Discovery of 1.5 million penguins Adélie isolated in Antarctica

SARAH BERGERON-OUELLET/QMI AGENCY

AFP

Friday, 2 march 2018 05:56

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Friday, 2 march 2018 05:56

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Over 1.5 million penguins Adélie isolated by the ice: this is the big surprise that was waiting on an archipelago of Antarctica researchers now anxious to see these colonies protected by a marine sanctuary.

A need of protection all the more necessary for these penguins of Dangers Islands, in the east of the antarctic peninsula, that certain colonies of the same species are in decline just a few tens of kilometres away, to the west of the peninsula affected by the melting of sea ice attributed to climate change.

The origin of this discovery, published Friday in the journal Scientific Reports, the analysis of satellite images of this small archipelago, the Weddell sea, tells the AFP Heather Lynch, of the american university of Stony Brook.

The scientists knew that penguins Adélie, with their white bellies, their black head and their eyes circled with white, were installed on at least one of the nine islands, where a census in 1996-97 was evaluated nests between 285 000 and 305 000.

But the satellite imagery program Landsat Earth observation Nasa have revealed the presence of guano on other islands and the algorithms were formal: the penguins are much more numerous.

“At the beginning, I thought that it was a mistake,” explains Heather Lynch. “But when we put the hand on satellite images, commercial, high-resolution, we knew that this was a major discovery”.

Taking advantage of a rare opening in the ice that trap this hostile area almost all the year, very rarely visited, an expedition goes on site in December 2015 to confirm first-hand discovery.

With the help of drones, photos, and manual counting of nests and birds, researchers have finally a complete census: 751 527 pairs of penguins Adélie, “than in all the rest of the antarctic peninsula”, the region most to the north of the continent, the study notes. The islands are home to the 3rd and 4th most important colony in the world.

“They have always been there”

“It has been an amazing experience, to find and count all the penguins,” said in a press release Tom Hart, a researcher in the department of zoology at Oxford and a member of this scientific team.

“Scientifically, even if it is a huge number of +new+ penguins, they are new for the science,” he continues.

The height of their census, the scientists have gone back in time, analyzing aerial images in black and white from 1957. “They have always been there,” insists Tom Hart.

In general, the population of penguins Adélie, installed all around the white continent, is overall on the rise for the past 30 years, according to the international Union for the conservation of nature (IUCN).

But previous studies have observed a decline of some colonies, especially on the west side of the antarctic peninsula. A “striking contrast” with the new discovery, note Tom Hart.

“The responsible of this decline is not clear for the moment”, he adds, evoking in spite of a few “candidates”: “climate change, fisheries, and disturbance by direct human”.

At the centre of the scientists ‘ concerns, the fishery on the krill, a tiny shrimp at the base of the diet of several species of penguins.

“Now that we know that a small group of islands is so important, one might consider the need to protect more of the fishing,” pleads Heather Lynch.

The researchers call as well to ensure that this area be included in future marine protected Areas should discuss the member States of the Commission for the conservation of fauna and marine flora of the Antarctic (CCAMLR).