Half Of Adelie Penguins Population Could Decline Due To Global Warming

The Adelie penguins' populations could decline at the end of the century as the sea temperatures rise, according to a new research from the University of Delaware.

The study was printed in Scientific Reports. It was led by Megan Cimino, an oceanographer from College of Earth Ocean & Environment and co-authored by Heather J. Lynch from Stony Brook University, Vincent S. Saba from NOAA National Marine Fisheries Service and Matthew J. Oliver from College of Earth Ocean & Environment. They discovered that up to 60 percent of the Adelie penguin in Antarctica could be incapable of hosting colonies by the end of the century.

The researchers stated that by 2060, 30 percent of the present Adelie colonies or 20 percent of the overall population may drop. An estimated 60 percent of the colonies may be in decline by 2099.

Cimino explained that it is only in recent decades that they know Adelie penguins' population declines are associated with warming. This indicates that many regions of Antarctica have warmed too much and that further warming is no longer positive for the species.

The researchers said that the colonies that would be affected most may be in the West Antarctic Peninsula and the surrounding islands. These areas in the Antarctic have already experienced a drop in penguin populations. This is due to warm sea surface temperatures that reduce the proper area for rearing chicks.

Cimino said that the Cape Adare region of the Ross Sea is the home to the earliest known penguin occupation and has the largest known Adelie penguin rookery in the world. She further said that though the climate there is expected to warm a bit, it looks like it could be refugia in the future, and if you look back over geologic time it was likely a refuge in the past.

The Adelie penguin (Pygoscelis adeliae) lives along the entire Antarctic coast. The name Adelie derived from Adele Dumont D'Urville, the wife of French Explorer Jules Dumont d'Urville who discovered these penguins in 1840.

The Adelie penguin belongs in the genus Pygoscelis. The mitochondrial and nuclear DNA evidence indicates that the genus split from other penguins around 38 million years ago, about 2 million years after the ancestors of the genus Aptenodytes. And around 19 million years ago, the Adelie penguins split off from the other members of the genus.