By Will Dunham
WASHINGTON (Reuters) - Penguin populations have plummetedat a key breeding colony in Argentina, mirroring declines inmany species of the marine flightless birds due to climatechange, pollution and other factors, a study shows.
Dee Boersma, a University of Washington professor who ledthe research, said the plight of the penguins is an indicatorof big changes in the world's oceans due to human activities.
"Penguins are in trouble," Boersma, whose study appears inthe journal BioScience, said in a telephone interview onTuesday. "They certainly are canaries in the coal mine."
For the past 25 years, Boersma has tracked the world'slargest breeding colony of Magellanic penguins located at PuntaTombo on Argentina's Atlantic coast. She said that since 1987she has observed a 22 percent decrease in the population ofthese penguins at the site.
Boersma said the decline appears to have begun in the early1980s after the population at the site peaked probably at about400,000 breeding pairs of Magellanic penguins between the late1960s and mid-1970s. Today's total is half of that.
The world's warming climate is only one of the causes ofthe penguins' problems, she said. They also are threatened byoil pollution, depletion of fisheries, becoming entangled infishing nets, and coastal development that eliminates breedinghabitats, according to Boersma.
"Penguins are sentinels of the marine environment, and byobserving and studying them, researchers can learn about therate and nature of changes occurring in the southern oceans. Asocean samplers, penguins provide insights into patterns ofregional ocean productivity and long-term climate variation,"Boersma wrote in the study.
Most scientists recognize 17 species of penguins, and theylive in Earth's southern hemisphere. Penguins are beautifullyadapted to life in the ocean, residing in places as differentas the warm Galapagos islands and icy Antarctica.
While a bit ungainly on land, they gracefully knife throughthe water, feeding on fish and other sea delicacies.
But many species have been experiencing population declinesin Antarctica, Africa, South America, Australia, New Zealandand the Falkland Islands, Boersma said.
The number of Galapagos penguins, the only species with arange that inches into the northern hemisphere, has slipped toaround 2,500 birds, about a quarter of its total in the 1970s.
Anton Seimon of the Wildlife Conservation Society, whichbacked Boersma's work, said the findings illustrate thedisruption that people have caused to penguins' ecosystems.
"These disruptions introduce instability into what had beensomewhat stable populations. That instability means we don'treally know what's going to be happening in the future. In manyinstances it does signify declines that may result, in the mostdrastic case, in extinctions," Seimon said.
(Editing by Julie Steenhuysen and Eric Walsh)
