Featured Research

from universities, journals, and other organizations

Melting sea ice threatens emperor penguins

Date:
June 20, 2012
Source:
Woods Hole Oceanographic Institution
Summary:
At nearly four feet tall, the Emperor penguin is Antarctica's largest sea bird -- and thanks to films like "March of the Penguins" and "Happy Feet," it's also one of the continent's most iconic. If global temperatures continue to rise, however, the Emperor penguins in Terre Adélie, in East Antarctica may eventually disappear, according to a new study.

At nearly four feet tall, the Emperor penguin is Antarctica’s largest sea bird. Unlike other sea birds, Emperor penguins breed and raise their young almost exclusively on sea ice. If global temperatures continue to rise, the Emperor penguins in Terre Adélie in East Antarctica may eventually disappear.
Credit: Photo courtesy Glen Grant, U.S. Antarctic Program, National Science Foundation

At nearly four feet tall, the Emperor penguin is Antarctica's largest sea bird -- and thanks to films like "March of the Penguins" and "Happy Feet," it's also one of the continent's most iconic. If global temperatures continue to rise, however, the Emperor penguins inTerre Adélie, in East Antarcticamay eventually disappear, according to a new study by led by researchers from the Woods Hole Oceanographic Institution (WHOI).

The study was published in the June 20th edition of the journal Global Change Biology.

"Over the last century, we have already observed the disappearance of the Dion Islets penguin colony, close to the West Antarctic Peninsula," says Stephanie Jenouvrier, WHOI biologist and lead author of the new study. "In 1948 and the 1970s, scientists recorded more than 150 breeding pairs there. By 1999, the population was down to just 20 pairs, and in 2009, it had vanished entirely." Like in Terre Adélie, Jenouvrier thinks the decline of those penguins might be connected to a simultaneous decline in Antarctic sea ice due to warming temperatures in the region.

Unlike other sea birds, Emperor penguins breed and raise their young almost exclusively on sea ice. If that ice breaks up and disappears early in the breeding season, massive breeding failure may occur, says Jenouvrier. "As it is, there's a huge mortality rate just at the breeding stages, because only 50 percent of chicks survive to the end of the breeding season, and then only half of those fledglings survive until the next year," she says.

Disappearing sea ice may also affect the penguins' food source. The birds feed primarily on fish, squid, and krill, a shrimplike animal, which in turn feeds on zooplankton and phytoplankton, tiny organisms that grow on the underside of the ice. If the ice goes, Jenouvrier says, so too will the plankton, causing a ripple effect through the food web that may starve the various species that penguins rely on as prey.

To project how penguin populations may fare in the future, Jenouvrier's team used data from several different sources, including climate models, sea ice forecasts, and a demographic model that Jenouvrier created of the Emperor penguin population at Terre Adélie, a coastal region of Antarctica where French scientists have conducted penguin observations for more than 50 years.

Combining this type of long-term population data with information on climate was key to the study, says Hal Caswell, a WHOI senior mathematical biologist and collaborator on the paper.

"If you want to study the effects of climate on a particular species, there are three pieces that you have to put together," he says. "The first is a description of the entire life cycle of the organism, and how individuals move through that life cycle. The second piece is how the cycle is affected by climate variables. And the crucial third piece is a prediction of what those variables may look like in the future, which involves collaboration with climate scientists."

Marika Holland of the National Center for Atmospheric Research is one such scientist. She specializes in studying the relationship between sea ice and global climate, and helped the team identify climate models for use in the study.

Working with Julienne Stroeve, another sea ice specialist from the National Snow and Ice Data Center, Holland ultimately recommended five distinct models. "We picked the models based on how well they calculated the sea ice cover for the 20th century," she says. "If a model predicted an outcome that matched what was actually observed, we felt it was likely that its projections of sea ice change in the future could be trusted."

Jenouvrier used the output from these various climate models to determine how changes in temperature and sea ice might affect the Emperor penguin population at Terre Adélie. She found that if greenhouse gas emissions continue to rise at levels similar to today -- causing temperatures to rise and Antarctic sea ice to shrink -- penguin population numbers will diminish slowly until about 2040, after which they would decline at a much steeper rate as sea ice coverage drops below a usable threshold.

"Our best projections show roughly 500 to 600 breeding pairs remaining by the year 2100. Today, the population size is around 3000 breeding pairs," says Jenouvrier.

The effect of rising temperature in the Antarctic isn't just a penguin problem, according to Caswell. As sea ice coverage continues to shrink, the resulting changes in the Antarctic marine environment will affect other species, and may affect humans as well.

"We rely on the functioning of those ecosystems. We eat fish that come from the Antarctic. We rely on nutrient cycles that involve species in the oceans all over the world," he says. "Understanding the effects of climate change on predators at the top of marine food chains -- like Emperor penguins -- is in our best interest, because it helps us understand ecosystems that provide important services to us."

Also collaborating on the study were Christophe Barbraud and Henri Weimerskirch of the Centre d'Etudes Biologiques de Chizé, in France, and Mark Serreze of the National Snow and Ice Data Center in the United States.


Story Source:

The above story is based on materials provided by Woods Hole Oceanographic Institution. Note: Materials may be edited for content and length.


Journal Reference:

  1. Stephanie Jenouvrier, Marika Holland, Julienne Stroeve, Christophe Barbraud, Henri Weimerskirch, Mark Serreze, Hal Caswell. Effects of climate change on an emperor penguin population: analysis of coupled demographic and climate models. Global Change Biology, 2012; DOI: 10.1111/j.1365-2486.2012.02744.x

Cite This Page:

Woods Hole Oceanographic Institution. "Melting sea ice threatens emperor penguins." ScienceDaily. ScienceDaily, 20 June 2012. <www.sciencedaily.com/releases/2012/06/120620113342.htm>.
Woods Hole Oceanographic Institution. (2012, June 20). Melting sea ice threatens emperor penguins. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2012/06/120620113342.htm
Woods Hole Oceanographic Institution. "Melting sea ice threatens emperor penguins." ScienceDaily. www.sciencedaily.com/releases/2012/06/120620113342.htm (accessed July 23, 2014).

Share This




More Earth & Climate News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Observation Boat to Protect Cetaceans During Ship Transfer

Observation Boat to Protect Cetaceans During Ship Transfer

AFP (July 22, 2014) — As part of the 14-ship convoy that will accompany the Costa Concordia from the port of Giglio to the port of Genoa, there will be a boat carrying experts to look out for dolphins and whales from crossing the path of the Concordia. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) — New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) — A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
Spectacular Lightning Storm Hits London

Spectacular Lightning Storm Hits London

AFP (July 19, 2014) — A spectaCular lightning storm struck the UK overnight Friday. Images of lightning strikes over the Shard and Tower Bridge in central London. Duration: 00:23 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins