Dispatches

After 3 years of extreme drought, California's vast Central Valley is so dry that millions of migrating birds have lost stopover points where they rest and feed. This region supports 30% of the shorebirds (such as plovers and sandpipers) and 60% of the waterfowl (including ducks and geese) that use the Pacific Flyway, but The Nature Conservancy (TNC) estimates that about 85% of the Valley's wetlands are dry. “We thought, ‘What can we do?’”, recalls Mark Reynolds, who leads TNC's Migratory Birds Initiative (San Francisco, CA). “We hit on the idea of paying rice farmers to create temporary habitat.” Instead of paying a flat rate, TNC invites farmers to submit bids. “This market-based approach stretches our conservation dollars and gives farmers the opportunity to be compensated for their true costs”, he explains. To decide when and where to fund these “pop-up” wetlands, TNC uses bird-tracking data from eBird, a citizen-science program run by the Cornell Lab of Ornithology (Ithaca, NY). Designed for shorebirds, these temporary wetlands also benefit cranes, ibises, and other avifauna. TNC piloted pop-up wetlands during last spring's northward migration, focusing on shorebirds because existing wetlands primarily serve waterfowl. Ducks and geese prefer water deeper than 15 cm while shorebirds need shallower wetlands. Altogether, the program created over 4000 ha of shallow temporary habitat. “The shorebird response was extraordinary”, Reynolds says. “Their density was 20 times higher on pop-up habitats than on neighboring fields.” One pop-up wetland had 20 000 dunlins (Calidris alpina), representing one-fifth of California's entire population of these small wading birds at the time. The program picked up again during the shorebirds' fall migration back south, when the need for stopover habitat was intensified by exceptionally large bird populations caused by prime conditions in their northern breeding grounds, according to a US Fish and Wildlife Service survey. TNC is optimizing its pop-up wetland program in collaboration with Point Blue Conservation Science (Petaluma, CA), which collected data on field conditions and habitat use at about 100 sites. “We're assessing how we allocated our resources and how shorebirds responded”, Reynolds says. “We hope to find the ‘sweet spot’ for the Flyway and for farming so both can flourish in California.” A US Environmental Protection Agency (EPA) decision that clears the way for a new wave of genetically modified (GM) crops has triggered lawsuits from environmental groups. Last month, the EPA approved the use of Dow AgroSciences' Enlist Duo – a combination of two existing herbicides: 2,4-D and glyphosate – in six states. The decision enables Dow to begin marketing a novel line of GM crops that are resistant to both herbicides. Another dual-herbicide crop system, from Monsanto, still awaits regulatory approval. The new products are intended to counter the increasing problem of glyphosate-resistant “superweeds”. Earlier GM crops were typically engineered to tolerate glyphosate, the key ingredient in Monsanto's Roundup, so that farmers could more easily kill weeds by spraying fields with this product. Such herbicide-tolerant GM crops now account for roughly 90% of all US corn, cotton, and soybean acreage. But as the planting of glyphosate-tolerant crops has expanded, so has the abundance of glyphosate-resistant weeds, which according to an industry survey affected 24.8 million ha of US farmland by 2012. As farmers switch to the latest dual-herbicide GM crops, the total usage of 2,4-D is expected to increase sharply. Environmental groups are suing the EPA, claiming the agency has inadequately recognized the potential impacts of this decision on human health, endangered species, and the environment. “We don't think the EPA did a good enough job of considering the epidemiology, the impact on surrounding vegetation and crops, and weed resistance management”, says Doug Gurian-Sherman, director of sustainable agriculture and senior scientist at the Center for Food Safety (Washington, DC). The EPA insists that Enlist Duo is safe, and notes several steps that Dow has taken to reduce risks, including the introduction of a less volatile 2,4-D formulation, intended to reduce the likelihood that the herbicide will spread from fields to neighboring areas. Matt Liebman, a crop scientist at Iowa State University (Ames, IA), believes that the increasing use of the new dual herbicides on GM crops will accelerate evolution of weeds that are resistant to multiple herbicides. He points to previous research documenting weeds that already display such resistance, including to synthetic auxins like 2,4-D. “The more a given control method is used, the more rapidly resistance will evolve”, he warns. “We are about to make more herbicides as heavily used as glyphosate, and they will promote resistance in the same way.” In late October, the government of The Netherlands announced that it is working to completely phase out microplastics from Dutch cosmetics, and will soon propose a ban on microbeads in cosmetics throughout the European Union. Dutch State Secretary for the Ministry of Infrastructure and the Environment, Wilma Mansveld, made the following statement in a letter to Dutch Parliament on October 28: “All members of the Netherlands Cosmetics Association that use micro-beads in cosmetics either have ceased to do so or are in the process of ending their use. This means that in time there will be no more microbeads in scrub, toothpaste, soap, and bath and shower gel. For 80% of the companies, many of which are multinational, this will be realized by 2017. The effect on the Dutch market is substantial, with impacts stretching over a far larger market due to the international nature of the cosmetics industry.” The action comes in direct response to the “Beat the Microbead” campaign, which was launched in August 2012 by the Plastic Soup Foundation (Amsterdam, The Netherlands) and The North Sea Foundation (Utrecht, The Netherlands). Maria Westerbos, founder and director of the former organization, says: “In recent years, the industry has been adding more and more plastic to products. Wastewater treatment plants are not designed to filter out microbeads, so they end up in the ocean and contribute to the ‘plastic soup’. We are very happy that The Netherlands is the first country in the world to aim for a ban on microplastics, both on a national and a European level. We are pushing for a worldwide ban; we need to fight this ‘Trojan horse’ in households all over the world.” Westerbos adds that there are currently 59 nongovernmental organizations from 29 countries supporting and raising awareness for the Beat the Microbead campaign, a number that increases daily. Central to the campaign is a smartphone app that allows consumers to scan barcodes on products to determine whether they contain microbeads. The app is available in several countries, including the US, and consumers are playing a key role in helping to build the product database. The environmental footprint of beef grabbed headlines recently with news that this meat requires 11 times more water per calorie of food produced than pork or chicken. However, research indicates that meat-lovers can use their purchasing power to make a big difference in the amount of water used in livestock production (Food Policy 2014; doi:10.1016/j.foodpol.2014.06.007). “By 2050, food demand is predicted to outpace water availability in most regions of the world”, explains Robin White, an economist with the National Animal Nutrition Program (Blacksburg, VA) and lead author of the study. Beef production is a big consumer of water, and top-down regulatory policies are often suggested to improve sustainability. But White wondered whether consumer preference for eco-labeled beef could drive water-conserving technologies such as better pasture management in beef production. White and her coauthor combed through 61 studies – looking at over 34 000 consumers – that quantified how much more shoppers would pay for beef with a smaller environmental footprint. Results showed that about 60–80% of North American consumers would be willing to pay 10% more for beef raised sustainably, half would pay 15% more, and very few would pay 30% more. “We then allowed the cost of producing beef to incrementally increase and assessed the types of on-farm management that could be employed to reduce water required per unit of beef in three regions of the US”, she says. Beef producers cut water use when consumers pay more. White found the biggest reductions in water use in those regions occurred when the premium for eco-labeled beef was set at 10% above the price for conventionally raised beef. At the farm level, this translated to a US$0.17 increase in the cost of raising a kilogram of beef and a 9% cut in water use. Although the water savings seem small, on a national scale this would save 289–490 billion liters of water per year, enough to supply the needs of 3.5 million people. “If we are to use this consumer-based incentive approach, the key component is getting more people to buy in, helping more producers afford to reduce water use”, she concludes. “White did a meta-analysis, which is the real strength of this study”, says Michael Tlusty, director of Ocean Sustainability Science at the New England Aquarium (Boston, MA). He points out that government regulations typically set a low bar for sustainability whereas voluntary market incentives such as eco-labels can drive food producers to aim for more ambitious conservation goals. Top predators such as lions have been lost in many ecosystems, but a new study shows that their prey may retain their fear for generations after the threat is gone (Behav Ecol 2014; doi:10.1093/beheco/aru180). This factor is crucial to the success of predator reintroduction efforts, since accumulating evidence indicates that predators affect their prey not only through direct mortality but also by causing behavioral changes. Predators from wolves to dragonflies can influence their respective prey – where they forage, how much they eat, and how alert they have to be – and these changes then have rippling effects through their ecosystems. Such behavioral responses help shape ecosystems, and as lead author Fredrik Dalerum (University of Pretoria, Pretoria, South Africa) explains, “predator recognition is the first step to exhibiting those kinds of responses”. Common warthogs (Phacochoerus africanus) still fear lions, even where these predators have been absent for generations. To this end, Dalerum and his colleague examined the ability of three species – common warthogs (Phacochoerus africanus), impala (Aepyceros melampus), and blue wildebeest (Connochaetes taurinus) – in two parks to recognize their lion predators by sound. Lions have been locally extinct from the area, likely since the early 20th century, but were reintroduced in one of the two parks in 1998. This difference between parks allowed researchers to examine whether the so-called “naïve” animals that have not encountered lions for generations still respond behaviorally to audio recordings of lion calls (for example, by running away or spending more time being vigilant) to the same extent as those that regularly encounter their feline predator. They also played recordings of wolf calls and “neutral” sounds, to make sure the animals were responding specifically to the calls of their own predator. The scientists found that the naïve animals responded just as strongly to lion calls as did experienced animals; if anything, “the difference was actually that there was a more radical behavioral response in the naïve animals”, Dalerum states. This analysis demonstrates the potential for prey to recognize and respond to long-absent predators if the latter are reintroduced to areas within their historical ranges, an important step for restoration given predators' wide-reaching roles in ecosystems. Apparently the fear of predators, burnt into the genome, doesn't easily fade. Many arid countries, particularly in the Arabian Peninsula and North Africa, have such limited water resources that they must import the bulk of their food. To increase food production without increasing water use, researchers are experimenting with next-generation greenhouses that are able to reuse and recycle as much as 90% of water added. A research project, funded by the United Nations Food and Agriculture Organization (FAO), is getting underway to test the feasibility of this approach in the United Arab Emirates. Speaking in October at the Water for Food conference (Seattle, WA), Pasquale Steduto – the FAO representative in the Near East and North Africa (Cairo, Egypt) – explained that the project will determine whether these greenhouses could prove viable in the Middle East. The key to efficient water use in a closed greenhouse is figuring out how to cheaply condense water vapor in the air back to usable droplets, an energy-intensive process. “By keeping a greenhouse closed, we can condense, and therefore reuse, the water vapor generated by the plant itself”, says Steduto. European Union-funded research supported the early development of prototype greenhouses, such as one built in Spain in 2003, which demonstrated that passive cooling, relying on cooler nighttime temperatures, could dehumidify the air. However, pulling the most moisture out of the air required an expensive heat exchanger. Building engineer Martin Buchholz at the Technical University of Berlin (Germany) found that simply adding a desiccant – the common salt magnesium chloride – to the greenhouse could inexpensively dry and cool the air to achieve 90% less water use. “Cutting water consumption by as much as an order of magnitude is an enormous amount”, comments Steduto. Preliminary evidence suggests that the crops grown in greenhouses can achieve 2–3 times the yield per liter of water used in traditional field-cropping systems, simply because greenhouses are able to trap higher levels of growth-promoting carbon dioxide, according to Buchholz. Such high yields will be necessary to offset the investment costs required to recycle water. At least in the near term, these greenhouses may make sense only in wealthy, water-limited countries. The United Arab Emirates greenhouse should be functional by spring 2015, and Steduto anticipates other experimental units being tried in Saudi Arabia or Oman. “Not only could greenhouses provide the nutritional value of vegetables or fruits, they could even offer an opportunity to grow feed for livestock, which could reduce the need to import meat”, Steduto points out. In December 1984, several thousand people were killed after being exposed to toxic gas – methyl isocyanate (MIC) – that leaked from the Union Carbide plant in Bhopal, India. Although the facility closed down shortly after the disaster, 15 years' worth of improperly disposed hazardous waste from the plant's operation have resulted in lingering environmental contamination. Besides producing MIC, the plant was licensed to manufacture phosgene, monomethylamine, and carbaryl. Traces of these products and intermediary chemicals have been detected in soil and groundwater samples collected onsite and in surrounding areas during field surveys conducted in the past two decades. Yet removal, decontamination, and environmental remediation efforts at Bhopal remain entangled in continuing legal procedures and are hampered by a lack of scientific consensus. “As many as 17 studies by government research laboratories and action groups have shown the presence of toxic chemicals in [samples]…some at locations as far as 3.5 km from the plant and at depths greater than 30 m”, according to Satinath Sarangi of the Bhopal Group for Information and Action (Bhopal). Over the years, personnel from various federal agencies tasked with exploring the site have discovered several pits where solid and liquid waste – apparently generated during normal production processes – was routinely dumped, thus contaminating the soil with aldicarb, carbaryl, α-naphthol, hexa-chlorocyclohexane isomers, dichloro-benzene, and mercury. Elsewhere on the premises, abandoned buildings containing stockpiles of chemicals and finished products represent additional sources of hazardous substances that have already or may soon pollute the nearby environment. In 2010, a report commissioned by India's Ministry of Environment and Forests estimated the volume of contaminated soil at Bhopal to be approximately 1.1 million metric tons. Furthermore, three nearby evaporation ponds that received supposedly “treated” wastewater from the factory also contribute to the pollution. “Overall, insufficient information exists to clearly identify all the contamination sources feeding the contamination spread. However, where sources can be assumed with reasonable confidence, these should be isolated to reduce groundwater-related impacts until adequate investigations are completed and remediation implemented”, concludes Paul Futter, a New Zealand-based environmental chemist who recently conducted a review of contamination-related studies. Futter believes that future investigations should be based on sound conceptual models of potential contamination pathways. “It's a historic opportunity to develop a realistic course of action”, asserts Chandra Bhushan, deputy director general of the Centre for Science and Environment (New Delhi, India). In the West Antarctic Peninsula, researchers are investigating the plight of diminishing populations of the Adélie penguin (Pygoscelis adeliae) to determine what factors contribute to their survival. Adélie penguin chicks are particularly sensitive to changes in their environment, and their survival has serious implications for future breeding populations. “The West Antarctic Peninsula is one of the most rapidly warming areas in the world, and in this region, the Adélie penguin population has dramatically declined since the 1970s”, says Megan Cimino (University of Delaware, Lewes, DE), lead author of a paper that specifically examines the variability in penguin chick weight as it relates to different environmental variables (Mar Ecol-Prog Ser 2014; doi:10.3354/meps10928). Cimino and her colleagues found that Adélie chick weight can serve as an indicator of the overall health of a penguin colony. 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