Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Laboratory-bred corals reproduce in the wild

01.02.2016

New hope for endangered corals: Scientists take an important step towards sustainable restoration of Caribbean reefs

Researchers of SECORE International (USA, Germany), the University of Amsterdam (Netherlands) and the Carmabi Marine Research Station (Curaçao) have for the first time successfully raised laboratory-bred colonies of a threatened Caribbean coral species to sexual maturity. These findings have been published in the latest issue of the scientific journal Bulletin of Marine Science.


At the age of four years, this artificially bred elkhorn coral colony is sexually mature.

Credit: Skylar Snowden - Pittsburgh Zoo & PPG Aquarium

"In 2011, offspring of the critically endangered elkhorn coral (Acropora palmata) were reared from gametes collected in the field and were outplanted to a reef one year later", explains Valérie Chamberland, coral reef ecologist working for SECORE and Carmabi.

"In four years, these branching corals have grown to a size of a soccer ball and reproduced, simultaneously with their natural population, in September 2015. This event marks the first ever successful rearing of a threatened Caribbean coral species to its reproductive age."

Due to its large size and branching shape, elkhorn corals created vast forests in shallow reef waters that protect shores from incoming storms and provide a critical habitat for a myriad of other reef organisms, including ecologically and economically important fish species. An estimated 80% of all Caribbean corals have disappeared over the last four decades and repopulating degraded reefs has since become a management priority throughout the Caribbean region.

The elkhorn coral was one of the species whose decline was so severe that it was one of the first coral species to be listed as threatened under the U.S. Endangered Species act in 2006, and as critically endangered under the IUCN Red List of Threatened species in 2008. Consequently, measures to aid Caribbean reef recovery often focus on the elkhorn coral given its major decline and its ecological importance.

Since 2010, SECORE, Carmabi, and partners from aquariums around the world started a project aimed at developing techniques to rear larger numbers of elkhorn coral offspring so they could eventually be outplanted to degraded reefs throughout the Caribbean. "Our approach differs substantially from the one generally used by the large number of reef restoration groups that operate throughout the Caribbean", explains Dirk Petersen, coral reef expert and director of SECORE.

"These groups generally use the 'coral gardening' approach, where small fragments are harvested from coral colonies on the reef. The fragments are then grown in special nurseries to larger sizes before they are returned to the reef." Although this method has been applied throughout the Caribbean, it does not allow for new genetic combinations as the fragments harbor the same genes as the donor colonies and are therefore copies of their parents. "By contrast, SECORE developed a technique whereby male and female gametes are caught in the wild and fertilized in the laboratory to raise larger numbers of genetically unique corals", says Dirk Petersen.

Elkhorn corals reproduce only once or twice a year, generally a few days after the full moon in August. During those nights, Acropora colonies synchronously release their gametes into the water column. The project team collects a small proportion of these gametes by gently placing special nets around spawning colonies to collect the floating gamete bundles. After collection, the researchers produce coral embryos by in vitro fertilization, mixing sperm and eggs in the laboratory.

Coral embryos develop into swimming larvae within days and eventually settle onto specifically designed substrates. After a short nursery period, the project team outplants the substrates with the newly settled corals to the reef. Details on the techniques developed by SECORE during this project were recently published in the scientific journal Global Ecology and Conservation.

"We just learned that elkhorn corals can reach sexual maturity in only 4 years. This is exciting news, as we now know that offspring raised in the laboratory and outplanted to a reef can contribute to the natural pool of gametes during the annual mass-spawning of elkhorn corals within 4 years", says Valérie Chamberland. By using a restoration method based on sexual rather than asexual (or clonal) reproduction, the SECORE method also promotes the formation of new genotypes that could potentially cope better with the conditions on modern reefs than their already struggling parents. These sexually-bred corals therefore not only aid in the recovery of dwindling elkhorn coral populations by increasing the number of colonies, but also by increasing the genetic diversity of this critically endangered species, thus giving evolution the opportunity to play its part.

While these initial results provide some hope for the restoration of endangered elkhorn populations, restoration cannot perform miracles. "Our techniques can only support natural recovery, which means that conditions have to be appropriate to allow long term survival of outplanted corals and succession by other organisms to restore ecosystem functions. Hence, outplanting efforts have best chances for success in well managed areas where stress has been reduced, but where, for some reason, no natural recruitment occurs. We don't get around to protect coral reefs and to apply additional management tools to reduce overfishing, pollution and other threats to coral reefs", underlines Dirk Petersen. "So far, any restoration effort is restricted to small areas and involves costly and labor intensive hands-on work. We now need to take the next step forward to apply our findings on a larger scale in Curaçao and elsewhere in the Caribbean. For that purpose, we started a joint pilot project last August."

###

This work would not have been possible without the cooperation and support of SECORE's partner aquariums such as Curaçao Sea Aquarium, Columbus Zoo and Aquarium, Pittsburgh Zoo & PPG Aquarium, Shedd Aquarium, and Henry Doorly Zoo.

References

Four-year-old Caribbean Acropora colonies reared from field-collected gametes are sexually mature. (2016) Bulletin of Marine Science, Chamberland VF, Petersen D, Latijnhouwers KRW, Snowden S, Mueller B, Vermeij MJA

Restoration of critically endangered elkhorn coral (Acropora palmata) populations using larvae reared from wild-caught gametes. (2016) Global Ecology and Conservation, Chamberland VF, Vermeij MJA, Brittsan M, Carl M, Schick M, Snowden S, Schrier S, Petersen D

Media Contact

Carin Jantzen
c.jantzen@secore.org
49-042-146-847-940

 @SECORE_coral

http://www.secore.org/site/home.html 

Carin Jantzen | EurekAlert!

Further reports about: Acropora palmata coral reef coral species corals

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: 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....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

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

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>