Google Earth Community: Penguin decline indicates state of world oceans

The struggle of penguins to survive is a clear sign that the world's marine systems are in trouble. Of the 17 penguin species more than half are listed as endangered or vulnerable.

A new study claims that penguins now run a gauntlet of environmental challenges, from climate change, commercial fishing, pollution and tourism.

Adelie penguin with chicks during a snowstorm in Antarctic

Professor P Dee Boersma, a conservation biologist at the University of Washington, who has been studying penguins for more than 25 years, said: "Penguins are sentinels of the marine environment, and by observing and studying them, researchers can learn about the rate and nature of changes occurring in the southern oceans.

"As ocean samplers, penguins provide insights into patterns of regional ocean productivity and long-term climate variation. Having studied several species of temperate penguins for more than 30 years, I know first hand how sensitive they are to their environment. I synthesise my observations to suggest that we have entered a new era of unprecedented challenges for marine systems."

She added: "Penguins are among those species that show us that we are making fundamental changes to our world.

Erect crested penguin

"The fate of all species is to go extinct, but there are some species that go extinct before their time and we are facing that possibility with some penguins."

As an example she said the erect-crested penguins (Eudyptes sclateri) that breed on the Antipodes Islands, almost 500 miles from the South Island of New Zealand, numbered 50,000 breeding pairs in 1995 - half of what they were in 1978.

Rockhopper penguin numbers on New Zealand's Campbell Island plunged from 1.6m breeding pairs in the 1940s to around 100,000 pairs by 1985,

In the Antarctic Peninsula region, from King George Island to the South Shetlands, both Adélie and Chinstrap penguins have declined by 50 per cent in the last 30 years.

Penguins which live in temperate areas and those that forage inshore such as the yellow-eyed (Megadyptes antipodes) and African penguins, are declining because of commercial fishing, guano mining, and oil and gas development

But in Antarctica it is the loss of sea ice caused by rising temperatures that it is hitting populations. The East Antarctic ice sheet, the largest reservoir of ice on the planet, has shown little change to its mass but other glaciers and sea ice are retreating, and even small variations can have major consequences for penguins.

Winter sea ice cover has decreased over the last 50 years which has reduced the amount of krill - tiny shrimp-like creatures on which the entire ecosystem depends on - available.

It means penguins having to travel much further to find food which puts them under greater pressure and cuts down the amount of time they have to feed their young.

Adelie penguin

The loss of the sea ice and the speed with which it is disappearing doesn't leave time for some penguins to raise chicks in their traditional breeding grounds.

In the study published in BioScience Boersma tells how she visited the French base at Dumont d'Urville in East Antarctica, where the movie March of the Penguins was filmed, to study Emperor penguins.

It incubates its eggs in the middle of the South Polar winter and the chicks usually fledge in December and early January. But by late September the sea ice had gone without sufficient time for the chicks to grow their waterproof covering they need to survive the freezing waters and resulting in the probable collective breeding failure of the entire colony.

She calls for the 43 remaining penguin 'hot-spots', mostly in the Southern Ocean, where at least 1 per cent of the global penguin population gathers to breed and which are important for the survival and health of each penguin species, to be much more closely monitored.

Chinstrap penguin

Determining the status and trends of penguin populations at these sites would provide insight into ocean ecosystem variability and viability,

Prof Boersma said there was an urgent need to begin assessing the impacts more people living in coastal areas was having on both marine and shore-based habitats used by a variety of species.

"I don't think we can wait. In 1960 we had 3bn people in the world. Now it's 6.7bn and it's expected to be 8bn by 2025," she said.

"We've waited a very long time. It's clear that humans have changed the face of the Earth and we have changed the face of the oceans, but we just can't see it. We've already waited too long."

Rockhopper penguin

She concluded in her report: "The changes in penguin populations reflect rapid changes in the marine environment and show that people are doing a poor job of managing the oceans.

"We are changing the world, the course of evolution, and the species with which we share the planet. Can people change to allow other species to persist and coexist? That is the real question: can we, and will we, manage ourselves?"

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King penguin faces extinction due to climate change

The prospect that the King penguin will go extinct as a result of climate warming is rising inexorably, scientists say today.

Second only to Emperor penguins in size, King Penguins - distinguished by their ear patches of bright golden-orange feathers - thrive on the islands at the northern reaches of Antarctica, with a total population of over two million breeding pairs.

King penguin : The study says they at high risk under current global warming conditions

Because King penguins sit on the food chain in their region, they are sensitive indicators of alterations to the marine ecosystem and feel the effects of climate change more keenly as a result - in this case, the warming is reducing their food supply.

Global warming is happening much more quickly in some parts of the frozen continent, particularly the north-west area known as the Antarctic Peninsula, where in the last 50 years temperatures have risen by about 2.5ºC - as much as five times the world average
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But for these penguins, which do not live near the peninsula, the effects are caused by a warming of sub polar sea surface temperatures.

Great colony of king penguins an Salisbury Plain in South Georgia

A decade ago, Yvon Le Maho of the CNRS Institut Pluridisciplinaire Hubert Curien, Strasbourg, and an engineer began a study of the breeding and survival of penguins on Possession Island in the Crozet Archipelago in the southern Indian Ocean that continued over the course of nine years, marking the birds with electronic tags under the skin as the penguins migrated.

With Céline Le Bohec and colleagues, Dr Le Maho shows today in the Proceedings of the National Academy of Sciences that high sea surface temperatures in the penguins wintering range, where two thirds of the world's population of this species reside, diminished the amount of available marine prey, which decreased the survival of adult King penguins since they had to travel greater distances to find food.

The birds feed on small fish and squid, relying less on krill and other small crustaceans than many other sea mammals, and the find suggests that these species are suffering as a result of warming of the Southern Ocean.

Using a mathematical model, the scientists calculate that there will be a nine per cent decline in the adult penguin population for every 0.26ºC of sea surface warming, suggesting that this population is at high risk under current global warming conditions, which predict an average increase of 0.2ºC per decade for the next two decades.

They conclude that there is a "heavy extinction risk" given current global warming predictions of a 0.4ºC rise over two decades, which cuts the chance of survival from 95 per cent to 80 per cent.

King penguins breed on seven sub-Antarctic island groups with large populations on the Falkland Islands, Macquarie Islands, Heard Island, Iles Crozet and Marion island and other sea birds will face similar problems.

A recent report by the environmental conservation group WWF is warning that rising temperatures and the resulting loss of sea ice is robbing other species of the emblematic birds of the nesting grounds they need to breed successfully while lading a reduction in the availability of krill which they rely on for food.

Emperor penguin

The most vulnerable is the biggest, the Emperor, but the Gentoo, Chinstrap, and Adélie have also suffered dramatic drops in population, according to the Antarctic Penguins and Climate Change report.

From left to right: Adelie penguin, Emperor penguin, Chinstrap penguin and Gentoo penguin

Source: Telegraph

For more on the penguins' plight, see Gerardo's excellent post here.