Dispatches

In the deserts of southern Bolivia, much of the region's limited water resources is tainted by pollution from nearby mining operations. However, a new passive water-treatment method developed by engineers from the University of Oklahoma may hold the key to improving the area's water quality in an ecologically responsible way. “In Bolivia, water is crucially important to agriculture. When irrigation waters are left untreated, the human health risk from consumption of staple root crops is unacceptable”, says Robert Nairn (Director of the Center for Restoration of Ecosystems and Watersheds, Norman, OK). This novel water-treatment system funnels untreated water through a series of filtration ponds, where natural biological or chemical processes remove pollutants from the water as it flows back toward natural waterways. “The general idea is to marry our understanding of ecosystem ecology and engineering design to create functional ecosystems that provide services to both human society and the natural environment”, explains Nairn. “If the passive treatment system provides long-term, low-maintenance solutions to water contamination caused by historical [mining] activities, degraded streams will have an opportunity to recover chemically and biologically.” Mayer Ranch passive treatment system at Tar Creek Superfund site, OK (February 2009). So far the system has been tested at two sites in the US, both in Oklahoma, and in Potosi, Bolivia. Each environment presents challenges to implementation, including radical differences in landscape geography. “Designs are site- and source-water specific, so process unit selection, sizing, and configurations will vary depending on site characteristics”, says Nairn. “Designs can be adjusted for geographic, climatological, ecological, and other conditions.” Improvements in water quality – such as decreased metal concentrations and stabilized pH and alkalinity levels – have already been documented, but the project still faces hurdles. According to Nairn, “contaminant retention in passive treatment systems raises concerns about the potential for bioaccumulation”. While the system is designed to mitigate such complications, comprehensive monitoring programs are necessary to ensure success. Although the passive water-treatment system uses natural ecological processes, the method is still a bit of a “black box”. Nairn's team seeks to understand and optimize the specific mechanisms at work and to evaluate “ecosystem services beyond water-quality improvements – such as carbon footprint analysis, habitat provision, and water supply – as well as environmental education efforts”. New research has found a connection between trees and human cardiovascular–respiratory health, thus adding a bit of statistical heft to a growing body of evidence that the natural environment can have public health benefits and providing stronger support for a causal link. Previous studies identifying such an association have typically relied on single time-point observational studies, which are often unable to rule out confounding factors. US Forest Service economist Geoffrey Donovan (Portland, OR) used county-level health records from 1990–2007 to track the impacts of a massive tree kill event that began in 2002 (Am J Prev Med 2013; doi: 10.1016/j.amepre.2012.09.066). The trees died after an outbreak of the emerald ash borer (Agrilus planipennis), an invasive species responsible for the loss of 100 million trees across 15 US states between 2002 and 2012. Donovan noticed increased human mortality – 15 080 deaths from cardiovascular disease and 6113 deaths from respiratory illness – following the pest outbreak; the magnitude of the effect was greater during the later stages of the infestation. The most plausible explanations for this relationship could be decreased physical activity, reduced air quality, or increased stress. Interestingly, the connection between tree infestation and human mortality was higher in wealthier counties. It's unclear why, but wealthier areas possibly have more tree cover to begin with and therefore would be more adversely affected by tree loss. “This research looks at a natural experiment that occurred somewhat randomly over a broad geographic area, offering yet another interesting way to push forward our understanding of whether environmental factors offer health benefits”, comments Gina Lovasi, an epidemiologist at Columbia University (New York, NY), whose own research detected decreased prevalence of asthma in children living in urban areas with more street trees (J Epidemiol Commun H 2008; doi:10.1136/jech.2007.071894). However, she cautions, ecological analyses such as this aren't always confirmed by more rigorous, follow-on studies at an individual level. “These studies are important because they give us an idea of what direction to take future research.” Donovan agrees. “We need to quantify the benefits, to help local governments make appropriate decisions when allocating money”, he says, adding “if we can't count a thing, it doesn't count.” In mid-January, after years of debate, delegates from 140 countries agreed to a legally binding treaty to reduce releases of mercury (Hg) from various products and industries, ranging from medical equipment to mining, cement production, and coal-fired power plants. Even as talks were underway, recent findings emphasized the need for global action to curb one of the planet's most serious threats to human and environmental health. A UN Environment Programme (UNEP) report released in January revealed that after declining from 10 000 metric tons (mt) to 1000 mt between 1971 and 2001, Hg mining output doubled over the past decade, largely due to the rising use of Hg in small-scale gold mining, energy-efficient lighting, and vinyl chloride plastics. At the same time, Hg emissions fell in some geographic areas, and overall emissions from 1990 to 2010 – estimated at 1960 mt – were roughly stable. Developing nations now account for more than 80% of those emissions. Wind-transported Hg can circulate vast distances before falling to Earth, where microbial activity converts it to toxic methylmercury, the form taken up by animals. During the 20th century, the total Hg deposited in the planet's oceans and freshwater doubled, according to UNEP. Furthermore, climate-change impacts are boosting the availability of Hg trapped for millennia in ice and snow. A study found that river flows amplified by warming-induced melting contributed most of the Hg detected in the Arctic Ocean (Nat Geosci 2012; doi:10.1038/ngeo1478). In addition, thawing permafrost and increasingly frequent forest fires are intensifying concentrations of Hg in high-latitude soils. New research suggests that reducing Hg emissions could have immediate environmental benefits (Sci Total Env 2012; doi:10.1016/j.sci-totenv.2012.10.069). When scientists in Ontario, Canada, added a particular Hg isotope to lake waters, lake perch showed surprisingly higher concentrations of it within months, compared to “older” Hg already present in the lake. Within a year, the “new” Hg had passed up the food chain to top predators. When Hg additions ceased, Hg levels in the fish dropped quickly. Many parts of the new treaty won't take effect until 2020 or later, and large-scale positive consequences could be decades away. David Lennett (Natural Resources Defense Council, Washington, DC) contends that “the provisions on product phase-outs are relatively strong, while the emissions control requirements for existing facilities are delayed far too long”. Still, he adds, “the agreement is a good starting point for building international cooperation, and there's room for improvements down the line”. The Wildlife Conservation Society (WCS) announced in late January that the Republic of Congo has declared a new national park that protects 4572 km2 of land, including a remote swamp dubbed the “green abyss” by the first WCS researcher to explore the area. The Ntokou-Pikounda National Park counts among its residents 8000 forest elephants, 950 chimpanzees, and a substantial hippopotamus population. With the addition of this new park, protected areas of the Republic of Congo now account for more than 11% of the country's land. James Deutsch, WCS Executive Director for Africa Programs (New York, NY), says the park is “extraordinary – it is highly inaccessible because of dense Marantaceae vegetation and seasonally flooded forests, and this inaccessibility has enabled the fauna and flora to remain unusually intact.” But the park's foremost distinction is that it is home to an estimated 15 000 western lowland gorillas, a critically endangered species with fewer than 200 000 remaining in the wild. Gorillas across central Africa are threatened by hunting for bushmeat, habitat destruction caused by deforestation, and the spread of the deadly Ebola virus. Creation of the Ntokou-Pikounda National Park fulfills a promise made by the Congolese Government to protect the area after the gorillas were discovered there by WCS researchers in 2008. A baby gorilla watches its mother and other family members forage for food. Because of the relative political stability in the Republic of Congo – unlike that in the neighboring Democratic Republic of Congo, where civil war continues to complicate conservation efforts – Deutsch believes this park will thrive. “No doubt there will be threats, including poaching for elephants and other valuable wildlife, but we believe that by working with the government, communities, and other partners, we can meet these challenges.” As for how the Congolese people might benefit from the new park, Deutsch points out, “The area itself is uninhabited, and we have worked with local communities to ‘grandfather’ their fishing rights in the river that forms one boundary of the park. We hope over time to be able to monetize the averted deforestation that has resulted from the park's creation and to use the proceeds to benefit local communities.” Wyoming has wind power when California needs it, making this renewable energy source potentially more reliable and cheaper for Californians, according to a new report. “Wyoming wind rips in the winter”, says Loyd Drain, Executive Director of the Wyoming Infrastructure Authority (Cheyenne, WY), which facilitates consumption of the state's electricity. In contrast, California's winds are weakest during the winter. In addition to being strong – often blowing at speeds of 10–12 m s−1 –Wyoming wind is steady. “It's amazingly consistent here”, observes Jonathan Naughton (University of Wyoming, Laramie), lead author of the January 2013 report Wind Diversity Enhancement of Wyoming/California Wind Energy Projects. Naughton's team projected wind power in Wyoming and California based on atmospheric data, and found that it is complementary year-round. Besides balancing each other in the winter, wind power in the two states has opposite daily patterns during the summer, peaking at noon and then dropping in Wyoming while the reverse occurs in California. Wyoming's wide open spaces make it ideal for wind ranches. Wyoming wind likewise complements California's solar power. “Solar goes to zero when the Sun goes down, and our wind could fill half that energy gap”, explains Drain. At present, renewable energy gaps are commonly filled with energy produced from fossil-fuel-burning power plants. Importing Wyoming wind power would also lower energy costs for Californians. Rates are already four to eight times higher in California than in Wyoming, and are predicted to rise further as California tries to meet its mandate of producing one-third of its energy from renewables by 2020. Buying Wyoming wind power would save California ratepayers $600 million per year, according to a 2011 study by the Western Electricity Coordinating Council (Salt Lake City, UT). Because the power grid that currently serves the western US is at capacity, sending wind-produced electricity from Wyoming to California would require the construction of a new high-voltage transmission line. The TransWest Express, a 1167-km line linking Wyoming to southern Nevada, is being planned; connecting that line to California's grid would be relatively easy, and it could be up and running by 2017. To actually build the Nevada–California extension would, however, require power purchasing agreements from public utilities in California. Drain is now in talks with energy officials there, but so far there are no takers. Adding even more long-distance transmission lines would facilitate moving electricity as needed throughout the western US. “Right now, each state maximizes its own resources, but we should maximize resources region-wide”, Naughton recommends. “This is the way to make renewables really work.” Endangered species in the Australian State of Victoria are at risk from a government commitment to burn at least 5% of the state's public land annually, in an effort to reduce fuel loads. The 5% target – 380 000 ha per year – was recommended by a Royal Commission investigating the deadly wildfires in February 2009, in which 173 people died. But scientists warn that such a blanket approach will lead to converse outcomes, with agencies burning vast remote regions rather than strategically important areas closer to towns. “If the rationale is to reduce the risk to life and property, then obviously you [take action] where life and property are at risk”, explains Mike Clarke (La Trobe University, Melbourne, Australia). “If you keep burning remote parts of Victoria, you're not making anyone safer, and you have the potential to do ecological harm.” The semi-arid Mallee country of Victoria's far northwest is a case in point. Some tracts in the Mallee have not burned for up to 140 years, allowing complex habitat structures to form – structures that would otherwise be lost, according to Clarke and his colleague Andrew Bennett of Deakin University (Melbourne). For example, the endangered Malleefowl (Leipoa ocellata) relies on ground litter that has accumulated over decades to rake into their large nest mounds, tree hollows take at least 40 years to form, and spinifex grass (Triodia spp) requires a minimum of 20–30 years to reach maturity. “So the concern is that if you burn 5% every year, logically after 20 years you've burned an area equivalent to 100% of the region. How do you then provide extensive areas of Mallee habitat that is 30, 40, or 80 years old?”, asks Bennett. “If you burn large areas repeatedly at intervals of less than 20 years, to allow other areas to develop older vegetation, it will put plant communities at risk.” The scientists are calling for the 5% target to be replaced with a risk management objective. “We're not opposed to planned burning per se, and absolutely we need to protect human life and property, but our argument is that targets should be based on reducing risk”, says Bennett. Because bat guano makes a rich fertilizer that is prized by farmers, quiet caves with unique and fragile ecosystems often become targets for those willing to wield shovels in the pursuit of quick cash. Biologists have observed that the bright lights and loud equipment used in guano excavation can cause residing bats to drop their pups or even abandon the cave altogether. Now, a team of conservation biologists has drafted a set of working guidelines that they hope could eventually be used to improve the sustainability of guano mining in many locations by reducing its negative impacts. Officials estimate that millions of bats have been lost worldwide as a result of guano mining, although accurate data are lacking. “We're receiving many reports of declines in cave bat populations”, says Nina Ingle (Davao City, Philippines), who has worked as a bat biologist for 20 years. “There's an urgent need for further research on their status as well as for cost-effective methods to monitor bats and the impacts of guano harvesting.” Guardhouse at the entrance to a Cambodian bat cave. That need was also recognized by several environmental organizations, which collaborated to sponsor the Emerging Wildlife Conservation Leaders Bat Group (EWCLBG), a team that was formed to examine guano mining issues. Some members of the EWCLBG accompanied Cambodian researchers in the field as they tested methods for improving sustainability during the guano harvest at several locations last year, and in January a working draft of mining guidelines was released to the public. According to Ryan Richards, a member of the EWCLBG and a fellow at the Smithsonian Institution (Washington, DC), the challenges associated with guano mining can vary widely from region to region. In some areas, the miners are well-known, well-organized, and deeply protective of their caves – at one site in Cambodia, for example, a local man had built a guardhouse at the entrance to a cave to defend his interests; this made it easy to know whom to talk to about the needs of the bats. At other locations, however, the identity of the miners is unknown. “It's very context dependent”, Richards explains. In addition to the guidelines, a series of informative posters about the topic of bats and mining was developed for use in a wide variety of communities. Such initiatives are just the beginning, however; as David Waldien (Bat Conservation International, Austin, TX) cautions, “This is a process that's going to take years”. Researchers report that African dung beetles (Scarabaeus satyrus) use the Milky Way to help them speedily steer their hard-won manure balls out of competitors' reach (Curr Biol 2013; doi:10.1016/j.cub.2012.12.034). This is the first evidence of such a navigation system being used by any animal. Dung beetles eat – and lay their eggs in – other animals' droppings, and competition around the nighttime manure can be a in a from the makes for the time to a explains University, the these by the and at we know they can use the But they can also a when there is no so we whether they were the beetles the Milky a African the researchers beetles with dung balls in a and the they as they to steer their to the away. from the by a over their made as as those no In a with a designed to ensure the beetles could no land the researchers how they to their balls to the the 40 15 their lines of much more The was therefore providing but what In the researchers showed the beetles to take the same time to the whether the or just the of the Milky Way was “In a they use the line of by the as their explains of be some beetles on New research suggests that are historical at locations across the of these sites are producing at very explains (University of at some sites there is of which the are starting to data that recent ecological declines are the potential of including and and global factors such as are to the of observed the To the of this on and used a approach which the by the of and other and of The researchers compared with those before and with those going back years from were at least lower than historical and of the sites had negative (Nat Commun 2013; The has been by disease and environmental have the of various comments University, this research us a first of the at a is that many of the to be on a in or in could them into the and both are to as “This to estimate the and in several locations suggests that some have too relative to the to to says (University of because other factors that such as are not these into the future is that although the local factors in can be relatively global are to says “the we can give to be able to with is to the local on them as much as The Forest announced that it will a National Forest to provide on forest resources At present, – roughly equivalent to million km2 – cover about of the With an of years, the will on a broad set of including field research and will be from 000 unique field locations on a grid across the areas will be in to be able to future of land to land, and At each site, such as tree and species will be data on and will be as The will be to allow for a more general of ecosystem researchers to with people living each point in to how local human communities and use the During the an forest one that on The of the however, is to public and also to in of reducing deforestation by 80% before the year 2020. According to Forest Service the is important to field data to improve of carbon in and also to further research and by the Although some states currently their own forest for government officials hope that the will provide comprehensive about forest health, and to help large-scale conservation to future conservation and to allow the country to more in international environmental

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.