Australian Broadcasting Corporation
Broadcast: 07/02/2012
Transcript
CHRIS UHLMANN, PRESENTER: Antarctica may be a long way from civilisation, but human activity has put its penguins on thin ice. Over-fishing, melting sea ice and pollution are threatening these iconic creatures which have so far managed to thrive in the world's harshest conditions. But one species is faring better than most - and researchers are using them to find out what's changing in this vast and fragile ecosystem. Karen Barlow reports from Antarctica.KAREN BARLOW, REPORTER: It is hard not to fall for Adelie Penguins. Their charm, playfulness and fearlessness will melt the coldest heart. And that affection appears to be returned. It's nesting season for the Adelie Penguins, but the ones out here are foraging for food.
They don't really see humans that much so they're interested in us, they're intrigued by us, they will come up close to us and look at us, they'll look at what we're doing and that's wonderful.
KAREN BARLOW: For biologists, having a research subject that doesn't flee on approach is certainly a bonus, but penguins are the perfect species for scientists to gauge what's happening in the southern ocean marine ecosystem.
COLIN SOUTHWELL, PENGUIN BIOLOGIST: They're used as indicator species for fisheries and climate change impact, and if we understand the impacts of these kind of processes from year to year or from place to place, the impacts of different sea ice changes on their breeding success, then we'll be able to predict forward on what kind of changes in sea ice will have on penguin populations in the future under changing environments.
KAREN BARLOW: There are dire predictions for some penguin species. Of the 17 types of penguins, some, like the African and Galapagos Penguins, are classed as threatened or vulnerable - and according to a climate model study by the private Woods Hole Oceanographic Institute, Emperor Penguins could be virtually extinct by the end of the century. Generally, penguin populations on the Antarctic Peninsula below South America are decreasing, while Adelie numbers in East Antarctica, below Australia, are on the rise. Over-fishing of the penguin's main diet, krill, is having an effect, but scientists say climate change is also a factor.
LOUISE EMMERSON, PENGUIN BIOLOGIST: Breeding phenology has changed for animals all over the world in relation to climate change. We know Adelie Penguins have shown changes. There have been penguins breeding earlier, and they think this is because there's a lot less snow in the area and due to warmer air temperatures, so the birds are able to get to their colonies and start nesting earlier. In East Antarctica it's a little bit harder to say whether any long-term changes are driven by environmental changes, or perhaps even changes in the prey availability.
KAREN BARLOW: Around East Antarctica's Commonwealth Bay, the home of Mawson's Huts, something unusual has been thrown into the mix. The large remnants of a giant iceberg, B9B, are grounded in the area, and have encouraged a vast expanse of ice to grow out from land.
COLIN SOUTHWELL: There's fast ice growing out to 10 miles from the breeding colonies, so the penguins have to travel a lot further to get to their foraging ground than they would normally.
KAREN BARLOW: The longer on the ice, the less time the parents have with their fledglings, and it reduces the amount of food which can be brought back to the pebbly nest. There are longer-term losses in sea ice here that have been monitored since the 1950s. Biologists Colin Southwell and Louise Emerson are the first to survey the penguins at Commonwealth Bay since 1982. They want to see how the Adelie population has changed in 30 years.
COLIN SOUTHWELL: We've done similar surveys over much of East Antarctica and compared it with historical counts, and found the populations have almost doubled over the last two to three decades. So we're seeing a very major signal, through penguins, from the marine ecosystem, and we're trying to understand what might be causing those changes.
KAREN BARLOW: First impressions from Commonwealth Bay are there fewer chicks in the nests, and that's likely to be related to the presence of fast ice, but there appears to have been a general population explosion.
LOUISE EMMERSON: Well I didn't think that the population was going to be quite as big as it is, and we've been walking around with the intention of counting all the penguin breeding colonies, but it's not going to be possible in the limited time that we're going to be here, so we will do some helicopter surveys to finish off the counts.
KAREN BARLOW: So how can sea ice loss for one lot of penguins be good, and for the others bad? Dr Collin Southwell said a melt on the Antarctic Peninsula may have gone too far.
COLIN SOUTHWELL: Over there, the sea ice is also declining at a greater rate than in Eastern Antarctica, and that appears contradictory or paradoxical. But we think perhaps the sea ice is above the optimal elements for Adelie Penguins in East Antarctica, so that the reduction in sea ice might be beneficial. It's one of the things we're trying to find out.
KAREN BARLOW: Two days of ground and aerial counts won't be enough for the penguin biologists. The team have set up a solar-powered camera to keep track of the lives and loves of the Adelies on Commonwealth Bay. Adelie TV may not be there for the ratings, but it may be the best picture yet of a changing continent.
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