Subscribe free to our newsletters via your
. 24/7 Space News .




CARBON WORLDS
Moving Iron in Antarctica
by Staff Writers
Atlanta GA (SPX) Jun 13, 2013


File image: Diatoms.

The seas around Antarctica can, at times, resemble a garden. Large-scale experiments where scientists spray iron into the waters, literally fertilizing phytoplankton, have created huge man-made algal blooms.

Such geoengineering experiments produce diatoms, which pull carbon dioxide out of the air. Experts argue that this practice can help offset Earth's rising carbon dioxide levels. However, the experiments are controversial and, according to a new study at the Georgia Institute of Technology, perhaps not as effective as expected.

Georgia Tech research published online Monday in Nature Communications indicates that diatoms stuff more iron into their silica shells than they actually need. As a result, there's not enough iron to go around, and the added iron may stimulate less productivity than expected. The study also says that the removal of iron through incorporation into diatom silica may be a profound factor controlling the Southern Ocean's bioavailable pool of iron, adversely affecting the ecosystem.

"Just like someone walking through a buffet line who takes the last two pieces of cake, even though they know they'll only eat one, they're hogging the food," said Ellery Ingall, a professor in Georgia Tech's College of Sciences. "Everyone else in line gets nothing; the person's decision affects these other people."

Ingall says, similarly, these "hogging" diatoms negatively affect the number of carbon-trapping plankton produced. They also outcompete other organisms for the iron.

"It appears the diatoms aren't using all of the iron for photosynthesis," he said. "They're incorporating iron in their shells for another purpose, keeping it from others and affecting the plankton ecosystem."

Researchers have known for years that diatoms can remove iron from oceans and carbon from the atmosphere, but little is known about how iron is cycled and removed from the Antarctic region.

Ingall and a former Georgia Tech graduate student, Julia Diaz, spent nearly six weeks in Antarctica's Ross Sea from 2008 to 2009, trying to learn more. They collected samples in the frigid waters and used them to create what is believed to be the first spectroscopic, compositional characterization of iron in marine biogenic silica. Ingall conducted an X-ray analysis of the phytoplankton at the U.S. Department of Energy's Argonne National Laboratory.

A major source of bioavailable iron in Antarctica is from melting snow and dust deposition. Ingall found that iron addition via these sources barely keeps pace with subtraction by diatoms.

"Uptake of iron by diatoms is significant compared to what Mother Nature is able to naturally add to the ocean," he said. "This uptake could shift microbial communities toward organisms with relatively lower iron requirements."

According to Ingall, removal of iron by diatom-dominated phytoplankton communities may dampen the intended outcome of enhanced carbon uptake through iron fertilization by reducing the productivity of other phytoplankton, which take up carbon dioxide more efficiently.

This research was published Monday in Nature Communications.

.


Related Links
College of Sciences at Georgia Institute of Technology
Carbon Worlds - where graphite, diamond, amorphous, fullerenes meet






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








CARBON WORLDS
Questions rise about seeding for ocean C02 sequestration
Lemont IL (SPX) Jun 13, 2013
A new study on the feeding habits of ocean microbes calls into question the potential use of algal blooms to trap carbon dioxide and offset rising global levels. These blooms contain iron-eating microscopic phytoplankton that absorb C02 from the air through the process of photosynthesis and provide nutrients for marine life. But one type of phytoplankton, a diatom, is using more iron that ... read more


CARBON WORLDS
LADEE Arrives at Wallops for Moon Mission

NASA's GRAIL Mission Solves Mystery of Moon's Surface Gravity

Moon dust samples missing for 40 years found in Calif. warehouse

Unusual minerals in moon craters may have been delivered from space

CARBON WORLDS
Mars Water-Ice Clouds Are Key to Odd Thermal Rhythm

Marks on Martian Dunes May Reveal Tracks of Dry-Ice Sleds

UH Astrobiologists Find Martian Clay Contains Chemical Implicated in the Origin of Life

Mars Rover Opportunity Trekking Toward More Layers

CARBON WORLDS
China confident in space exploration

A letter to China's first space teacher from U.S. predecessor

Space enthusiasts dream big after Shenzhou-10 launch

The Body Electric: Researchers Move Closer to Low-Cost, Implantable Electronics

CARBON WORLDS
China's Naughty Space Models

China's space dream crystallized with Shenzhou-10 launch

China astronauts enter space module

China to send second woman into space: officials

CARBON WORLDS
Europe's space truck docks with ISS

Russian cargo supply craft separates from International Space Station

Russian Space Freighter to Depart From Orbital Station

Star Canadian spaceman Chris Hadfield retiring

CARBON WORLDS
INSAT-3D is delivered to French Guiana for Arianespace's next Ariane 5 launch

A dream launch for Shenzhou X

Mitsubishi Heavy and Arianespace conclude MOU on commercial launches

Sea Launch IS-27 FROB Report Complete

CARBON WORLDS
Sunny Super-Earth?

Kepler Stars and Planets are Bigger than Previously Thought

Astronomers gear up to discover Earth-like planets

Stars Don't Obliterate Their Planets (Very Often)

CARBON WORLDS
MakerBot Opens New Manufacturing Factory in Brooklyn

Echoes can reveal the shape of a room

Chinese astronauts complete warm-up maintenance work in space module

Raytheon awarded contract for F-15C AESA radars




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement