About 150,000 penguins have died since being stranded by a vast iceberg that became lodged off the coast of Antarctica six years ago, according to the journal Antarctic Science.
Combined with expanding ice, the B09B iceberg, which at 1,120 square miles is almost the size of Rhode Island, has cut off the Adelie penguins’ food supply and changed the landscape of their home, according to a February report in the peer-reviewed journal published by Cambridge University Press.
The towering mass of water ice first ran aground into the penguins’ habitat of Cape Denison in Commonwealth Bay in 2010. Before that it was floating along the coast for nearly 20 years before colliding into the bay. The iceberg essentially has landlocked the penguins, forcing the animals to trek across a desolate stretch of nearly 40 miles to find food.
Adelies are one of the most abundant of the penguin species. They can be found in large colonies and on icebergs and coastal areas in Antarctica waters.
The once 160,000-strong colony has now dwindled to 10,000 penguins.
Adelie penguins group dive, Antarctic Peninsula pic.twitter.com/W4pBd2bzvo
â€” Earth Pics (@ThatsOurEarth) February 13, 2016
“The arrival of iceberg B09B in Commonwealth Bay, East Antarctica… has dramatically increased the distance AdÃ©lie penguins breeding at Cape Denison must travel in search of food,” said researchers in the report.
Since 2011, the colony’s population has fallen dramatically, according to the Climate Change Research Center at Australia’s University of New South Wales.
150,000 AdÃ©lie penguins die after iceberg the size of Rome crashes into colony, forcing a 60km trek to feed pic.twitter.com/KKBD4nu13g
â€” TIMES NOW (@TimesNow) February 13, 2016
The outlook for the Cape Denison Adelie penguins remains dire. Unless the colossal iceberg is broken up by sea ice, scientists predict the colony will disappear in 20 years.
About 5,500 pairs are still breeding in the area, but there has been a significant decline in their population compared with a century ago, according to estimates based on satellite images and a census in 1997.
However, it isn’t the end for all Adelie penguins. About five miles from the Commonwealth Bay, another colony is thriving, which leaves scientists to conclude that the iceberg has had a direct impact of the species that is now landlocked. About 30% of the Adelie penguin population lives in East Antarctica.
Research on the iceberg’s impact on the Adelie penguins can give scientists insight into the wider implications on the effects of increasing sea ice in the area.
Long-term environmental changes are projected for the Southern Ocean, which will likely affect marine predators, according to a 2015 report published the peer-reviewed journal BMC Evolutionary Biology. Environmental shifts because of climate change could also affect the breeding habitats of land creatures, finding food in a marine environment and the availability of prey for larger predators
Deglaciation, the gradual melting of glaciers, is a key driver in the Adelie penguins’ population over a millennium, according to scientists. But while changes in sea ice can directly affect the species, scientists say it’s important to keep perspective on the penguins’ population over a larger time frame.
on 16/02/2016 1:28am
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. This is what he says
“I have just returned from two months at Cape Denison. The Adelie penguins there are in good health. Their numbers are down, perhaps a bit under half of what I’ve seen in the previous four expeditions I’ve been on there since 1997 but the ones that remain are not starving or silent but rather in rude and noisy form and breeding well. There are many tens of thousands of penguins and chicks present.
The actual decline in numbers in Dr Turney’s paper is hard to determine. These are the figures quoted in table 1 of the original paper: Mawson reported perhaps 200,000 birds.In 1931 there was 10,000. In 1974 there was 2000 adults. In 1982 there was 3500. In 1997 there was 24,000. The iceberg arrived in 2010. In 2011 there was 26,000 birds. In 2013 he reports 5230 occupied nests, so something like 10,000 adults plus chicks. (So the suggestion 150,000 birds have disappeared is way off). But Dr Turney was at Cape Denison barely a day and in my experience a proper survey of penguin numbers at this site takes several days if not weeks. My suspicions is the counts don’t really tell us much. Certainly this summer there was tens of thousands of birds at the site, far in excess of what Dr Turney has reported.
The good news is a fresh count was conducted this summer by a fastidious observer over several weeks. I suspect it will go some way to allaying fears that the Adelie penguins of Cape Denison are dying out. The other good news is the walk across the sea ice is only 12km at present, much less in most cases because there are plentiful tide cracks further in.”