Scientists shine a light on coral photosynthesis

Jan 31, 2014 by Marea Martlew
Placing a microsensor in the coral test species, Montastraea curta. Credit: Kasper Elgetti Brodersen

(Phys.org) —Balancing budgets isn't just a matter for governments, as scientists have observed in a study of the way light is used in the symbiotic relationship between animal and plant that we know as coral.

Scientists from UTS and the University of Copenhagen have for the first time measured a balanced energy budget for a coral – essentially the calculation of just how efficiently the coral's symbiotic microalgae use and regulate light in coral tissue.

The partnership between the and the microscopic algae (zooxanthellae) provides the polyp with oxygen and other nutrients from photosynthesis in return for carbon dioxide and other substances the algae needs.

This new insight into the unique of coral paves the way for improved understanding of how environmental stress causes events such as and potentially how to better direct management resources.

Using innovative, advanced microsensor technology, researchers from the UTS's Plant Functional Biology and Climate Change Cluster (C3) and their University of Copenhagen collaborators measured the light energy budget of photosynthesising microalgae in coral, under healthy conditions, controlled in the laboratory.

The brain-shaped coral test species, Montastraea curta, is common to the Great Barrier Reef, inhabiting shallow reef flats. The challenging microscale approach of the research meant the team had to design an experiment that would allow them to measure light and oxygen by inserting microsensors as fine as one hundredth of a millimetre into coral tissue, in increments of a tenth of a millimetre at a time.

The results, published in the Journal of the Royal Society Interface, show that although the vast majority of light absorbed by the coral was lost as heat the microalgae actually use light highly efficiently during photosynthesis.

"This highlights the very special optical properties of corals. They appear to be very efficient light collectors and distributors," said lead author and C3 PhD candidate Kasper Elgetti Brodersen.

"This research is very timely as it strongly advances our basic concept of light and corals. We know that significant changes in local occur on a microscale, some corals are hotter and receive more light than others, although they are just next to each other.

"Using the techniques we've developed, future studies can now investigate this variability in a more detailed way, under different environmental conditions, and redirect management efforts towards the most susceptible corals."

Mr Brodersen said the study also provided further insight into the impact of elevated seawater temperatures, predicted under , on coral health.

"The large amount of energy dissipated as heat means that coral light absorption can increase the temperature in the microenvironment relative to the surrounding water, potentially aggravating bleaching events," he said.

Explore further: Clues in coral bleaching mystery

add to favorites email to friend print save as pdf

Related Stories

Clues in coral bleaching mystery

Sep 05, 2013

Coral reefs are tremendously important for ocean biodiversity, as well as for the economic and aesthetic value they provide to their surrounding communities. Unfortunately they have been in great decline in ...

Viruses linked to algae that control coral health

Jul 12, 2012

Scientists have discovered two viruses that appear to infect the single-celled microalgae that reside in corals and are important for coral growth and health, and they say the viruses could play a role in ...

Recommended for you

Chimpanzees prefer firm, stable beds

4 hours ago

Chimpanzees may select a certain type of wood, Ugandan Ironwood, over other options for its firm, stable, and resilient properties to make their bed, according to a study published April 16, 2014 in the open-access ...

Offspring benefit from mum sending the right message

12 hours ago

(Phys.org) —Researchers have uncovered a previously unforeseen interaction between the sexes which reveals that offspring survival is affected by chemical signals emitted from the females' eggs.

Lemurs match scent of a friend to sound of her voice

Apr 15, 2014

Humans aren't alone in their ability to match a voice to a face—animals such as dogs, horses, crows and monkeys are able to recognize familiar individuals this way too, a growing body of research shows.

User comments : 0

More news stories

Chimpanzees prefer firm, stable beds

Chimpanzees may select a certain type of wood, Ugandan Ironwood, over other options for its firm, stable, and resilient properties to make their bed, according to a study published April 16, 2014 in the open-access ...

Revealing camouflaged bacteria

A research team at the Biozentrum of the University of Basel has discovered an protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells. The so cal ...