Winners and losers as climate change hits Antarctica
Thursday 4 Apr 2013 8:55 a.m.
Scientists in Antarctica say climate change is having two very different effects on the region's Adélie penguins.
At Cape Bird on Ross Island the penguins are thriving, but further north – where the continent is warming more rapidly – the penguins are disappearing.
Cape Bird is an hour's flight from Scott Base, and home to 160,000 Adélie penguins, an Antarctic landscape teaming with life and personality.
But the future of the Adélie is in jeopardy.
"We're actually predicting for Antarctica in the next 30 or 40 years, we'll lose 70 percent of the population due to sea ice loss," says Phil Lyver, Landcare Research ecologist.
Dr Lyver has spent many summers in sub-zero conditions monitoring Antarctica's canary in the coalmine.
He weighs 50 chicks by hand every week to check their condition. But measuring the adults' foraging success is much simpler – in fact, it's as easy as scanning groceries at the supermarket.
The sub-colony is fenced off and the only way in and out is over a specially designed weighbridge.
"Each of the birds that we're monitoring has a microchip in it, and as the bird leaves the weighbridge colony we can weigh it so we know how heavy it is, and then it goes to sea, it feeds, when that parent comes back in the weighbridge records its arrival and then it weighs it again," says Dr Lyver.
"This season the chicks are in excellent condition."
That's because the sea ice here is at an optimum level. The penguins use it to launch from to catch things like silverfish and krill, but a further increase in sea ice means they might not make it to the open water and they'll starve, and if there's no ice, there's nothing to fish from.
"In the Ross Sea it's quite different from other parts of Antarctica, which are experiencing climate change," says Dr Lyver.
"Our sea ice season here has increased by three months in duration, which is quite in contrast to the peninsula region where they're losing sea ice. It's actually been three months less in that region, and as a consequence we've actually seen penguin colonies disappearing."
So while the penguins here are climate change winners, the losers are on the Antarctic Peninsula where the temperature has warmed by 2.5 degrees – a change scientists say is significant enough to erase more than two-thirds of Antarctica's Adélie penguins in just a few decades.