Portal de Periódicos da CAPES

Dispatches

2011; Wiley; Volume: 9; Issue: 4 Linguagem: Inglês

10.1890/1540-9295-9.4.200

1540-9309

ESA,

Wildlife-Road Interactions and Conservation

The first “International Serengeti Day”, held on March 19th, was no happy celebration of the Tanzanian national park's wonders, but a global demonstration against the planned building of a road that will cut straight across the path of one of the greatest migration spectacles on Earth: the mass movement of 1.5 million wildebeest (Connochaetes taurinus) and zebra (Equus quagga) following the seasonal rains. Unfortunately, this is only one of many of the world's protected areas facing peril, bringing into question what “protected” really means. In late January, the Tanzanian Government stated its intention to begin building a 54-km-long, unpaved road to connect the Lake Victoria area west of the Serengeti with the Arusha area east of the park, a project it believes is essential to the country's development. “The Serengeti is a jewel of our nation, as well as for the international community”, Tanzanian President Jakaya Mrisho Kikwete insisted in a press release. “We want to give you our assurances that we cannot be irresponsible by destroying the Serengeti. We will do nothing to hurt the Serengeti, and we would like the international community to know this”. However, he continued, “we cannot deny these people living on the northern side of the Serengeti border a road.” “This road would cut directly across the main wildebeest and zebra migration routes, leading to an environmental disaster”, says Andrew Dobson, a professor in the Department of Ecology and Evolutionary Biology at Princeton University (Princeton, NJ). “Tanzanian predictions suggest traffic loads for this road of 800 vehicles per day by 2015, and 3000 per day by 2035. Night-driving, currently forbidden [in the park], will also be allowed.” Wildebeest migrate across the Serengeti. Since no unpaved road could withstand such traffic, especially in the rainy season, the specter of tarmac looms, and animal collisions would likely become a huge problem. “Fencing would have to follow”, says Dobson, “leading to the migration being cut off, dramatic reductions in the size of wildebeest and zebra herds, and all the knock-on ecological effects that would have on the Serengeti ecosystem, [including] a decline in predators, an increase in grass fires, and more poaching”. An alternative southern route, which both the German government and the World Bank have expressed interest in funding, would be 50 km longer. “But this route could be cheaper to make and would prevent a huge loss of ecotourism revenue from a collapsed migration”, says Dobson. “It would also supply infrastructure to ten times as many people, so economically, ethically, and environmentally, it's a much better deal.” However, Tanzania has rejected the southern route, and flags marking out the original route through the “protected” area are already going in the ground. Construction could begin in 2012. While better news from the Democratic Republic of Congo (DRC) announces that oil exploration will now not proceed in Virunga National Park, it is clear that “protected” doesn't always mean what it should. In a letter dated March 14th sent to WWF and other environmental organizations, and “cc'd” to the DRC's Prime Minister and Parliament, the country's Minister of the Environment José Endun-do wrote: “In view of the threat that oil exploration activities potentially represent for the survival of Virunga National Park, I can confirm to you…the suspension of the given oil exploration activities. We have rejected the recommendations of an environmental impact assessment developed by the oil company, Soco, which we consider premature, superficial, and which does not conform to the standards that we would expect. [I] have also received assurances from senior managers [that they will not] attempt any prospection work in the park unless a positive consensus is achieved in their favor, based on an open and transparent process that takes account of the real costs and benefits of such a project.” The letter does not say “protected” means forever, but it at least provides the park some respite. Recent weeks have provided even more examples of the need to protect “protected” lands. For example, the diversion of water for agriculture from Spain's Doñana National Park, plus plans to make the Guadalquivir River – which flows adjacent to the park – navigable to larger ships, have placed the park's UN World Heritage status at risk, while in the US, a legal battle was required – and fortunately won – to return the Tongass National Forest its protection under the US “roadless rule”. “One might assume that ‘protected’ would mean ‘protected for all time’”, says Paul Racey (Emeritus Regius Professor of Natural History, University of Aberdeen, Aberdeen, UK). “But even now loggers are removing trees from the ‘protected’ forests of Madagascar, and oil companies are looking to drill in Alaska's Arctic Refuge area. And when enough silver changes hands, the definition of ‘protected’ can alter shamelessly. Sadly, since you cannot shame the shameless, the fight to maintain the right definition of ‘protected’ will never be over.” Approximately 51 million people in the Democratic Republic of the Congo (DRC) – 74% of the country's population – lack access to safe drinking water, even though the country holds more than half of Africa's fresh water reserves, according to a new study by the UN Environment Programme (UNEP; http://postconflict.unep.ch/publications/UNEP_DRC_water.pdf). These findings and recommended solutions were presented at an event in Kinshasa, DRC, marking World Water Day, on March 22, 2011. The UNEP report attributes the water crisis to years of mismanagement, conflict, environmental degradation, rapid urbanization, and underinvestment in water infrastructure, calling the networks in DRC “insufficient, aging, and overloaded”. Compounding the problem is the uncontrolled clearing of critical forested watersheds surrounding urban areas for the construction of homes and gardens, the production of crops, and for firewood. Congolese women can spend hours every day fetching water. UNEP's DRC Program Manager, Hassan Partow, says, “Improving the water situation is not only necessary to alleviate the high incidence of water-borne diseases in the DRC, but is equally critical to improving the daily living conditions of DRC's population – particularly women and children – who have to toil several hours every day to fetch water, which is often contaminated. Investing in the water sector is equally important for kick-starting development in a number of key economic sectors, including agriculture, transportation, and energy.” The UNEP report recommends promoting micro-investment strategies, such as communal tap areas and rainwater harvesting, stating that “the development of local solutions can help make significant headway in areas where the government is reluctant, or does not have the capacity, to invest.” Partow continues, “What is needed in the DRC is a broad vision and practical strategies drawing on a mixture of both macro- and micro-solutions, from large-scale infrastructure investments to autonomous community-based water supply systems, which have shown impressive potential in the DRC”. The UNEP report estimates that US$169 million is needed over the next 5 years to implement its recommendations, which include “support to water sector governance reform, technical and institutional capacity-building, and establishing the scientific information base to strengthen water resources management.” That estimate excludes major infrastructure projects. According to Partow, US$500 million has already been committed by donors to the country's water sector, although gaining access to the funding can be a complicated undertaking at the local level. “And this is precisely where UNEP is recommending that the funding should be targeted”, Partow concludes. The war on weeds in California just got easier, thanks to a new smart-phone application – or “app” – that takes much of the drudgery out of reporting and tracking invasive species. The app, which will be available this spring, also maps native plant distributions and could reveal climate-induced vegetation shifts. Called Observer, the app takes advantage of smartphone cameras and GPS capabilities, geo-tagging plant photos and notes for future uploading to an online database via cellular signals. Observer also facilitates plant identification by displaying lists with thumbnail pictures, ranging from all 12 000 taxa statewide, to just the 2000 invasives, to just those invasives within a quarter mile of the user's location. Spearheaded by habitat restoration expert Daniel Gluesenkamp (Audubon Canyon Ranch; Stinson Beach, CA), the app has freed his staff from the nuisance of having to carry cumbersome equipment and software into the field. “We used to have to gear up for mapping, but now the tool is already in our pockets”, he says. Observer is based on What's Invasive!, a simpler app developed by the US National Park Service (NPS) and the Center for Embedded Networked Sensing (CENS). “We took a ‘Top Ten’ approach that lets managers focus citizen-science efforts on their worst invaders, those that are also easily recognized without much training”, explains CENS app developer Eric Graham. What's Invasive! can improve volunteer-collected data, according to NPS vegetation ecologist Robert Steers (San Francisco, CA). “GPS makes the spatial location more accurate, and it's easy to verify the species by looking at the picture”, he points out. “Early detection is critical to controlling invasives, and this app helps us have more eyes on the ground.” Gluesenkamp predicts that the more complex Observer program will increase volunteer contributions to weed control. “We're trying to curate the information”, he explains. “Registration is required and users report their level of botanical expertise, so professionals can choose to include data only from experts or from everyone.” Mapping apps may soon be even more powerful. “My contacts at Google think we're 5 to 10 years away from identifying species just from their photos”, says Gluesenkamp. An international group of researchers has developed a new, eco-friendly method for greatly reducing damage to stored grains by insects and molds. The pesticide-free method could increase global food security while delivering healthier staples to potentially billions of consumers. Post-harvest food losses vary by crop, country, and climatic region, but global estimates range from 10–40% annually, says project collaborator Shlomo Navarro, formerly with the Israeli Agricultural Research Organization (Bet-Dagan, Israel). In developed countries, stored commodities are typically cooled by aeration and treated with fumigants. However, fumigation by methyl bromide, once used widely, is now banned due to its contribution to stratospheric ozone depletion. Moreover, insects have become increasingly resistant to phosphine, another commonly used pesticide. “In the developing world, farmers keep up to 80% of their crops for home consumption, and poor storage methods under warm, humid conditions often lead to major food losses”, says Navarro. In 2006, Maria Otilia Carvalho, a researcher with the Tropical Reearch Institute of Portugal (Lisbon), invited scientists working on alternatives for preserving stored rice to cooperate in devising an integrated pest management (IPM) system that could wean agricultural producers off pesticides. “We combined and improved on known technologies for protecting stored grains – none of which, individually, could duplicate the protective benefits of pesticides”, Carvalho explains. To assess the need for treatments, the team used probes for temperature monitoring and innovative electronic traps to detect insects at a rice mill in Portugal. Ventilation and refrigeration (during winter and summer, respectively) of rice-storage silos reduced insect infestations dramatically. The third tool, applied as needed, was to manipulate the interior atmosphere of the silos by flooding them with CO2 – recycled from an industrial source – to deprive pests and fungi of oxygen. Using this strategy trimmed the mill's losses by approximately 94%, says Carvalho. The results of the study are soon to be published in the International Organisation for Biological Control Bulletin. While the costs for the IPM system will likely remain prohibitive for developing regions with limited infrastructure, Navarro has pioneered the development of gas-tight, plastic bags – now in the early stages of distribution – for grain storage, wherein respiration by pests generates CO2, thus curbing their own populations. “Hermetically sealed bags can allow subsistence farmers to prevent major crop losses and give them the option to hold out for better prices”, he says. The Asian bird flu grabbed headlines in 2005, when it suddenly spread from China and infected poultry in Africa, Europe, and central Asia. This rapid proliferation sparked a debate over whether wild birds might be circulating H5N1, the virus that causes bird flu. Now, a new study provides the first evidence of a mechanism for transmission of the H5N1 virus between domestic farm birds and wild birds. The researchers focused on China's Qinghai Lake National Nature Reserve, a remote wildlife reserve where 6000 birds – mostly bar-headed geese (Anser indicus) – died as a result of an H5N1 outbreak in 2005. “Because Qinghai Lake is far from poultry farms, which are the main reservoir for the disease, we wondered how H5N1 got there”, explains Diann Prosser, a wildlife ecologist with the US Geological Survey (Beltsville, MD). Diann Prosser releases a bar-headed goose fitted with a GPS tracking device. Prosser and her team equipped 29 bar-headed geese at the Qinghai Lake breeding range with GPS transmitters that recorded the birds' location every 2 hours. The scientists mapped the migration routes and overwintering ranges of the geese and compared them to both the locations of poultry farms and the timing of H5N1 outbreaks at domestic bird farms in China and Tibet. They also mined a genetics database to determine the degree of relatedness between viruses isolated from poultry and other wild birds in the flyway of the tagged geese. The analysis revealed that the bar-headed geese overwinter in fields outside Lhasa, Tibet, near farms that have previously experienced virus outbreaks. The study also showed that 14 out of 16 H5N1 outbreaks in domestic chickens and wild birds were located within the bar-headed goose flyway (PLoS ONE 2011; doi:10.1371/journal.pone.0017622). Although none of the tagged birds contracted H5N1, bar-headed geese were the primary species infected during other outbreaks. “This paper provides evidence that suggests there is potential for wild birds to move the virus from poultry outbreaks in Lhasa to the breeding grounds at Qinghai Lake”, says Justin Brown, a research scientist at the University of Georgia (Athens). This research will help target new areas for future studies and monitoring, he adds. The World Health Organization reports that at least 300 people worldwide have died from bird flu since 2003. Scientists in New Zealand are using plastic seagrass beds to study how juvenile fish respond to changes in a vital but shrinking habitat. While meadows teeming with fish survive in remote areas, sediment in runoff from adjacent land development has killed much of New Zealand's subtidal seagrass and degraded what little remains. Fisheries ecologist Mark Morrison (National Institute of Water and Atmospheric Research, Auckland, New Zealand) says that creating fake mats allows researchers to control the density and length of fronds, and then measure the effect of increasingly dense seagrass on fish abundance. The mats (24 in all, each 3 m2) used in the experiment covered a range of six densities, from sparse to very thick, and were spread over 2000 m2 in the Whangapoua Estuary, near Auckland, just before the fish recruitment period over the southern summer. The study found that the denser the seagrass, the more abundant and diverse the fish. Maximum abundance for some species was reached at the highest grass-blade densities, with food limitation then probably kicking in as fish consumed all the zooplankton passing over the mats. Plastic seagrass is a haven for juvenile fish. “There is only one seagrass species in New Zealand, and it grows in both the intertidal and subtidal zones”, Morrison explains. “Subtidal seagrass beds are thought of as being rare, but I don't think it was always so. I think we have just lost a lot of it over the past 100 years. When the system is stressed, the subtidal beds are the first to thin out and disappear. But if only the intertidal beds are left, then much of its habitat value disappears, because the fish may have to move out into bare seafloor areas, where they are susceptible to predation when the tide goes out.” While seagrass is making a tentative comeback in some areas, threats continue from land-based activities. One problem is that people view recovering seagrass as a weed to be removed, to keep beaches sandy. “Coastal managers need to protect dense seagrass beds in the subtidal zone”, says Morrison. “Restoration of seagrass is very expensive, so the take-home message is to look after what you've got and create the right conditions, by controlling degrading activities, so seagrass can restore itself.” In a recently published paper, ecologists Ken Thompson (University of Sheffield, Sheffield, UK) and Mark Davis (Macalester College, St Paul, MN) assert that global changes in nutrient deposition, climate, and landscape disturbance are making the distinction between native and non-native species less ecologically meaningful (Trends Ecol Evol 2011; doi: 10.1016/j.tree.2011.01.007). “Species are simply winners – plants able to thrive in these conditions – or losers, those that can't”, says Thompson. “There's nothing special about being alien or non-native.” A number of invasive species experts agree with the essence of Davis and Thompson's claims. “There is nothing really fundamental about a species status as ‘native’ or ‘alien’ that explains how they ‘work’”, agrees Dave Richardson, Deputy Director of Science Strategy at the University of Stellenbosch's Center of Excellence for Invasion Biology (Stellenbosch, South Africa). At issue is whether or not country of origin matters. Many ecologists believe that distinguishing plants into native or non-native does still has value. “Plant traits are only one aspect of invasions”, points out Thomas Stohlgren, a research ecologist at the US Geological Survey's Fort Collins Science Center (Fort Collins, CO); other factors – eg the pathways responsible for moving species, as well as their current and potential distribution – also play a role in determining whether a plant has the potential to become invasive when introduced. “The best, most consistent predictor of species invasion is whether they have successfully invaded another habitat”, says Doria Gordon, Director of Conservation Science for The Nature Conservancy (Gainesville, FL). While Thompson says this is consistent with the view that winners will be winners anywhere, Gordon suggests that predictive tools based on traits, history of invasiveness, and biogeography avoid the import of “winners” with high economic and environmental costs. While Thompson and Davis split species into winners and losers, alternative ways to classify species are appearing in the literature. For example, Richardson characterizes invasiveness as inherent or induced. He hypothesizes that in some plant groups invasiveness has a strong inherent component (species are either likely or unlikely to become invasive), whereas in others, invasiveness is induced, influenced more by humans moving species or modifying the environment. Philip Hulme, a plant ecologist at the Bio-Protection Research Centre in Christchurch, New Zealand, suggests splitting species into “passengers” or “drivers” of environmental change. “Unfortunately, we can't yet predict impact-based traits”, he says. As researchers