Lost 43% of Adélie penguins in East Antarctica



by LORENZO CIOTTI

Lost 43% of Adélie penguins in East Antarctica

According to monitoring results published in Global Change Biology, the nesting population of Adélie penguins in Antarctica has shrunk by 43% in 10 years. In total, over 154,000 penguins have been lost. Scientists from the Australian Antarctic Division have observed this rather worrying collapse in the population of Adélie penguins, which live near Mawson Station.
According to the study authors, this decline was caused by a sudden change in environmental conditions, which effectively prevented seabirds from accessing fishing grounds.

The decrease in numbers would have started with some periods of summer fast ice of the water surface, recorded from 2004 to 2005 and in 2009-10. According to the researchers, this extensive ice surface would have prevented the penguins from accessing marine fishing areas, with the result that practically no chicks survived in those years.

With few chicks surviving, there is also a decline in the population leaving the colony and surviving the winter.

Lost 43% of Adélie penguins in East Antarctica

The researchers counted nests and breeding pairs living near the Mawson Research Station each year from 2010 through 2020.

In these ten years of monitoring, the total number of nests has gone from 176,622 to just 99,946, a drop of about 77,000 nests. This decline is in contrast to population trends observed for the same species in other areas in East Antarctica, where penguin numbers have remained stable or are even increasing.

A similar collapse had already been observed in the populations of the Antarctic Peninsula as well, due to overfishing, climate change and other human activities. The decline in numbers had another negative cascading effect.

Less small means greater ease of capture by predators, such as leopard seals, which have an easy life with the very young specimens grappling with their first dives in the Southern Ocean. Dr Louise Emmerson explained: 'We think this population decline was initially triggered by five years of extensive summer sea ice adjacent to the colony in the mid-2000s, which impeded access to adult foraging areas and virtually no chicks survived. ."