Airdate: Nov 13, 2002
Scientist: Dr. Bill Fraser
Penguins and Global Warming
Global warming threatens the delicate balance of sea ice and life sustaining nutrients for Adelie penguins living in Antarctica.
ambience: Adelie penguins
Many scientists now believe that the earth's climate is warming and the changes are particularly noticeable in the polar regions. Global warming is apparently already affecting Anarctica's ecosystem. I'm Jim Metzner, and this is the Pulse of the Planet. We're with Dr. Bill Fraser of Montana State University, listening to the sounds of Adelie penguins in Antarctica. Dr. Fraser's been studying how changes in the planet's climate are affecting life on earth. He's convinced that understanding the ecology of Adelie penguins will provide us with valuable insights.
"We’ve done it every year consecutively for a decade, that we have historical records that go back to 1972. In that period of time, Adelie penguin populations in the area as a whole have decreased by about forty percent."
Well, this close to the south pole, the sea surface freezes for six months of the year and forms pack ice. For most of their lives, penguins live amidst this drifting ice. They use the pack ice to rest between feeding bouts, and to keep safe from predatory leopard seals. The ice also serves as a nursery for the penguins main food supply, the tiny shrimp-like crustaceans known as krill.
"We now know that krill larvae can not survive the winter without sea ice. Sea ice during the winter develops algal communities which end up being preyed of krill."
According to Dr. Fraser, there’s been an increase of eight degrees Fahrenheit in Antarctica's midwinter air temperatures over the past fifty years. That trend will mean less winter ice, less algae and less krill, which could have a devastating effect on Adelie penguins and the rest of the Antarctic ecosystem.
Pulse of the Planet is presented with support provided by the National Science Foundation.