Navigation Links
Questions rise about seeding for ocean C02 sequestration
Date:6/12/2013

LEMONT, Ill --- 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 it needs for photosynthesis and storing the extra in its silica skeletons and shells, according to an X-ray analysis of phytoplankton conducted at the U.S. Department of Energy's Argonne National Laboratory. This reduces the amount of iron left over to support the carbon-eating plankton

"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 at Georgia's Institute of Technology and co-lead author on this result. "Everyone else in line gets nothing; the person's decision affects these other people."

Because of this iron-hogging behavior the process of adding iron to surface water, called iron fertilization or iron seeding, may have only a short-lived environmental benefit. And, the process may actually reduce over the long-term how much C02 the ocean can trap.

Rather than feed the growth of extra plankton, triggering algal blooms, the iron fertilization may instead stimulate the gluttonous diatoms to take up even more iron to build larger shells. When the shells get large enough, they sink to the ocean floor sequestering the iron and further starve off the diatom's plankton peers.

Over time, this reduction in the amount of iron in surface waters could trigger the growth of microbial populations that require less iron for nutrients, reducing the amount of phytoplankton blooms available to take in C02 and to feed marine life.

While scientists have known for a long time that phytoplankton using iron to fuel the process of photosynthesis there are gaps in their understanding of how this iron cycling process works. Those gaps led scientists to miss how large an amount of iron was getting trapped in those sinking skeletons and removed permanently from the food chain. X-ray studies at the Advanced Photon Source at Argonne gave scientists a way to measure the ratio of iron and silica in the plankton and surface water.

"Being able to use X-rays and see the element content of individual microscopic phytoplankton has completely altered our perspective on how these organisms use iron and how that could affect C02 levels," Ingall said.

In the paper "Role of biogenic silica in the removal of iron from the Antarctic seas" published June 10 in the journal Nature Communications, scientists conservatively estimate that 2.5 milligrams of iron annually is removed from every square meter of surface water in the Ross Sea and sequestered in silica skeletons on the ocean floor. This is roughly equivalent to the total amount of iron deposited annually into the Ross Sea surface through snow melt, dust and upwelling of seawater.

The same process may be occurring in the Southern Ocean and have a greater impact there, because this region dictates the nutrient mix for the rest of the world's oceans through migratory current patterns.

More study is needed to know just how much iron is used to make the silica skeletons and how much gets trapped on the ocean floor, the researchers said.

"This gap in our knowledge, combined with renewed interest in iron fertilization as an approach to the current climate crisis, makes it crucial that we have an improved understanding of iron cycling in marine systems," Ingall said.

Measurements of iron and silicon content in silica from living phytoplankton collected in the coastal seas of West Antarctica was derived through X-ray analysis on beamlines 2-ID-D and 2-ID-E at the Advanced Photon Source using microscopy and fluorescence techniques. High-resolution imaging, chemical identification and the ability to focus X-rays on an ultra small area of about 200 by 200 nanometers were key to this analysis. For comparison, it would take 500 samples of this size to fit across the width of a single human hair.


'/>"/>

Contact: Tona Kunz
tkunz@anl.gov
630-252-5560
DOE/Argonne National Laboratory
Source:Eurekalert

Related biology news :

1. After the Genome tackles tough questions about medicine, miracles and morality
2. Study questions the role of kinship in mass strandings of pilot whales
3. Yeast we can! New report answers questions on microbiology and beer
4. New Geology study raises questions about long-held theories of human evolution
5. Questions about biosafety? Ask a biosafety expert
6. In search of the big questions: Conserving the European Alps
7. Prospectus addresses most pressing marine science questions
8. Mount Sinai researchers awarded Provocative Questions grant from National Cancer Institute
9. Columbia awarded 1 of first Provocative Questions grants from NCI
10. New research questions how fat influences flavor perception
11. Study raises questions about use of anti-epilepsy drugs in newborns
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/23/2017)... ITHACA, N.Y. , June 23, 2017  IBM ... in dairy research, today announced a new collaboration using ... the chances that the global milk supply is impacted ... project, Cornell University has become the newest academic institution ... Chain, a food safety initiative that includes IBM Research, ...
(Date:5/6/2017)... 2017 RAM Group , Singaporean ... breakthrough in biometric authentication based on a ... to perform biometric authentication. These new sensors are based ... by Ram Group and its partners. This sensor will ... chains and security. Ram Group is a next ...
(Date:4/13/2017)... , April 13, 2017 UBM,s Advanced ... will feature emerging and evolving technology through ... Innovation Summits will run alongside the expo portion of ... sessions, panels and demonstrations focused on trending topics within ... advanced design and manufacturing event will take place June ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... DuPont Pioneer and recently formed ... entered into a multiyear collaboration to identify and characterize novel CRISPR-Cas nucleases. The ... gene editing across all applications. , Under the terms of the agreement, Pioneer ...
(Date:10/12/2017)... ... October 12, 2017 , ... BioMedGPS announces expanded ... of its newest module, US Hemostats & Sealants. , SmartTRAK’s US Market for ... fibrin sealants, synthetic sealants and biologic sealants used in surgical applications. BioMedGPS estimates ...
(Date:10/12/2017)... , ... October 12, 2017 ... ... has launched Rosalind™, the first-ever genomics analysis platform specifically designed for life ... Named in honor of pioneering researcher Rosalind Franklin, who made a major ...
(Date:10/11/2017)... ... October 11, 2017 , ... The CRISPR-Cas9 ... enabling overexpression experiments and avoiding the use of exogenous expression plasmids. The simplicity ... for performing systematic gain-of-function studies. , This complement to loss-of-function studies, such ...
Breaking Biology Technology: