Ignore Chris Turney, Adelies Are Thriving
By Paul Homewood
The latest scare story about penguins has been attracting headlines lately. It all stems from a study by Chris Turney, who readers may recall was the leader of the Ship of Fools expedition, which got stuck in the sea ice in Antarctica two years ago.
Apparently before they got stuck, they spent a day counting Adelie penguins.
The SMH takes up the story:
More than 150,000 Adélie penguins have perished in a single colony in Antarctica after the grounding of a giant iceberg.
The penguins used to thrive at Cape Denison in Commonwealth Bay, where strong winds blowing off the ice sheet kept a large area of water open near the shore.
But in December 2010 an iceberg bigger than the ACT grounded in the bay, trapping floating sea ice near the coast. The penguins now have to make a round trip of more than 120km to feed in the sea and since 2011 the population has plummeted from 160,000 to just 10,000.
According to new research co-authored by the University of NSW’s Climate Change Research Centre and published in the journal Antarctic Science, the colony could be wiped out within 20 years unless the sea ice breaks up or the iceberg, with an area of about 2900 square kilometres, moves.
The penguins were counted as part of the Australasian Antarctic Expedition 2013-14, led by Professor of Climate Change and Earth Sciences at UNSW, Chris Turney.
Professor Turney said penguin numbers had been recorded for 100 years at Cape Denison, where explorer Sir Douglas Mawson’s research station was based in 1911-14. Members of that expedition complained of the noise generated by 100,000 inquisitive Adélie penguins.
"It’s eerily silent now," Professor Turney said. "The ones that we saw at Cape Denison were incredibly docile, lethargic, almost unaware of your existence. The ones that are surviving are clearly struggling. They can barely survive themselves, let alone hatch the next generation. We saw lots of dead birds on the ground … it’s just heartbreaking to see."
Lead author Dr Kerry-Jayne Wilson, of the West Coast Penguin Trust, said regional changes triggered by the iceberg had led to a "catastrophic breeding failure". She said it was "heart wrenching" to see the impact on the penguins, with researchers walking "amongst thousands of freeze-dried chicks from the previous season and hundreds of abandoned eggs".
In contrast, an Adélie colony in a different part of Commonwealth Bay, just eight kilometres from the edge of the sea ice, was thriving.
Known as B09B, the 97-kilometre long iceberg had moved around the Antarctic coast for 20 years before crashing into a glacier then grounding in Commonwealth Bay.
"Iceberg doesn’t really do it justice," Professor Turney said. "It’s like a small country, it’s enormous.
"As the planet warms you’re going to get more ice melting. The reality is, more icebergs will be released from Antarctica and just embed themselves along the coastline, and make the travelling distances for some of these colonies even further than they have been."
Adélie penguins usually return to the colony where they hatched and try to return to the same mate and nest. Professor Turney said the Cape Denison penguins could face a grim future. "They don’t migrate," he said. "They’re stuck there. They’re dying."
Co-author Chris Fogwill, of the UNSW Climate Change Research Centre, said there was some good news for the colony. "Over the last year the fast ice associated with B09B has begun to break up in Commonwealth Bay," he said.
The effects of the recent changes on the ecosystems in and around Commonwealth Bay "will help us better understand the impacts of such large-scale events on the fragile Antarctic ecosystem", he said.
The idea that global warming causes icebergs would be laughable if it had not come from a supposed scientist. But what is really interesting is this comment on the SMH web page:
I originally dismissed the comment as unverifiable, but on checking it turns out that David Killick is the official photographer, sent as part of a team of six to dig out one of the Mawson’s huts at Cape Dension. (See here)
Mawson, you may recall, was one of Australia’s most famous Antarctic explorers, who explored the region a century ago.
Also, the figures Killick quotes are correctly sourced from Turney’s own paper here. Clearly, if the figures are correct, there have been large variations in the Adelie population over the years. The idea that the recent decline is of any real significance is potty.
Killick’s criticism about making the count in just a day also appears valid. Stacey Adlard works for the British Antarctic Survey, and spends five months every year on Signy Island, part of the South Orkneys, doing little but count bird populations. Her blog is here.
Nature, unfortunately, is cruel, and there will always be local events which affect animal populations. But there is no evidence whatsoever that Adelie populations are in decline, or under any stress. Quite the contrary, as this study in 2014 found:
We report on the first global census of the Adélie Penguin (Pygoscelis adeliae), achieved using a combination of ground counts and satellite imagery, and find a breeding population 53% larger (3.79 million breeding pairs) than the last estimate in 1993. We provide the first abundance estimates for 41 previously unsurveyed colonies, which collectively contain 420,000 breeding pairs, and report on 17 previously unknown colonies, 11 of which may be recent colonizations. These recent colonizations represent ∼5% of the increase in known breeding population and provide insight into the ability of these highly philopatric seabirds to colonize new breeding territories. Additionally, we report on 13 colonies not found in the survey, including 8 that we conclude have gone extinct. We find that Adélie Penguin declines on the Antarctic Peninsula are more than offset by increases in East Antarctica. Our global population assessment provides a robust baseline for understanding future changes in abundance and distribution. These results are a critically needed contribution to ongoing negotiations regarding the design and implementation of Marine Protected Areas for the Southern Ocean.
It is worth noting the comment about new colonies, which rather makes a nonsense of Turney’s claim that they don’t migrate.
But I guess that’s par for the course for the guy who got his ship stuck in the ice and needed to be helicoptered to safety!