Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


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 Nature’s 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.

“It’s 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. It’s 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 Earth’s 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.

More information:
Prof. David Yellowlees, CoECRS and JCU, 0438 164 824 or 07 4781 6249/6402 (o)
Dr Bill Leggat, CoECRS and JCU, 07 47581372 (ah) or 07 4781 6923 (o)
Jim O’Brien, James Cook University Media Office, 0418 892 449 or 07 4781 4822

David Yellowlees | EurekAlert!
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

3-D-printed structures shrink when heated

26.10.2016 | Materials Sciences

Indian roadside refuse fires produce toxic rainbow

26.10.2016 | Health and Medicine

First results of NSTX-U research operations

26.10.2016 | Physics and Astronomy

More VideoLinks >>>