explore these new paradigms, it seems unlikely that relying on native or non-native status alone will prove sufficient to identifying invaders. For the past 20 years, divers have observed sharks visiting the Monad Shoal, a seamount off Malapascua Island in the Philippines, but couldn't figure out why the flat-topped, relatively barren area was such a popular shark hang-out. The answer came in 2005, when researchers from the Philippines, the UK, and Canada used remote video cameras to monitor shark behavior. The sharks were enlisting the assistance of small cleaner fish (eg the yellownose goby, Elacatinus randalli) that inhabit the shoal to remove various parasites. The study was published this March (PLoS ONE 2011; doi:10.1371/journal.pone.0014755). “Interactions with cleaner fish are the principal method by which sharks remove parasites, but little information on shark–cleaner interactions has been documented”, explains Nigel Hussey, a post-doctoral fellow at the University of Windsor's Great Lakes Institute for Environmental Research (Windsor, Canada), and a coauthor of the study. “The Monad Shoal seamount – in the case of pelagic thresher sharks [Alopias pelagicus] – is therefore extremely important for facilitating this interaction to maintain shark fitness.” A pelagic thresher shark (Alopias pelagicus). The migration of sharks to the shoal is more than just a beauty routine. The study shows that parasites, such as monogenean flatworms, commonly infest pelagic thresher sharks' pelvic and gill areas, the region most favored by cleaner fish. To prevent infection, sharks that usually live in deep, open water periodically venture into shallow-water shoals for cleaning. Having parasites removed is so important that visiting sharks of different species “can be observed together at the same cleaning station”, says Hussey. Pelagic thresher sharks are joined at the Monad Shoal by grey reef sharks (Carcharhinus amblyrhynchos), manta rays (Manta birostris), and devil rays (Mobula spp), and the various species have adopted different strategies for getting cleaned. While thresher sharks swim in a circular path around the “cleaning stations”, grey reef sharks “pose in a near-vertical, [head-down] position with their mouths open during the cleaning interactions”. This odd pose may help the cleaner fish to access parasites around the sharks' gills and mouth. As the UK's National [Animal] Vaccination Month gets underway this May, veterinarians are encouraging pet owners – particularly those in rural areas – to vaccinate their animals against infectious disease, and ecological research is demonstrating that the vets have a point. Wherever human development encroaches on intact ecosystems, diseases can be exchanged between domestic and wild animals. This sort of transmission appears to be occurring in the Brazilian Pantanal, where a recent publication reports that leptospirosis may be carried from wetland to farm (and back) by wild white-lipped peccaries (Tayassu pecari) (Trop Anim Health Prod 2010; doi:10.1007/s11250-010-9622-2). Caused by Leptospira, a genus of spirochaete bacteria, leptospirosis affects a variety of vertebrates – including humans and other mammals. The disease is especially devastating for livestock operations, causing miscarriages in cattle, as well as reductions in milk production and body mass, and even death. Midnight meeting: peccaries and cattle forage together for fruit. In Brazil, leptospirosis is a major concern for the extensive livestock industry in the Pantanal. White-lipped peccaries – wild ungulates related to pigs and native to the region – are particularly bold and nomadic, and are therefore likely to cross into agricultural land where they can come into contact with domestic animals, creating the opportunity for disease transmission. To investigate the potential for such contact to facilitate leptospirosis, the researchers trapped peccaries and tested their blood for antibodies to Leptospira interrogans. They found that 70% of the peccaries sampled had a high prevalence of Leptospira antibodies, representing a potentially large reservoir of disease. Alexine Keuroghlian (Wildlife Conservation Society, Rio de Janeiro, Brazil), a coauthor of the study, explains, “The high percentage of sero-positive animals that we observed…is probably related both to favorable environmental conditions and to the coexistence of wild and domestic animals.” The authors note that there is insufficient information to assess whether Leptospira flows primarily from wild to domestic animals or vice versa. Tatiana Tavares de Freitas (Federal University of Mato Grosso, Cuiaba, Brazil), the primary author of the paper, suggests that “Further studies will be required to understand the effects of leptospirosis on the population dynamics and reproduction of wild white-lipped peccaries and other wildlife species. Forest fragmentation and increased exposure to exotic animals may cause diseases to emerge that threaten the persistence of wildlife populations.” What Winston Churchill branded “the Iron Curtain” – the