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A new model for understanding biodiversity

noreply@blogger.com (Sans) — Fri, 25 Nov 2011 02:38:03 PST

Researchers develop a unified theory of ecosystem change by combining spatial modelling and food web analysis

Animals like foxes and raccoons are highly adaptable. They move around and eat everything from insects to eggs. They and other “generalist feeders” like them may also be crucial to sustaining biological diversity, according to a new study published this week in the Proceedings of the National Academy of Sciences (PNAS).

McGill biology researchers have developed a unified, spatially based understanding of biodiversity that takes into account the complex food webs of predators and prey. “Biodiversity exists within a landscape. Predators and prey are continuously on the move as their habitats change – it’s a complex dynamic system,” says lead author Pradeep Pillai, a former doctoral candidate at McGill, now a research associate at the University of Oregon.

Previous theories of biodiversity have either concentrated on the complex network of feeding interactions that connects all species into food webs or have focused on the way that species are connected in space. “A unified theory of ecological diversity requires understanding how species interact both in space and time, and this is what is different about our work,” explains co-author Michel Loreau, who holds the Canada Research Chair in Theoretical Community and Ecosystem Ecology.

What they discovered was that a “branching network” maintained by generalist species, like foxes or coyotes, that are able to move around and prey on different species in different locations, have an important role in promoting complex food webs and thereby in maintaining biodiversity. The researchers concluded that these generalist species have the advantage of being able to find prey no matter where they are as they move from one place to another, and this sustains the network.

This theory also lays a foundation for understanding the effects human activities – like deforestation – are likely to have not simply on a single species but on whole food webs. The researchers show how food webs are eroded by species extinction when disturbed by habitat destruction. “The theory is useful because it helps us understand how biodiversity is maintained, but also the impacts humans have when they disrupt ecological networks by destroying and fragmenting habitat,” concludes co-author Andrew Gonzalez, Canada Research Chair in Biodiversity Science and Director of the Quebec Centre for Biodiversity Science.

This research was funded by the Natural Sciences and Engineering Research Council and the Fonds québécois de la recherche sur la nature et les technologies.

Global warming effects of CO2 could be less that those foreseen by the IPCC

noreply@blogger.com (Sans) — Thu, 24 Nov 2011 12:36:59 PST

According to the most accurate predictions on increasing CO2 levels and effects on the climate, published this week in Science, the Earth's temperature will rise less than expected even if current levels of CO2 emissions continue. The new prediction lowers the maximum increase in temperature from 4.5K to 2.6K, below that expected by the Intergovernmental Panel on Climate Change (IPCC), and discards the possibility of increases superior to 6K if CO2 levels in the atmosphere double in comparison to preindustrial levels. Taking part in the research was Universitat Autònoma de Barcelona (UAB) researcher Antoni Rosell.

Climate sensitivity measures how Earth's surface temperature is affected by changes in the atmosphere. Scientists have developed models to calculate climate sensitivity in relation to an increase in CO2, i.e. to calculate how temperature would rise depending on the increase in CO2 concentration in the atmosphere.

According to the latest report by the Intergovernmental Panel on Climate Change (IPCC), if CO2 concentrations in the atmosphere doubled in relation to preindustrial levels, the temperature of the Earth's surface would rise an average of 3K. This is a probabilistic estimation and scientists point out a 66% chance of a rise between 2 and 4.5K, and a not negligible chance of reaching a 6K increase. Nevertheless, scientists have not been able to narrow down this estimation in the past 32 years.

A research published this week in Science, in which UAB researcher Antoni Rosell took part, significantly reduces the temperature increase predicted by IPCC. According to the research, the average increase in temperature could be of 2.3K. It also shortens the difference between minimum and maximum temperature increase, with a 66% chance of it ranging from 1.7K to 2.6K and in no way reaching more than a 6K increase. The data is lower than that offered by the Intergovernmental Panel on Climate Change (IPCC) in its latest report in 2007.

Researchers arrived at these results by reconstructing temperatures from the Ice Age (21,000 years ago) using climate simulation models. The Ice Age is a very adequate climate period with which to make predictions on the effect of the rise of CO2 levels in the atmosphere and rises in temperature, given that concentrations of greenhouse gases were far lower than those found immediately before the preindustrial era (little over a century ago), and because surface temperatures and characteristics of the atmosphere at that period are well known thanks to palaeoclimate reconstructions.

According to the authors, "if climate restrictions 20,000 years ago can be applied to future predictions, as can be seen in the model, the probabilities of extreme climate changes in the near future are low compared to what was believed until now". Nevertheless, scientists do emphasise the fact that global warming is real and that the increase in atmospheric CO2 will have important effects.

The research, which included the participation of Antoni Rosell, ICREA researcher of the UAB Institute for Environmental Science and Technology, was directed by researchers from Oregon State University, and included members of Princeton University, Harvard University, Cornell University, and University of Oregon. Funding for the research was provided by the US National Science Foundation.

Hydrocarbon pollution along the coast of Galicia shot up five years after the Prestige oil spill

noreply@blogger.com (Sans) — Thu, 24 Nov 2011 12:30:45 PST

The results of a recent study by the University of Santiago de Compostela on Kentish Plover eggs has shown that there was a unexpected increase in hydrocarbon levels along the coast of Galicia five years after the Prestige oil spill. Worsened in previous years by works to remove the wreck, pollution levels began to rise again in the summer of 2006 along with numerous forest fires.

On 19th November 2002 the oil tanker Prestige sank off the coast of Galicia and spilled 63,000 tonnes of fuel oil into the sea, which reached coasts from the north of Portugal to France. The mass arrival of oil to the coast months after the accident was catastrophic.

A study by researchers at the University of Santiago de Compostela shows how progressively declining pollution levels experienced a surprising increase in 2007 due to “the wave of forest fires in Galicia in 2006,” explains Jesús Domínguez, co-author of the study.

He explains that “the badly-handled course that the ship took from north to south from the moment of the accident to its sinking increased pollution between 2004 and 2006. However, the dramatic increase of 2007 can only be attributed to the forest fires.”

Data were obtained through a 4 year-long observation of the levels of polycyclic aromatic hydrocarbons (50% of the fuel oil released by Prestige) in the eggs of the Kentish Plover (Charadrius alexandrinus), the only costal nesting bird on the beaches of Galicia’s Atlantic Coast.

The data from before 2007 showed a progressive decline in pollution levels. Until then, figures did not exceed 120 micrograms per kilogram in any of the studied areas. Pollution levels between 2004 and 2006 are in keeping with the results obtained from the study of waters, sediment, and other marine organisms after the Prestige oil spill.

Surprisingly, an unexpected increase in pollution was recorded in 2007. According to Jesús Domínguez, researcher at the University of Santiago de Compostela, this rise could have been caused to a large extent by “the large forest fires observed during the summer of 2006 in Galicia and in other coastal areas.” This suggests that oil pollution also reached the affected area by air.

According to data from the study, in 2007 pollution levels were very high. They exceeded 400 micrograms per kilogram in those areas closest to the oil spill and even exceeded 700 micrograms in those areas furthest away. In his study Domínguez concludes that this change is due to pyrogenic pollution sources, such as fires, which normally go unnoticed.

The expert recognises that “the interannual variations recorded during the study point towards a clear risk of getting close to dangerous levels” for the wildlife of the affected area. He goes on to add that the “course of the ship after the accident was so badly handled that that the fuel spread a lot more, which affected the entire Cantabrian and Atlantic coasts.”

The study focused on analysing the polycyclic aromatic hydrocarbons (PAH) levels in bird eggs “given that they are easily detectable and are considered good biomonitors of pollution in this faunal group.” For each egg, a study was carried out of 16 kinds of PAH classified as significant by the US Environmental Protection Agency due to their toxicity to marine organisms.

Samples were taken for four years in 10 of the species’ breeding locations, nine of which are on the Galician coast beaches and one in Ría de Aveiro, Portugal. Sample areas were grouped together according to their distance from the Prestige oil spill. Three area types were established: less than 50 kilometres, between 50 and 200 kilometres, and more than 200 kilometres.

The Kentish Plover is the only wading bird that nests and breeds on Northern Spain’s Atlantic Coast or, more precisely, in Galicia. This species shows signs of decline in various parts of Spain and Europe and is a priority for conservation in the European Union.

Everyday substances increase risk of allergies

noreply@blogger.com (Sans) — Thu, 24 Nov 2011 12:27:51 PST

The use of chemicals in our everyday lives entails increased risks of allergies in children, according to a study at Karlstad University in Sweden. The prevalence of PGEs, propylene glycol and glycol ethers, in bedroom air is associated with asthma, hay fever, and eczema, but also with antibodies against common allergens in children. The study shows a risk increase of up to 180 percent.

“The study shows for the first time that the concentration of PGEs, propylene glycol and glycol ethers, in bedroom air was linked to an increased risk of developing asthma, hay fever, and eczema in children,” says Carl-Gustaf Bornehag, professor of public health science at Karlstad University and associated with the SP Technical Research Institute of Sweden. “The increase in risk varied between 50 and 180 percent. It was also found that a higher concentration of PGEs in indoor air was associated with children evincing antibodies (IgE) against allergens such as cats, dogs, pollen. Our analyses also revealed that the use of water-based paint in the dwelling, as well as water-based cleansers, was linked to a higher concentration of PGEs in bedroom air.”

What does this mean?

In recent decades a huge number of chemicals have been introduced into our everyday environments. Such chemicals are primarily related to construction materials, paints, etc. and a great number of common consumer products such as cleansers, plastics, toys, cosmetics, and packaging.

“We have previously shown that phthalates from soft PVD could be tied to allergic conditions in children,” says Carl-Gustaf Bornehag. “Now we have focused on PGEs, which are a group of volatile organic compounds found in water-based indoor paints and cleansers, for example. Among the PGE substances identified are compounds suspected of disturbing hormones, which was also the case regarding the phthalates we studied earlier.”

“Our findings once again raise the question of the health-related aspects of the use of chemicals in our everyday lives,” says Carl-Gustaf Bornehag. “Particularly when it comes to exposure in our home environments, since small children and pregnant women spend a great deal of their time there and there are many indications that exposing fetuses and infants is probably more risky. Our current research is addressing this, that is, what does it entail in terms of chronic conditions later in life that we expose fetuses and infants to a great number of chemicals that are suspected of being toxic.”

The study comprised 198 preschool children with asthma and allergy and 202 healthy controls included in the Housing-Children-Health Study in the county of Värmland. Dwellings were examined by professional inspectors, and air samples were taken in the children’s bedrooms, where eight groups of volatile compounds were analyzed. The children were examined by physicians. Moreover, parents responded to a questionnaire about the family’s health, lifestyle, etc. The article is a result of a collaboration between Karlstad University and the Harvard School of Public Health in the U.S.

Rhino horn demand leads to record poaching

noreply@blogger.com (Sans) — Mon, 21 Nov 2011 05:55:06 PST

More rhinos have been killed in South Africa in the past 10 months than were killed in all of 2010, new poaching numbers reveal. Statistics from South Africa National Parks show that 341 animals have been lost to poaching so far in 2011, compared to a record total of 333 last year.

South Africa’s grim milestone comes on the heels of an announcement by WWF last week that rhinos have gone extinct in Vietnam. The carcass of Vietnam’s last Javan rhino was found with a gunshot wound and without its horn.

At a meeting of the Convention on International Trade in Endangered Species (CITES) last year, the international community concluded that the increase in rhino poaching has been caused largely by demand for horn products in Vietnam. Law enforcement efforts, while increasing, are not yet sufficient to protect rhinos from poachers or stop the smuggling and sale of their horns by organized crime rings.

Rhino population statistics

African species
Black Rhino: 4,838 IUCN Red List Classification: Critically endangered
White Rhino: Approx 20,000, up from fewer than 100 in 1900. IUCN Red List Classification: Near threatened
South Africa rhino population: 1,916 Black, 18,780 White

Asian species
Greater-one horned: 2,913. IUCN Red List Classification: Vulnerable
Javan: No more than 50. IUCN Red List Classification: Critically endangered
Sumatran: Fewer than 200. IUCN Red List Classification: Critically endangered

South Africa poaching numbers
Source: SANParks
Number recorded since 2000: 999 rhinos over past 12 years
2010: 333 rhinos total
2011: 341 rhinos through Oct, at least 16 critically endangered black. At least 197 in Kruger National Park
Arrests in 2010: 165
Arrests in 2011: 186“It's hardly surprising the horn was missing from the last rhino as Vietnam is the preeminent market destination for illegally sourced rhino horns," says Tom Milliken, TRAFFIC rhino programme coordinator.
In addition to being the biggest consumer of rhino horn, Vietnam is also a major market for tiger parts and other products derived from endangered species. Populations of tigers in the country are alarmingly low and could soon follow the Vietnamese Javan rhino into extinction.

“The unfounded rumour that rhino horn can cure cancer most likely sealed the fate of the last Javan rhino in Vietnam,” says Dr. A. Christy Williams, WWF’s Asian rhino expert, “This same problem is now threatening other rhino populations across Africa and South Asia.”

Of the five species of rhinoceros, three are critically endangered. With the loss of the Vietnamese Javan rhino, there are now fewer than 50 Javan rhinos remaining, all in one national park in Indonesia.

"It's tragic that the Javan rhino has been wiped out in Vietnam by the same forces that are driving rhino poaching in Africa. This is the ultimate wake-up call for the Vietnamese government to turn aggressively on its internal rhino horn market," Milliken added.

South Africa has been the focal point of poaching because it has the largest population of rhinos in the world. Law enforcement efforts there have been scaled up resulting in more arrests, and some of those convicted are being sentenced to lengthy prison terms.

However, demand for medicinal products containing rhino horn continues to increase in Vietnam and other parts of Asia. Rhino horn has no proven ability to treat cancer and is no longer a part of the official Chinese traditional medicine pharmacopeia.

Despite an international ban on commercial trade under CITES, rhino horn continues to be smuggled illegally from Africa to Asia. Additionally, legal loopholes allowing for the export of rhino hunting trophies are being exploited in some South African provinces. Improvements are needed in the regulation of hunting permits and the management rhino horn stock piles in the country.

“Since armed protection for rhinos in South African national parks is strong, poaching syndicates are likely to shift to countries with weaker enforcement power, including possibly Asian countries that may be caught off-guard,” said Dr. Carlos Drews, Global Species Programme Director at WWF. “To break the illegal trade chain, governments in source, transit and consumer countries must all scale up their efforts.”

In September a delegation of Vietnamese officials visited South Africa to discuss enhancing law enforcement cooperation between the two countries. Last year TRAFFIC facilitated a similar visit to Vietnam for South African authorities.

“Vietnam should follow South Africa’s example and start sending poachers, traders, smugglers and sellers to jail,” says Dr. Joseph Okori, WWF’s African rhino programme coordinator. “In order to save rhinos from extinction, the criminal syndicates operating between South Africa and Vietnam must be uncovered and shut down for good.”

Nissan named Low Carbon Car Manufacturer of the year

noreply@blogger.com (Sans) — Thu, 24 Nov 2011 01:45:13 PST

NISSAN Leaf Nissan was named Low Carbon Car/Van Manufacturer of the Year at the LowCVP Low Carbon Champions Awards ceremony held at the Institution of Mechanical Engineers (IMechE) in London.

The judges said that Nissan has been at the forefront of EV and battery technology development which culminated in the launch of the ground-breaking fully electric Nissan LEAF in March 2011. The judges referred to Nissan ‘as a leader in the electrification of transport' as well as applauding the car company on its innovative technology and its extensive activity and partnerships.

The judges acknowledged that the company's effort had helped place electric vehicles firmly in the minds of the motoring public as well as ensuring a network of charging and servicing points, thereby making the transition to electric motorist as seamless as possible for both consumers and company car drivers.

Nissan also received the Outstanding Achievement in Low Carbon Transport award for its overall undisputed achievement across the full range of activities to encourage the shift to decarbonised motoring.

The LowCVP Low Carbon Champions Awards recognise best practice from vehicle manufacturing and fleet operations to the development of products and services that reduce greenhouse gases from road transport operations. Nissan beat off tough opposition - a total of 44 companies and organisations shortlisted - throughout the rigorous judging process.

These accolades are the latest in a long line of awards the Nissan LEAF has picked up this year including the Ultra Low Carbon Award in the What Car? Car of the Year Awards 2011.

Jim Wright, managing director at Nissan Motor (GB) said: "These latest awards reflect the industry's confidence in the Nissan LEAF, its innovative technology, quality build, durability and appeal to the motorist. We blazed a trail with the LEAF and our inherent belief that we were creating a vehicle that could help move us towards no-carbon driving has paid off for us as a company, for the motorist and ultimately for the environment. We are delighted that our foresight and vision continues to be recognised."

Nissan research has found that 80% of daily driving in Britain is below 30 miles, well within the LEAF's 110 mile range. With the ability to carry five passengers and a 90mph top speed, it marks a significant development in the environmentally-friendly options available for motorists.

Effects of climate change to further degrade fisheries resources: UBC researchers

noreply@blogger.com (Sans) — Mon, 21 Nov 2011 03:47:34 PST

A new study led by University of British Columbia researchers reveals how the effect of climate change can further impact the economic viability of current fisheries practices.

“Fisheries are already providing fewer fish and making less money than they could if we curbed overfishing,” says Rashid Sumaila, principal investigator of the Fisheries Economics Research Unit at UBC and lead author of the study. “We could be earning interest, but instead we’re fishing away the capital. Climate change is likely to cause more losses unless we choose to act.”

Partly supported by the Pew Charitable Trusts, National Geographic, the World Bank and U.S. National Oceanic and Atmospheric Administration, the study is a broad view of the impact of climate change on fisheries and their profitability. It is published online today in the journal Nature Climate Change.

Over the last century the ocean has become warmer and more acidic. Other human-led factors, such as pollution and overfishing, have also been hard on marine species. With ocean warming, many species will move further towards the poles and into deeper water.

While fisheries in a few regions, such as the far north, may benefit from climate change, many other regions, particularly those in the tropics, can expect losses in revenues. Regional examples can help inform what could happen globally. For example, the reduction in landings of pelagic fisheries in Peru as a result of changes in sea surface temperature during the 1997-1998 El Niño event caused more than US$26 million of revenue loss.

“Changes in temperature and ocean chemistry directly affect the physiology, growth, reproduction and distribution of these organisms,” says William Cheung, a biologist at the UBC Fisheries Centre. “Fish in warmer waters will probably have a smaller body size, be smaller at first maturity, with higher mortality rates and be caught in different areas. These are important factors when we think of how climate change will impact fisheries.”

“This study provides an early glimpse of how climate change might impact the economics of fishing,” says Sam Herrick, a NOAA scientist and co-author. “We must continue to study how climate change, combined with other factors, will affect marine ecosystems and the productivity of fishery resources.”

Biologically, maintaining more abundant populations can help increase fish’s capacity to adapt to environmental change. Curbing overfishing is crucial to making marine systems more robust and ready for changes that are already underway.

“This study highlights the potential negative impacts of climate change on the profitability of fisheries,” said Vicky Lam, UBC graduate student and co-author. “The next generation of scientists must put more effort on exploring ways to minimize the impacts of climate change.”

Fish stocks will also be more robust to climate change if the combined stresses from overfishing, habitat degradation, pollution runoff, land-use transformation, competing aquatic resource uses and other anthropogenic factors are minimized.

“We have to remember that the effect of climate change on the marine environment will occur alongside the impacts on land,” says Daniel Pauly, a UBC fisheries biologist and co-author. “It will not be easy to divert resources from one sector to help another sector. This is why a strong governance system is needed – to temper the losses on the sectors that are worst hit.”

“Governments must be anticipatory, rather than reactive,” says Sumaila. “We all need to think more of the future while we act now.”

McDonald's Animal Cruelty

noreply@blogger.com (Sans) — Mon, 21 Nov 2011 03:47:53 PST

A new Mercy For Animals undercover investigation into a McDonald's egg supplier, Sparboe Egg Farms, exposes the fast-food giant's secret ingredient: shocking cruelty to animals.

Hidden-camera footage taken at Sparboe facilities in Iowa, Minnesota and Colorado reveals:

Hens crammed into filthy wire cages with less space for each bird than a standard-sized sheet of paper to live her entire miserable life, unable to fully stretch her wings or engage in most other natural behaviors
Workers burning off the beaks of young chicks without any painkillers and callously throwing them into cages, some missing the cage doors and hitting the floor
Workers grabbing hens by their throats and ramming them into battery cages
Rotted hens, decomposed beyond recognition as birds, left in cages with hens still laying eggs for human consumption
A worker tormenting a bird by swinging her around in the air while her legs were caught in a grabbing device - violence described as "torture" by another worker
A worker shoving a bird into the pocket of another employee without any regard for the animal's fear and suffering
Chicks trapped and mangled in cage wire - others suffering from open wounds and torn beaks
Live chicks thrown into plastic bags to be suffocated

Pesticide in food: Apples, Celery top the list

noreply@blogger.com (Sans) — Mon, 13 Jun 2011 21:07:03 PDT

Environmental Working Group has released the seventh edition of its Shopper’s Guide to Pesticides in Produce with updated information on 53 fruits and vegetables and their total pesticide loads. EWG highlights the worst offenders with its “Dirty Dozen” list and the cleanest conventional produce with its “Clean 15” list.

Analysts at EWG synthesized data collected from the U.S. Department of Agriculture and the Food and Drug Administration from 2000 to 2009. Produce is ranked based on a composite score, equally weighing six factors that reflect how many pesticides was found in testing of on each type of the produce and at what levels. Most samples are washed and peeled prior to being tested, so the rankings reflect the amounts of the chemicals likely present on the food when is it eaten.

Notable changes in the new guide included apples’ rank as the most contaminated produce, jumping three spots from last year to replace celery at the top of the “Dirty Dozen” list. According to USDA, pesticides showed up on 98 percent of the more than 700 apple samples tested.

Making an appearance in the guide for the first time is the herb cilantro, which had never been tested by USDA until now. The data showed 33 unapproved pesticides on 44 percent of the cilantro samples tested, which is the highest percentage of unapproved pesticides recorded on any item included in the guide since EWG started tracking the data in 1995.

Also appearing in the guide for the first time are green onions, cranberries and mushrooms. Mushrooms made the “Clean 15” list, while honeydew was the only item to drop off that list this year. Cherries dropped off the “Dirty Dozen” list, but lettuce, which has made the list in previous years, were back on.

“Though buying organic is always the best choice, we know that sometimes people do not have access to that produce or cannot afford it,” said EWG President Ken Cook. “Our guide helps consumers concerned about pesticides to make better choices among conventional produce, and lets them know which fruits and vegetables they may want to buy organic.”

Pesticides can be extremely toxic to human health and the environment. U.S. and international government agencies alike have linked pesticides to nervous system toxicity, cancer, hormone system disruption and IQ deficits among children.

"I really worry that pesticides on food are unhealthy for the tender, developing brains and bodies of young children," said Dr. Harvey Karp, MD, FAAP, creator of the book/DVD The Happiest Baby on the Block. "Parents don't realize they're often feeding their little ones fruits and veggies with the highest pesticide residues. Studies show even small amounts of these chemicals add up and can impair a child's health when they're exposed during the early, critical stages of their development. When pesticide sprayers have to bundle up in astronaut-like suits for protection, it's clear parents want to feed their families food containing as little of these toxic chemicals as possible."

"Pesticides, while designed specifically to kill certain organisms, are also associated with a host of very serious health problems in people, including neurological deficits, ADHD, endocrine system disruption and cancer," said Andrew Weil, MD, Founder and Director, Arizona Center for Integrative Medicine and a renowned medical expert on natural health and wellness. "My advice to consumers is to whenever possible avoid exposure to pesticides, including pesticide residues on food."

Consumers who choose five servings of fruits and vegetables a day from EWG's Clean 15 list rather than from the Dirty Dozen can lower the volume of pesticides they consume by 92 percent, according to EWG’s calculations. They will also eat fewer types of pesticides. Picking five servings of fruits and vegetables from the 12 most-contaminated products would result in consuming an average of 14 different pesticides a day. Choosing five servings from the 15 least contaminated fruits and vegetables would result in consuming fewer than two pesticides per day.

The health benefits of a diet rich in fruits and vegetables outweigh the risks of pesticide exposure, and EWG strongly recommends that everyone follow USDA’s recommendation to eat five servings of fruits and vegetables every day. EWG’s Shopper’s Guide makes it easy to meet that goal while reducing your exposure to pesticides.

“Pesticides are toxic,” said Sonya Lunder, Senior Analyst at EWG. “They are designed to kill things and most are not good for you. The question is, how bad are they?”

EWG’s Shoppers Guide is available for fee as a PDF download at http://www.ewg.org/foodnews/.

New research finds mangroves key to climate change

noreply@blogger.com (Miti) — Sun, 10 Apr 2011 04:38:31 PDT

New research shows that mangroves store exceptionally more carbon than most tropical forests, but they are being destroyed from coastlines at a rapid rate causing significant emissions of greenhouse gases.

The findings from the study, which was carried out by scientists from the Center for International Forestry Research (CIFOR) and the USDA Forest Service, underscore a call by scientists for mangroves to be protected as part of global efforts to combat climate change.

"Mangroves are being destroyed at an alarming rate. This needs to stop. Our research shows that mangroves play a key role in climate change mitigation strategies," said Daniel Murdiyarso, Senior Scientist at CIFOR, a co-author of the paper, entitled Mangroves among the most carbon-rich forests in the topics.

In the study, which was published on April 3 in Nature GeoScience, scientists quantified carbon storage in mangroves across a large tract of the Indo-pacific region. No studies to date have integrated the necessary measurements for total mangrove carbon storage across broad geographic domains.

From the results, the scientists estimated that the destruction and degradation of mangrove forests may be generating as much as 10% of all the global deforestation emissions despite accounting for just 0.7% of tropical forest area. Much of that carbon is stored in the ground below the mangroves forests that can be seen above the ground and water.

Deforestation and land-use change currently account for 8% to 20% of all global carbon emissions, second only to the use of fossil fuels. An international initiative known as REDD+ (reduced emissions from deforestation and forest degradation) is considered one of the most cost-effective ways to slow the rate of climate change.

Mangroves occur along the coasts of most major oceans in some 118 countries. A 30% to 50% decline in mangroves over the past half-century has raised fears that they may disappear altogether in as little as 100 years.

Rapid 21st century sea level rise has also been cited as a primary threat to mangroves, which have responded to past more gradual sea-level changes by migrating landward or upward. Under current climate trends, sea level is projected to rise 18-79 centimeters this century - and even higher if ice-sheet melting continues accelerating.

Mangroves are also being threatened by increasing pressures from urban and industrial developments, as well as fish farms.

"There is a lack of awareness of the full implications of mangrove loss for humankind," Murdiyarso said. "There is an urgent need for governments to acknowledge their importance and develop better policies to ensure their protection."

Mangroves are not only key to climate change mitigation efforts, they also play important roles in adapting to the changing climate. They protect coastlines from storm surges and fluctuations in sea levels, including from tsunamis.

CO2-chomping microbes battling for ocean iron

noreply@blogger.com (Sans) — Mon, 24 Jan 2011 02:05:47 PST

Australian, Belgian and New Zealand scientists have expanded our understanding of the way phyoplankton take up scarce iron in the ocean – a process that regulates ocean food chains from the bottom up and helps remove up to 40 per cent of carbon dioxide (CO2) from the atmosphere.

Research published recently in the Proceedings of the National Academy of Science explores the relationship between iron, which limits primary productivity in vast regions of the ocean, and its uptake by phytoplankton species.

It has identified how natural organic compounds in the Southern Ocean can control iron availability to phytoplankton in iron-deficient waters and, in particular, for high-nutrient but low-chlorophyll regions.

"The anaemic regions of the oceans are a ‘battlefield’ for iron, which drives photosynthesis and enhances growth of phytoplankton and other microbes in the oceanic food chain for the benefit of all marine species," said the project team’s leader, former CSIRO Postdoctoral Fellow and now University of Technology Sydney researcher, Dr Christel Hassler.

"Ocean chemists are eager to know more about this process, which mediates uptake of CO2 and its subsequent storage in the ocean interior, as species die and sink.

“This research reveals the significance of a newly identified organic mechanism controlling the bio-availability of iron to oceanic life," Dr Hassler said.

According to co-author, CSIRO’s Dr Carol Nichols, given that marine phytoplankton contribute up to 40 per cent of global biological carbon fixation, it is important to understand what features control the availability of iron to these organisms.

“Phytoplankton and other microbes living in the oceans produce long sugar polymers, or polysaccharides, as a survival strategy,” Dr Nichols said. “Polysaccharides help the microbial community stick to each other and to nutrients that may otherwise be difficult to access from the surrounding ocean.

“Working with laboratory cultures of Southern Ocean phytoplankton, the study shows that biologically-produced polysaccharides help keep iron accessible to phytoplankton by increasing its solubility in the upper layers of the oceans where photosynthesis occurs,.

"In the ocean, most of the iron is bound to organic materials whose nature is largely unknown. Most marine microorganisms release saccharides or sugars, resulting in high levels being reported. These observations originally motivated our study," Dr Nichols said.

Iron fertilisation of the ocean has long been mooted as an option to engineer change in the amount of CO2 in the ocean.

"If we can understand the processes behind cycling of iron and other micronutrients in the oceans more fully, then we will be in a better position to counsel on proposals for such environmental engineering," Dr Nichols said.

New melt record for Greenland ice sheet

noreply@blogger.com (Sans) — Mon, 24 Jan 2011 02:11:59 PST

CCNY's Marco Tedesco says 'exceptional' season stretched up to 50 days longer than average

New research shows that 2010 set new records for the melting of the Greenland Ice Sheet, expected to be a major contributor to projected sea level rises in coming decades.

"This past melt season was exceptional, with melting in some areas stretching up to 50 days longer than average," said Dr. Marco Tedesco, director of the Cryospheric Processes Laboratory at The City College of New York (CCNY – CUNY), who is leading a project studying variables that affect ice sheet melting.

"Melting in 2010 started exceptionally early at the end of April and ended quite late in mid- September."

The study, with different aspects sponsored by World Wildlife Fund (WWF), the National Science Foundation and NASA, examined surface temperature anomalies over the Greenland ice sheet surface, as well as estimates of surface melting from satellite data, ground observations and models.

In an article published today in "Environmental Research Letters," Professor Tedesco and co-authors note that in 2010, summer temperatures up to 3C above the average were combined with reduced snowfall.

The capital of Greenland, Nuuk, had the warmest spring and summer since records began in 1873.

Bare ice was exposed earlier than the average and longer than previous years, contributing to the extreme record.

"Bare ice is much darker than snow and absorbs more solar radiation," said Professor Tedesco. "Other ice melting feedback loops that we are examining include the impact of lakes on the glacial surface, of dust and soot deposited over the ice sheet and how surface meltwater affects the flow of the ice toward the ocean."

WWF climate specialist Dr. Martin Sommerkorn said "Sea level rise is expected to top 1 metre by 2100, largely due to melting from ice sheets. And it will not stop there – the longer we take to limit greenhouse gas production, the more melting and water level rise will continue."

Loss of reflectivity in the Arctic doubles estimate of climate models

noreply@blogger.com (Sans) — Mon, 24 Jan 2011 02:12:53 PST

A new analysis of the Northern Hemisphere's "albedo feedback" over a 30-year period concludes that the region's loss of reflectivity due to snow and sea ice decline is more than double what state-of-the-art climate models estimate.

The findings are important, researchers say, because they suggest that Arctic warming amplified by the loss of reflectivity could be even more significant than previously thought.

The study was published online this week in Nature Geoscience. It was funded primarily by the National Science Foundation, with data also culled from projects funded by NASA, the Department of Energy and others.

"The cryosphere isn't cooling the Earth as much as it did 30 years ago, and climate model simulations do not reproduce this recent effect," said Karen Shell, an Oregon State University atmospheric scientist and one of the authors of the study. "Though we don't necessarily attribute this to global warming, it is interesting to note that none of the climate models used for the 2007 International Panel on Climate Change report showed a decrease of this magnitude."

The cryosphere is the collective portion of the Earth's surface where water is in solid form and includes sea ice, snow, lake and river ice, glaciers, ice sheets and frozen ground. Most of these frozen areas are highly reflective, and "bounce" sunlight back into the atmosphere, keeping the Earth cooler than it would be without the cryosphere.

But as temperatures warm, ice and snow melts and reflectivity decreases, noted Shell, an assistant professor in OSU's College of Oceanic and Atmospheric Sciences.

"Instead of being reflected back into the atmosphere, the energy of the sun is absorbed by the Earth, which amplifies the warming," Shell said. "Scientists have known for some time that there is this amplification effect, but almost all of the climate models we examined underestimated the impact – and they contained a pretty broad range of scenarios."

As part of the study, Shell, lead author Mark Flanner of the University of Michigan, and their colleagues compared Northern Hemisphere cryosphere changes between 1979 and 2008 in 18 different climate models to changes in actual snow, ice and reflectivity measurements of the same period. They determined that mean radiative forcing – or the amount of energy reflected into the atmosphere – ranged from 4.6 to 2.2 watts per meter squared.

During the 30-year study period, cryosphere cooling declined by 0.45 watts per meter squared. The authors attribute that decline equally to loss of snow and sea ice.

"Some of the decline may be natural climate variability," Shell said. "Thirty years isn't a long enough time period to attribute this entirely to 'forcing,' or anthropogenic influence. But the loss of cooling is significant. The rate of energy being absorbed by the Earth through cryosphere decline – instead of being reflected back to the atmosphere – is almost 30 percent of the rate of extra energy absorption due to carbon dioxide increase between pre-industrial values and today."

The "albedo" or reflectivity process is simple, scientists say, but difficult to measure on a broad scale. The reflectivity of ice and snow is obviously much greater than that of darker, unfrozen ground, or open sea water. But researchers also have discovered that variations in the snow and ice result in different albedo impacts.

For example, pools of melted water on top of sea ice can have significantly less reflectivity, which in essence may speed up the warming and possibly melting of that sea ice.

"While the current group of models underestimates these Northern Hemisphere cryosphere changes, new models will be released this year that will have better representations of snow and ice," Shell said. "This study will help climate modelers improve the new generation of models to better predict the rate of cryosphere and albedo decline in the future."

Volcanoes have shifted Asian rainfall

noreply@blogger.com (Sans) — Mon, 08 Nov 2010 21:14:50 PST

Scientists have long known that large volcanic explosions can affect the weather by spewing particles that block solar energy and cool the air. Some suspect that extended "volcanic winters" from gigantic blowups helped kill off dinosaurs and Neanderthals. In the summer following Indonesia's 1815 Tambora eruption, frost wrecked crops as far off as New England, and the 1991 blowout of the Philippines' Mount Pinatubo lowered average global temperatures by 0.7 degrees F — enough to mask the effects of man-made greenhouse gases for a year or so.

Now, scientists have shown that eruptions also affect rainfall over the Asian monsoon region, where seasonal storms water crops for nearly half of earth's population. Tree-ring researchers at Columbia University's Lamont-Doherty Earth Observatory showed that big eruptions tend to dry up much of central Asia, but bring more rain to southeast Asian countries including Vietnam, Laos, Cambodia, Thailand and Myanmar — the opposite of what many climate models predict. Their paper appears in an advance online version of the journal Geophysical Research Letters.

The growth rings of some tree species can be correlated with rainfall, and the observatory's Tree Ring Lab used rings from some 300 sites across Asia to measure the effects of 54 eruptions going back about 800 years. The data came from Lamont's new 1,000-year tree-ring atlas of Asian weather, which has already produced evidence of long, devastating droughts; the researchers also have done a prior study of volcanic cooling in the tropics. "We might think of the study of the solid earth and the atmosphere as two different things, but really everything in the system is interconnected," said Kevin Anchukaitis, the study's lead author. "Volcanoes can be important players in climate over time."

Large explosive eruptions send up sulfur compounds that turn into tiny sulfate particles high into the atmosphere, where they deflect solar radiation. Resulting cooling on earth's surface can last for months or years. (Not all eruptions will do it; for instance, the continuing eruption of Indonesia's Merapi this fall has killed dozens, but this latest episode is probably not big enough by itself to effect large-scale weather changes.) As for rainfall, in the simplest models, lowered temperatures decrease evaporation of water from the surface into the air; and less water vapor translates to less rain. But matters are greatly complicated by atmospheric circulation patterns, cyclic changes in temperatures over the oceans, and the shapes of land masses. Up to now, most climate models incorporating known forces such as changes in the sun and atmosphere have predicted that volcanic explosions would disrupt the monsoon by bringing less rain to southeast Asia--but the researchers found the opposite.

The researchers studied eruptions including one in 1258 from an unknown tropical site, thought to be the largest of the last millennium; the 1600-1601 eruption of Peru's Huaynaputina; Tambora in 1815; the 1883 explosion of Indonesia's Krakatau; Mexico's El Chichón, in 1982; and Pinatubo. The tree rings showed that huge swaths of southern China, Mongolia and surrounding areas consistently dried up in the year or two following big events, while mainland southeast Asia got increased rain. The researchers say there are many possible factors involved, and it would speculative at this point to say exactly why it works this way.

"The data only recently became available to test the models," said Rosanne D'Arrigo, one of the study's coauthors. "Now, it's obvious there's a lot of work to be done to understand how all these different forces interact." For instance, in some episodes pinpointed by the study, it appears that strong cycles of the El Niño-Southern Oscillation, which drives temperatures over the Pacific and Indian oceans and is thought to strongly affect the Asian monsoon, might have counteracted eruptions, lessening their drying or moistening effects. But it could work the other way, too, said Anchukaitis; if atmospheric dynamics and volcanic eruptions come together with the right timing, they could reinforce one another, with drastic results. "Then you get flooding or drought, and neither flooding nor drought is good for the people living in those regions," he said. The study also raises questions whether proposed "geo-engineering" schemes to counteract man-made climate change with huge artificial releases of volcanism-like particles might have complex unintended consequences.

Ultimately, said Anchukaitis, such studies should help scientists refine models of how natural and man-made forces might act together to in the future to shift weather patterns — a vital question for all areas of the world.

US river flows altered by land and water management

noreply@blogger.com (Sans) — Mon, 08 Nov 2010 20:58:54 PST

Credit: USGSThe amount of water flowing in streams and rivers has been significantly altered in nearly 90 percent of waters that were assessed in a new nationwide USGS study. Flow alterations are a primary contributor to degraded river ecosystems and loss of native species.

"This USGS assessment provides the most geographically extensive analysis to date of stream flow alteration," said Bill Werkheiser, USGS Associate Director for Water. "Findings show the pervasiveness of stream flow alteration resulting from land and water management, the significant impact of altered stream flow on aquatic organisms, and the importance of considering this factor for sustaining and restoring the health of the Nation's streams and ecosystems."

Flows are altered by a variety of land- and water-management activities, including reservoirs, diversions, subsurface tile drains, groundwater withdrawals, wastewater inputs, and impervious surfaces, such as parking lots, sidewalks and roads.

"Altered river flows lead to the loss of native fish and invertebrate species whose survival and reproduction are tightly linked to specific flow conditions," said Daren Carlisle, USGS ecologist and lead scientist on this study. "These consequences can also affect water quality, recreational opportunities and the maintenance of sport fish populations."

For example, in streams with severely diminished flow, native trout, a popular sport fish that requires fast-flowing streams with gravel bottoms, are replaced by less desirable non-native species, such as carp. Overall, the USGS study indicated that streams with diminished flow contained aquatic communities that prefer slow moving currents more characteristic of lake or pond habitats.

"Management practices related to water demand continue to alter stream flows in many places," said Jeff Ostermiller, Water Quality Manager with the Utah Division of Water Quality. "Understanding the ecological effects of these flow alterations helps water managers develop effective strategies to ensure that water remains sufficiently clean and abundant to support fisheries and recreation opportunities, while simultaneously supporting economic development."

Annual and seasonal cycles of water flows — particularly the low and high flows — shape ecological processes in rivers and streams. An adequate minimum flow is important to maintain suitable water conditions and habitat for fish and other aquatic life. High flows are important because they replenish floodplains and flush out accumulated sediment that can degrade habitat.

"While this study provided the first, national assessment of flow alteration, focused studies within specific geographic regions will provide a better understanding of the ecological effects of altered stream flows, which can be more effectively applied to local water management challenges," said Carlisle.

The severity and type of stream flow alteration varies among regions, due to natural landscape features, land practices, degree of development, and water demand. Differences are especially large between arid and wet climates. In wet climates, watershed management is often focused on flood control, which can result in lower maximum flows and higher minimum flows. Extremely low flows are the greatest concern in arid climates, in large part due to groundwater withdrawals and high water use for irrigation.

The study identified over 1,000 unimpaired streams to use as reference points to create stream flow models. The models were applied to estimate expected flows for 2,888 additional streams where the USGS had flow monitoring gauges from 1980-2007. The estimated values for the 2,888 streams were compared to actual, measured flows to determine the degree to which streams have been altered.

New ocean acidification study shows added danger to already struggling reefs

noreply@blogger.com (Sans) — Mon, 08 Nov 2010 21:06:33 PST

Rosenstiel School scientists illustrate threat of increased carbon dioxide to coral reproduction

A new study led by scientists at the University of Miami Rosenstiel School of Marine and Atmospheric Science suggests that over the next century recruitment of new corals could drop by 73 per cent, as rising CO₂ levels turn the oceans more acidic. The research findings reveal a new danger to the already threatened Caribbean and Florida reef Elkhorn corals

“Ocean acidification is widely viewed as an emerging threat to coral reefs,” said Rosenstiel School graduate student Rebecca Albright. “Our study is one of the first to document the impacts of ocean acidification on coral recruitment.”

Albright and colleagues report that ocean acidification could compromise the successful fertilization, larval settlement and survivorship of Elkhorn corals. The research results suggest that ocean acidification could severely impact the ability of coral reefs to recover from disturbance, said the authors.

Elkhorn coral, known as Acropora palmata, is recognized as a critical reef-building species that once dominated tropical coral reef ecosystems. In 2006, Elkhorn was included on the U.S. Endangered Species List largely due to severe population declines over the past several decades.

The absorption of carbon dioxide by seawater, which results in a decline in pH level, is termed ocean acidification. The increased acidity in the seawater is felt throughout the marine food web as calcifying organisms, such as corals, oysters and sea urchins, find it more difficult to build their shells and skeletons making them more susceptible to predation and damage.
Recent studies, such as this one conducted by Albright and colleagues, are beginning to reveal how ocean acidification affects non-calcifying stages of marine organisms, such as reproduction.

“Reproductive failure of young coral species is an increasing concern since reefs are already highly stressed from bleaching, hurricanes, disease and poor water quality,” said Chris Langdon, associate professor at the Rosenstiel School and co-author of the study.

The paper, "Ocean acidification compromises recruitment success of the threatened Caribbean coral Acropora palmata," will be published in the Nov. 9 issue of Proceeding of the National Academy of Sciences (PNAS). The paper’s co-authors include, Benjamin Mason of the UM Rosenstiel School and Margaret Miller of the National Oceanic and Atmospheric Administration Fisheries Service.

The Rosenstiel School Climate Change Laboratory conducts research on the effects of ocean acidification on coral reef ecosystems.

Breakthrough in cancer vaccine research

noreply@blogger.com (Sans) — Fri, 05 Nov 2010 06:51:37 PDT

Researchers at the University of Cambridge hope to revolutionise cancer therapy after discovering one of the reasons why many previous attempts to harness the immune system to treat cancerous tumours have failed.

New research, published in the journal Science, reveals that a type of stromal cell found in many cancers which expresses fibroblast activation protein alpha (FAP), plays a major role in suppressing the immune response in cancerous tumours - thereby restricting the use of vaccines and other therapies which rely on the body's immune system to work. They have also found that if they destroy these cells in a tumour immune suppression is relieved, allowing the immune system to control the previously uncontrolled tumour.

Douglas Fearon, Sheila Joan Smith Professor of Immunology of the Department of Medicine at the University of Cambridge, said: "Finding the specific cells within the complex mixture of the cancer stroma that prevents immune killing is an important step. Further studying how these cells exert their effects may contribute to improved immunological therapies by allowing us to remove a barrier that the cancer has constructed."

Vaccines created to prompt the immune system to attack cancerous cells in tumours have shown to activate an immune response in the body but have, inexplicably, almost never affected the growth of tumours. Immunologists who specialise in tumours have suspected that within the tumour microenvironment the activity of immune cells is somehow suppressed, but they have thus far been unable to fully reverse this suppression.

The new research, funded by the Wellcome Trust and the Sheila Joan Smith Professorship endowment, sheds light on why the immune response is suppressed. The Cambridge study found that at least one immune suppressive component is contained within normal tissue cells (called stromal cells) the cancer has coerced to assist its survival. The cell they studied specifically expresses a unique protein often associated with wound healing - fibroblast activation protein alpha (FAP). The FAP expressing cells are found in many cancers, including breast and colorectal cancers.

In order to determine if FAP expressing stromal cells contribute to the resistance of a tumour to vaccination, the researchers created a transgenic mouse model which allowed them to destroy cells which expressed FAP. When FAP-expressing cells were destroyed in tumours in mice with established Lewis lung carcinomas (of which only 2% of the tumour cells are FAP-expressing), the cancer began to rapidly 'die'. The Fearon lab now hopes to collaborate with scientists at the CRUK Cambridge Research Institute to evaluate the effects of depleting FAP-expressing cells in a mouse model that more closely resemble human cancer, and to examine FAP-expressing cells of human tumours.

Professor Fearon continued: "These studies are in the mouse, and although there is much overlap between the mouse and human immune systems, we will not know the relevance of these findings in humans until we are able to interrupt the function of the tumour stromal cells expressing FAP in patients with cancer.

"It should be noted, however, that the FAP-expressing stromal cell was actually first found in human cancer by Lloyd Old and his colleagues 20 years ago."

Plants play larger role than thought in cleaning up air pollution

noreply@blogger.com (Sans) — Mon, 25 Oct 2010 07:48:11 PDT

Poplars, aspens, other trees provide extensive "ecosystem services."
Credit: USDAChemicals known as oxygenated volatile organic compounds (oVOCs) affect environment, human health

Vegetation plays an unexpectedly large role in cleansing the atmosphere, a new study finds.

The research, led by scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., uses observations, gene expression studies, and computer modeling to show that deciduous plants absorb about a third more of a common class of air-polluting chemicals than previously thought.

The new study, results of which are being published this week in Science Express, was conducted with co-authors from the University of Northern Colorado and the University of Arizona. It was supported in part by the National Science Foundation (NSF), NCAR's sponsor.

"Plants clean our air to a greater extent than we had realized," says NCAR scientist Thomas Karl, the lead author. "They actively consume certain types of air pollution."

The research team focused on a class of chemicals known as oxygenated volatile organic compounds (oVOCs), which can have long-term impacts on the environment and human health.

"The team has made significant progress in understanding the complex interactions between plants and the atmosphere," says Anne-Marie Schmoltner of NSF's Division of Atmospheric and Geospace Sciences, which funded the research.

The compounds form in abundance in the atmosphere from hydrocarbons and other chemicals that are emitted from both natural sources--including plants--and sources related to human activities, including vehicles and construction materials.

The compounds help shape atmospheric chemistry and influence climate.

Eventually, some oVOCs evolve into tiny airborne particles, known as aerosols, that have important effects on both clouds and human health.

By measuring oVOC levels in a number of ecosystems in the United States and other countries, the researchers determined that deciduous plants appear to be taking up the compounds at an unexpectedly fast rate--as much as four times more rapidly than previously thought.

The uptake was especially rapid in dense forests and most evident near the tops of forest canopies, which accounted for as much as 97 percent of the oVOC uptake that was observed.

Karl and his colleagues then tackled a follow-up question: How do plants absorb such large quantities of these chemicals?

The scientists moved their research into their laboratories and focused on poplar trees. The species offered a significant advantage in that its genome has been sequenced.

The team found that when the study trees were under stress, either because of a physical wound or because of exposure to an irritant such as ozone pollution, they began sharply increasing their uptake of oVOCs.

At the same time, changes took place in expression levels of certain genes that indicated heightened metabolic activity in the poplars.

The uptake of oVOCs, the scientists concluded, appeared to be part of a larger metabolic cycle.

Plants can produce chemicals to protect themselves from irritants and repel invaders such as insects, much as a human body may increase its production of white blood cells in reaction to an infection.

But these chemicals, if produced in enough quantity, can become toxic to the plant itself.

In order to metabolize these chemicals, the plants start increasing the levels of enzymes that transform the chemicals into less toxic substances.

At the same time, as it turns out, the plant draws down more oVOCs, which can be metabolized by the enzymes.

"Our results show that plants can actually adjust their metabolism and increase their uptake of atmospheric chemicals as a response to various types of stress," says Chhandak Basu of the University of Northern Colorado, a co-author.

"This complex metabolic process within plants has the side effect of cleansing our atmosphere."

Once they understood the extent to which plants absorb oVOCs, the research team fed the information into a computer model that simulates chemicals in the atmosphere worldwide.

The results indicated that, on a global level, plants are taking in 36 percent more oVOCs than had previously been accounted for in studies of atmospheric chemistry.

Additionally, since plants are directly removing the oVOCs, fewer of the compounds are evolving into aerosols.

"This really transforms our understanding of some fundamental processes taking place in our atmosphere," Karl says.

Climate Change May Create Tipping Points for Populations, Not Just Species

noreply@blogger.com (Sans) — Mon, 25 Oct 2010 05:34:25 PDT

A single moss campion plant shows the influence of climate change on entire populations.
Credit: Tracy Feldman Researchers measure survival, reproduction of thousands of arctic and alpine plants over six years

As Earth's climate warms, species are expected to shift their geographical ranges away from the equator or to higher elevations.

While scientists have documented such shifts for many plants and animals, the ranges of others seem stable.

When species respond in different ways to the same amount of warming, it becomes more difficult for ecologists to predict future biological effects of climate change--and to plan for these effects.

In a study published this week in the journal Nature, University of Wyoming ecologist Daniel Doak and Duke University ecologist William Morris report on a long-term study of arctic and alpine plants.

The results show why some species may be slow to shift their geographic ranges in the face of climate change, and why we might expect to see sudden shifts as warming continues.

"This study illustrates the critical need for long-term research to address our most pressing ecological challenges," says Saran Twombly, program director in the National Science Foundation (NSF)'s Division of Environmental Biology, which funded the research.

"Without the temporal and spatial scales employed here, we have little hope of understanding the complex ways in which organisms will respond to climate change."

The plant species targeted by Morris and Doak range from populations in the high mountains of Colorado and New Mexico to species growing along the arctic coastline in far northern Alaska.

These regions include habitats that have undergone substantial climate change, leading to the expectation, says Doak, that--especially at the southern edge of their range--populations of the plants should be collapsing.

However, after studying the growth and survival of tens of thousands of individual plants over six years, the researchers show a more complex pattern of responses.

At the southern edge of their ranges, the plants indeed show negative effects of warmer conditions, with lower survival.

"But in most years," says Doak, "these effects are balanced by plants in the south growing more rapidly, so that populations there are no less stable than those in the north."

The opposing trends mean that under current conditions, even across the huge range of conditions Morris and Doak studied, populations of these plants are doing equally well across 30 degrees of latitude--one-third the distance from the equator to the north pole.

However, the researchers' results don't indicate that these plants, or other species, will be unaffected by warming conditions.

By looking at the performance of individual plants in particularly hot and cold years, they found that the compensatory effects across moderately cold to moderately warm years (lower survival balanced by more rapid growth) will not hold up with increased warming.

Instead, in the warmest years at all study sites, both survival and growth of the plants fell.

"Up to a point," says Doak, "we may see little effect of warming for many organisms. But past a climatic tipping point, the balance of opposing effects of warming will likely cease, leading to subsequent rapid declines in populations."

While this tipping point will be different for each species, responses of natural populations to gradual shifts in climate will not necessarily in turn be gradual.

"We shouldn't interpret a lack of ecological response to past warming to mean that little or no effects are likely in the future," says Doak.

The researchers' work also points to a methodology with which to better understand and predict how climate effects on one species will combine to create overall population-wide effects.

"A key part of this approach is the need for long-term studies so we can observe and use the rare years with extreme climates to anticipate what the average future climate will bring," Doak says.

Small Dams Yield Smart Energy

noreply@blogger.com (Sans) — Mon, 25 Oct 2010 05:28:30 PDT

Small is beautiful in hydroelectric power plant design, and good for the environment

Hydroelectric power is the oldest and the "greenest" source of renewable energy. In Germany, the potential would appear to be completely exploited, while large-scale projects in developing countries are eliciting strong criticism due to their major impact on the environment.
Researchers at Technische Universitaet Muenchen (TUM) have developed a small-scale hydroelectric power plant that solves a number of problems at the same time: The construction is so simple, and thereby cost-efficient, that the power generation system is capable of operating profitably in connection with even modest dam heights. Moreover, the system is concealed in a shaft, minimizing the impact on the landscape and waterways. There are thousands of locations in Europe where such power plants would be viable, in addition to regions throughout the world where hydroelectric power remains an untapped resource.

In Germany, hydroelectric power accounts for some three percent of the electricity consumed – a long-standing figure that was not expected to change in any significant way. After all, the good locations for hydroelectric power plants have long since been developed. In a number of newly industrialized nations, huge dams are being discussed that would flood settled landscapes and destroy ecosystems. In many underdeveloped countries, the funds and engineering know-how that would be necessary to bring hydroelectric power on line are not available.

Smaller power stations entail considerable financial input and are also not without negative environmental impact. Until now, the use of hydroelectric power in connection with a relatively low dam height meant that part of the water had to be guided past the dam by way of a so-called bay-type power plant – a design with inherent disadvantages:

The large size of the plant, which includes concrete construction for the diversion of water and a power house, involves high construction costs and destruction of natural riverside landscapes.

Each plant is a custom-designed, one-off project. In order to achieve the optimal flow conditions at the power plant, the construction must be planned individually according to the dam height and the surrounding topography. How can an even flow of water to the turbines be achieved? How will the water be guided away from the turbines in its further course?

Fish-passage facilities need to be provided to help fish bypass the power station. In many instances, their downstream passage does not succeed as the current forces them in the direction of the power plant. Larger fish are pressed against the rakes protecting the intake of the power plant, while smaller fish can be injured by the turbine.

A solution to all of these problems has now been demonstrated, in the small-scale hydroelectric power plant developed as a model by a team headed by Prof. Peter Rutschmann and Dipl.-Ing. Albert Sepp at the Oskar von Miller-Institut, the TUM research institution for hydraulic and water resources engineering. Their approach incurs very little impact on the landscape. Only a small transformer station is visible on the banks of the river. In place of a large power station building on the riverside, a shaft dug into the riverbed in front of the dam conceals most of the power generation system. The water flows into a box-shaped construction, drives the turbine, and is guided back into the river underneath the dam. This solution has become practical due to the fact that several manufacturers have developed generators that are capable of underwater operation – thereby dispensing with the need for a riverbank power house.

The TUM researchers still had additional problems to solve: how to prevent undesirable vortex formation where water suddenly flows downward; and how to best protect the fish. Rutschmann and Sepp solved two problems with a single solution – by providing a gate in the dam above the power plant shaft. In this way, enough water flows through to enable fish to pass. At the same time, the flow inhibits vortex formation that would reduce the plant's efficiency and increase wear and tear on the turbine.

The core of the concept is not optimizing efficiency, however, but optimizing cost: Standardized pre-fabricated modules should make it possible to order a "power plant kit" just like ordering from a catalog. "We assume that the costs are between 30 and 50 percent lower by comparison with a bay-type hydropower plant," Peter Rutschmann says. The shaft power plant is capable of operating economically given a low "head" of water of only one to two meters, while a bay-type power plant requires at least twice this head of water. Series production could offer an additional advantage: In the case of wider bodies of water, several shafts could be dug next to each other – also at different points in time, as determined by demand and available financing.

Investors can now consider locations for the utilization of hydropower that had hardly been interesting before. This potential has gained special significance in light of the EU Water Framework Directive. The directive stipulates that fish obstacles are to be removed even in smaller rivers. In Bavaria alone, there are several thousand existing transverse structures, such as weirs, that will have to be converted, many of which also meet the prerequisites for shaft power plants. Construction of thousands of fish ladders would not only cost billions but would also load the atmosphere with tons of climate-altering greenhouse gas emissions. If in the process shaft power plants with fish gates and additional upstream fish ladders were installed, investors could shoulder the costs and ensure the generation of climate-friendly energy over the long term – providing enough power for smaller communities from small, neighborhood hydroelectric plants.

Shaft power plants could also play a significant role in developing countries. "Major portions of the world's population have no access to electricity at all," Rutschmann notes. "Distributed, local power generation by lower-cost, easy-to-operate, low-maintenance power plants is the only solution. For cases in which turbines are not financially feasible, Rutschmann has already come up with an alternative: "It would be possible to use a cheap submersible pump and run it in reverse – something that also works in our power plant."

Disease in rural China linked to polluted coal

noreply@blogger.com (Sans) — Mon, 25 Oct 2010 08:59:44 PDT

In remote, rural areas of southwestern China, villagers cook and dry their clothes by burning pieces of coal they pick up off the ground. This fuel releases a toxin that may be poisoning millions of people, according to an ongoing investigation by chemists at the University at Buffalo in New York. The researchers are presenting their work today at the AVS 57th International Symposium & Exhibition, which takes place this week at the Albuquerque Convention Center in New Mexico.

The toxin in question is fluoride, which binds to calcium in the human body and causes the disease fluorosis. This condition, which affects millions in China's Guizhou province, can cause dental problems, such as discolored and pitted teeth, as well as joint pain, muscular degeneration, and deformities in joints and the spine.

Worldwide, the most common source of excess fluoride is polluted water. But according to Joseph Gardella, a chemist at UB who has collaborated on a research project with Professor Handong Liang of the China University of Mining and Technology, Beijing (CUMTB), polluted coal may also be to blame.

"Careful research supported by the Chinese government eliminated water as the source, and pointed to air pollution from coal fired home fireplace," says Gardella. "The government has focused on finding solutions to the health issues resulting from the pollution in the villages and in identifying solutions to eliminating the pollution sources."

Gardella and graduate student Brett Yatzor analyzed samples of the coal gathered by the villagers using a variety of imaging techniques -- including Time-of-Flight Secondary Ion Mass Spectrometry, which reveals not only the composition of a sample but also its chemical structure.

"When you just look at coal, it looks pretty homogenous," says Yatzor. "But when you do a chemical ion image, you can see that it's very heterogeneous."

Yatzor's imaging showed that -- like purer coals burned by power plants -- the carbon in the coal itself contained little fluorine. However, the inorganic clay used as an additive for coal-burning and as a binder in briquette-making by local residents showed very high levels of fluorine.

The scientists are still investigating exactly how this fluorine enters the human body. It might be inhaled in the particles produced when coal is burned in the villagers' closed, ventless huts. It could also be ingested; preliminary analyses of food samples such as chilies and corn have shown high levels of the toxin.

As the scientists' work continues, the Chinese government has put in place programs to install chimneys that would improve the ventilation of smoke in the huts and allow particulates to escape.

Worst coral death strikes at SE Asia

noreply@blogger.com (Sans) — Mon, 25 Oct 2010 05:20:50 PDT

International marine scientists say that a huge coral death which has struck Southeast Asian and Indian Ocean reefs over recent months has highlighted the urgency of controlling global carbon emissions.

Many reefs are dead or dying across the Indian Ocean and into the Coral Triangle following a bleaching event that extends from the Seychelles in the west to Sulawesi and the Philippines in the east and include reefs in Sri Lanka, Burma, Thailand, Malaysia, Singapore, and many sites in western and eastern Indonesia.

“It is certainly the worst coral die-off we have seen since 1998. It may prove to be the worst such event known to science,” says Dr Andrew Baird of the ARC Centre of Excellence for Coral Reef Studies and James Cook Universities. “So far around 80 percent of Acropora colonies and 50 per cent of colonies from other species have died since the outbreak began in May this year.”

This means coral cover in the region could drop from an average of 50% to around 10%, and the spatial scale of the event could mean it will take years to recover, striking at local fishing and regional tourism industries, he says.

The bleaching event has also hit the richest marine biodiversity zone on the planet, the ‘Amazon Rainforest’ of the seas, known as the Coral Triangle (CT), which is bounded by Indonesia, Malaysia and the Philippines.

“Although the Coral Triangle is the richest region for corals on Earth, it relies on other regions around its fringes to supply the coral spawn and fish larvae that help keep it so rich,” Dr Baird explains. “So there are both direct and indirect effects on CT reefs which will affect their ability to recover from future disturbance.”

“Also the reefs of the region support tens of millions of people who make their living from the sea and so plays a vital role in both the regional economy and political stability. For example, in Aceh, northern Sumatera, where the bleaching is most severe, a high proportion of the people rely on fishing and tourism for their livelihoods. While it may take up to two years for some fish species to be affected by the loss of coral habitat, fisheries yields will decline and this combined with a drop in the number of SCUBA divers visiting could have major long-term effects on the local economy.”

The cause of the bleaching event was a large pool of super-hot water which swept into the eastern Indian Ocean region several months ago, shocking the corals and causing them to shed the symbiotic algae that nourish them, thereby losing color and “bleaching”. If the corals do not regain their algae they starve to death.

According to the National Oceanic and Atmospheric Administration’s Coral Hotspots website, sea surface temperatures in the region peaked in late May, 2010, and by July the accumulated heat stress was greater than in 1998. Local dive operators recorded water temperatures of 34 C, over 4 degrees higher that than long term average for the area.

The event was first detected on reefs in Aceh by marine ecologists from Wildlife Conservation Society, CoECRS and Syiah Kuala University. They already rate it as one of the worst coral diebacks ever recorded.

“My colleagues and I have high confidence these successive ocean warming episodes, which exceed the normal tolerance range of warm-water corals, are driven by human-induced global warming. They underline that the planet is already taking heavy hits from climate change – and will continue to do so unless we can reduce carbon emissions very quickly.

“They also show this is not just about warmer temperatures: it is also threatening the livelihoods of tens of millions of people and potentially the stability of our region.”

Dr Baird said it was not yet clear whether Australia would suffer a similar coral bleaching event this year: this would emerge only with the arrival of warmer waters from the north in January/February 2011. The previous worst events to strike the Great Barrier Reef were in 1998 and 2002 when over 40% of the reefs along the length of the GBR were affected.

Contaminants in groundwater used for public supply

noreply@blogger.com (Sans) — Sun, 23 May 2010 05:53:32 PDT

More than 20 per cent of untreated water samples from 932 public wells across the United States contained at least one contaminant at levels of potential health concern, according to a new study by the U.S. Geological Survey.

About 105 million people — or more than one-third of the nation’s population — receive their drinking water from one of the 140,000 public water systems across the United States that rely on groundwater pumped from public wells. The USGS study focused primarily on source (untreated) water collected from public wells before treatment or blending rather than the finished (treated) drinking water that water utilities deliver to their customers.

“By focusing primarily on source-water quality, and by testing for many contaminants that are not regulated in drinking water, this USGS study complements the extensive monitoring of public water systems that is routinely conducted for regulatory and compliance purposes by federal, state and local drinking-water programs,” said Matthew C. Larsen, USGS Associate Director for Water. “Findings assist water utility managers and regulators in making decisions about future monitoring needs and drinking-water issues.”

Findings showed that naturally occurring contaminants, such as radon and arsenic, accounted for about three-quarters of contaminant concentrations greater than human-health benchmarks in untreated source water. Naturally occurring contaminants are mostly derived from the natural geologic materials that make up the aquifers from which well water is withdrawn.

Man-made contaminants were also found in untreated water sampled from the public wells, including herbicides, insecticides, solvents, disinfection by-products, nitrate, and gasoline chemicals. Man-made contaminants accounted for about one-quarter of contaminant concentrations greater than human-health benchmarks, but were detected in 64 per cent of the samples, predominantly in samples from unconfined aquifers.

“Detections of contaminants do not necessarily indicate a concern for human health because USGS analytical methods can detect many contaminants at concentrations that are 100-fold to 1,000-fold lower than human-health benchmarks,” said lead scientist Patricia Toccalino. “Assessing contaminants in these small amounts helps to track emerging issues in our water resources and to identify contaminants that may warrant inclusion in future monitoring.”

Scientists tested water samples for 337 properties and chemical contaminants, including nutrients, radionuclides, trace elements, pesticides, solvents, gasoline hydrocarbons, disinfection by-products and manufacturing additives. This study did not assess pharmaceuticals or hormones.

Most (279) of the contaminants analysed in this study are not federally regulated in finished drinking water under the Safe Drinking Water Act.

The USGS also sampled paired source and finished (treated) water from a smaller subset of 94 public wells. Findings showed that many man-made organic contaminants detected in source water generally were detected in finished water at similar concentrations. Organic contaminants detected in both treated and source water typically were detected at concentrations well below human-health benchmarks, however.

Additionally, the study shows that contaminants found in public wells usually co-occurred with other contaminants as mixtures. Mixtures can be a concern because the total combined toxicity of contaminants in water may be greater than that of any single contaminant. Mixtures of contaminants with concentrations approaching benchmarks were found in 84 percent of wells, but mixtures of contaminants above health benchmarks were found less frequently, in 4 percent of wells.

This USGS study identifies which contaminant mixtures may be of most concern in groundwater used for public-water supply and can help human-health researchers to target and prioritize toxicity assessments of contaminant mixtures. The USGS report identifies the need for continued research because relatively little is known about the potential health effects of most mixtures of contaminants.

Wells included in this study are located in 41 states and withdraw water from parts of 30 regionally extensive aquifers, which constitute about one-half of the principal aquifers used for water supply in the United States.

Human-health benchmarks used in this study include U.S. Environmental Protection Agency Maximum Contaminant Levels for regulated contaminants and USGS Health-Based Screening Levels for unregulated contaminants, which are non-enforceable guidelines developed by the USGS in collaboration with the EPA and other water partners.
Treated drinking water from public wells is regulated under the Safe Drinking Water Act. Water utilities, however, are not required to treat water for unregulated contaminants. The EPA uses USGS information on the occurrence of unregulated contaminants to identify contaminants that may require drinking-water regulation in the future.

This study and additional information about public wells can be found on the Quality of Water from Public-Supply Wells in the United States website.

Climate threatens trout and salmon

noreply@blogger.com (Sans) — Sun, 23 May 2010 05:08:19 PDT

Trout and salmon are among the world's most familiar freshwater fishes, but numbers have fallen over recent decades – in some areas, dramatically. Pollution, habitat loss and over-fishing have all been blamed in the past, but new evidence from Cardiff University shows that climate change could be a major factor, putting both species at risk.

The scientists studied populations of young salmon and trout in the River Wye in Wales, traditionally one of the UK's best angling rivers. Professor Steve Ormerod and colleagues from the Cardiff School of Biosciences found salmon numbers fell by 50% and trout numbers by 67% between 1985 and 2004 - even though the river itself became cleaner.

The fish were hit hardest following hot, dry summers such as 1990, 2000 and 2003. The results suggest that warmer water and lower river levels combine to affect both species. As both trout and salmon favour cool water, they face potentially major problems if climate warming continues as expected in the next two to three decades.

"Huge efforts have been put into bringing salmon back into Europe's formerly polluted rivers such as the Taff, Thames, Clyde, Seine and Rhine, so these results are a major worry," said Professor Ormerod.

"Salmon and trout fishing also generate many jobs and large economic benefits. In Wales alone, salmon fishing contributes around £90 million annually. Any risk of eventually losing these species to climate warming is therefore one we must consider very seriously. We suggest measures to ensure that river levels are maintained in hotter conditions alongside the use of riverside trees to create shade and protect against the highest temperatures. This week's Wales Sustainability Week is an ideal opportunity for us to consider action for Welsh rivers, particularly because trout and salmon are such important sustainability indicators."

The Cardiff team used data on fish population collected each year by the Environment Agency at more than 50 locations spread throughout the Wye. Stream temperatures increased over the study period by 0.5 – 0.7ºC in summer and 0.7 - 1.0ºC in winter, with the latter effects apparently affecting the fish at low flow. Water temperature is known to affect growth and susceptibility to disease in these fish, while lower water levels restrict their access to cooler habitats.

Peter Gough, fisheries scientist with Environment Agency Wales, added,
"We recognise that climate warming is probably already affecting many elements of our natural environment, including salmon, trout and sea trout, and this detailed analysis of our long-term data is extremely interesting and, if proven correct, would be of great concern. We are currently examining these and other data further.

There is a suggestion that earlier migration to sea of salmon smolts might account for at least part of the apparent decline, but this doesn't explain the reduction in trout numbers. More work is needed to clarify some important issues."
The comparison between trout and salmon is important because, unlike salmon, trout from the Wye never migrate to the sea. Only factors affecting the river can therefore explain their decline.

A paper on the findings has been published in one of the world's leading environmental journals, Global Change Biology.

Commonly used Atrazine herbicide adversely affects fish reproduction

noreply@blogger.com (Sans) — Sun, 23 May 2010 04:41:58 PDT

Atrazine, one of the most commonly used herbicides in the world, has been shown to affect reproduction of fish, according to a new U.S. Geological Survey (USGS) study.

“Concentrations of atrazine commonly found in agricultural streams and rivers caused reduced reproduction and spawning, as well as tissue abnormalities in laboratory studies with fish,” said USGS scientist Donald Tillitt, the lead author of the study published in Aquatic Toxicology. Fathead minnows were exposed to atrazine at the USGS Columbia Environmental Research Center in Columbia, Mo., and observed for effects on egg production, tissue abnormalities and hormone levels.

Fish were exposed to concentrations ranging from zero to 50 micrograms per liter of atrazine for up to 30 days. All tested levels of exposure are less than the USEPA Office of Pesticides Aquatic Life Benchmark of 65 micrograms per liter for chronic exposure of fish. Thus, substantial reproductive effects were observed in this study at concentrations below the USEPA water-quality guideline.

Study results show that normal reproductive cycling was disrupted by atrazine and fish did not spawn as much or as well when exposed to atrazine. Researchers found that total egg production was lower in all atrazine-exposed fish, as compared to the non-exposed fish, within 17 to 20 days of exposure. In addition, atrazine-exposed fish spawned less and there were abnormalities in reproductive tissues of both males and females.

Atrazine is one of the most commonly used herbicides in the world and is used on most corn, sugarcane and sorghum acreage in the United States. It is used to stop pre- and post-emergence broadleaf and grassy weeds, and is generally applied in the spring. Thus, noted Tillitt, atrazine concentrations are greatest in streams during the spring, when most fish in North America are attempting to reproduce.

“The reproductive effects observed in this study warrant further investigation and evaluation of the potential risks posed by atrazine, particularly in wild populations of fish from streams in agricultural areas with high use of this herbicide,” said Tillitt.

The results of this study add an important ecological perspective to findings on atrazine concentrations in streams reported by the USGS National Water-Quality Assessment (NAWQA) Program, as well as others, and highlights the potential risks to aquatic species of this high-use chemical, Tillitt said.

“Results of studies over the past 20 years show that atrazine is the most frequently detected pesticide in agricultural streams and rivers nationwide, and particularly in the Corn Belt states,” according to Robert Gilliom, Chief of the NAWQA Pesticide National Synthesis Project. “Atrazine concentration data for Corn Belt streams and rivers show that 21-day average concentrations, similar to the exposure conditions studied by Dr. Tillitt, exceeded levels found to affect fish reproduction for most sites and years sampled.”

Endocrine-active compounds are associated with intersex and reproductive effects in fish. These chemicals have the ability to adversely affect endocrine systems and include some pesticides, PCBs, certain heavy metals, certain household products, and many pharmaceuticals specifically designed to interact with endocrine function.

"Atrazine Reduces Reproduction in Fathead Minnow (Pimephales promelas)," was authored by U.S. Geological Survey scientists Donald Tillitt, Diana Papoulias, Jeffrey Whyte, and Catherine Richter. It appears in this week’s edition of Aquatic Toxicology.