the population bottleneck may actually have been so short that the penguins never really lost their genetic diversity”. Importantly, all three researchers conclude, these results indicate that – if managed correctly – even populations close to extinction can quickly recover both their numbers and levels of genetic diversity. On March 1, the European Commission's Joint Research Centre (JRC) released an extensive report, Renewable Energies in Africa, that details how African countries use renewable energy, and how this could be expanded sustainably in the future. “Our maps show not only the current infrastructure of the electricity grid across the continent, but also the individual contributions and potential of biomass, wind, solar, and hydroelectric power”, explains Fabio Monforti-Ferrario, editor of the report and Action Leader of Renewable Energy Mapping and Monitoring at the JRC (Ispra, Italy). Africa still currently has a predominantly rural population, with close to 60% of people living outside urban networks. Around 600 million people – approximately 58% of the continent's entire population – have no access to electricity; of the rural population in sub-Saharan Africa, nearly 99% lack electricity. “Africa definitely has the potential to expand its use of renewable energy, and our data suggest how renewable resources and technology can be deployed to meet the long-standing demand for rural access to energy generally, and electricity particularly”, continues Monforti-Ferrario. He stresses, however, that if renewable energy exploitation is going to be effective, the technology must be developed from within Africa itself. “A key vehicle for knowledge transfer will be the Africa–EU [European Union] Strategic Partnership on Energy, which was set up at the 2007 EU–Africa Summit in Lisbon [Portugal]”, he continues. Monforti-Ferrario believes that different types of renewable energy will play different roles in Northern Africa and in the sub-Saharan regions, pointing out that “in Northern Africa, renewable energies have to compete with cheap and often heavily subsidized fossil fuels within the context of a mature infrastructure”. The lack of a grid infrastructure in rural areas is a problem; the grid in outlying areas is usually overloaded and unreliable, characterized by frequent power outages. “In these areas, it is unlikely that future investment could ever achieve expansion of the grid to a national level”, says Monforti-Ferrario. The main challenges in sub-Saharan areas involve making current methods more sustainable and reversing the net loss in wood resources that is already apparent because of the increased demand for wood fuel and charcoal. “Solar power will also be important. In many rural areas, establishing a stand-alone photovoltaic solar generator has been estimated to be more convenient than the current ‘typical’ solution of putting one or more diesel generators in the village”, he adds. To meet current US biofuel targets using current technology, about 80% of existing US cropland would have to be used to grow corn or other crops for ethanol production, according to a recent study (Environ Sci Technol 2012; doi:10.1021/es203935d). Alternatively, 60% of available rangeland could be converted to growing bio-fuel crops. In their analysis, the authors set out to determine the realistic US capacity for bioenergy production, noting that the US Energy Independence and Security Act of 2007 aims to increase domestic ethanol biofuel production from 40 billion liters in 2009 to 136 billion liters by 2022. To approximate how much biofuel the nation can actually produce, the authors estimated potential yields by analyzing fine-grained satellite and meteorological data across all vegetated land in the US and concluded that potential yields are much lower than previous estimates. For example, the potential to increase production through agricultural expansion is roughly five times lower than earlier estimates cited by the US Government and the UN when justifying biofuel policy goals. According to lead author Bill Smith (University of Montana, Missoula), potential rangeland yield was calculated at 3.4–10.6 megajoules per square meter per year – or less than one-third of previous US Department of Agriculture estimates. Therefore, to reach existing bioenergy targets, vast areas currently used for growing food crops or for grazing would have to be converted to biofuel crops – an unlikely prospect. Smith explains: “On the basis of the large amounts of rangeland or agricultural productivity that would need to be dedicated to bioenergy, we feel that the targets are unrealistic under current technology.” Smith believes that the majority of previous studies greatly overestimate potential productivity, by basing theoretical average yields on a handful of field-measured values and then extrapolating those values across large areas presumed to be homogeneous. In reality, variations in temperature and precipitation greatly reduce actual productivity. “These yield potentials are unrealistic because they do not adequately account for geographic variability of biophysical factors”, he explains. “While details such as feedstock type and energy conversion technology may change in the future, we feel it is unlikely that the bioenergy potential will exceed our reported range.” The authors also showed that converting large areas of agricultural land or rangeland to biofuel production could have far-reaching consequences, including driving up global food prices, increasing pollution due to agricultural fertilizer runoff, and intensifying demand for scarce water resources. In Australia's capital, Canberra, eastern grey kangaroos (Macropus giganteus) are a common sight, hopping down roads and grazing in parks and gardens. Yet for all its charm, it's an uneasy coexistence – with the safety of both animals and people at stake. “Canberra is the only place where large numbers of kangaroos and large numbers of people coexist, so there is unique potential for conflict in various areas”, explains ecologist Don Fletcher (Australian Capital Territory Government, Canberra). Not least is the need to protect the remnants of imperiled grassland and woodland communities in some of the city's 40 or so nature reserves; less than 1% of natural temperate grassland remains across Australia. “But these are also fantastic areas for kangaroos, with no predators now that dingoes have disappeared from settled areas”, Fletcher says. “So kangaroo numbers can become high enough to eat these grassy ecosystems to such an extent that there's little food or shelter for reptiles.” Canberra's urban kangaroos pose a management challenge. Annual culls are undertaken for conservation purposes, but while surveys show most residents accept these actions as necessary, animal rights activists respond with angry protests and court action. Research is underway into alternatives. Trials with an injected contraceptive have been promising; the ultimate goal is an oral form. In the meantime, urban kangaroos have been fitted with GPS collars in a 12-month study to learn more about their natural behavior and to help reduce the nearly 6000 collisions per year between cars and roos. “With a population of only 300 000 people in Canberra, that is a high collision rate by anyone's standard”, continues Fletcher. The surprise finding was an aspect of road sense. “The same roos that readily entered suburban streets were wary of 80–100 kilometer per hour roads. Where roos face predators, they venture farther at night into risky areas, and we saw the same instinct in urban roos. The anomaly is, if roos have some road sense, why do they get run over? We lost a third of the males in our study to cars, so perhaps cars are a stronger population-limiting factor than we realized. Maybe the car is partly replacing the dingo?” Some results of prairie restoration are easier to see than others. When cornfields are replaced with native grasses and wildflowers, for example, most observers notice the blooming flowers and the spreading grasses. What's harder to see, however, are the impacts that restoration can have on water quality, when chemical fertilizer application stops. So when a team of researchers from the US Department of Agriculture's (USDA's) Agricultural Research Service learned that a corn and soybean field – near Iowa's Neal Smith National Wildlife Refuge – was soon to be returned to prairie, they jumped on the chance to monitor changes in the adjacent waterways. The group, led by Mark Tomer (Ames, Iowa), began to study groundwater at the 6.8-ha field in 2002 by taking their first samples just before the area was converted from corn and soybean row-cropping into reconstructed prairie. Some of their results were highlighted in the most recent edition of the USDA's Agricultural Research magazine. The team found that the nitrate levels declined and stabilized in 5 years. This was due, he says, to two factors: the amount of carbon available and the depth of the water table. Areas where the soil was saturated tended to be rich in carbon, which helped to denitrify the water fairly rapidly – sometimes within one growing season. Drier, upland areas have less available carbon. “The nitrate loss in these areas occurred more slowly”, he explains. Prairie restoration doesn't always restore water quality, since “legacy nutrients” may endure. Phosphorus levels, however, did not decline in the same manner as the nitrates. Between 2006 and 2009, concentrations averaged between 0.02 and 0.14 parts per million – sometimes reaching levels high enough to threaten local water quality. The higher concentrations were mainly found in shallow groundwater and along ephemeral waterways. Understanding these nutrients is key to both local and national water issues; high phosphorus concentrations can be dangerous or detrimental to wildlife and humans, and high nitrate levels in the US Midwest are known to fuel the development of the “dead zone” downstream in the Gulf of Mexico. Andrew Sharpley (University of Arkansas, Fayetteville) points out that what is most important about Tomer's research is the documentation of the problem. People often assume that nitrogen and phosphorus will decrease if we revert to pre-agricultural conditions, Sharpley says, “but we can't just go on good faith”. This research may eventually help farmers manage for water quality, even when the fields they own remain in crop rotation. In 2008, biologists with the Illinois Natural History Service Prairie Research Institute who were monitoring a small population of eastern massasauga rattlesnakes (Sistrurus catenatus catenatus) in southern Illinois captured three individuals with extensive lesions, ulcers, and swellings on their heads; all three died within weeks of their discovery. A fourth snake exhibiting similar deformities was found in the same area in 2010. Already a candidate for protection under the US Endangered Species Act, the eastern massasauga – and possibly other snake species as well, scientists worry – may now be facing a new and potentially deadly threat. Matt Allender, a wildlife veterinarian in the Department of Comparative Biosciences at the University of Illinois at Urbana-Champaign (Urbana, IL), performed necropsies on the affected snakes and identified a fungus, Chrysosporium sp, as the pathogen causing the deformities. While uncommon in captive reptiles, infection by Chrysosporium is extremely rare in wild populations. “There is no clear evidence of where this infection originated”, explains Allender. “It is likely a soil contaminant, and either was recently introduced to the soil or has always been there and something has caused the snakes to be susceptible now.” Allender suggests that environmental stressors may have weakened the snakes' immune systems, rendering them more vulnerable to infection; alternatively, habitat loss may have facilitated the spread of the fungus by forcing snakes into closer contact. The findings were reported in the December 2011 issue of Emerging Infectious Diseases (doi:10.3201/eid1712.110240). Fungal pathogens have been associated with several wildlife epidemics in recent years, most notably as the causative agents of the chytridiomycosis pandemic that has devastated frog populations and the white-nose syndrome that has decimated cave-dwelling bat colonies throughout eastern North America. Some biologists are concerned that snakes may be the next victims of a similar fungal epidemic. “The big fear is that this [Chrysosporium infection] is spreading or occurring in several locations and going undiagnosed due to the lack of monitoring of snake populations”, says Allender, who adds that similar deformities have been observed in several snake species in other parts of the US. “We could lose a tremendous amount of biodiversity before even knowing that this has happened.”