Environment

Year In Science

Sunday, January 13, 2002

Trees Toppled
"Save the planet: Plant a tree!" the environmental movement has cried for more than 20 years. But studies in the past two years have shown that it isn't quite that simple. First, climatologist Richard Betts of the British Meteorological Office found that planting trees in snowy regions could actually raise temperatures. The trees would pull carbon dioxide out of the air, weakening the greenhouse effect, but they would also absorb more of the sun's heat than a snowy landscape. Then, in July, Britain's Royal Society declared that carbon sequestering forests and crops are at best a short-term solution: They could account for a quarter of the CO2 reductions required globally by the Kyoto Protocol by 2050, but then they would be saturated and might even begin to release CO2 in the future.
— Rabiya S. Tuma


Great White Reefs
More coral reefs have died in the past 20 years than in the previous 5,000, and the disaster shows signs of getting worse. As sea temperatures have risen in the past two decades, reefs worldwide have suffered from an unprecedented wave of disease, and many are rejecting the dinoflagellate algae on which they depend for food. Still, there may be some good news in all of this. A study published in June by Andrew Baker of the Wildlife Conservation Society in New York City indicates that when some coral purge resident algae (a process known as bleaching), they may simply be making way for more heat-tolerant strains to move in. However, Richard Aronson, a coral specialist at the Dauphin Island Sea Lab in Alabama, says: "To think that this is a panacea for coral reefs in the era of global warming is pretty hasty. If it gets really hot really quickly, then that will overwhelm the capacity of even these heat-tolerant zooxanthellae to continue a healthy symbiosis with the coral."
— Rabiya S. Tuma


BT Corn again
Genetically engineered BT corn was put on trial last year for threatening monarch butterfly populations. Then in May two scientists shot down its best defense. Bt corn uses a bacterium gene to produce an insecticide against the European corn borer and was designed, in part, to reduce the need for chemical insecticide. But John Obrycki, an entomologist at Iowa State University, and John Losey, an entomologist at Cornell, found when reviewing studies from the corn belt that farmers had used just as much insecticide on Bt corn as on regular corn. "Farmers are using the Bt corn just in case there's an outbreak," Obrycki says. "They want to make sure they are ready for it." Meanwhile, the Environmental Protection Agency has ruled that Bt corn is safe for humans to eat, even in taco shells.
— Diane Martindale


Yo, Condor: ¿Que Pasa?

California condors rarely hatch more than one chick every other year. The egg is typically 4 1/2 inches long, weighs 10 ounces, and takes between 54 and 58 days to incubate. This egg, laid by condors in captivity in Idaho, is infertile.
Photograph by Holly Lindem
On a remote cliff face in the northeast corner of the Grand Canyon last March, wildlife biologist Sophie Osborn spied an object that hadn't been seen in the wild for 15 years—the egg of a California condor. "All of a sudden, in this cave entrance was this beautiful, elliptical-shaped object," she says. "One of the females lifted it up, and I could see that it was a hollowed-out egg."

That an egg had been laid by a pair of captive-bred condors living on their own is a triumph, says Jeff Cilek, vice president of the Peregrine Fund, which raises condors and manages the population of released birds in Arizona. "It's the first, and a sign that everything is on track, that these birds can eventually reestablish themselves in the wild," he says. That the egg was broken is regarded as only a minor setback. "With mating pairs, sometimes the first egg is infertile, and sometimes it takes them an egg or two to learn how to care for it without damage," Cilek says.

Of course, the condor isn't out of the wilderness—or, rather, into the wilderness—yet. Since the last 27 were rounded up in 1986, their population has grown to 130 in captivity and 53 in the wild. But the released birds have a high mortality rate: Some die from lead poisoning contracted when they scavenge carcasses contaminated with bullet fragments. "During the summer of 2000, we lost five of them here in Arizona to lead poisoning, and at least 10 others had to be treated," says Osborn. "The egg is an incredibly hopeful sign—but, obviously, we still have a long, long way to go."
— Curtis Rist


Are the Salmon Back?
Pacific Northwest salmon returned from the sea in record numbers last spring and summer—468,623 chinook showed up at the Bonneville Dam on their way home to spawning grounds in the Columbia River, compared with 25,243 in 1995, the worst year on record. After a grim decade in which 26 Northwest salmon subspecies were listed as endangered, the rebound seemed cause for cheering.

But the celebration may have come too soon. Much of the salmon's dramatic resurgence is attributed to favorable ocean conditions, which are cyclic. James Anderson, director of the Columbia Basin Research group at the University of Washington, says decade-long temperature oscillations that occur naturally in the seas off the Pacific Northwest coast can drive away salmon predators. In 1998, he says, the ocean cooled by a few degrees, and predators left for warmer waters. Because juvenile salmon, or smolt, leave their freshwater spawning grounds to spend an average of two to three years maturing at sea, the boom in 2001 was right on schedule.

Ongoing disagreement among scientists over how to sustain high survival rates for salmon once the ocean warms up again placed the National Marine Fisheries Service in a cross fire last year. A coalition of environmental groups filed suit against the federal agency in May, accusing it of violating the Endangered Species Act and driving salmon to extinction by delaying interventions in the Columbia River Basin. One measure, a proposal to tear down four dams along a 140-mile stretch of Oregon's Snake River, has made farmers and hydroelectric companies livid, especially in a year of local droughts and power shortages. They point to the record salmon runs as proof that dam-busting is unnecessary.

The National Marine Fisheries Service postponed a final decision on the dams until 2008, after it collects and analyzes more data.
— Christine Soares


Take a Deep Breath of Platinum Dust
The road to cleaner air has been paved with good intentions, but metal particles lodged in the pristine snows of Greenland suggest that we may be trading one type of pollution for another in our attempts to lessen the impact of car exhaust.

Catalytic converters have helped cut U.S. vehicular emissions of carbon monoxide and ozone-producing compounds by 29 percent since the 1970s. But in breaking down those pollutants, catalytic converters also churn out a dust variously composed of the heavy metals platinum, rhodium, and palladium. To see how quickly these particles are accumulating in the atmosphere, Carlo Barbante, an environmental chemist at the University of Venice, looked at snowpack and ice cores brought from Greenland.

Sampling 7,000-year-old ice cores as well as snowpack dating from 1969 through the mid-1990s, Barbante's team found that concentrations of the metals had risen almost sevenfold since the mid-1970s, when catalytic converters first came into widespread use. They observed a particularly dramatic jump in the 1990s (a rise that coincides with the increased use of the converters in Europe). As yet little is known about the health effects of breathing the metal particles, and recent air-quality studies conducted in European cities suggest levels are still relatively low. But Barbante believes their buildup in Greenland signals a trend that bears close watching. "Catalytic converters are really powerful devices, and they really solve a lot of problems," he notes, "but the lesson of the story is that a technology without any environmental impact doesn't exist."
— Christine Soares


Survival of the Slickest
The image was achingly familiar: a pristine marine environment, a foundering oil tanker, a smear of leaking oil threatening an entire ecosystem. This time the culprit was the Ecuadoran tanker Jessica, carrying 160,000 gallons of diesel fuel and 80,000 gallons of bunker fuel. Its captain apparently mistook a signal buoy for a lighthouse and plowed into the bottom of the fatefully named Wreck Bay of San Cristóbal Island in the Galápagos, a treasure-house of biology. About two-thirds of the fuel eventually seeped from the ship's hold. Miraculously, the islands escaped serious damage when most of the oil drifted to the open sea. A few pelicans and seagulls were discovered dead, and dozens of other pelicans and sea lions had to be cleaned. Yet the Galápagos penguin and the lava gull—the two most endangered and fragile species in the islands—escaped unharmed. The spill has nevertheless galvanized efforts to further protect the 100,000-square-mile Galápagos Marine Reserve, which is administered by Ecuador. "The image of the Jessica spewing fuel into this unique environment has dismayed all who value the natural wonders of the world," says Robert Bensted-Smith, director of the Charles Darwin Research Station in the Galápagos Islands.
— Curtis Rist


Rare Species Backlog

The Ventura Marsh milk vetch's only remaining habitat is a beach dune previously used for waste disposal from oil fields.
Illustration by Dugald Stermer
2001 was a tough year to be an endangered species in the United States. The process of listing plants and animals at risk of extinction almost ground to a halt as the U.S. Fish & Wildlife Service turned toward defending itself in expensive legal battles with conservation groups. The problem began when a successful 1997 suit against the agency for failing to list the critical habitat of the California gnatcatcher prompted suits on behalf of other species. Last year the suits multiplied until so much of the agency's money was tied up in attorneys' fees that there was virtually none left to use for listing endangered species. By August, only the Ventura Marsh milk vetch had been listed for all of 2001. (About 55 species had been listed in each of the previous four years.) The logjam finally broke when conservation groups agreed to relax their demands that the agency act immediately on all court orders to list critical habitats for endangered species. That freed up what was left of the 2001 budget to revive the stalled listing process. More than 275 cases are still waiting in the queue.
— Lauren Gravitz

Listed as of November
Ventura Marsh milk vetch (California)
White abalone (California)*
Ohlone tiger beetle (California)
Spalding's catchfly (Idaho, Montana, Oregon, Washington)
Scaleshell mussel (Arkansas, Missouri, Oklahoma, S. Dakota)
Holmgren milk vetch and Shivwitz milk vetch (Arizona, Utah) Delisted
Aleutian Canada goose (Alaska, California, Oregon, Washington) emergency listings being processed now
Tumbling Creek cavesnail (Missouri)
Pygmy rabbit (Washington)
Carson wandering skipper (California, Nevada)
(*listed by National Marine Fisheries Service)


Make Up Your Mind
In a telephone survey conducted in the United States last January by the Pew Initiative on Food and Biotechnology, more than half of the 1,001 respondents said they would not want to eat genetically modified foods. Only 14 percent realized that such food products already occupy more than half of the grocery shelf space in this country.

While a quarter of those surveyed said they believed modified foods are unsafe, slightly more—29 percent—considered them to be edible without risk. When participants were told how much genetically modified food is already being scanned at the checkout counter, the number who felt it was safe shot up to 48 percent. "The survey results suggest that consumer opinions about safety are not strongly held," says Mike Rodemeyer, executive director of the Pew Initiative. "They may, in fact, be up for grabs."
— Curtis Rist


Polishing Golden Rice
Golden rice has been, quite literally, the golden child of the genetically modified foods movement. Spliced with genes that code for beta-carotene, the precursor to vitamin A, the grain has been touted as an antidote to vitamin A deficiency in Asia— a condition that affects more than 100 million children, leaving some half a million blind. But in March, critics pointed out that an adult would have to eat nearly 20 pounds of the cooked rice per day—30 times the amount in the average Asian diet—to get a full dose of the vitamin. Gordon Conway, president of the Rockefeller Foundation, which is funding tests of the rice, admitted that claims for it have been exaggerated. Nevertheless, he said, golden rice could provide 10 to 20 percent of a child's beta-carotene needs—enough to keep more children healthy.
— Curtis Rist


Easy Target
How vulnerable are America's oil supplies? In October, a 37-year-old man with a hunting rifle single-handedly stopped 20 percent of domestic oil production when he aimed his weapon at the trans-Alaska pipeline. The holes took three days to repair. Said Alaska state trooper Tim DeSpain: "Alcohol was a factor."


The Big Melt
Definitive proof of global warming has not been nailed down yet, but something is robbing Mt. Kilimanjaro of its famous snows. Geologist Lonnie Thompson of Ohio State University reported in February that the majestic Tanzanian mountain has lost 82 percent of its ice pack since 1912. If the peak continues to melt at the present rate, it will be bare in 20 years.


New Pacific Migration
Life on the Pacific island nation of Tuvalu has never been easy. Two-thirds of the 11,000 inhabitants depend on subsistence farming for all their income, yet there are no streams or rivers. Rainfall is the only source of freshwater. Now increasing global temperatures seem to be making life in Tuvalu more difficult. The weather has grown more temperamental, with lengthening droughts and more frequent cyclones, and seas have risen. At their highest point the islands lie only 15 feet above sea level, so flooding and coastal erosion have become commonplace. As seawater seeps into the soil and wells, it is turning the water table salty, endangering crops such as taro, the islanders' mainstay of life. "People are very frightened," says Enele Sopoaga, who is Tuvalu's ambassador to the United Nations.

Jerry Meehl, a climate scientist at the National Center for Atmospheric Research in Boulder, Colorado, says the Pacific has been rising by a millimeter or two a year for a century—largely because the water expands as its surface temperatures rise. Meehl, who has visited Tuvalu, says the islanders' concerns are legitimate. "A very high tide becomes more problematic because more areas flood when the sea level is higher," he says. "And these effects will get worse over time."

If the islands' woes continue, a growing number of Tuvaluans may need to relocate—if anyone will have them. Every year, 80 Tuvaluans are allowed to come to New Zealand as part of the Tuvalu Work Scheme. But their stay is limited to a mere three years.
— Josie Glausiusz

Comment on this article
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT
ADVERTISEMENT
Collapse bottom bar
DSC-JanFeb15
+

Log in to your account

X
Email address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it emailed to you.

Not registered yet?

Register now for FREE. It takes only a few seconds to complete. Register now »