A severe decline in the population of Adélie penguins off the east Antarctic coast has sent alarm bells ringing among scientists worldwide. The monitoring by the Australian Antarctic Division revealed a 43 per cent drop over a decade in the number of birds that breed across 52 islands near the Mawson research station.
This is reportedly in contrast to other Adélie penguin populations in east Antarctica where numbers have been stable or increasing.
It is also contrary to models that had anticipated a continued rise in the Adélie populations.
Seabird ecologists reportedly surveyed the islands along a 100 km stretch of coastline every year from 2010 to 2020. The number of occupied nests fell from 176,622 to 99,946, which means a decline of about 77,000 nests or 154,000 breeding birds.
“Fast ice” and decline in number of birds
A research published in Global Change Biology said that the decline in Adélie populations came about during a period of simultaneous increase in “fast ice”. It refers to the ice that is attached to land but covers sea water. The researchers estimate the population in a good breeding season had 80,000 fewer fledglings compared to the population peak in the early 2000s.
The research said that “an increased frequency of extensive summer ice across the study period led to poor breeding conditions and as the population declined, resulted in an overall reduction in chick productivity”.
There has been an overall decline in fast ice in Antarctica, however scientists have noted there is regional variability, with declines detected in some areas and increases in others.
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