Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ocean Acidification and Coral Reefs

31.05.2011
Natural CO2 seeps show what could happen to Coral Reefs in a world of increasing green house gas emissions

Natural carbon dioxide (CO2) seeps in Papua New Guinea have given scientists rare insights into what tropical coral reefs could look like if human-induced atmospheric CO2 concentrations continue to rise unabated. At present rates of increase, the Intergovernmental Panel on Climate Change (IPCC) forecasts atmospheric CO2 levels of about 750ppm or more by 2100. About a third of this extra atmospheric CO2 is absorbed by the world’s oceans. As a consequence, pH levels will drop from 8.1 to 7.8, resulting in increased ocean acidification which will severely impact marine ecosystems.


Site exposed to very high concentrations of CO2 concentrations where coral developement ceases to exist. Katharina Fabricius, AIMS


Seascape at control site
Katharina Fabricius, AIMS

The coral reefs, having the highest biodiversity of all marine ecosystems, are probably the most vulnerable.

Dr Katharina Fabricius, scientist at the Australian Institute of Marine Science (AIMS) has led two research expeditions, with researchers from six countries including Germany, USA and Papua New Guinea. Among the international team of scientists was a group from the Max Planck Institute for Marine Microbiology in Bremen, experts in the field of microsensors, a valuable tool for studying coral reefs.

The team of scientists studied three natural CO2 seeps in Milne Bay Province, Papua New Guinea. This unique location was discovered by chance during a field trip to document biodiversity and is the only presently known cool CO2 seep site in tropical waters containing coral reef ecosystems. The study has given scientists unprecedented insights into what coral reefs would look like if greenhouse gas emissions and resulting ocean acidification continues to increase at present rates. At the seeps, streams of CO2 bubbles emanate from the ocean floor due to volcanic activity.

This week a scientific paper on the first results of this study is published in the prestigious, international scientific journal Nature Climate Change. It is the first scientific paper to present data on tropical coral reef ecosystems that are naturally adapted and acclimatised to elevated CO2. “Our research showed us there will be some winners, but many more losers, when tropical coral reefs are exposed to ocean acidification,” said principal investigator Dr. Fabricius. “In the past, we have relied on short-term laboratory experiments to tell us what happens to marine organisms exposed to ocean acidification,” she said. “Those experiments indicated deleterious effects on the performance of many species.”

While laboratory experiments are important, Dr Fabricius said the natural CO2 seeps in Milne Bay provided a more complete picture about the ecological consequences for coral reef communities when exposed to higher levels of CO2 for many decades. This natural setting allowed scientists to compare coral reef communities along a gradient from normal present day to low pH.

“We found that as pH decreases the number and types of corals making up coral reefs are much reduced. Diversity of corals drops by 40 per cent, and the reef becomes dominated by one form of corals, massive boulder corals (Porites).

“The cover of the more delicate tabulate, foliose and branching corals was reduced three-fold near the CO2 seeps. Similarly, the abundance of soft corals and sponges were also significantly reduced. Most importantly we found that reef development ceased below pH level 7.7.”

One of the MPI co-authors, Martin Glas said: “Not only did coral abundance change, also other calcifiers like foraminifera and calcifying algae were strongly reduced under elevated CO2 levels. This is disturbing news as they represent key-species for the formation of a healthy coral reef and contribute significantly to the reefs calcium carbonate production.”

Amongst the few winners at higher levels of CO2 were seagrasses which showed increased cover with three to four times more shoots and roots than under normal conditions.

Dr Fabricius said the study showed that ocean acidification leads to profound changes in coral reefs ecosystems. “The decline of the structurally complex corals means the reef will be much simpler and there will be less habitat for the hundreds of thousands of species we associate with today’s coral reefs.

“They would not be the richly diverse and beautiful habitats we currently see in places such as the Great Barrier Reef.”

“There are also fewer juvenile corals in areas with high CO2 levels, therefore coral reefs in those environments face greater challenges recovering from disturbances such as tropical storms.

“Ultimately, what we observed was that the diversity of reefs progressively declines with increasing CO2. At concentrations similar to those predicted for the end of this century at a ‘business as usual’ emissions scenario, the “coral reef” observed was depauperate and lacked the structural complexity of present healthy tropical coral reefs. These changes are simply due to ocean acidification, i.e., even without the projected +2°C warming of the oceans associated with rising greenhouse gases. The 0.5°C warming we have already observed in the tropics in the last 50 years has already caused mass coral bleaching events and declining coral calcification.”

Dr Fabricius said: “The rate of increase of atmospheric CO2 continues to accelerate due to human activities. The range of exposures at the Milne Bay seep sites are comparable to end-of-century CO2 projections.

“It would be catastrophic if pH levels dropped below 7.8."
“This study proves we must urgently transition to a low CO2emissions future or we face the risk of profound losses of coral ecosystems.”

Dr Fabricius said it was important for the researchers to continue their study in the unique location in Papua New Guinea and future expeditions are in preparation.

For further information contact:
Dr Katharina Fabricius, AIMS Principal Research Scientist, +49 15259173182
k.fabriciusaims.gov.au (at present in Germany)
Dr Dirk de Beer
Group leader at the
Max Planck Institute for Marine Microbiology
+49 421 2028 802 dbeermpi-bremen.de
Martin Glas
Max Planck Institute for Marine Microbiology
+49 421 2028 838 mglasmpi-bremen.de
Dr Manfred Schloesser
Press spokesman at the
Max Planck Institute for Marine Microbiology
+49 421 2028 704 mschloesmpi-bremen.de
A video is available for download at: ftp://ftp.aims.gov.au/pub/Clarke/Media/
Link to article
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1122.html
Information on acidification at:
http://www.aims.gov.au/docs/research/climate-change/position-paper.html
Participating institutions
Australian Institute of Marine Science (AIMS) www.aims.gov.au/
Max Planck Institute for Marine Microbiology www.mpi-bremen.de
Rosenstiel School of Marine and Atmospheric Science, University of Miami, Florida, USA www.rsmas.miami.edu/

Dr. Manfred Schloesser | Max-Planck-Institut
Further information:
http://www.mpi-bremen.de

More articles from Earth Sciences:

nachricht Impacts of mass coral die-off on Indian Ocean reefs revealed
21.02.2017 | University of Exeter

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>