The increasingly pronounced melting of the Antarctic sea ice is decimating emperor penguin chicks. This is the implacable conclusion of a study published Thursday in the journal Antarctic Science which once again sounds the alarm. The result of six years of groundbreaking work by cartographer Peter T. Fretwell and his team at the British Antarctic Survey, this research establishes a direct link between the retreat of Antarctic sea ice and the death of almost all young emperor penguins from the colonies concerned.
Indeed, although adult penguins have waterproof plumage allowing them to live in waters approaching zero degrees, this is not the case for their chicks. Before they are six or seven months old, they do not normally come into contact with water. Their down is insufficient to withstand such temperatures. But the absence of ice does not allow them to stay on the surface and condemns them to certain death.
A publication by the same authors had already documented this massive phenomenon in August 2023. During the previous year, 19 colonies out of the 66 existing on the continent had been affected – a colony that could number up to several thousand individuals.
El Niño and La Niña disturbances
According to cartographer Peter T. Fretwell, the decline of bird populations whose litters are regularly destroyed could lead to the extinction of this emblematic Antarctic species within seventy-five years. And this, “in a scenario where we continue to produce fossil fuels at the same level as today”specifies the British scientist, who is based on the work of the Intergovernmental Panel on Climate Change.
Read also: Article reserved for our subscribers Warming in Antarctica greater than models predicted
Add to your selections
The ice on the Antarctic coasts on which the chicks grow, before the so-called “fledged” season during the austral summer, between mid-December and mid-January, is melting more quickly than that on the rest of the continent. Already in 2022, then again in 2023, the summer surface area of Antarctica has fallen below the unprecedented threshold of 2 million km2a record recorded using satellite data accumulated since 1979. “The Sentinel satellite allows us to observe how the ecosystem evolves on a large scale, summarizes Peter T. Fretwell. And emperor penguins represent the fragility of this whole system. »
Variations in temperatures and the formation of sea ice from one year to the next are also due to ocean-atmospheric disturbances such as El Niño and La Niña phenomena. As the climate warms, these cycles are lengthening and intensifying – and Antarctica is no exception. “In 2021, 2022 and 2023, we have had three years of La Niñareports Peter T. Fretwell. This is the first time that the phenomenon has lasted over such a long period. The sea ice appears to have been under pressure for three consecutive years, with 2022 being particularly bad. In 2023, we transitioned to El Niño. And it’s not as severe right now. » These cycles remaining unpredictable, it is difficult for scientists to anticipate their medium and long-term effects.
You have 28.28% of this article left to read. The rest is reserved for subscribers.
