Alonzo
06-19-2006, 09:42 AM
SYDNEY (AFP) - Coral reefs have suffered more damage since the 1970s than any time in the last 220,000 years, according to a study that warns of the threats of overfishing and coastal development.
Scientists from Australia found that coral reefs in the Caribbean island of Barbados were unchanged over tens of thousands of years, despite rising and falling sea levels.
But according to the paper published in the science journal "Ecology Letters," modern day reefs are now startlingly different and dominated by different species of coral.
Associate Professor John Pandolfi, of the Australian Research Council's Centre of Excellence for Coral Reef Studies, said that human activity had made reefs far more susceptible to change.
"Our biggest fear is that humans have pushed them to a completely different state where they are far more vulnerable to change than ever before. We have to be on guard," said Pandolfi, who led the study.
"There is evidence of very dramatic difference over the last 30 years," he told AFP.
Pandolfi studied the preserved remains of entire coral reef communities that lived in the Caribbean up to 220,000 years ago.
He analyzed four periods in the reef's history, when geological activity pushed it to the surface and wiped out the coral community.
Each time, the sea floor was recolonized and the coral reef returned in a very similar structure with the same species.
But since the 1970s the Elkhorn coral that once dominated the reef has virtually disappeared and algae and seaweed have taken over, he said.
Overfishing was partly to blame, as there were no longer enough large fish and turtles to eat the algae.
Coastal development -- such as destroying forests for sugar cane plantations and other agriculture -- had also impacted on the reef as increased levels of nutrients in the water favoured the algae, he added.
"This study is a warning bell that if Australia is not proactive in its coral reef management we will see similar changes in the Great Barrier Reef," Pandolfi said.
"If our reefs are going to survive the impacts of climate change, they have to be at the peak of their health."
Coral reefs have been experiencing a global decline that scientists attribute to a combination of pollution, destructive fishing and global warming.
One of the worst dangers is bleaching, caused when the plant-like organisms which make up coral die and leave behind the white limestone skeleton on the reef.
A rise in coral bleaching has been linked to global warming, but scientists are still trying to fully understand the phenomenon.
Pandolfi told AFP that damage to coral reefs would have an impact on nations that depend on them for food and the natural protection they offer from storms.
Damage to the Great Barrier Reef could also have an impact on a tourism market worth 5 billion Australian dollars (US 3.68 billion) a year, he added.
Stretching over more than 345,000 square kilometers (133,000 sq miles) off Queensland's coast, the reef is the world's biggest coral system and the marine park there has been listed by the United Nations as a World Heritage site.
The centre of excellence is a partnership between Australia's James Cook University, the Australian Institute of Marine Science, The Australian National University, the
http://news.yahoo.com/s/afp/20060619/sc_afp/australiaenvironmentreefsdamage_060619053946;_ylt= Aqe936raf0cFZRF2Xob6ymGs0NUE;_ylu=X3oDMTA3MzV0MTdm BHNlYwM3NTM-
Scientists from Australia found that coral reefs in the Caribbean island of Barbados were unchanged over tens of thousands of years, despite rising and falling sea levels.
But according to the paper published in the science journal "Ecology Letters," modern day reefs are now startlingly different and dominated by different species of coral.
Associate Professor John Pandolfi, of the Australian Research Council's Centre of Excellence for Coral Reef Studies, said that human activity had made reefs far more susceptible to change.
"Our biggest fear is that humans have pushed them to a completely different state where they are far more vulnerable to change than ever before. We have to be on guard," said Pandolfi, who led the study.
"There is evidence of very dramatic difference over the last 30 years," he told AFP.
Pandolfi studied the preserved remains of entire coral reef communities that lived in the Caribbean up to 220,000 years ago.
He analyzed four periods in the reef's history, when geological activity pushed it to the surface and wiped out the coral community.
Each time, the sea floor was recolonized and the coral reef returned in a very similar structure with the same species.
But since the 1970s the Elkhorn coral that once dominated the reef has virtually disappeared and algae and seaweed have taken over, he said.
Overfishing was partly to blame, as there were no longer enough large fish and turtles to eat the algae.
Coastal development -- such as destroying forests for sugar cane plantations and other agriculture -- had also impacted on the reef as increased levels of nutrients in the water favoured the algae, he added.
"This study is a warning bell that if Australia is not proactive in its coral reef management we will see similar changes in the Great Barrier Reef," Pandolfi said.
"If our reefs are going to survive the impacts of climate change, they have to be at the peak of their health."
Coral reefs have been experiencing a global decline that scientists attribute to a combination of pollution, destructive fishing and global warming.
One of the worst dangers is bleaching, caused when the plant-like organisms which make up coral die and leave behind the white limestone skeleton on the reef.
A rise in coral bleaching has been linked to global warming, but scientists are still trying to fully understand the phenomenon.
Pandolfi told AFP that damage to coral reefs would have an impact on nations that depend on them for food and the natural protection they offer from storms.
Damage to the Great Barrier Reef could also have an impact on a tourism market worth 5 billion Australian dollars (US 3.68 billion) a year, he added.
Stretching over more than 345,000 square kilometers (133,000 sq miles) off Queensland's coast, the reef is the world's biggest coral system and the marine park there has been listed by the United Nations as a World Heritage site.
The centre of excellence is a partnership between Australia's James Cook University, the Australian Institute of Marine Science, The Australian National University, the
http://news.yahoo.com/s/afp/20060619/sc_afp/australiaenvironmentreefsdamage_060619053946;_ylt= Aqe936raf0cFZRF2Xob6ymGs0NUE;_ylu=X3oDMTA3MzV0MTdm BHNlYwM3NTM-