Iceberg B09B killing Adélie penguin colony

Adelie, Commonwealth Bay, Aus GeographicTrust Chair, Kerry-Jayne Wilson, is lead author of a report published this week in the journal Antarctic Science, which concludes that the Cape Denison colony could be wiped out within 20 years.

This conclusion has been made following the visit of the Australasian Antarctic Expedition 2013/14.   A giant iceberg, known as B09B, had broken off and then become stuck in Commonwealth Bay and surrounded by year-round fast ice.  As a result, the colony of Adélie penguins, numbering more than 100,000 in Mawson’s day a century ago, now has to travel more than 60km, rather than 8km, to find food in the bay. 

The scientists estimate the size of the colony to number 5520 pairs at the time of their expedition two years ago, a massive decline since Mawson’s day, but also less than half of the number counted in 2011 of 13,834 pairs. 

Kerry-Jayne, co author and expedition leader, Chris Turney, and other co authors Christopher Fogwill and Estelle Blair, attribute this recent decline to the now vast distance the penguins have to travel for food.  They recorded many sad observations including hundreds of abandoned eggs and the ground being “littered with the freeze-dried carcasses of previous season’s chicks.”  They noted that “during the 2013 visit, the Cape Denison penguin colony was uncharacteristically silent …. the normally noisy, aggressive penguins were quiet, and incubating birds hardly acknowledged our intrustion into their realm.”

No prospecting penguins were recorded, which are critical to the future of the colony.  “If young birds do not visit Cape Denison, there will probably be few recruits to replace older established breeders, and numbers breeding there are likely to continue to decline even after the ice finally breaks up.”

A short video (2m 19s) is available telling a little of the story here: Giant iceberg decimates Adélie penguin colony at Cape Denison and the journal article can be read here: Antarctic Science 2016 Wilson et al Adelies Denison S0954102015000644a

MODIS image of fast ice extent in the Commonwealth Bay and Mertz Polynya region on 15 December 2013 (credit: Dr Jan Liester, AAD). Locations of the Cape Denison, Mackellar and Hodgeman islands Adélie penguin census sites. Inset: Location of Commonwealth Bay region, East Antarctica.

MODIS image of fast ice extent in the Commonwealth Bay and Mertz Polynya region on 15 December 2013 (credit: Dr Jan Liester, AAD). Locations of the Cape Denison, Mackellar and Hodgeman islands Adélie penguin census sites. Inset: Location of Commonwealth Bay region, East Antarctica.