Navigation Links
Coral's addiction to 'junk food'

Over two hundred million humans depend for their subsistence on the fact that coral has an addiction to junk food - and orders its partners, the symbiotic algae, to make it.

This curious arrangement is one of Natures most delicate and complex partnerships a collaboration now facing grave threats from climate change.

The symbiosis between coral a primitive animal and zooxanthellae, tiny one-celled plants, is not only powerful enough to build the largest living organism on the planet, the Great Barrier Reef but also underpins the economies and living standards of many tropical nations and societies who harvest their food from the reefs or have developing tourism industries.

The issue of whether the partnership is robust enough to withstand the challenges of climate change is driving a worldwide scientific effort to decipher how corals and their symbiotic algae communicate with one another, says Professor David Yellowlees of the ARC Centre of Excellence for Coral Reef Studies (CoECRS) and James Cook University.

Its an incredibly intricate relationship in which the corals feed the algae and try to control their diet, and the algae in turn use sunlight to produce junk food carbohydrates and fats for the corals to consume.

Where it all breaks down is when heated water lingers over the reef and the corals expel the algae and then begin to slowly starve to death. This is the bleaching phenomenon Australians are by now so familiar with, and which is such a feature of global warming.

The challenge for scientists is to understand the chemical conversation that goes on between the corals and zooxanthellae, the genes which control it and to explore whether corals which lose their primary partners can survive using other algae or must inevitably die.

Prof Yellowlees and Dr Bill Leggat will shortly release a new review of the current state of knowledge about the metabolism of the coral symbiosis in the journal Plant Cell and Environment.

Coral symbiosis takes place mainly in clear, clean nutrient-poor waters where food is so scarce the corals need a partner to help feed them.

We know for example the corals provide carbon as CO2 which is processed by the algae to reprocess into carbohydrates and fats using energy from sunlight, so they can feed. Its a beautiful recycling process.

The corals control the diet of the algae, to ensure it produces what they need. You could say they farm the algae, much as we farm crops.

And the algae serve as the junk food chefs, providing the corals favourite food to order.

Researchers in the Centre of Excellence are trying to understand the chemical and genetic basis for the conversation that goes on between a coral and its particular algae, and to establish whether, if it loses its algae in a bleaching event, it can establish the same relationship with a different strain of algae.

In other words, how robust this symbiotic system is and whether it can withstand shocks from warming, ocean acidification, changes in sunlight levels and other likely impacts from human activity.

The bottom line here is the survival of the Great Barrier Reef and coral reefs the world over.

Five times in the Earths history corals have been wiped out, or very close to it, suggesting they are highly vulnerable to changes in ocean conditions, Prof. Yellowlees says. Some of these past events were probably triggered by past global warming and ocean acidification.

Some scientists have speculated whether corals in crisis can be given a helping hand by humans in the form of new symbiotic algae reared for the purpose but these are very hard to grow outside of their coral hosts, and Prof Yellowlees is doubtful this is a practical solution to major bleaching events affecting thousands of square kilometres of reef.

More likely, he feels, is that cryptic strains of algae which currently play little role in the symbiosis but are present in corals may be able to take over the role of junk food chef and keep the corals going on their preferred diet. To what extent this can happen is not yet known.


Contact: David Yellowlees
ARC Centre of Excellence in Coral Reef Studies

Related biology news :

1. New south Florida nursery to focus on staghorn corals
2. Wildlife Conservation Society study finds seasonal seas save corals with tough love
3. Immediate action needed to save corals from climate change
4. Starfish outbreak threatens corals
5. Stanford researchers say living corals thousands of years old hold clues to past climate changes
6. Nicotinic receptors may be important targets for treatment of multiple addictions
7. New genetic research into nicotine addiction shows promise for personalized treatment
8. Can plant-based ethanol save us from our fossil fuel addiction?
9. Cognitive, genetic clues identified in imaging study of alcohol addiction
10. Hungry mothers risk addiction in their adult children
11. Bits of junk RNA aid master tumor-suppressor gene
Post Your Comments:
(Date:11/20/2015)... 20, 2015 NXTD ) ("NXT-ID" ... the growing mobile commerce market and creator of the ... , was recently interviewed on The RedChip Money ... this weekend on Bloomberg Europe , Bloomberg Asia, ... --> NXTD ) ("NXT-ID" or the "Company"), a ...
(Date:11/18/2015)... new scientific discoveries deepen our understanding of how cancer ... challenges in better using that knowledge to guide treatment ... children continue to survive pediatric cancer, that counseling may ... John M. Maris, M.D ., a pediatric oncologist ... --> John M. Maris, M.D ., ...
(Date:11/17/2015)... -- Paris , qui s,est ... Paris , qui s,est tenu du 17 ... de l,innovation biométrique, a inventé le premier scanner couplé, ... la même surface de balayage. Jusqu,ici, deux scanners étaient ... empreintes digitales. Désormais, un seul scanner est en mesure ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... 2015 Studies reveal the differences ... and pave the way for more effective treatment for one ...   --> --> ... problems in cats, yet relatively little was understood about the ... have been conducted by researchers from the WALTHAM Centre for ...
(Date:11/25/2015)... Nov. 25, 2015 Orexigen® Therapeutics, Inc. (Nasdaq: ... in a fireside chat discussion at the Piper Jaffray ... . The discussion is scheduled for Wednesday, December ... .  A replay will be available for 14 ... , Julie NormartVP, Corporate Communications and Business Development ...
(Date:11/24/2015)... Calif. , Nov. 24, 2015 Cepheid ... will be speaking at the following conference, and invited ... New York, NY      Tuesday, December 1, 2015 ... New York, NY      Tuesday, December 1, 2015 ... Jaffray Healthcare Conference, New York, NY ...
(Date:11/24/2015)... 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS) (TSX: AEZ) ... of the Toronto Stock Exchange, confirms that as of ... corporate developments that would cause the recent movements in ... --> About Aeterna Zentaris Inc. ... Aeterna Zentaris is a specialty biopharmaceutical company engaged ...
Breaking Biology Technology: