A view of a coral polyp show the Symbiodinium (highlighed green)
A view of a coral polyp show the Symbiodinium (highlighed green). (c) ARC Centre of Excellence for Coral Reef
Environment
Study of wolves will help scientists predict climate effects on endangered animals — Scientists studying populations of grey wolves in the USA's Yellowstone National Park have developed a way to predict how changes in the environment will impact on the animals' number,…
Climate sensitivity to CO2 more limited than extreme projections — A new study suggests that the rate of global warming from doubling of atmospheric carbon dioxide may be less than the most dire estimates of some previous studies - and, in fact, may…
Saving Da Vinci's Last Supper from air pollution — Having survived long centuries, political upheaval, and even bombings during World War II, Leonardo Da Vinci's masterpiece Last Supper now faces the risk of damage from air pollution…
After 25 years, sustainability is a growing science that's here to stay — Sustainability has not only become a science in the past 25 years, but it is one that continues to be fast-growing with widespread international collaboration, broad disciplinary composition…
Markets drive conservation in Central Africa — Certification has shown that commercial forestry can co-exist with conservation objectives in the Congo Basin, according to conclusions reached at an international seminar 'Forest management…
Great Plains river basins threatened by pumping of aquifers — Suitable habitat for native fishes in many Great Plains streams has been significantly reduced by the pumping of groundwater from the High Plains aquifer - and scientists analysing…
Rivers may aid climate control in cities — Speaking at the URSULA (Urban River Corridors and Sustainable Living Agendas) Conference, in Sheffield, Dr Abigail Hathway, of the University of Sheffield, will demonstrate how rivers…
Vultures dying at alarming rate — Vultures in South Asia were on the brink of extinction until Lindsay Oaks and Richard Watson, from The Peregrine Fund in the US, undertook observational and forensic studies to find…
Predicting future threats for global amphibian biodiversity — Amphibian populations are declining worldwide, and their declines far exceed those of other animal groups: more than 30% of all species are listed as threatened according to the Red…
Study shows deforestation causes cooling — Deforestation, considered by scientists to contribute significantly to global warming, has been shown by a Yale-led team to actually cool the local climate in northern latitudes, according…
Where am I? > Home > News > Environment

Weird engine of the reef revealed

Science Centric | 31 August 2007 13:59 GMT
Printable version A clip for your blog or website E-mail the story to a friend
Bookmark or share the story on your social network Vote for this article Decrease text size Increase text size
DON'T MISS —
Smarter energy storage for solar and wind power
Smarter energy storage for solar and wind power — CSIRO and Cleantech Ventures have invested in technology start-up Smart Storage Pty Ltd to develop and commercialise battery-based…
Wildfire letdowns and wake-up calls
Wildfire letdowns and wake-up calls — With damage estimates at more than $1 billion following recent October wildfires in the state of California, an important…
More Environment

A team of coral researchers has taken a major stride towards revealing the workings of the mysterious 'engine' that drives Australia's Great Barrier Reef, and corals the world over. The science has critical importance in understanding why coral reefs bleach and die, how they respond to climate change - and how that might affect humanity, they say.

Scientists at the ARC Centre of Excellence for Coral Reef Studies, James Cook University and the University of Queensland have compiled the world's first detailed gene expression library for Symbiodinium, the microscopic algae that feed the corals - and so provide the primary energy source for the entire Reef.

'Symbiodinium uses sunlight to convert CO2 into carbohydrates for the corals to feed on. At the same time there's evidence the corals control its output, suggesting that they are farming their captive plants' Professor David Yellowlees explains. 'But these microscopic algae are quite weird and unlike any other life form. They have different photosynthetic machinery from all other light harvesting organisms. They have 100 times more DNA than we do and we have no idea why such a small organism needs so much. They really are like no other living creature we know.

This is echoed by team member Prof. Ove Hoegh-Guldberg who comments it is 'like no other organism on planet,' jokingly labelling it 'like an alien.'

This strange beast not only rules the fate of the world's coral reefs - it also plays a significant role in soaking up carbon dioxide from the atmosphere, turning it into nourishment for the corals and powering calcification. Its decline would not only kill the reefs but accelerate CO2 buildup.

Dr Bill Leggat says the team has focused particularly on understanding the biochemical relationship between Symbiodinium and corals when they are stressed by heat, light, increased CO2 levels and pollutants from land run-off.

These stressful conditions cause corals to 'bleach' by expelling the Symbiodinium and - if they do not recover them within a few days - the corals die. Large-scale bleaching struck half of the Great Barrier Reef in 2002, and eight major bleaching episodes have been reported worldwide in the last 30 years due to warming sea water.

'Our aim is to identify the genes that make the symbiotic plants susceptible to these stresses, and lead to the coral expelling them,' Dr Leggat says.

In experiments at Heron Island Research Station they exposed corals to various stresses associated with climate change and then analysed the gene composition in the symbiotic algae. Another team analysed the effects in corals.

Working together and using the powerful micro-array technology, they hope to assemble a picture of the 'chemical conversation' that goes on between the corals and its symbiotic plants that leads to a breakdown in the relationship, a divorce - and the corals starving themselves to death.

'An example of the challenge we face is the gene which is expressed the most when Symbiodinium is stressed. It's obviously important - but at this stage we have no idea what it does. It is even stranger when you consider that this gene was originally acquired from a bacterium' Prof. Yellowlees says.

So far the team has identified about 4500 genes in Symbiodinium, compiling them into the world's first gene expression library for this symbiotic organism. It is hoped this will have value for understanding other symbiotic relationships in nature.

Symbiodinium is part of a larger group of organisms called dinoflagellates, responsible for events like red tides and ciguatera poisoning. Together, the dinoflagellates process about one third of all CO2 entering the oceans - and are thus vital players in helping to remove CO2 from the atmosphere. Understanding how they function will help fill in one of the critical gaps in our understanding of climate change - how much CO2 the oceans can trap and how this will affect ultimate climate change.

Details of the team's research findings will be published in the Journal of Phycology later this year.

Source: ARC Centre of Excellence in Coral Reef Studies


Leave a comment
The details you provide on this page [e-mail address] will not be used to send unsolicited e-mail, and will not be supplied to a third party! Please note that we can not promise to give everyone a response. Comments are fully moderated. Once approved they will be posted within 24 hours.
Expand the form to leave a comment

RSS FEEDS, NEWSLETTER
Find the topic you want. Science Centric offers several RSS feeds for the News section.

Or subscribe for our Newsletter, a free e-mail publication. It is published practically every day.

Water and climate: making the linkWater and climate: making the link

— Australia's leading scientists in climate change and water research will meet in Canberra tomorrow and Friday to discuss the consequences of climate change on Australia's…

Sustainability expert available to discuss the new initiative of Bill Clinton with Wal-MartSustainability expert available to discuss the new initiative of Bill Clinton with Wal-Mart

— Tom Kelly, director of the Office of Sustainability at the University of New Hampshire, is available to discuss Bill Clinton's new initiative with Wal-Mart to make…

New NASA satellite images from California firesNew NASA satellite images from California fires

— NASA satellites continue to capture remarkable new images of the wildfires raging in Southern California. At least 14 massive fires are reported to have scorched…

Carbon sink slowdown contributing to rapid growth in atmospheric CO2Carbon sink slowdown contributing to rapid growth in atmospheric CO2

— There has been a decline in the efficiency of natural land and ocean sinks which soak up carbon dioxide (CO2) emitted to the atmosphere by human activities, according…

Popular tags in Environment: climate · ecosystem · nitrogen · pollution