PNAS - Southern Ocean Krill Population Down 80% Since 1970s - Adelies, Chinstraps Losing Numbers

Climate change has hit species of Antarctic penguins by causing a staggering decline in their prey: krill. A new study in the Proceedings of the National Academy of Sciences (PNAS) has found that both chinstrap penguins (Pygoscelis antarcticus) and Adélie penguins (Pygoscelis adeliae) have seen their populations decline likely do to less krill, instead of habitat changes. Since 1970 krill populations have fallen by 80% in the Southern Ocean surrounding Antarctica. Because krill require sea ice to reproduce, shrinking sea ice from climate change has made it more difficult for them to breed. "As warming continues, the loss of krill will have a profound effect throughout the Antarctic ecosystem," says Dr. Wayne Trivelpiece, lead author of the paper with NOAA's Antarctic Ecosystem Research Division, in a press release.

The study overturns conventional wisdom about how chinstrap penguins would fare in a warmer world. Chinstrap penguins select habitat without sea ice, allowing researchers to predict that this species may actually benefit from a warmer Antarctica. But the new study proves that the decline in krill has stolen any advantage chinstrap penguins might have seen in a changing Antarctic. Over the past 10 years chinstrap penguin populations have fallen by 4.3% annually.

"For penguins and other species, krill is the linchpin in the food web. Regardless of their environmental preferences, we see a connection between climate change and penguin populations through the loss of habitat for their main food source," explains Trivelpiece.

Adélie penguins are faring little better than their chinstrap cousins: these penguins have fallen by 2.9% annually over the last decade. Researchers say Adélie penguins are probably in less danger than chinstrap because they have breeding populations outside of Western Antarctica, although unlike chinstrap penguins they depend on habitats with sea ice.

EDIT

http://news.mongabay.com/2011/0411-hance_penguin_krill.html

n/t

:puke:

... has no effect on krill populations at all ... no siree!

:argh: