Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

"Sundried tide" — silent, natural disaster

05.07.2007
Australian researchers have studied and documented the effect of the "sundried tide", a force of nature that can silently wipe out coral reefs.

Their analyses have revealed for the first time that these are highly predictable events that can seriously impact the state of coral reefs at a time when they are preparing for the stresses of summer.

In a paper published in scientific journal Marine Biology, Dr Ken Anthony and Dr Ailsa Kerswell, of the ARC Centre of Excellence for Coral Reef Studies (CoECRS) have revealed that extreme low tides on clear sunny days can lead to widespread damage of coastal coral colonies.

"Really low tides, where the local sea level gets to its extreme low for the year, can occur at different times of the day," UQ's Dr Anthony said.

"In years where this occurs during the middle of the day when the sunlight is at its most intense and the reefs are almost fully exposed, there is a real risk of severe coral stress and death in the shallow reef zone."

Just like cyclones and other natural disasters, these severe ‘sun-dry tides' rarely occurred since they relied on the alignment of numerous natural extremes, he said.

However, when these factors all aligned, by a combination of sun, moon and chance weather, an extreme event occurred which could leave coral colonies bleached and devastated.

One such event occurred in September 2005 while Dr Anthony and Dr Kerswell were taking JCU students on a field trip to Orpheus Island off the Queensland coast.

“While doing some field work we noticed that all the corals in the area were about to die, so we took the opportunity to record the event,” Dr Kerswell said.

Their observations led Dr Anthony and Dr Kerswell to investigate the mysterious coral deaths on Orpheus Island — a study which would reveal that what they had witnessed was a rare event, the extent of which had never previously been recorded on the Great Barrier Reef .

“At first we thought it was a major outbreak of disease," Dr Kerswell said.

"We collected samples and took hundreds of photos and sent a series off to colleagues to be analysed. The response was that it was not a disease, but something else.

“[So] we looked back through hourly records of tidal patterns over the previous eight years and combined it with data on solar records and models."

Dr Anthony said the researchers aligned what the tide would do with the sun and weather patterns and ran an analysis of the risk of corals being out of the water and exposed to the sun.

During September 2005 Dr Anthony, Dr Kerswell and the students were present the week following a rare extremely low tide during which the sun had been shining from a clear sky.

These "natural disasters" occur silently but can devastate the tidal zone. From past records Dr Anthony estimated that the September 2005 event was the worst in the eight-year record.

However, the "sundried tides" could also be anticipated.

"These events are highly predictable," Dr Anthony said.

"We can go into the weather reports, align them with tidal charts and predict the times of greatest risk.

"The high-risk time of year is July–October, when corals are building up resources for spawning and preparing for summer stressors such as thermal bleaching."

Since studying the cause and impacts of these major events, Dr Anthony hopes that their predictable nature will lead to improved warning systems and better models for predicting stress and mortality in corals.

Although predictable and natural, "sundried tides" were unavoidable and compounded the stresses already felt by corals due to climate change and human impacts, he said.

"However, if we better understand the timing and severity of natural stressors on reefs, we will be able to better predict the risks of human-induced stressors, and hopefully better manage for healthy reefs," he said.

Paper:
Anthony, K and Kerswell, A (2007). Coral mortality following extreme low tides and high solar radiation. Marine Biology 151(5): 1623-1631.

Link to full text or pdf

More information:
Dr Ken Anthony, CoECRS & UQ, 07 3365 9154, 0427 177 290

Dr. Ken Anthony | EurekAlert!
Further information:
http://www.coralcoe.org.au/

More articles from Ecology, The Environment and Conservation:

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

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: Can we see monkeys from space? Emerging technologies to map biodiversity

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...

Im Focus: Climate satellite: Tracking methane with robust laser technology

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...

Im Focus: How protons move through a fuel cell

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...

Im Focus: A unique data centre for cosmological simulations

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...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

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)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>