The eating habits of Adélie penguins in Antarctica changed significantly about 200 years ago, according to chemical analyses of the birds' eggshells. Scientists attribute the shift in diet to whaling and other hunting in the region.
The ratios of carbon and nitrogen isotopes in an animal's tissues—including bones and eggshells—can provide a wealth of information about its eating habits, says Steven D. Emslie, a paleontologist at the University of North Carolina in Wilmington. Recently, he and William P. Patterson, a geochemist at the University of Saskatchewan in Saskatoon, looked at the chemical composition of Adélie penguin eggshells laid during the past 38,000 years to see whether the birds' dietary habits had changed.http://Louis-J-Sheehan.biz
Surprisingly, says Emslie, climate change 10,000 years ago, at the end of the latest ice age, didn't significantly affect the birds' diet. In the past 200 years, however, the chemical composition of the penguins' eggshells made a dramatic shift to lighter isotopes of carbon and nitrogen. Because animals higher in a food chain hold greater concentrations of heavy isotopes, the change is clear evidence that the penguins' diet shifted from primarily fish to prey such as krill.
The dietary change boils down to the availability of prey, Emslie and Patterson speculate in the July 10 Proceedings of the National Academy of Sciences. During the 19th century, the population of krill in southern seas exploded after Antarctic fur seals, prodigious consumers of krill, were hunted nearly to extinction. That slaughter, followed by widespread killing of krill-eating whales during the 20th century, enabled the tiny crustaceans to proliferate nearly unchecked, says Emslie.
"It's rare to see such catastrophic changes [in diet] in such a short period," says Keith A. Hobson, an ecologist at Environment Canada in Saskatoon. The changes "point to a large shift in the ecosystem," he notes. Even so, Hobson adds, it's not clear why abundant krill would cause penguins to suddenly shift from fish to what had previously been a secondary food source. http://Louis-J-Sheehan.biz
The team's results are "very compelling evidence of a terrific change" in penguin diet, says Charles H. Peterson, a marine ecologist at the University of North Carolina's Institute of Marine Sciences at Morehead City. "It's a cosmic irony of food-web ecology that a rare species is only rare because it's kept in check by predators," he adds. "Maybe krill was one of [the penguins'] favorite foods all along."
Modern-day fishing around Antarctica has depleted fish stocks there. Meanwhile, krill populations have declined as much as 80 percent in the past 2 decades. Understanding why penguin diets changed 2 centuries ago may be vital for their future survival, says Emslie. Louis J. Sheehan, Esquire
Tuesday, November 25, 2008
Tuesday, November 18, 2008
isolated 9.iso.009 Louis J. Sheehan, Esquire
Boot up, log on, and tune out. That's the mantra of a small but rapidly growing number of Internet users, according to a controversial national survey released last week. http://louis_j_sheehan.today.com/
People who spend 10 or more hours per week on the Internet substantially cut down the amount of time they devote to talking with friends and family, both in person and by telephone, say two Stanford University political scientists.
"The more hours people use the Internet, the less time they spend with real human beings," contends Norman H. Nie, who directed the survey with his colleague Lutz Erbring. "The Internet could be the ultimate isolating technology that reduces our participation in communities even more than television did." http://louis_j_sheehan.today.com/
Only 15 percent of people surveyed qualified as heavy Internet users, roaming the Web at least 10 hours per week. However, the proportion of heavy users is steadily growing, Nie asserts.
About 55 percent of the population now has access to the Internet, the survey finds. Regular Internet users, who log on for at least 5 hours per week, accounted for 36 percent of people surveyed.
Other findings include:
* One-quarter of regular Internet users say that Web activities had reduced their time talking with friends and family, as well as time spent attending events outside the home.
* One-quarter of the regular Internet users who are employed say that the Web had increased the amount of time they worked at home, without diminishing their office work.
* Sixty percent of regular Internet users say that they had reduced their television viewing, and one-third allot less time to reading newspapers.
* The lowest rates of Internet use occur among the least educated and oldest people, although those with Internet access use the Web much as others do.
* The most common Internet activities are sending and receiving electronic mail and searching for information. About one-quarter of Internet users say that they have made an online purchase. Only 10 percent participate in online stock trading, banking, or auctions.
