Outbreaks can consume live corals over large areas, a change that can promote algal growth, alter reef fish populations, and reduce the aesthetic value of coral reefs, which in turn negatively affects tourism.
Despite more than 30 years of research, the triggers and spread of COT outbreaks are not fully understood. Human impacts such as urbanization, runoff, and fishing have been correlated with outbreaks, but some outbreaks continue to occur in the absence of known anthropogenic triggers. Waves of a spreading outbreak that moves southerly along the Great Barrier Reef are termed secondary outbreaks because they are thought to be seeded from dispersing larvae of a primary outbreak upstream.
This secondary outbreak hypothesis has been widely accepted as the mechanism by which COT outbreaks spread across broad regions of the Pacific Ocean and impact remote locations such as Hawai'i, Guam, or French Polynesia - until now. A team of scientists from the Hawai'i Institute of Marine Biology and the Joint Institute for Marine and Atmospheric Research at the University of Hawai'i and Rutgers University have recently used genetic techniques to evaluate the spatial scale at which COT outbreaks can occur via larval dispersal across the central Pacific Ocean.
The results of this work have demonstrated that unlike on the Great Barrier Reef, COT larvae are not moving en masse among central Pacific archipelagos. In fact, contrary to expectations under the secondary outbreak hypothesis, all COT outbreaks in the study came from local populations. On a finer scale, genetic differences were detected among reefs around islands and even between lagoon and forereef habitats of the same island, indicating that the larvae of this species are not routinely reaching their full dispersal potential, and are certainly not fueling outbreaks at distant sites.
This research has proved that outbreaks are not some rogue population that expands and ravages across central Pacific reefs. Instead, the authors hypothesize that nutrient inputs and favorable climatic and ecological conditions likely fuel outbreaks of local populations.
This work is particularly important because most current management strategies are focused on stopping secondary spread rather than preventing human activities that can start an outbreak. This study is the first genetic survey of COT populations in which both outbreak and non-outbreak populations are surveyed across a broad region of the Pacific and the results are pretty clear that outbreaks are not jumping across large expanses of open ocean. Dr. Rob Toonen, one of the researchers involved in this project, explains "the genetic differences found among COT populations clearly indicate that outbreaks are not spreading from the Hawaiian Archipelago to elsewhere.
Furthermore, the similarity between outbreak and non-outbreak COT populations within each archipelago indicates that outbreaks are a local phenomenon. Our recommendation to managers is to seriously consider the role that environmental conditions and local nutrient inputs play in driving COT outbreaks."
The full paper is free online at http://dx.plos.org/10.1371/journal.pone.00311599
Carlie Wiener | EurekAlert!
Making Oceans Plastic Free - Project tackles the problem of plastic pollution in the oceans
31.05.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)
Nitrogen Oxides Emissions: Traffic Dramatically Underestimated as Major Polluter
31.05.2017 | Universität Innsbruck
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)...
Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.
New Manufacturing Technologies for New Products
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
22.06.2017 | Life Sciences
22.06.2017 | Materials Sciences
22.06.2017 | Materials Sciences