Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Increasing levels of atmospheric CO2 cause a rise in ocean plankton calcification

21.04.2008
Increased carbon dioxide in the Earth's atmosphere is causing microscopic ocean plants to produce greater amounts of calcium carbonate (chalk) - with potentially wide ranging implications for predicting the cycling of carbon in the oceans and climate modelling.

That is the conclusion of an international team of scientists led by investigators based at the UK's National Oceanography Centre, Southampton and the University of Oxford, published in the journal, Science, on Friday, 18 April 2008.

Co lead-author, Dr M Debora Iglesias-Rodriguez, of the University of Southampton's School of Ocean and Earth Science at the National Oceanography Centre, Southampton said:

'This work contradicts previous findings and shows, for the first time, that calcification by phytoplankton could double by the end of this century. This is important because the majority of ocean calcification is carried out by coccolithophores such as Emiliania huxleyi and the amount of calcium carbonate produced at the ocean surface is known to have a direct influence on levels of atmospheric carbon dioxide.'

Previously, the fact that carbon dioxide made the oceans more acidic was thought to be harmful to all organisms that produce calcium carbonate - for example, corals and coccolithophores (a group of calcium carbonate-producing phytoplankton). However, observations in the laboratory and the deep ocean have shown that the calcification of coccolithophores increases significantly with rising carbon dioxide (CO2) levels, produced by human activity.

When coccolithophores make plates of calcium carbonate they also release carbon dioxide. But because these organisms photosynthesize they also consume CO2. It is the balance between calcification - which produces carbon dioxide - and the consumption of CO2 by photosynthesis that will determine whether coccolithophores act as a "sink" (absorbing CO2) or as a source of CO2 to the atmosphere. These results, based on experiments that directly replicate how the oceans take up carbon dioxide, show that the rise in CO2 produced by increased calcification is mitigated by its removal through increased photosynthesis, with a net effect that is unlikely to either contribute greatly or significantly reduce the rise in atmospheric CO2.

Co-lead author, PhD student Paul Halloran based at the Department of Earth Sciences, University of Oxford said:

'Our research has also revealed that, over the past 220 years, coccolithophores have increased the mass of calcium carbonate they each produce by around 40 per cent. These results are in agreement with previous observations that coccolithophores are abundant through past periods of ocean acidification such as 55 million years ago - the Paleocene Eocene Thermal Maximum.

Dr Iglesias-Rodriguez from the University of Southampton continued: 'Our widely held assumption that the acidification of the oceans causes a decrease in calcification in all coccolithophores needs to be reappraised in the light of our findings. Our data reveal that these microscopic organisms, which are major players in the Earth's cycling of carbon, have been responding to climate change by increasing the size of the cells and their calcium carbonate plates.

'What is unclear from our research is exactly what will be the effect of ocean acidification in natural ecosystems and how the response of calcification in the oceans will affect the levels of carbon dioxide in the atmosphere. Our next step is to conduct field research, particularly in the most susceptible waters to ocean acidification, such as Antarctic waters.'

The main conclusions of this work are:

* Ocean acidification remains one of the most important environmental and societal concerns of the 21st century

* Contrary to previous suggestions of decreased calcification under high CO2 levels, which could potentially act as a negative feedback on atmospheric CO2 levels, the observed increase in both calcification (CO2 outgassing) and photosynthesis (CO2 ingassing) suggest that future coccolithophore populations will neither greatly ameliorate nor exacerbate atmospheric CO2 rise.

* These results have important implications in palaeoreconstruction and in forecasting the future marine carbon cycle and climate.

* This work *does not* suggest that the observed increase in calcification will be followed by a positive feedback of CO2 to the atmosphere.

* The present work shows the physiological response of an important component of the food chain but the response of the natural communities remains an open question. There is an urgent need to conduct these studies in the most vulnerable ecosystems to ocean acidification, such as Antarctic waters.

* This work is in agreement with the observed resilience of coccolithophores in the geological record. However other important marine calcifiers, such as corals, remain vulnerable to the increasing CO2 levels. The coccolithophores are unusual among cacifiers in that they calcify inside the cells, and therefore there is a strong biological control compared to corals that calcify externally. Concern about the fate of corals and other calcifiers in high CO2 scenarios still remains.

ENDS

For more information contact the NOCS Press Officer Kim Marshall-Brown
on +44 (0)23 8059 6170 Email: kxm@noc.soton.ac.uk
University of Oxford Press Officer Pete Wilton
on +44 (0)1865 283877, Email: pete.wilton@admin.ox.ac.uk
Author contacts: Dr Iglesias-Rodriguez on +44 (0)23 8059 3240
Email: dir@noc.soton.ac.uk
Paul Halloran: +44 (0)1865 282116

Sarah Watts | alfa
Further information:
http://www.soton.ac.uk

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>