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 Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>