The team demonstrated that natural selection acting on the species of algae living within corals may determine which partnerships will survive when confronted with extreme temperatures changes. The results will be published online in the May 5 issue of the journal Proceedings of the Royal Society B.
Corals form symbiotic relationships with photosynthetic algae in order to survive. The algae provide the corals with nutrients and energy, while the corals provide the algae with nutrients and a place to live. According to the scientists, this delicate symbiosis is sensitive to changes in the environment, and especially to changes in temperature. “A change in sea-surface temperature of just a few degrees above the summer high or below the winter low can cause many coral-algal symbioses to break down and the algae to be expelled,” said Mark Warner, an associate professor of marine biosciences at the University of Delaware and one of the team’s leaders. This process is known as bleaching because it leaves behind the translucent animal tissue and the white skeleton underneath.
The scientists — which include Todd LaJeunesse, an assistant professor of biology at Penn State University, and Hector Reyes-Bonilla, a professor at Universidad Autonoma de Baja California Sur — found that corals harboring certain species of symbiotic algae survived a severe cold-water event that took place in 2008 in the Gulf of California (eastern Pacific Ocean), while corals harboring a different species of algae died.
The team focused their research on a genus of coral called Pocillopora that comprises approximately 95 percent of the coral community in the Gulf of California and the larger eastern Pacific Ocean. “In this region, Pocillopora corals typically harbor one of two types of symbiotic algae: a species that is sensitive to environmental changes or another species that is stress-tolerant,” said LaJeunesse. The team found that colonies of Pocillopora corals harboring the sensitive species of algae were bleached following the 2008 cold-water event, which led to a high mortality rate in these corals. In contrast, Pocillopora colonies harboring the stress-tolerant alga were virtually unaffected by the episode.
In addition to their work in the Gulf of California, the team also surveyed reefs along the western coast of Mexico and into Panama. Pocillopora corals were significantly impacted at several of these sites during substantial warming and cooling when there was a particularly strong El Niño/La Niña in 1997 and 1998. In fact, up to 90 percent of all corals died after bleaching. Much like their work further north, the team noted that the majority of corals growing in these locations contained the more tolerant species of algae. “The differential mortality that we witnessed suggests that the relationship between certain populations of Pocillopora and the species of algae they associate with is quite stable,” said Warner. “And this stability, ultimately, is an Achilles heel for Pocillopora. The inability of the corals to shuffle their symbionts or to establish symbioses with different species of algae means that we may see a significant loss of coral populations in the future, especially if extreme temperature disturbances, such as the cold anomaly we documented in 2008 or the hot anomaly that took place in 1997, become more frequent or severe.”
Andrea Boyle | Newswise Science News
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology