Monday, January 10, 2011

More trees in a city bring surprising benefit, Portland study finds

You've heard all the obvious benefits of urban trees -- shading buildings, sheltering wildlife, filtering air pollution, stopping erosion. A new Portland study suggests a more surprising benefit: healthier newborns.

Researchers used satellite images to compare tree cover around the houses of 5,696 women who gave birth in Portland in 2006 and 2007. Pregnant women living in houses graced by more trees were significantly less likely to deliver undersized babies.

Tree cover made no difference in the rate of pre-term births, but researchers found a consistent link to the prevalence of infants who were small for their gestational age. For each 10 percent increase in tree coverage within about 50 yards of a home, the rate of undersized newborns decreased by 1.42 per 1000 births. As it stands, about 70 of every 1,000 newborns in Portland are small for gestational age.

"Maybe it sounds a bit daft at first," says lead author Geoffrey Donovan, a scientist with the U.S. Forest Service's Pacific Northwest Research Station in Portland. But he says it's plausible that having lots of trees nearby counteracts the stress experienced by pregnant women.

Studies in animals and people make clear that maternal stress is harmful to a developing fetus and can increase the probability of underweight birth. In a variety of human clinical trials, exposure to nature and greenery significantly reduced people's stress levels and helped them withstand high-stress situations.

"That may be the mechanism," says Donovan, a specialist in forest economics whose work for the Forest Service includes studying urban trees and their effects on crime, energy use and health. The birth study, co-authored by researchers with Multnomah County Health Department, Drexel University and the National Institute of Standards and Technology, was published online by the journal Health & Place.

Dr. Stephen Fortmann, a senior investigator at the Kaiser Permanente Center for Health Research in Portland who was not involved in the study, finds the results intriguing. "It points out that some of the neighborhood level factors that effect health might work in ways we haven't thought about," Fortmann says.

more from the Oregonian

Tuesday, November 30, 2010

BP Oil Well Capped, But Trauma Still Flowing

These are hard times in the hard-working town of Bayou La Batre, Ala. It's known as the state's seafood capital — and it struggled to get back in business after Hurricane Karina.

But once again, the processing plants and shrimp boats lining the bayou are mostly idle after the BP oil spill.

So when Feed the Children trucks recently arrived at the community center, the turnout was huge. About a dozen volunteers worked quickly handing out big cartons packed with food and household goods. Residents had to sign up in advance, so some were reluctantly turned away.

"We're out. We only had 800 cards and 800 boxes of groceries," a volunteer gently tells those without tickets for the day's goods. "I'm sorry, we just don't have any more."

No one makes a scene. This is not a place where asking for help comes easily.

"It almost makes you not even want to walk up and ask," says Lena Hofer, 25. "Because of how many times I've had to do this, it's really hard when they send you away after you do, especially when you need it like I do. I'm about to cry. It's hard."

The red circles around Hofer's blue eyes and frail frame are evidence of the toll from the spill.

"I'm a homemaker," she laughs, as if she no longer believes it. "My husband was a shrimper. It's bad. It's put us in a really bad spot."

"We are very, very close on the edge of losing everything," says Aaron Hofer, Lena's husband, holding back tears. "But, you know, God feeds the birds. How much more does he love us? I have to tell myself that, like, 100 times a day."

more from NPR

Friday, November 26, 2010

Front-Line City in Virginia Tackles Rise in Sea

In this section of the Larchmont neighborhood, built in a sharp “u” around a bay off the Lafayette River, residents pay close attention to the lunar calendar, much as other suburbanites might attend to the daily flow of commuter traffic.

If the moon is going to be full the night before Hazel Peck needs her car, for example, she parks it on a parallel block, away from the river. The next morning, she walks through a neighbor’s backyard to avoid the two-to-three-foot-deep puddle that routinely accumulates on her street after high tides.

For Ms. Peck and her neighbors, it is the only way to live with the encroaching sea.

As sea levels rise, tidal flooding is increasingly disrupting life here and all along the East Coast, a development many climate scientists link to global warming.

But Norfolk is worse off. Situated just west of the mouth of Chesapeake Bay, it is bordered on three sides by water, including several rivers, like the Lafayette, that are actually long tidal streams that feed into the bay and eventually the ocean.

more from the NY Times

Thursday, October 21, 2010

Gulf Oil Spill Six Months Later

The crude has stopped gushing and coastlines are largely clear of the thick goo that washed ashore for months, but the impact of the worst offshore oil spill in U.S. history will no doubt linger for years.
Six months after the April 20 Deepwater Horizon explosion, the environment and economy of the entire northern Gulf of Mexico region remain in a state of uncertainty, with overturned livelihoods, out-of-work fishermen, reluctant tourists, widespread emotional anguish and untold damage to the sea and its shores.
It could be years before the spill's true effects are understood. The science is largely scattered about what the roughly 200 million gallons of oil that spewed from BP PLC's blown-out well—some 170 million gallons of which actually spilled into the Gulf—will ultimately mean for the animals and plant life that inhabit one of the world's most diverse bodies of water.
"There are some things that are starting to reveal themselves already," said Steve Murawski, chief fisheries scientist for the National Oceanic and Atmospheric Administration. "But it's going to take a while for us to gain some perspective."
Murawski predicted scientists will be studying the region for years, as they have been doing since 1989's much smaller Exxon Valdez spill in Alaska.
"This will be with us for decades for sure," he said.
The doomsday scenarios feared during the worst period of the gushing well did not play themselves out, as much of the oil is believed to have evaporated or been dispersed, marshes have sprung back to life and fewer dead animals than feared have been found.
But that good news does not mask concerns that the country might be turning its attention away prematurely, considering the very real damage that has been done.
"I can honestly say, I guess, I'm very pessimistic about it," said Byron Encalade, president of the Louisiana Oystermen Association, whose oyster beds are all dead or dying. "We don't know where we're at. We don't even have a complete assessment of the damage or how long it's going to take to correct it. This is our life, though. We have nowhere else to go."

more from US New and World Report

Thursday, October 07, 2010

Louisiana revival: Eco-engineering on a giant scale

STANDING knee-deep in the waters of Bay Jimmy in south-eastern Louisiana, Daniel Deocampo pours a bucket of clay mixed with seawater into the marsh. Oil swirls around our legs and the air reeks of burnt petroleum. With oil from BP's Deepwater Horizon spill sitting in the bay, the burning question is - remove the oil or wait for nature to take its course?

R. Eugene Turner, a coastal ecologist at Louisiana State University (LSU) in Baton Rouge, says that interfering with nature could backfire. Even just wiping oil off leaves, he says, spreads the toxic residue around. But Deocampo, a sedimentary geochemist at Georgia State University, Atlanta, and his colleague Kuk-Jeong Chin say leaving the oil will doom the marsh, and are testing ways to give oil-munching bacteria a turboboost. "If we do nothing, all the plants will die," Chin says. "Nature will take too long."

The disagreement underscores a debate that has been raging over marsh restoration for decades. Even before the spill, the marshes were disappearing at an alarming rate - the consequence of the dams, levees and canals built to provide shipping channels and protect New Orleans from flooding. Without intervention Louisiana's bayous could become open water within 50 years.

As a result, support has been growing for a suite of projects to resurrect the marshes (see map). At one end of the spectrum are those who advocate minimal intervention and letting nature take its course. At the other, the call is for yet more engineering: new, hardier breeds of grasses, seeding from the air and artificial reefs to shore up the sinking sediment.

Ultimately, the marshes are vanishing because sediment is in short supply. Wind and waves constantly erode the shoreline, and dams and levees hold back sediment flowing down the Mississippi. What's more, a network of canals dredged by the oil and gas industry carry saltwater inland, killing freshwater marshes. Add to all this rising sea levels and the largest oil spill in US history and the situation is desperate. Without its marshes, Louisiana's thriving seafood industry would crumble and the state's coast would lose its natural defences against the powerful storms that blow in from the Gulf of Mexico.

Turner advocates small-scale intervention: filling in thousands of kilometres of abandoned canals with the dredged sediment that is still piled up alongside them. He also favours helping sediment flow to the marshes. Historically, when the Mississippi's waters ran high, "crevasses" appeared in the river banks and carried sediment into the deltas. Dams and levees now prevent this, so Turner suggests punching holes in the river's embankment to spur the process. "So many marsh restoration ideas assume we can do better than nature," says Turner. "I think that's pretty arrogant."

Others say we need to think big. "Over the years, we've done all kinds of patchwork projects," says Harry Roberts, a retired sedimentary geologist at LSU. "They're not long-term solutions." Roberts has calculated that 18 to 24 billion tonnes of sediment will be needed to maintain the delta as the sea level rises in the next century (Nature Geoscience, DOI: 10.1038/NGEO553). Small crevasses can never meet that demand, he says.

For researchers like Roberts the question has become not how to restore Louisiana's lost Eden but how to create a new, improved one. As part of that, in April, a $23 million project kicked off to pipe mud more than 6 kilometres from Cote Blanche Bay to Vermilion Bay's Marsh Island Wildlife Refuge. The aim is to recreate 160 hectares of marsh.

Once the soil is in place, you need grasses - and not just any grasses. Two decades ago, Michael Materne, a wetland plant specialist at LSU's AgCenter, collected varieties of the native smooth cord grass (Spartina alterniflora) from across the US, searching for the hardiest ones. Today, Materne's Vermilion variety, named after the Louisiana parish it originated in, is the only one used in re-vegetation projects. To increase genetic diversity in the restored ecosystems, it will be joined next year by up to six more varieties that he has cross-bred.

Tuesday, September 28, 2010

GM corn 'has polluted rivers across the United States'

An insecticide used in genetically modified (GM) crops grown extensively in the United States and other parts of the world has leached into the water of the surrounding environment.
The insecticide is the product of a bacterial gene inserted into GM maize and other cereal crops to protect them against insects such as the European corn borer beetle. Scientists have detected the insecticide in a significant number of streams draining the great corn belt of the American mid-West.
The researchers detected the bacterial protein in the plant detritus that was washed off the corn fields into streams up to 500 metres away. They are not yet able to determine how significant this is in terms of the risk to either human health or the wider environment.
"Our research adds to the growing body of evidence that corn crop byproducts can be dispersed throughout a stream network, and that the compounds associated with genetically modified crops, such as insecticidal proteins, can enter nearby water bodies," said Emma Rosi-Marshall of the Cary Institute of Ecosystem Studies in Millbrook, New York.
GM crops are widely cultivated except in Britain and other parts of Europe. In 2009, more than 85 per cent of American corn crops were genetically modified to either repel pests or to be tolerant to herbicides used to kill weeds in a cultivated field.
The GM maize, or corn as it is called in the US, has a gene from the bacterium Bacillus thuriengensis (Bt) inserted into it to repel the corn borer beetle. The Bt gene produces a protein called Cry(12A)b which has insectidical properties.
The study, published in the journal Proceedings of the National Academy of Science, analysed 217 streams in Indiana. The scientists found 86 per cent of the sites contained corn leaves, husks, stalks or cereal cobs in their channels and 13 per cent contained detectable levels of the insectidical Cry(12A)b proteins.
"The tight linkage between corn fields and streams warrants further research into how corn byproducts, including Cr(12A)b insecticidal proteins, potentially impact non-target ecosystems, such as streams and wetlands," Dr Rosi-Marshall said.
All of the stream sites with detectable insecticidal proteins were located within 500 metres of a corn field. The ramifications are vast just in Iowa, Illinois, and Indiana, where about 90 per cent of the streams and rivers – some 159,000 miles of waterways – are also located within 500 metres of corn fields.
After corn crops are harvested, a common agricultural practice is to leave discarded plant material on the fields. This "no-till" form of agriculture minimises soil erosion, but it then also sets the stage for corn byproducts to enter nearby stream channels.

Monday, September 13, 2010

The Oil Spill’s Money Squeeze

In May, Harriet M. Perry, the director of the fisheries program at the Gulf Coast Research Laboratory, was asked to examine some mysterious droplets found on blue crab larvae by scientists at Tulane University. An early test indicated that the droplets were oil, and she has continued to find similar droplets on fresh larvae samples taken all along the northern Gulf of Mexico.

Despite the potential significance of the discovery, Dr. Perry does not have research money to cover further tests. And like other scientists across the Gulf Coast who are racing to sketch out the contours of the BP oil spill’s effects, she has few places to turn for help.

The only federal agency to distribute any significant grant money for oil spill research, the National Science Foundation, is out of money until the next fiscal year begins Oct. 1. The Environmental Protection Agency, which has only $2 million to give out, is still gearing up its program. A $500 million initiative for independent research promised by BP, which was to be awarded by an international panel of scientists, has become mired in a political fight over control. State agencies, too, are stymied.

“We have met with every possible person we can regarding this issue, built the templates, sent in the requests, and we are waiting to see,” said Hank M. Bounds, the Mississippi commissioner of higher education, speaking of the needs of Ms. Perry and other scientists.

There is plenty of science being done on the spill, but most of it is in the service of either the response effort, the federal Natural Damage Resource Assessment that will determine BP’s liability, or BP’s legal defense. Scientists who participate in those efforts may face restrictions on how they can use or publish their data. More important, they do not have a free hand in determining the scope of their studies.

“Independent research is being squeezed by federal agencies on one side and BP on the other,” said Dr. Perry, whose only offer of help has come from BP (she declined). “It’s difficult for the fishing community and the environmentalists to understand why we are not receiving the money that we need.”

more from the NY Times