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

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Air pollution leads to cardiovascular diseases

21.08.2018 | Ecology, The Environment and Conservation

Researchers target protein that protects bacteria's DNA 'recipes'

21.08.2018 | Life Sciences

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>