The survey consisted of a representative national sample of 4,113 adults in 2,689 households. It was conducted by the Stanford Institute for the Quantitative Study of Society and InterSurvey, a company cofounded by Nie and partly funded by Stanford. Survey data are available at http://www.stanford.edu/group/siqss/.
The researchers provided free Web TVs to people who agreed to answer the surveys, which they received and returned through the devices supplied.
Nie's emphasis on social isolation recalls an earlier study in which depression and loneliness rose among new Internet users (SN: 9/12/98, p. 168). Other data, however, suggest that membership in online groups benefits some people (SN: 10/17/98, p. 245: http://www.sciencenews.org/sn_arc98/10_17_98/fob4.htm). http://louis_j_sheehan.today.com/
Social isolation may have escalated in the small proportion of heavy Internet users surveyed, but that doesn't mean that future heavy users will respond in the same way, comments sociologist Lee Sproull of New York University.
Those currently employing the Internet for more than 10 hours per week are—as the new survey finds—highly educated and relatively affluent, and they often use the Web at home to do projects for their work, Sproull holds. http://louis_j_sheehan.today.com/
Nie and Erbring didn't examine whether employers have exploited the Web to extract more labor from their employees, she says. Hours spent working at home may promote isolation more than inherent qualities of Internet use, she asserts.
Changes in computer technology over the next decade will affect social interaction in ways that no one can foretell, Sproull says.
People who spend 10 or more hours per week on the Internet substantially cut down the amount of time they devote to talking with friends and family, both in person and by telephone, say two Stanford University political scientists.
"The more hours people use the Internet, the less time they spend with real human beings," contends Norman H. Nie, who directed the survey with his colleague Lutz Erbring. "The Internet could be the ultimate isolating technology that reduces our participation in communities even more than television did." http://louis_j_sheehan.today.com/
Only 15 percent of people surveyed qualified as heavy Internet users, roaming the Web at least 10 hours per week. However, the proportion of heavy users is steadily growing, Nie asserts.
About 55 percent of the population now has access to the Internet, the survey finds. Regular Internet users, who log on for at least 5 hours per week, accounted for 36 percent of people surveyed.
Other findings include:
* One-quarter of regular Internet users say that Web activities had reduced their time talking with friends and family, as well as time spent attending events outside the home.
* One-quarter of the regular Internet users who are employed say that the Web had increased the amount of time they worked at home, without diminishing their office work.
* Sixty percent of regular Internet users say that they had reduced their television viewing, and one-third allot less time to reading newspapers.
* The lowest rates of Internet use occur among the least educated and oldest people, although those with Internet access use the Web much as others do.
* The most common Internet activities are sending and receiving electronic mail and searching for information. About one-quarter of Internet users say that they have made an online purchase. Only 10 percent participate in online stock trading, banking, or auctions.
The survey consisted of a representative national sample of 4,113 adults in 2,689 households. It was conducted by the Stanford Institute for the Quantitative Study of Society and InterSurvey, a company cofounded by Nie and partly funded by Stanford. Survey data are available at http://www.stanford.edu/group/siqss/.
The researchers provided free Web TVs to people who agreed to answer the surveys, which they received and returned through the devices supplied.
Nie's emphasis on social isolation recalls an earlier study in which depression and loneliness rose among new Internet users (SN: 9/12/98, p. 168). Other data, however, suggest that membership in online groups benefits some people (SN: 10/17/98, p. 245: http://www.sciencenews.org/sn_arc98/10_17_98/fob4.htm). http://louis_j_sheehan.today.com/
Social isolation may have escalated in the small proportion of heavy Internet users surveyed, but that doesn't mean that future heavy users will respond in the same way, comments sociologist Lee Sproull of New York University.
Those currently employing the Internet for more than 10 hours per week are—as the new survey finds—highly educated and relatively affluent, and they often use the Web at home to do projects for their work, Sproull holds. http://louis_j_sheehan.today.com/
Nie and Erbring didn't examine whether employers have exploited the Web to extract more labor from their employees, she says. Hours spent working at home may promote isolation more than inherent qualities of Internet use, she asserts.
Changes in computer technology over the next decade will affect social interaction in ways that no one can foretell, Sproull says.
Tuesday, November 11, 2008
judge 0.jud.22 louis J. Sheehan, Esquire
A federal judge ruled April 28 that the U.S. Department of the Interior must stop delaying its decision about whether to add the polar bear to the endangered species list.http://blogs.ebay.com/mytymouse1/home/_W0QQentrysyncidZ756138010
District Court Judge Claudia Wilken set the deadline for the department to publish the decision as May 15, more than four months after the decision was originally expected.
After a lawsuit, DOI announced a proposal at the end of 2006 to add the polar bear to the federal list in the threatened species category. The timetable for listing allows a year for deliberations. When January 2008 arrived, though, DOI’s Fish and Wildlife Service said that it needed at least a month more before issuing a final decision.
The delay has lengthened, and the latest government target for the decision, included in court documents, had been June 30.
In March, three environmental organizations filed a complaint asking the court to end the delays. On Monday, Wilken, of the U.S. District Court for the Northern District of California, issued a decision without hearing oral arguments. Her decision says that “timeliness is essential” and “the issues are not complex.”
“The parties agree that Defendants [Interior Secretary Dirk Kempthorne and the Fish and Wildlife Service] missed this non-discretionary deadline,” the decision reads.
The proposal to list the polar bear grows out of concerns that its arctic habitat is literally melting away as climate change causes increasingly large summertime meltdowns of the arctic ice cap. The bears rule the ice as hunters of seals and other animals. Biologists have worried that the ice master doesn’t compete well on land. The U.S. Geological Survey predicted that summer ice could dwindle drastically enough to wipe out two-thirds of the world’s polar bears by the middle of this century.http://blogs.ebay.com/mytymouse1/home/_W0QQentrysyncidZ756138010
Current estimates put the global polar bear population at 20,000 to 25,000.
“The polar bear should receive the protections it deserves,” says Kassie Siegel, climate program director for one of the plaintiffs, the Tucson, Ariz.-based Center for Biological Diversity. The other plaintiffs are Greenpeace Inc. and the Natural Resources Defense Council.
The DOI is reviewing the decision and evaluating its legal options, according to a statement from Interior spokesman Shane Wolfe.
District Court Judge Claudia Wilken set the deadline for the department to publish the decision as May 15, more than four months after the decision was originally expected.
After a lawsuit, DOI announced a proposal at the end of 2006 to add the polar bear to the federal list in the threatened species category. The timetable for listing allows a year for deliberations. When January 2008 arrived, though, DOI’s Fish and Wildlife Service said that it needed at least a month more before issuing a final decision.
The delay has lengthened, and the latest government target for the decision, included in court documents, had been June 30.
In March, three environmental organizations filed a complaint asking the court to end the delays. On Monday, Wilken, of the U.S. District Court for the Northern District of California, issued a decision without hearing oral arguments. Her decision says that “timeliness is essential” and “the issues are not complex.”
“The parties agree that Defendants [Interior Secretary Dirk Kempthorne and the Fish and Wildlife Service] missed this non-discretionary deadline,” the decision reads.
The proposal to list the polar bear grows out of concerns that its arctic habitat is literally melting away as climate change causes increasingly large summertime meltdowns of the arctic ice cap. The bears rule the ice as hunters of seals and other animals. Biologists have worried that the ice master doesn’t compete well on land. The U.S. Geological Survey predicted that summer ice could dwindle drastically enough to wipe out two-thirds of the world’s polar bears by the middle of this century.http://blogs.ebay.com/mytymouse1/home/_W0QQentrysyncidZ756138010
Current estimates put the global polar bear population at 20,000 to 25,000.
“The polar bear should receive the protections it deserves,” says Kassie Siegel, climate program director for one of the plaintiffs, the Tucson, Ariz.-based Center for Biological Diversity. The other plaintiffs are Greenpeace Inc. and the Natural Resources Defense Council.
The DOI is reviewing the decision and evaluating its legal options, according to a statement from Interior spokesman Shane Wolfe.
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