Chinstrap Penguins suffering at the hands of global warming

We've been watching Adelie Penguin populations crash along the western Antarctic Peninsula, down something like 50 to 90% at the colonies I know the best. This is pretty clearly due to disappearing ice cover...... but now, apparently, Chinstrap Penguins are following the same course. I haven't seen this myself.... anyone have access to the original paper in Proceedings of the National Academy of Sciences to see where the documented Chinstrap decline is happening?

Not happy news. Thanks to Mary for brining this to my attention.

http://www.signonsandiego.com/news/2011/apr/11/penguin-decline-linked-warming-antarctic/

Penguin decline linked to warming in Antarctica
BY MIKE LEE ~ MONDAY, APRIL 11, 2011 AT 1:25 P.M.

Climate change appears to be harming a population of penguins that some researchers figured would benefit from warming temperatures, according to a new study by scientists at the National Marine Fisheries Service in La Jolla.

Instead of enjoying a reduction of sea ice, the ice-avoiding chinstrap penguins may be among the most vulnerable to temperature changes that threaten their staple food source, said a paper published online Monday in the peer-reviewed Proceedings of the National Academy of Sciences.

The findings may indicate more profound changes in the Antarctic ecosystem than previously thought. Antarctica is among the fastest-warming spots on the planet and a focus of studies by local researchers for decades.

One hypothesis about global warming is that it will create a variety of "winners" and "losers" in Antarctica. Under that scenario, ice-loving Adélie penguins would suffer but chinstrap penguins would benefit as the temperatures moderate and sea ice shrinks.

Adélie populations in the study area have fallen by an average of 2.9 percent per year for 10 years or more, while chinstrap numbers have decreased by even more -- an average of 4.3 percent per year over the same period, the study authors said.

“When we see steep declines in populations, as we have been documenting with both chinstrap and Adélie penguins, we know there’s a much larger ecological problem,” said Wayne Trivelpiece, the lead author of the study a seabird expert for the fisheries service.

“Penguins are excellent indicators of changes to the biological and environmental health of the broader ecosystem because they are easily accessible while breeding on land, yet they depend entirely on food resources from the sea," he said. "In addition, unlike many other krill-eating top predators in the Antarctic, such as whales and fur seals, they were not hunted by humans."

The La Jolla scientists link the shrinking penguin population to the decline of shrimp-like food source called krill, which penguins rely on heavily. Sea ice is a necessary part of the krill reproductive cycle and warming temperatures have undermined the population. The researchers said krill fishing also may play a role in krill numbers, which have plummeted by as much as 80 percent since the 1970s.

Adélie penguins are hampered by shrinking habitat and food shortages, but they have more breeding populations than chinstrap penquins and therefore researchers said they may not be as threatened by environmental changes.

"Long thought to be ecological winners in the climate-warming scenario, the chinstrap penguin instead may be among the most vulnerable species affected by a warming climate," the paper said.