virtually impenetrable barrier of concrete walls, barbed wire, guard towers, and land mines that long separated Eastern Europe from the West – is gradually being converted into a ribbon of green snaking its way through Central Europe. The European Green Belt initiative, as it is called, is backed by the International Union for Conservation of Nature (IUCN) in partnership with an array of local, regional, national, and international organizations and government agencies throughout Europe. The long-term goal of the initiative is to transform the remaining strips of the largely depopulated border zones between the nations of the former Eastern and Western European realms into natural corridors, linking together the “core areas” of national parks, biosphere reserves, and wildlife preserves. Representative slices of almost all of Europe"s biophysical regions will be included within the Belt, conferring at least some measure of protection for, and connectivity between, remnants of the continent"s natural heritage. “The Green Belt harbors many endangered species and ecosystems”, explains Uwe Riecken, a senior scientist with the German Federal Agency for Nature Conservation (Bonn, Germany). “It connects many large natural landscapes and forms an important backbone for an ecological network across Europe.” A section of the European Green Belt winds its way through Germany. Initiated in 2004, in a transboundary park located in the former border zone between Hungary and Austria, the Green Belt currently stretches from the Barents Sea in the north to the Black Sea in the south, spanning nearly 8500 km over 23 countries. Because of its length, the Belt is separated into three distinct regional sections – Scandinavia and the Baltic, Central Europe, and Southeastern Europe – with each section overseen by a regional coordinator, while the project as a whole is managed by the IUCN. The time frame for completion of the Green Belt is “difficult to say”, according to Riecken. “In Germany, we are close to full implementation. In other countries, the situation is not that well developed.” “An increasing number of people visit this area for recreation and to experience nature”, adds Riecken. “The Green Belt is a living historic monument that reminds people of the former division of Europe.” In response to the unprecedented oil disaster in the Gulf of Mexico, in 2010, President Obama issued an Executive Order to establish the Gulf Coast Ecosystem Restoration Task Force (www.epa.gov/gulfcoasttaskforce). In late February, in Louisiana, the Executive Director of the Task Force, John Hankinson (EPA, Washington, DC), held the second of five public meetings scheduled for each Gulf state. The Task Force has until October 2011 to engage with stakeholders, including local governments, business and industry, and scientists – along with 11 federal agencies – to prepare an Ecosystem Restoration Strategy for the Gulf. Hankinson's experience in the 1990s with the Everglades restoration project informs his work in the Gulf, he explains. As with that massive ecosystem restoration project, determining the end goal is a major part of the debate. “Fortunately, ecosystem restoration for this project is clearly defined in the Executive Order, but it is broader than an ecological definition”, continues Hankinson. “It also discusses strengthening the ability of the ecosystem to support the diverse economies, communities, and cultures of the Gulf Coast. One thing it does not spell out, however, is a target ‘recover to’ date.” “The Gulf ecosystem is highly dynamic”, explains Scott Eustis, Coastal Wetlands Specialist with the Gulf Restoration Network (www.healthygulf.org; New Orleans, LA). “The goals for restoration need to be helping the system become what it might have evolved to in the future, if it hadn't been so disturbed.” Determining restoration targets in this complex ecosystem is further complicated by the fact that industrial-scale extraction of both seafood and oil and gas in the Gulf began decades before anyone started monitoring impacts to the natural state of the system, so baseline data are limited. Funding such a major undertaking presents another hurdle. Although BP faces legal fines for the Gulf spill, the amount of those fines and whether they could be spent on Gulf restoration remain unclear. The Department of Justice filed suit, claiming BP could owe from $4 billion to $20 billion, based on fines mandated by the Clean Water and the Oil Pollution Acts. BP, in recent court filings, claimed it was not willfully negligent and suggested fines from $2.8 million to $4.9 million. Current law dictates that any fines collected go into the Oil Spill Liability Trust Fund, which is used for initial clean-up of oil spills and to cover uncompensated damages, and then, once the $2.7 billion funding cap is reached, directly into the general US Treasury. A Commission created by the President to examine federal law following the disaster recommended redirecting 80% of fines to Gulf restoration, which would require legislative changes.