However, she noted in presenting a paper at the annual meeting of the American Association for the Advancement of Science in San Francisco, Feb. 18, Caribbean gorgonian sea fan corals show surprising warm-weather tenacity -- they not only are somewhat temperature resilient but can also boost their cellular and enzymatic defenses to fight lethal microorganisms as temperatures rise. These abilities may someday be harnessed to help protect other fragile coral reefs, Harvell said.
The head of the Coral Disease Working Group of the Global Environmental Facility Coral Reef Targeted Research Program, Harvell describes these latest findings in detail in the March issue of the journal Oceanography. The working group is an international collaboration with stations in the Caribbean, Philippines, Australia and East Africa that seeks to understand how rising ocean temperatures (which are monitored with high-resolution satellite detectors) are related to lethal coral reef epidemics.
The warm temperatures that have been occurring worldwide as a result of global warming appear to be facilitating fatal epidemics in coral reefs across the globe, according to Harvell and her co-researchers. For example, in 2005, the Caribbean experienced unusually warm weather and a spate of coral deaths caused directly by temperature stress and indirectly by opportunistic infections contracted during the warm period.
"Below the waves, the warm temperatures triggered a series of events lethal to coral reefs: massive loss of critical symbionts, compromised immunity and ability to fight pathogens, and increased susceptibility to lethal infectious microorganisms," reported Harvell.
However, the precise connection between warmer waters and coral disease is unclear. "It is difficult to pinpoint yet how temperature stress decreases the immune response," said Harvell. "Although corals are near the base of the evolutionary tree, they are complicated animals."
The complexities arise from different levels of symbiosis within a coral, both with bacteria on the surface and algae in the interior. Moreover, the warmer waters cause increased virulence of some pathogens as well as a diminished ability of corals to fight them. But these complications can also be keys to coral reef survival.
"A first line of defense is provided by surface microorganisms … [that] produce antibiotics that can help corals fight pathogenic bacteria," reported Harvell.
However, not all corals are able to produce such defenses under thermal stress. "Some corals show unusual resilience to the double threat [of pathogens and warming seas], and we should look to these hardy corals for clues that might enhance others," said Harvell. "Other corals are more sensitive and will not survive the continued warming trend."
Yet there seems to be future promise for boosting the immunity of coral reefs, Harvell reported. Collaborators Rotem Effrony and Eugene Rosenberg in Tel Aviv, Israel, have isolated viruses that can consume several bacteria that are deadly to the more sensitive corals.
Graduate student Anne Poduska is a writer intern at the Cornell Chronicle.
Press Relations Office | EurekAlert!
Dune ecosystem modelling
23.06.2017 | 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
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology