Coral stress 'like never in history'

Dec 13, 2006

Large scale coral die-offs are now occurring more frequently than at any time in the last 11 000 years, according to a new study by Australian-based scientists.

Investigations by Associate Professor John Pandolfi, of the ARC Centre of Excellence in Coral Reef Studies and The University of Queensland, of fossilized reefs in Papua New Guinea show how often the reefs were ‘wiped out’ by disastrous events in past times.

"What we found was in stark contrast to what we see in the modern day," says Ass. Prof. Pandolfi. "The frequency of reef [die-off] events in the fossils is at least an order of magnitude less than it is today," he says.

Studying the fossil reefs of the Huon Peninsula, which are now cliff faces rising up to 25 metres above the beach, A/Prof. Pandolfi and his team were able to see where large scale disturbances had occurred in the history of these reefs which dated back as far as 11 000 years ago.

"The sequence of fossils is like a three dimensional movie of what happened in the reefs’ past," says Pandolfi.

Over the 6000 years recorded in the fossil strata the team found 4 devastating events which resulted in the death of most of the reef – indicating such events had occurred about once every 1500 years.

"The cause of some of these events was volcanic, but others may have been due to bleaching, disease, or something else - we just don’t know. Regardless, what is clear is that the frequency of die-off was so much lower than it is today," says Pandolfi of his findings.

The results, published in the scientific journal ‘Geology’, sound a warning bell to modern day reef management practices as today’s reefs face more stress than ever.

But while the ancient reefs warn that we are seeing abnormal die-off rates, they also show that the reefs of the past recovered rapidly after these events, taking as little as 100 years to be repopulated by the corals that normally occurred there.

Although they are struck by more high impact events, some of today’s reefs are still proving to be able to ‘bounce back’ to good health – with a little help.

"The recovery of the Great Barrier Reef from the devastating impact of the crown of thorns starfish took less than a few decades, at least in part due to comprehensive reef management," says Pandolfi,"…but this rate of recovery isn’t seen in other parts of the world….some reefs still haven’t recovered from [events in the last century]," he says.

With the help of the ARC Centre of Excellence in Coral Reef Studies, A/Prof. Pandolfi plans to continue studying fossil coral reefs around the world in order to help build a bigger picture of how the world’s reefs have survived devastation in the past – so that managers can help them continue to survive into the future.

Source: James Cook University

Explore further: Predicting bioavailable cadmium levels in soils

add to favorites email to friend print save as pdf

Related Stories

Reef fish arrived in two waves

Apr 10, 2014

(Phys.org) —The world's reefs are hotbeds of biological diversity, including over 4,500 species of fish. A new study shows that the ancestors of these fish colonized reefs in two distinct waves, before ...

Dissolving the future of coral reefs

Apr 10, 2014

Swimming through the liquid turquoise waters off the island of Viti Levu, Fiji, I am surrounded by iridescent fish of all colors, schooling around healthy branching corals. With a slight movement of my fins ...

Sydney switches off for Earth Hour

Mar 29, 2014

Sydney's Opera House and Harbour Bridge plunged into darkness Saturday for the Earth Hour environmental campaign, among the first landmarks around the world to dim their lights for the event.

Recommended for you

Predicting bioavailable cadmium levels in soils

17 hours ago

New Zealand's pastoral landscapes are some of the loveliest in the world, but they also contain a hidden threat. Many of the country's pasture soils have become enriched in cadmium. Grasses take up this toxic heavy metal, ...

Oil drilling possible 'trigger' for deadly Italy quakes

21 hours ago

Italy's Emilia-Romagna region on Tuesday suspended new drilling as it published a report that warned that hydrocarbon exploitation may have acted as a "trigger" in twin earthquakes that killed 26 people in ...

Snow is largely a no-show for Iditarod Trail Sled Dog Race

21 hours ago

On March 1, 65 mushers and their teams of dogs left Anchorage, Alaska, on a quest to win the Iditarod—a race covering 1,000 miles of mountain ranges, frozen rivers, dense forest, tundra and coastline. According ...

UN weather agency warns of 'El Nino' this year

22 hours ago

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

Study shows less snowpack will harm ecosystem

22 hours ago

(Phys.org) —A new study by CAS Professor of Biology Pamela Templer shows that milder winters can have a negative impact both on trees and on the water quality of nearby aquatic ecosystems, far into the warm growing season.

User comments : 0

More news stories

Warm US West, cold East: A 4,000-year pattern

Last winter's curvy jet stream pattern brought mild temperatures to western North America and harsh cold to the East. A University of Utah-led study shows that pattern became more pronounced 4,000 years ago, ...

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

Making 'bucky-balls' in spin-out's sights

(Phys.org) —A new Oxford spin-out firm is targeting the difficult challenge of manufacturing fullerenes, known as 'bucky-balls' because of their spherical shape, a type of carbon nanomaterial which, like ...