Portal de Periódicos da CAPES

Dispatches

2014; Wiley; Volume: 12; Issue: 8 Linguagem: Inglês

10.1890/1540-9295-12.8.428

1540-9309

ESA,

Aquatic Invertebrate Ecology and Behavior

On August 26, workers blasted out the final section of the 64-m Glines Canyon Dam on Washington State's Elwha River, completely freeing 110-plus kilometers of streams – largely within Olympic National Park (ONP) – that a century ago supported some of the Pacific Northwest's most prolific salmon fisheries. The biggest US dam removal project ever undertaken (it also entailed demolishing the ~33-m Elwha Dam lower on the river), it began in 2011 following three decades of legal and political wrangling between government agencies, the Lower Elwha Klallam tribe, and river conservationists. “The pace of the coastal recovery has been exciting and fascinating”, says USGS geomorphologist Jonathan Warrick (Santa Cruz, CA). To date, the river has eroded about one-third of the roughly 20 million cubic meters of sediment previously trapped behind the dams, moving over 95% of it downstream to form a massive new river-mouth delta and spill out into nearshore ocean waters. “Over the past 100 years, due to the dams, approximately 200 m of coastal shoreline eroded away, but since 2011, half again as much land [ie 300 m] has been rebuilt in the same area, creating habitat for crabs, bait fish, clams, and other species”, he explains. In time, the Klallam may once again harvest shellfish there. The recovering Elwha River and nearshore waters, circa 2014. Signs of transformation are equally apparent upstream. “Willows, alders, and other riparian plants are recolonizing the reservoir beds, which resembled a moonscape only 2 years ago”, says ONP ranger Denison Rauw. Additionally, more than 67 000 seedlings have been planted to restore native vegetation. “The river itself is recreating prime fish habitat by redistributing woody debris and building gravel bars and deep pools”, she adds. Biologists radio-tagging salmonids migrating from coastal waters have recaptured them many kilometers upstream, fueling optimism that fish numbers could rebound to pre-dam levels (annual runs approaching 400 000) within 20–30 years. Adult salmon and their eggs, fry, and carcasses provide nutrient-rich sustenance for all kinds of insects, birds, and mammals; dippers and other aquatic species have been quick to take advantage of the newly available prey. Scientists have shown that the salmon's bounty is spread across the forested watershed, and researchers examining tree stumps in the Elwha basin have discovered that the tree rings in the Elwha Basin were narrower during the time period when the dams largely excluded salmon from the river. “The efforts of so many people have come to fruition”, Rauw muses. “Now the powerful Elwha River is restoring itself, and we get to witness this transformation.” Japan's solar energy capacity grows every year, but the country is running low on land needed for siting conventional utility-scale solar photovoltaic (PV) farms. “Historically, Japan's solar market has been dominated by the residential [mainly rooftop] market”, explains Ted James of the US National Renewable Energy Laboratory (Golden, CO), “but policy developments in the past few years have resulted in strong growth in non-residential and utility-scale segments”. One emerging segment in Japan consists of solar PV farms that float on water, as seasonal extremes in rainfall have created a landscape peppered generously with reservoirs, the surfaces of which would otherwise remain unused. Taking advantage of two such reservoirs in the city of Kato, Japanese electronics and ceramics manufacturer Kyocera is constructing the world's largest-yet floating solar PV farm (in terms of output). Collectively, the 1.7-megawatt (MW) array on Nishihira Pond (the aforementioned record-breaker) and the 1.2-MW installation on Higashihira Pond are projected to provide enough electricity for roughly 920 households by April 2015. Financing for the project, which by March 2015 is expected to include additional floating solar PV farms generating 60 MW countrywide, is provided by Kyocera's partnership with Century Tokyo Leasing. While the project will deploy Kyocera's own PV panels, the patented floating platforms are to be supplied by Ciel et Terre (Lille, France), which has been designing and operating floating solar PV systems since 2011. Installing a solar PV farm on the surface of a reservoir, quarry lake, canal, or pond affords several benefits as compared with panels placed on rooftops or terrain, according to a statement from Kyocera. First, the cooling effect of the surrounding water preserves PV panel efficiency, meaning that a floating panel produces more electricity than its ground- or roof-mounted counterpart. Second, Kyocera claims that the shade cast by floating solar installations onto the water's surface reduces both the loss of water by evaporation and the growth of nuisance algae. However, “factors such as operations and maintenance costs, unique mounting structures, and installation labor costs are likely to be higher than those associated with typical ground-mounted systems”, suggests James. Once considered an extreme intervention, the deliberate movement of species to new and former habitats is gaining more acceptance in conservation circles. Until recently, however, it was unclear to what extent species translocations were underway in the marine environment. At the Ecological Society of America's 2014 meeting in Sacramento, CA, biologist Kelly Swan (Calgary Zoo's Centre for Conservation Research, Calgary, Canada) presented the first global review of marine translocations. Evaluating over 12 000 papers, she documented >500 conservation-motivated marine organism releases. Of those, 356 were meant to reinforce populations, 130 were reintroductions, 18 were assisted colonizations, and one was an ecological replacement. “We found a rapid increase in terms of publications in recent years, related to conservation-minded translocation of marine species – a trend we traced back to 1975”, says Swan. While a diverse mix of species – including fish, mangroves, seagrasses, reptiles, and mammals – have been moved, the vast majority have been invertebrates or coastal plants. In fact, one-third of translocated species in Swan and colleagues' database are corals. Yet only 24% of reinforcement projects and 24% of reintroduction projects involved species classified as “at risk” on the International Union of Conservation's Red List. “We suspect that conservation biologists tend to have a local focus when reintroducing a species”, explains Swan, adding that “countries are concerned about what is threatened within their own national boundaries”. In fact, governments are involved in 80% of reintroductions. The US leads the way with 178 conservation-based translocations, the Philippines has undertaken 52 projects and Australia between 10 and 25. There is no single metric of success. “It depends on the goals of the release and how well the projects have been monitored”, continues Swan. Baruch Rinkevich, a coral reef biologist at the National Institute of Oceanography (Haifa, Israel), has so far transplanted over 86 coral species – including a number of IUCN Red List species. He raises them in underwater nurseries before transplanting them to denuded reef areas around the world (Curr Opin Environ Sustain 2014; doi:10.1016/j.cosust.2013.11.018). Consistent with his argument that success should be evaluated against defined factors such as survivorship over time, Rinkevich has achieved up to 90–95% survivorship in the first year. Still, Ove Hoegh-Guldberg, director of the Global Change Institute (University of Queensland, Brisbane, Australia), notes that the high level of connectivity in marine environments – which can make reintroductions difficult to control – makes it all the more important to have decision frameworks (Science 2008; doi:10.1126/science.1157897) in place to guide the implementation of “radical” conservation measures. A coalition formed by the Center for Biological Diversity, the Center for Food Safety, the Xerces Society, and Lincoln Brower (Sweet Briar College, Sweet Briar, VA) has petitioned the US Fish and Wildlife Service (FWS) to provide the monarch butterfly (Danaus plexippus) protection under the US Endangered Species Act (ESA). The reason: a 90% decline in the species' abundance during the past 20 years, from 1 billion to just 35 million – the lowest number ever recorded. Monarch butterflies are famed for their multigenerational migrations from overwintering sites – consisting of just a few trees in central Mexico and California – across the US and into Canada. They were once so numerous that they became the state insect for seven US states, stretching from Texas to Vermont. Their numbers are now so low, however, that a single adverse event in their Mexican winter enclave – for example, a storm – could almost wipe them out. A monarch butterfly (Danaus plexippus). “The main reason for their decline over the past decade has been the loss of milkweed [Asclepias spp], the only plants on which monarchs lay their eggs, across the US Midwest”, explains Brower. “Farmers there have been planting crops genetically engineered to resist Monsanto's Roundup herbicide, but this product is estimated to have destroyed milkweed over some 67 million hectares.” The petition, submitted on 26 August, requests that the monarch be given protection under the terms of the ESA, which allows species to be listed as “threatened” when they are at risk over a substantial portion of their range. “Sadly, monarchs now fit that bill very well”, says Brower. The petition also requests that critical habitat be designated for the species. By law, the FWS must now consider the petition and issue a finding within 90 days on whether it warrants further review. “Experts say a number of factors are contributing to the decline”, maintains Charla Lord of the Corporate Engagement department at Monsanto (St Louis, MO), producer of both the genetically engineered “Roundup Ready” crops and the Roundup herbicide. “One is habitat, especially milkweeds. Farmers need weed control in their fields. That's why we're joining experts to create habitat outside farm fields.” This summer, two species of mountain frogs – with bright yellow underbellies and large tadpoles the size of a Snickers bar – have won protection under the US Endangered Species Act (ESA). Rana muscosa and Rana sierrae, collectively known as mountain yellow-legged frogs, were once the most abundant amphibians in Sierra Nevada high-elevation aquatic ecosystems. But after a century of stocking fishless lakes with non-native predatory fish, combined with the more recent arrival of the chytrid fungus (Batrachochytrium dendrobatidis), the frog populations have been severely depleted. “These frogs are apex predators in an [undisturbed] aquatic ecosystem, and we've lost them from 95% of their former range”, laments Roland Knapp, a research biologist at the University of California Sierra Nevada Aquatic Research Laboratory (Mammoth Lakes, CA). “It's like taking the grizzly bears out of Yellowstone.” The Sierra Nevada yellow-legged frog. The listing comes as resource managers from Sequoia and Kings Canyon National Parks (SEKI) have proposed a restoration plan for the frogs' aquatic habitat within park boundaries. The two parks are the only federal lands where both species occur, and together contain about one-third of the 536 978 ha that the US Fish and Wildlife Service identified as potential critical habitat for the frogs. If adopted as proposed, the SEKI plan would eliminate fish from 87 (16%) of the park's 549 lakes that now contain stocked fish. According to national park aquatic ecologist Daniel Boiano (Three Rivers, CA), the piscicide rotenone would be used where gill-netting and electrofishing are infeasible. The plan builds on an existing SEKI pilot program initiated in 2001, in which fish were removed from 26 lakes. In some of those lake systems, post-treatment frog abundance jumped as much as 60-fold. “When you take the fish out, the ecosystem rebounds quickly”, Boiano says. Nevertheless, chytrid fungus is “the 800 pound gorilla”, as Knapp puts it, and remains a formidable challenge. However, he also noted that some heavily infested Yosemite frog populations have rebounded in spite of the infection. “I'm actually more hopeful now than I've ever been. There are frogs in places today where they weren't 10 years ago.” Studies are also underway to examine how treatment with an antifungal drug or with a naturally occurring bacterial species might be used to improve survival in targeted frog populations. Both of these options are included in the SEKI plan, and will likely play a role in the multi-agency, comprehensive recovery efforts required by the ESA listing. On the front lines of the fight against illegal timber harvesting in sensitive environments, Chuck Cannon (Texas Tech University, Lubbock, TX) is developing a new method that uses DNA fingerprinting to determine the legality of harvested trees based on identifying their species and geographic origins. Previously, Cannon observed a strong geographic signal in the genetic code of trees, convincing him that one can identify the collection site of a wood sample with high probability, given just the genetic data. “If you know where a log came from, you can determine whether it was legally obtained”, says Cannon. This genetic method could be a powerful tool for customs officials and members of other agencies that attempt to regulate the timber industry and discourage illegal logging. “Currently, the legality of wood is determined through a process called the ‘chain of custody'”, explains Cannon. “The log is basically tracked with a paper trail. Each log is documented in the field when harvested. Then, each time the log is bought and sold, the documents are updated and reflect this change in custody.” Unlike the “chain of custody” records, DNA fingerprinting evidence would be very difficult to circumvent or fake, and the results of the legality test could be independently reproduced. In short, illegal loggers would effectively be pushed out of the market, unable to sell their product through legal channels. While the method is still under development, Cannon envisions numerous potential ecological benefits from its implementation. For instance, it might help legal wood producers corner the market and invest more into the management and protection of their forest stocks: “sustainable management could be profitable, maintaining higher levels of ecosystem services and conservation value”. One major hurdle to widespread implementation of timber DNA fingerprinting is creating an accurate and robust database for the entire global timber market – a daunting task. However, prioritizing forests and habitats by their ecological importance may simplify the process. Success of the method ultimately depends on creating incentives for enforcement and devaluing illegally harvested timber. “I think the scientific basis and technology are already there for many species”, declares Cannon. According to recent research, over 40% of the world's garbage is burned in open fires (Environ Sci Technol 2014; doi:10.1021/es502250z), suggesting that burning trash is a much bigger contributor to global pollution than previously thought. The study's authors assert that in many countries, emissions from burning trash in open fires are excluded from national inventories of air pollution. Those inventories may therefore substantially underestimate emissions of hazardous pollutants and greenhouse gases, especially in developing nations where this practice is more prevalent. The study claims to be the most comprehensive effort to date to create consistent country-by-country estimates of pollution from open waste burning. “If we're going to try to solve air-quality problems around the world, we can't ignore this source”, says lead author Christine Wiedinmyer, a scientist at the National Center for Atmospheric Research (Boulder, CO). Because trash burning is unmonitored, the study's calculations are based on estimated information about per capita waste production, waste composition, and other factors. Consequently, Wiedinmyer says that in some cases, values of actual emissions may differ from their figures by a factor of two. However, even with this margin of error, the global impact of burning waste is considerable. Worldwide, the study suggests that nearly 1 billion metric tons – 41% of total waste generated annually – are disposed of through unregulated burning. This produces and CO2 mercury estimated to be equivalent to 5% and 10%, respectively, of the 2010 total global anthropogenic emissions. Open waste burning also releases substantial amounts of particulates as well as carbon monoxide, dioxins, benzene, and sulfur dioxide. The regional effects of waste burning, as reported in the study, are even more startling. For example, open waste burning contributes significantly to China's notorious air-quality problems, generating particulate emissions (PM10) reckoned to be equivalent to 22% of the country's reported anthropogenic emissions. For several developing countries in Africa and Asia, such as Sri Lanka, Lesotho, and Somalia, emissions of some pollutants, including CO2, are actually greater than the reported emissions from all other human sources. “Waste burning has a big impact on regional air quality in some countries”, Wiedinmyer continues. “But I don't think this is a simple problem to address. In developing countries, there is very little waste management, particularly in rural areas, and burning trash is one of the only ways to get rid of it. In addition, people may use waste to heat their homes or for cooking.” In India, a traditional religious ritual – immersing idols depicting Hindu deities into water bodies – is jeopardizing water quality in many of the country's lakes and rivers. Small idols traditionally made from clay and decorated with natural dyes have more recently been replaced with large statues made from quicksetting gypsum plaster (plaster of Paris) and adorned with synthetic colors and non-biodegradable decorative materials. For religious festivals, communities vie with each other to produce the largest, most elaborate idols. India's Central Pollution Control Board (CPCB) estimates that the immersion of a large number of such idols can cause water quality to deteriorate in terms of reduced conductivity, increased biochemical oxygen demand, and elevated heavy metal concentrations. “Lead-based paint on the idols is the most dangerous pollutant. In our assessment, several hundred tons of lead are getting into the environment – including the food chain –due to this annual ritual”, according to Thuppil Venkatesh, head of the National Referral Centre for Lead Poisoning (Bangalore, India). “Gypsum plaster may not affect water quality directly but it settles on the bottom, forming a solid layer, thereby impacting the recharge capacity of water bodies.” A religious procession with large idols in Mumbai, India. Idol immersion is currently unregulated. In 2010, the CPCB formulated guidelines promoting the use of natural clay and water-soluble natural dyes in idol-making, in addition to suggesting the removal of any accompanying flowers, clothes, and other decorations prior to immersion. In some regions, courts have prohibited the use of gypsum plaster in making the idols, while a few states have encouraged the immersion ritual to be practiced in artificial, confined water tanks. “The present guidelines on idol immersion are not mandatory and many states are not following them. What we need is a uniform and practical set of standard operating procedures for the entire country”, argues Subhas Dutta (Kolkata), an India-based environmental activist. “The competitive spirit of the immersion ceremonies is not backed by religious necessity. Large idols can just be immersed once, taken out and recycled. We should encourage such practices.” Climate change is making parts of the world not just warmer, but sicker too. A study published in August showed that Lyme disease is likely to expand 250–500 km northward in the next 40 years, as a result of climate-induced range shifts in the animal vectors of the disease (Evol Appl 2014; doi:10.1111/eva.12165). In North America, Lyme disease, caused by the Borrelia genus of bacteria, is transmitted to humans primarily through the black-legged or deer tick, Ixodes scapularis. This arachnid has a complex life cycle, requiring different kinds of mammals as hosts at different life stages – and because both ticks and mammals may perish in the winter cold, a warming climate can create new territory for both species and any diseases they carry. The team who carried out the study sampled rodent and tick populations in 34 sites throughout southern Quebec, along the edge of the current range of Lyme disease. Captured animals were tested for the presence of the bacterium Borrelia burgdorferi; the researchers then modeled these data to explain why Lyme disease occurs where it does. While the presence of ticks was an important predictor of the presence of Lyme disease, the most important culprit was something a bit bigger. “When you have ticks, what's really driving the occurrence and risk of Borrelia is the white-footed mouse”, explains Virginie Millien, Assistant Professor and Curator at the Redpath Museum (McGill University, Montreal, Canada). “And what's really driving the presence of the mouse is the climate.” Millien and her colleagues applied climate projections for the year 2050 to their model and predicted that the disease is likely to creep northward by 3.5–11 km per year due to increasingly warm winters. A white-footed mouse (Peromyscus leucopus) collected from a park near Montreal. This expansion of Lyme disease means that the illness is popping up more often where it has never been experienced before, causing potential public health issues for an unaware populace. “We're finding that high-risk areas for Borrelia are matching areas where human population densities are highest, in Quebec”, adds Millien. “The health system in the province needs to move fast to deal with that.” Given current threats to the world's biodiversity, scientists and governments are calling for rigorous assessment of the planet's natural resources. But there just aren't enough scientists to do it all. Now, a new study finds that interviewing local community members provides data on species abundance that are just as accurate as data from surveys conducted by trained scientists – and at one-eighth the cost (Conserv Lett 2014; doi:10.1111/conl.12100). Researchers often worry that bio-diversity surveys conducted by indigenous people will be biased by their personal involvement in subsistence hunting, says study author Finn Danielsen, an ecologist at the Nordic Agency for Development and Ecology (Copenhagen, Denmark). But earlier studies by Danielsen and others have shown that local people and scientists walking the same route through a forest produce comparable data on species abundance. Taking those studies to the next level, Danielsen and his team wondered whether the output from a community-level focus group discussion could compare with data from field surveys. Village leaders helped recruit knowledgeable people from the Miskito and Mayangna communities in Nicaragua's Bosawás Biosphere Reserve. The scientists and community members agreed on 10 organisms to be surveyed: mammals, birds, and plants important for food and other uses. Every 3 months for 2 years, focus groups of 10–20 individuals were queried about the population size of these species. On the same schedule, but on different days, a scientist and a local person would walk for 2 hours along a 2-km tropical forest transect, noting numbers of each species. “The information from the focus groups matched what the trained scientists and local people found on the transects”, says Danielsen. “Indigenous knowledge is a large and living library and this study is like opening the doors of the library, empowering community members and giving them a voice”, Danielsen continues. The key is to ensure that it is a two-way process, controlled and led by the community members. “By respecting and involving local people in biodiversity surveys, there's a greater chance that scientific knowledge will be used to manage their resources”, he says. “The study is valuable because it found an eight-fold saving in the cost of surveys by local people”, points out William Sutherland, a conservation biologist at Cambridge University (Cambridge, UK). The results will be useful for the Intergovernmental Platform on Biodiversity and Ecosystem Services, a UN panel to support natural resources that is committed to working alongside local experts.