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 funded by the National Science Foundation (EDI-0849494, PLY-0836144, and EDI-1060884). The findings and conclusions are those of the authors and do not necessarily represent the official views of the NSF.
Jason Maderer | EurekAlert!
Ice cave in Transylvania yields window into region's past
28.04.2017 | National Science Foundation
Citizen science campaign to aid disaster response
28.04.2017 | International Institute for Applied Systems Analysis (IIASA)
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences