Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bremen Marine Researchers find a new explanation for the Coral Reef Paradox

30.10.2015

Tropical coral reefs are the most biodiverse habitats on the planet. They are also highly productive, although the regions of the oceans they live in have extremely low levels of nutrients. Until now, this so-called “reef paradox” has baffled scientists. In an international journal publication, Bremen Marine researchers have now put forward a plausible explanation for this puzzling contradiction.

A team of international researchers led by Prof. Dr. Christian Wild from University of Bremen’s faculty of Biology & Chemistry recently made the following surprising discovery: It transpires that the conversion of nitrogen, or nitrogen fixation, by micro-organisms that are associated with corals clearly in turn supports the conversion of carbon, or carbon fixation, by the micro-algae in the coral tissue. This is one of the main findings of the Bremen study that has now been published in the renowned journal “Proceedings of the Royal Society”.


One of the investigated coral colonies (species: Stylophora pistillata) with erected polyp tentacles at night

Foto: Dr. Ulisse Cardini


Maintenance of hard coral fragments for subsequent incubation experiments to quantify C and N fixation

Foto: Dr. Malik Naumann

Coral Holobiont

Although corals are animals, so-called cnidarians, they host such a lot of micro-algae and other micro-organisms like bacteria in their tissue that they develop their own micro-ecosystems and are classified as holobionts. With the aid of their tiny co-inhabitants, coral holobionts are capable of carrying out processes thoroughly untypical of animals.

Carbon fixation by means of the photosynthesis of micro-algae is especially important for the productivity of corals: What happens is that carbon dioxide is converted into organic material with the aid of light energy. Thanks to this process, corals are able to grow at extremely fast rates, creating not only new habitats, but also nourishment for other organisms. Coral holobionts carry out carbon fixation with extraordinary intensity – and they do this although they dispose of almost no nitrogen with which to produce biomass.

How does the paradox come about?

Could parallel processes, especially nitrogen fixation by bacteria and carbon fixation by micro-algae, possibly be playing a role here? This is the unorthodox hypothesis that has engaged the attention of Bremen marine researcher Professor Christian Wild for a very long time.

Funded by the German Research Foundation, he and his team of PhD students – in particular the Italian early-career researcher and lead author of the study, Ulisse Cardini – and other colleagues set out to research the interrelation between carbon and nitrogen fixation by corals.

The team examined these processes in all the dominant hard corals found on a coral reef in the northern region of the Red Sea in Jordan. They carried out their research during several lengthy expeditions in all four seasons of the year 2013. They chose this location for their research because of its high seasonality: That is the pronounced natural fluctuation in nutrient concentrations contained in the water across the seasons.

Somewhat to their surprise, they discovered that carbon fixation was highly constant for all corals throughout the whole year. This was true even in the summer months when nutrient concentrations are especially low. The key to answering this puzzle, they found, clearly lies in the process of nitrogen fixation by micro-organisms that inhabit the coral. The large number of measurements they took showed that in summer this process was about tenfold more intense than at other times of the year.

A major finding of the study is that the process of nitrogen fixation by micro-organisms compensates for the extreme nitrogen limitation of the summer months. Thus, processes by bacteria support the processes by micro-algae in the coral tissue so that in the end there is a beneficial effect not only for the coral but also for the whole reef. The study showed that corals are good examples of animals, humans included, where beneficial internal microbes fulfill roles important for the health of the host organisms.

The article by Cardini et al. breaks new scientific ground in several respects. It is now clear how the individual processes carried out by the different coral inhabitants are intertwined. And it furthermore reveals that the important role micro-organisms play in these interrelations has until now been underestimated. The international research team around University of Bremen Professor Christian Wild and his research associate Dr. Ulisse Cardini have delivered an important new explanation for the Darwinian reef paradox.

You can obtain more information on this topic by contacting:

University of Bremen
Faculty Biology / Chemistry
Marine Ecology
Prof. Dr. Christian Wild
Phone. 0421 218 63387
e-mail: christian.wild@uni-bremen.de

Dr. Ulisse Cardini
Division of Microbial Ecology
Department of Microbiology and Ecosystem Science
Research Network "Chemistry meets Microbiology"
University of Vienna, Althanstr. 14, 1090 Vienna (AT)
www.microbial-ecology.net
www.ulissecardini.info
Telefon: +43 677 61633148
E-mail: cardini@microbial-ecology.net

Eberhard Scholz | idw - Informationsdienst Wissenschaft
Further information:
http://www.uni-bremen.de

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>