Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers explore plankton's shifting role in deep sea carbon storage

14.10.2011
The tiny phytoplankton Emiliania huxleyi, invisible to the naked eye, plays an outsized role in drawing carbon from the atmosphere and sequestering it deep in the seas. But this role may change as ocean water becomes warmer and more acidic, according to a San Francisco State University research team.

In a study published this week in the journal Global Change Biology, SF State Assistant Professor of Biology Jonathon Stillman and colleagues show how climate-driven changes in nitrogen sources and carbon dioxide levels in seawater could work together to make Emiliania huxleyi a less effective agent of carbon storage in the deep ocean, the world's largest carbon sink.

Changes to this massive carbon sink could have a critical effect on the planet's future climate, Stillman said, especially as atmospheric carbon dioxide levels continue to rise sharply as a result of fossil fuel burning and other human activities.

While floating free in the sunny top layers of the oceans, the phytoplankton develop elaborate plates of calcified armor called coccoliths. The coccoliths form a hard and heavy shell that eventually sinks to the ocean depths. "About 80 percent of inorganic carbon trapped down there is from coccoliths like these," said Stillman.

Stillman and his colleagues wanted to discover how ocean acidification and changes in the ocean's nitrogen cycle—both hallmarks of climate warming—might effect coccolith development. So they raised more than 200 generations of Emiliania huxleyi in the lab, adjusting carbon dioxide levels and the type of nitrogen in the phytoplankton's seawater bath.

They found that high levels of carbon dioxide—which make the water more acidic—along with a shift in the prevailing nitrogen type from nitrates to ammonium—"had a synergistic effect" on the phytoplankton's biology and growth.

In particular, coccoliths formed under conditions of high carbon dioxide and high ammonium levels were incomplete or hollow, and contained less than the usual amount of inorganic carbon, the researchers noted.

"The ratio of inorganic to organic carbon is important," Stillman explained. "As inorganic carbon increases, it adds more ballast to the hard shell, which makes it sink and makes it more likely to be transported to the deep ocean. Without this, the carbon is more likely to be recycled into the Earth's atmosphere."

"Our results suggest in the future there will be overall lower amounts of calcification and overall lower amount of transport of carbon to the deep ocean," he added.

Emiliania huxleyi typically use nitrates to make proteins, but this form of nitrogen may be in shorter supply for the phytoplankton as the world's oceans grow warmer and more acidic, Stillman and colleagues suggest. In the open ocean, nitrates are upwelled from deep waters, but a thickening layer of warmer surface water could inhibit this upwelling. At the same time, the warmer temperatures favor bacteria that turn recycled nitrogen from surface waters and the atmosphere into ammonium, and acidification inhibits the bacteria that turn ammonium into nitrate.

"It is likely that in the future, the ocean surface will contain more ammonium," which the phytoplankton will assimilate instead of nitrates, Stillman suggested. "Metabolizing nitrogen as ammonium versus nitrates requires different biochemical constituents that impact how well the cells make their coccoliths. They will survive just fine, but their biology will be different as a result."

The study by Stillman and colleagues is the first to look at the intertwined effects of ocean acidification and changes in nitrogen on phytoplankton like Emiliania huxleyi. It's also one of the first studies to observe these effects continuously over a long time scale, "so the responses of the phytoplankton are likely what we'll see in the ocean itself," Stillman said.

Stephane Lefebrve, the SF State postdoctoral student who developed the experiments for the study, said he is now looking for phytoplankton genes that "will help us to build the genetic blueprint of their responses to elevated carbon dioxide and a nitrogen source"

Lefebvre, Ina Benner, Alexander Parker, Michelle Drake, Pascale Rossignol, Kristine Okimura, Tomoko Komada, and Edward Carpenter, all from SF State's Romberg Tiburon Center for Environmental Studies, were co-authors on the Global Change Biology study.

"Nitrogen source and pCO2 synergistically affect carbon allocation, growth and morphology of the coccolithophore Emiliania huxleyi: implications of ocean acidification for the carbon cycle," was published online in October by the journal Global Change Biology.

Jonathon Stillman and Stephane Lefebvre may be reached by contacting Nan Broadbent at SF State: nbroadbe@sfsu.edu or at 415-338-7108.

Nan Broadbent | EurekAlert!
Further information:
http://www.sfsu.edu

More articles from Life Sciences:

nachricht A Varied Menu
25.03.2019 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Key evidence associating hydrophobicity with effective acid catalysis
25.03.2019 | Tokyo Metropolitan University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Laser processing is a matter for the head – LZH at the Hannover Messe 2019

25.03.2019 | Trade Fair News

A Varied Menu

25.03.2019 | Life Sciences

‘Time Machine’ heralds new era

25.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>