Featured Research

from universities, journals, and other organizations

Antarctic Icebergs: Hotspots Of Ocean Life

Date:
June 22, 2007
Source:
University of California - San Diego
Summary:
Global climate change is causing Antarctic ice shelves to shrink and split apart, yielding thousands of free-drifting icebergs in the nearby Weddell Sea. According to a new study these floating islands of ice -- some as large as a dozen miles across -- are having a major impact on the ecology of the ocean around them, serving as "hotspots" for ocean life, with thriving communities of seabirds above and a web of phytoplankton, krill and fish below.

Icebergs hold trapped terrestrial material, which they release far out at sea as they melt.
Credit: Nicolle Rager Fuller, National Science Foundation

Global climate change is causing Antarctic ice shelves to shrink and split apart, yielding thousands of free-drifting icebergs in the nearby Weddell Sea. According to a new study in this week's journal Science these floating islands of ice -- some as large as a dozen miles across -- are having a major impact on the ecology of the ocean around them, serving as "hotspots" for ocean life, with thriving communities of seabirds above and a web of phytoplankton, krill, and fish below.

The icebergs hold trapped terrestrial material, which they release far out at sea as they melt. The researchers discovered that this process produces a "halo effect" with significantly increased phytoplankton, krill and seabirds out to a radius of more than two miles around the icebergs. They may also play a surprising role in global climate change.

"One important consequence of the increased biological productivity is that free-floating icebergs can serve as a route for carbon dioxide drawdown and sequestration of particulate carbon as it sinks into the deep sea," said oceanographer Ken Smith of the Monterey Bay Aquarium Research Institute (MBARI), first author and principal investigator for the research.

"While the melting of Antarctic ice shelves is contributing to rising sea levels and other climate change dynamics in complex ways, this additional role of removing carbon from the atmosphere may have implications for global climate models that need to be further studied," added Smith.

To understand the icebergs' complex impacts, the multidisciplinary team of researchers carried out the most comprehensive study ever done of individual icebergs and their immediate environment, taking a wide array of measurements -- physical, biological and chemical, and using satellite images provided by NASA.

At the same time, the wealth of data brought new challenges in how to manage this avalanche of information. "The whole is definitely greater than the sum of the parts, and to answer questions across the different areas from ecology to chemistry and climate, scientists need access to all the data," explained researcher John Helly of the San Diego Supercomputer Center (SDSC) at UC San Diego who managed the data. "And we need to reliably harvest this information at sea, thousands of miles from our shore-based labs, and to preserve it as a unique snapshot of these iceberg ecosystems at this point in history."

Using SDSC-developed technologies, Helly collected the data using the SIOExplorer-in-a-Box digital library system and then stored the information in collections at SDSC for access and analysis by scientists now and in the future.

Just getting to the icebergs was a challenge. First the scientists used satellite images to select two icebergs to study in detail. Then they sailed aboard the Antarctic research vessel Laurence M. Gould to reach their targets in the remote Weddell Sea, an arm of the Southern Atlantic Ocean that cuts into the Antarctic continent southeast of Cape Horn. The icebergs in the study were up to a dozen miles long and more than 120 feet high, with one extending nearly 1,000 feet into the depths.

Despite the risks of getting close to these mountains of ice -- which can shed huge pieces or overturn without warning -- the scientists began their shipboard sampling mere hundreds of feet from the icebergs and continued out to a distance of some five miles, where the icebergs' influence was no longer detectable.

"Phytoplankton around the icebergs was enriched with large diatom cells, known for their role in productive systems such as upwelling areas of the west coast of the U.S. or ice-edge communities in polar oceans. As diatoms are the preferred food for krill, we expect the changes in phytoplankton community composition to favor grazing as a key biological process involved in carbon sequestration around free-floating icebergs," said oceanographer Maria Vernet from Scripps Institution of Oceanography at UC San Diego, one of the members of the research team.

"We used a small, remotely operated vehicle (ROV) to explore the submerged sides of the icebergs and the waters between the bergs and where the ship was, standing off at a safe distance," said Bruce Robison of MBARI, an oceanographer and ROV pilot. "We flew the ROV into underwater caves and to the undersides of the icebergs, identifying and counting animals with its color video camera, collecting samples, and surveying its topography."

Based on their new understanding of the impacts of the icebergs and their growing numbers -- the researchers counted close to 1,000 in satellite images of some 4,300 square miles of ocean -- the scientists estimate that overall the icebergs are raising the biological productivity of nearly 40 percent of the Weddell Sea's area.

In addition to Smith, Robison, Vernet and Helly, the study's authors include Henry Ruhl of MBARI, Ronald Kaufmann of the University of San Diego, Timothy Shaw and Benjamin Twining of the University of South Carolina. These preliminary results were gathered as part of a small exploratory study funded by the National Science Foundation's Office of Polar Programs. Many research questions remain to be answered about the role of icebergs in the pelagic ecosystem of the Southern Ocean. This research is funded to continue these studies in 2008 and 2009.


Story Source:

The above story is based on materials provided by University of California - San Diego. Note: Materials may be edited for content and length.


Cite This Page:

University of California - San Diego. "Antarctic Icebergs: Hotspots Of Ocean Life." ScienceDaily. ScienceDaily, 22 June 2007. <www.sciencedaily.com/releases/2007/06/070621140754.htm>.
University of California - San Diego. (2007, June 22). Antarctic Icebergs: Hotspots Of Ocean Life. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2007/06/070621140754.htm
University of California - San Diego. "Antarctic Icebergs: Hotspots Of Ocean Life." ScienceDaily. www.sciencedaily.com/releases/2007/06/070621140754.htm (accessed October 1, 2014).

Share This



More Earth & Climate News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: 12 More Bodies Found on Japan Volcano

Raw: 12 More Bodies Found on Japan Volcano

AP (Oct. 1, 2014) — A dozen more bodies were found Wednesday as Japanese rescuers resumed efforts to find survivors and retrieve bodies of those trapped by Mount Ontake's eruption. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Raw: Trapped Scientist Rescued from Cave in Peru

Raw: Trapped Scientist Rescued from Cave in Peru

AP (Oct. 1, 2014) — A Spanish scientist, who spent 12 days trapped about 1300 feet underground in a cave in Peru's remote Amazon region, was rescued on Tuesday. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Media, Industry Groups React To Calif. Plastic Bag Ban

Media, Industry Groups React To Calif. Plastic Bag Ban

Newsy (Sep. 30, 2014) — California is the first state in the country to ban single-use plastic bags in grocery, liquor and convenience stores. Video provided by Newsy
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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