Navigation Links
Corals can sense what's coming
Date:11/18/2011

Australian scientists have thrown new light on the mechanism behind the mass death of corals worldwide as the Earth's climate warms.

Coral bleaching, one of the most devastating events affecting coral reefs around the planet, is triggered by rising water temperatures. It occurs when the corals and their symbiotic algae become heat-stressed, and the algae which feed the corals either die or are expelled by the coral.

There have been seven major bleaching events globally in the past 30 years, the most recent being in 2010 across the Indian Ocean and Coral Triangle. Australia's Great Barrier Reef has suffered eight events since 1980, the worst being in 2002 when 55% of the total reef area was affected. The frequency of these events appears to be increasing.

Now a team of scientists from the ARC Centre of Excellence for Coral Reef Studies and James Cook University has shown that a complex cascade of molecular signals leading up to the self-inflicted death of corals and their symbiotic algae is triggered as sea water begins to warm.

Working with Acropora corals from the reef at Heron Island, the researchers found the cascade begins at ocean temperatures as much as 3 degrees lower than those normally associated with coral bleaching.

And the process culminates in 'apoptosis' or programmed cell-death a situation in which living organisms (including corals and humans) deliberately destroy their weakened or infected body cells, effectively a form of 'cell suicide' or amputation designed to protect the organism as a whole.

"Our results suggest that the control of apoptosis is highly complex in the coral-algae symbiosis and that apoptotic cell death cascades potentially play key roles in tipping the cellular life or death balance during environmental stress prior to the onset of coral bleaching," explains lead author Dr Tracy Ainsworth.

"It is also clear that this chain reaction responds significantly to subtle, daily changes in the environment and to sea temperatures which were generally thought till now to have little impact on the function of coral and its symbiotic algae."

Paradoxically, the team's research identified molecular signals both promoting and discouraging programmed cell-death in the corals.

This has led them to a theory that corals respond to the stresses caused by warming sea water by killing off some of the cells, while strengthening others in order to stage a possible recovery after the hot water has moved off the reef and conditions have returned to normal.

"This would explain why some corals are able to recover quite quickly from a bleaching event, if it has not gone too far.

"It is far too early to speculate, but understanding the recovery process for any living organism is always a big help, as human medicine has constantly demonstrated, Dr Ainsworth says.

"The next step in our research will be to see how we can use this new insight into the processes of coral bleaching to understand their recovery mechanisms. We also need to know more about how this process works at lower temperatures, or under varying temperatures.

"That in turn will lead us to explore ways that coral reef managers and users can perhaps minimise other stresses on the reef in order to give it the best possible chance of recovery from bleaching."

However the team cautions that "further study of the tissue function and cellular differentiation and recovery processes in coral is needed before this complicated cell death system can be fully understood".


'/>"/>
Contact: Tracy Ainsworth
tracy.ainsworth@jcu.edu.au
61-747-814-442
ARC Centre of Excellence in Coral Reef Studies
Source:Eurekalert

Related biology news :

1. Fishy lawnmowers help save Pacific corals
2. Study identifies molecules used by certain species of seaweed to harm corals
3. New study of Glovers Reef challenges whether corals will benefit from Marine Reserves protection
4. New study of Glovers Reef challenges whether corals will benefit from Marine Reserves protection
5. Human pathogen killing corals in the Florida Keys
6. How soft corals defy their environment
7. Coral algae (symbiodinium) discovered in black corals at never seen before depths
8. NOAA webcasts corals research to nations classrooms live from undersea lab
9. How corals fight back
10. Baby corals dance their way home
11. Not a fish story: Protected corals increase fishing profits
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/28/2017)... , March 28, 2017 The ... Hardware (Camera, Monitors, Servers, Storage Devices), Software (Video Analytics, ... Region - Global Forecast to 2022", published by MarketsandMarkets, ... 2016 and is projected to reach USD 75.64 Billion ... and 2022. The base year considered for the study ...
(Date:3/24/2017)... 24, 2017 The Controller General of Immigration from ... Abdulla Algeen have received the prestigious international IAIR Award for the ... Continue Reading ... ... Controller Abdulla Algeen (small picture on the right) have received the IAIR ...
(Date:3/23/2017)... The report "Gesture Recognition and Touchless Sensing Market by Technology (Touch-based ... to 2022", published by MarketsandMarkets, the market is expected to be worth USD ... 2022. Continue Reading ... ... ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... and LAGUNA HILLS, Calif. , Oct. ... Cancer Research, London (ICR) and University ... SKY92, SkylineDx,s prognostic tool to risk-stratify patients with multiple myeloma ... MUK nine . The University of Leeds ... partly funded by Myeloma UK, and ICR will perform the ...
(Date:10/10/2017)... ... 2017 , ... San Diego-based team building and cooking events company, Lajollacooks4u, has ... The bold new look is part of a transformation to increase awareness, appeal to ... period. , It will also expand its service offering from its signature gourmet cooking ...
(Date:10/10/2017)... 10, 2017 International research firm Parks Associates announced ... at the TMA 2017 Annual Meeting , October 11 in ... residential home security market and how smart safety and security products impact ... Parks Associates: Smart Home ... "The residential security market has ...
(Date:10/9/2017)... DIEGO , Oct. 9, 2017  BioTech ... biological mechanism by which its ProCell stem cell ... critical limb ischemia.  The Company, demonstrated that treatment ... amount of limbs saved as compared to standard ... the molecule HGF resulted in reduction of therapeutic ...
Breaking Biology Technology: