Young penguins dying due to lack of food: study

A A A

Young penguins in the Antarctic may be dying because they are having a tougher time finding food, as melting sea ice cuts back on the tiny fish they eat, US researchers suggested on Monday.

Only about 10 percent of baby penguins tagged by researchers are coming back in two to four years to breed, down from 40-50 percent in the 1970s, said the study in the Proceedings of the National Academy of Sciences.

Chinstrap penguins, known for their characteristic head markings that resemble a cap with a black line just under the neck, are the second largest group in the area after the macaroni penguins, and are at particular risk because their population is restricted to one area, the South Shetland Islands.

"It is a dramatic change," lead researcher Wayne Trivelpiece, of the National Oceanic and Atmospheric Administration's Antarctic Ecosystem Research Division, told AFP.

"There are still two to three million chinstrap pairs in this region but there were seven to eight million two decades ago," he said.

"There is some concern now. We need to follow these animals and track them."

The 30-year study included chinstrap and Adelie penguins in the West Antarctic and tracked the abundance of their main food source, krill, which are the small shrimp-like crustacean mainly eaten by whales, seals and penguins.

Trivelpiece was a co-author on a study published in 1992 that suggested penguin populations were surging and subsiding according to changes in sea ice - with the chinstrap doing better in warm years and the Adelie thriving in cold years.

Chinstrap penguins eat and make their nests away from the snow and ice and so are considered ice-avoiding animals, unlike their Adelie counterparts who feed in icy habitats and are seen as more vulnerable when there is less ice.

However, Trivelpiece and his co-authors now believe that krill are the real culprit for the disappearing penguin populations, and the damage affects both types of penguins.

Krill needs ice to survive, and as climate change causes more polar sea ice to melt, the tiny sea creatures cannot breed or feast on phytoplankton in the ice and their numbers fall, taking away an important source of nourishment for penguins.

"Under a scenario of global warming and increasing temperature we had prophesized that Adelies and ice-loving animals like Adelies should decline while chinstraps and ice-avoiding animals should increase," Trivelpiece said.

But shortly after the team's paper was published in the early 90s, the data began to change.

"From that point shortly thereafter onward, we lost those large fluxes and both species started behaving the same way and both started declining dramatically," he said.

"By the time we had enough data to realize what was going on with the youngsters, we realized that the big difference was between the early years when there was a lot of krill around, and the later years when there wasn't."

Over the past three decades, krill biomass has declined 38 to 81 percent, said the study.

"If warming continues, winter sea-ice may disappear from much of this region and exacerbate krill and penguin declines," it said.

The main driver of the decline in krill is climate change, but resurgent numbers of whales - on the rise after cuts in hunting - could be increasing the number of predators that eat krill as well, Trivelpiece said.

A large commercial fishery that is using the krill for aquaculture feeds could also be cutting back on the natural numbers, the study noted.

While the penguins are far from the verge of extinction, the researchers have urged the International Union for the Conservation of Nature to assess their status and possibly bump them higher on Red List of vulnerable species.

Have you tried new the Independent Digital Edition apps?
Arts and Entertainment
Reimagined: Gwyneth Paltrow and Toni Collette in the film adaptation of Jane Austen's Emma
books
Arts and Entertainment
Jesuthasan Antonythasan as Dheepan
Cannes 2015Dheepan, film review
Sport
sport
News
Richard Blair is concerned the trenches are falling into disrepair
newsGeorge Orwell's son wants to save war site that inspired book
Arts and Entertainment
The pair in their heyday in 1967
music
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Guru Careers: Software Developer / C# Developer

£40-50K: Guru Careers: We are seeking an experienced Software / C# Developer w...

Guru Careers: Software Developer

£35 - 40k + Benefits: Guru Careers: We are seeking a Software Developer (JavaS...

SThree: Trainee Recruitment Consultant / Resourcer

£18000 - £23000 per annum + Commission: SThree: As a Trainee Recruitment Consu...

Ashdown Group: UI Developer - (UI, HTML, CSS, JavaScript, AngularJS)

£25000 - £40000 per annum: Ashdown Group: UI Developer - (UI, JavaScript, HTML...

Day In a Page

Abuse - and the hell that came afterwards

Abuse - and the hell that follows

James Rhodes on the extraordinary legal battle to publish his memoir
Why we need a 'tranquility map' of England, according to campaigners

It's oh so quiet!

The case for a 'tranquility map' of England
'Timeless fashion': It may be a paradox, but the industry loves it

'Timeless fashion'

It may be a paradox, but the industry loves it
If the West needs a bridge to the 'moderates' inside Isis, maybe we could have done with Osama bin Laden staying alive after all

Could have done with Osama bin Laden staying alive?

Robert Fisk on the Fountainheads of World Evil in 2011 - and 2015
New exhibition celebrates the evolution of swimwear

Evolution of swimwear

From bathing dresses in the twenties to modern bikinis
Sun, sex and an anthropological study: One British academic's summer of hell in Magaluf

Sun, sex and an anthropological study

One academic’s summer of hell in Magaluf
From Shakespeare to Rising Damp... to Vicious

Frances de la Tour's 50-year triumph

'Rising Damp' brought De la Tour such recognition that she could be forgiven if she'd never been able to move on. But at 70, she continues to flourish - and to beguile
'That Whitsun, I was late getting away...'

Ian McMillan on the Whitsun Weddings

This weekend is Whitsun, and while the festival may no longer resonate, Larkin's best-loved poem, lives on - along with the train journey at the heart of it
Kathryn Williams explores the works and influences of Sylvia Plath in a new light

Songs from the bell jar

Kathryn Williams explores the works and influences of Sylvia Plath
How one man's day in high heels showed him that Cannes must change its 'no flats' policy

One man's day in high heels

...showed him that Cannes must change its 'flats' policy
Is a quiet crusade to reform executive pay bearing fruit?

Is a quiet crusade to reform executive pay bearing fruit?

Dominic Rossi of Fidelity says his pressure on business to control rewards is working. But why aren’t other fund managers helping?
The King David Hotel gives precious work to Palestinians - unless peace talks are on

King David Hotel: Palestinians not included

The King David is special to Jerusalem. Nick Kochan checked in and discovered it has some special arrangements, too
More people moving from Australia to New Zealand than in the other direction for first time in 24 years

End of the Aussie brain drain

More people moving from Australia to New Zealand than in the other direction for first time in 24 years
Meditation is touted as a cure for mental instability but can it actually be bad for you?

Can meditation be bad for you?

Researching a mass murder, Dr Miguel Farias discovered that, far from bringing inner peace, meditation can leave devotees in pieces
Eurovision 2015: Australians will be cheering on their first-ever entrant this Saturday

Australia's first-ever Eurovision entrant

Australia, a nation of kitsch-worshippers, has always loved the Eurovision Song Contest. Maggie Alderson says it'll fit in fine