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 Minimized water consumption in CSP plants - EU project MinWaterCSP is making good progress
05.12.2017 | Steinbeis-Europa-Zentrum

nachricht Jena Experiment: Loss of species destroys ecosystems
28.11.2017 | Technische Universität München

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: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

Im Focus: A transistor of graphene nanoribbons

Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."

Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

Blockchain is becoming more important in the energy market

05.12.2017 | Event News

 
Latest News

Making fuel out of thick air

08.12.2017 | Life Sciences

Rules for superconductivity mirrored in 'excitonic insulator'

08.12.2017 | Information Technology

Smartphone case offers blood glucose monitoring on the go

08.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>