Post by LSDeep on Oct 24, 2005 9:39:43 GMT -5
Mark Meredith
Sunday, October 23rd 2005
Coral reefs across the Caribbean are undergoing a mass bleaching event which threatens life below and above the water.
In the last month, coral reefs across the Caribbean have become affected by a sudden and life-threatening bleaching epidemic brought on by sea temperature rise; the same temperatures which have unleashed a record 12 hurricanes on the region this season. Should the affected corals not recover, the long-term consequences for the Caribbean could be far more "devastating" than any number of storms.
Beneath Tobago's blue waters, out of sight and out of mind, death stalks the wondrous creations that are the island's coral reef systems. Marine cities more complex and beautiful than anything imagined on land, but which are essential to Tobago's terrestrial sustainability, are in the throes of a creeping, ghostly and possibly fatal plague-a White Death.
"Tobago's coral reefs are currently experiencing their worst mass bleaching event for many years and, according to some dive operators, the worst in living memory."
That was the warning from Dr Owen Day of the Buccoo Reef Trust last week, a few days after he had issued an alert over the internet to conservation groups and individuals requesting help in monitoring the growing coral crisis along Tobago's leeward coast, from Speyside to Crown Point.
Even more alarming was his revelation that bleaching is being reported over "the entire Caribbean region", affecting vast swathes of coral communities, including those in Panama, Cuba, Puerto Rico, Florida and Barbados. The Bajan situation was said to be "terrible".
Dr Hazel Oxenford, Senior Lecturer at the Centre for Resource Management and Environmental Studies (CERMES) at the University of the West Indies Cave Hill Campus in Barbados, told me: "We are seeing bleaching of almost all coral species on all reefs. The values (affected areas) are around 65-70 per cent for our deep reefs and up to 86 per cent for shallow reefs. Water temperatures are exceptionally high at depth and have been in excess of 30oC, even at 22 metres deep."
Owen Day, who has been personally monitoring Tobago's sea temperatures and videoing horrific scenes of an alien transformation of the rainbow-hued coral sculptures, told me: "The sea surface temperatures have been about two degrees above average for the time of year. In the last 20 years, the dramatic increases in the reported incidences of mass coral bleaching events has been undisputable. I can't understand why the international media hasn't picked up on this," he said of the Caribbean's current crisis.
In Tobago the bleaching started with fire corals losing their vibrant warning colours in early September. A few weeks later it spread to the brain corals and in October began crossing to new species, affecting many different varieties. Day said reefs on the Caribbean coast "seem particularly badly affected", notably Buccoo Reef, Mt Irvine, Arnos Vale, Culloden, Castara and Englishman's Bay. The reefs at Speyside and south of Crown Point are also showing signs of bleaching, he added. Corals appear to be affected down to a depth of about 50 feet.
When coral bleaches it does the same as your laundry and turns "brilliant white". It occurs because of environmental stress, said Day; specifically, "high or low temperatures, sediment, excessive sunlight, exposure to air, freshwater or pollutants".
Think of bleaching as the coral equivalent of HIV/AIDS: species weakened and highly vulnerable to stresses and infections. When the phenomenon happens, said Day, the corals expel their symbiotic microscopic algal cells (zooxanthellae) in response to the environmental stress. The condition turns coral colonies white as their calcium carbonate skeletons become visible through their unpigmented tissue (bleached). Day explained that zooxanthellae typically provide the coral with around 90 per cent of the energy required for a healthy life, the remaining 10 per cent being obtained from mostly nocturnal filter feeding.
But unlike today's terrestrial AIDS patients, there are no life-prolonging wonder drugs available for corals, only a death sentence once the sources of the stresses persist for more than about eight to ten weeks or so, said Day. The exact length of time it takes before they die is dependent on various factors, such as the severity of the bleaching, the type of coral species, and the depth at which they live. Corals can recover once favourable conditions return in time.
Day pointed out that this week's heavy swells through the Caribbean will have resuspended the sediment in the seawater, brought there by unsustainable land practices. When corals are bleached they are unable to produce the mucous needed to clean themselves, and they die beneath their newly-settled, grainy blanket.
They also need sunlight to survive, but that becomes temporarily filtered out by swirling silt clouds in such conditions. Cloudy water through tidal action is also exacerbated by the rainy conditions that accompany weather systems: surging outflows of silt and polluted run-off from the land.
The importance and fragility of coral reefs cannot be overstated: they cover just 0.02 per cent of our planet's entire ocean floor-but a quarter of all known marine species call them home. A reason, no doubt, why Dr Oxenford was "very happy" someone was reporting this "Caribbean-wide mass bleaching event".
She told me: "It certainly will have some devastating consequences if the coral we are seeing bleached now, does not recover. We are hoping against hope that it will, but the longer it remains bleached the greater the chance of widespread coral mortality.
"Of course, if the living hard corals die, then the reef structures (built by living hard corals) will continue to erode without repair and will become less and less effective in protection of our coastlines, production of white sand for our beaches, and in harbouring a myriad of coral reef fish species, many of which are of commercial importance to fisheries," she said.
"The economic consequences will be severe-with huge implications for tourism (loss of beaches, loss of quality snorkelling and diving); for coastal property owners (reduced natural protection, coastal erosion, loss of beach sand); and for fishers (loss of livelihood for coastal reef fishers). There will also be a loss of recreational opportunity and aesthetic value; a huge loss in biodiversity and increased vulnerability to other impacts of climate change such as sea level rise and increased severity of storms,"she warned.
Well before this bleaching event became evident, the stresses to Caribbean coral reefs had already become a wholly Caribbean-made epidemic through human activities; specifically, "land-based sources of pollution", often from the very tourism industry that profits from such attractions.
The Washington-based World Resources Institute have a map of threatened Caribbean reefs. The threat levels are illustrated as orange for "high" and red for "very high". The overall impression is of a region with coastlines painted like sunsets.
Two thirds of Caribbean coral reefs are under threat from humans, said the Institute in their 2004 publication "Reefs at Risk in the Caribbean". They advised: "Coral reefs are extremely important to the economies of Caribbean countries today, and they are the capital stock for future economic and political security ... Ensuring the vitality of the coral reefs and their ability to continue providing benefits to society is critically important ."
The Institute also warns of overfishing, leading to a change in the reefs' ecological balance; and of "poorly understood coral diseases that have spread rapidly throughout the region, devastating some of the main reef-building corals".
Many scientists concur that the major cause of bleaching is not Caribbean-made at all. It is the global pandemic to end all pandemics-Climate Change-in this case abnormal sea temperatures. While Caribbean nations alone cannot halt Climate Change, they can lessen the chances of the AIDS-like bleaching condition from becoming terminal , preventing land-based sources of pollution.
"Barbados is very aware of the importance of its reefs," said Oxenford. "It's put a great deal of effort (and money) over the last decade or so into mitigation of negative impacts on coastal water quality to ensure coral reef health. This includes sewage treatment, strict coastal building practices, effluent standards, and watercourse/coastal zone management."
"Also, direct protection is given through fisheries legislation which makes coral harvesting illegal island wide, and forbids the use of destructive fishing practices such as dynamite and use of toxins. Other efforts include the installation of mooring buoys and designated anchoring areas to prevent physical damage.
Like most islands, "improved agricultural practises to prevent soil erosion and pesticide contamination, and better drainage management to prevent land water runoff, needed attention", she added.
In Tobago's case, the Buccoo Reef Trust (BRT) isn't prepared to wait for the life-enhancing, self-administered medicine the island needs to save itself. It has formed an alliance with UK-based Coral Cay Conservation (CCC), a non-profit organisation based in the UK with "extensive experience in coral reef monitoring worldwide". They have offered to send out a team of four experienced divers to Tobago in mid-October to help establish and implement a bleaching monitoring programme.
Owen Day has sent a proposal to the Tobago House of Assembly (THA) for the monitoring programme called "Urgent Assistance for Monitoring of Coral Bleaching Event in Tobago", that BRT would coordinate. The THA have agreed to assist by providing some of the required funding for the immediate surveys, and a collaborative project is now being planned. But, "additional assistance will be required to fully assess the medium and long-term mortality associated with this bleaching event", Day said.
BRT's project aims to provide stakeholders with the "relevant information for the management and protection of Tobago's coral reefs". "In particular, the project will highlight the need to improve the management of Tobago's watersheds and coastal areas in order to reduce pollution and sedimentation - issues that are currently threatening the sustainability of the island's tourism industry," they say.
They want to find out the extent and severity of the bleaching; what the prospects are of medium and long-term recovery of the corals; and the effects of additional stresses of sedimentation and sewage pollution. BRT say it is essential to improve awareness "among all stakeholders of coral bleaching and other issues related to the conservation of Tobago's coral reefs".
As Day admitted, monitoring is all very well, but what really matters is action to reverse the human impacts. Deeds to defy the death sentence. The Caribbean bleaching event, he said, "is a dramatic reminder of the mantra of the environmental movement-'Think Globally and Act Locally'."
source: www.trinidadexpress.com/index.pl/article_news?id=110478347
Sunday, October 23rd 2005
Coral reefs across the Caribbean are undergoing a mass bleaching event which threatens life below and above the water.
In the last month, coral reefs across the Caribbean have become affected by a sudden and life-threatening bleaching epidemic brought on by sea temperature rise; the same temperatures which have unleashed a record 12 hurricanes on the region this season. Should the affected corals not recover, the long-term consequences for the Caribbean could be far more "devastating" than any number of storms.
Beneath Tobago's blue waters, out of sight and out of mind, death stalks the wondrous creations that are the island's coral reef systems. Marine cities more complex and beautiful than anything imagined on land, but which are essential to Tobago's terrestrial sustainability, are in the throes of a creeping, ghostly and possibly fatal plague-a White Death.
"Tobago's coral reefs are currently experiencing their worst mass bleaching event for many years and, according to some dive operators, the worst in living memory."
That was the warning from Dr Owen Day of the Buccoo Reef Trust last week, a few days after he had issued an alert over the internet to conservation groups and individuals requesting help in monitoring the growing coral crisis along Tobago's leeward coast, from Speyside to Crown Point.
Even more alarming was his revelation that bleaching is being reported over "the entire Caribbean region", affecting vast swathes of coral communities, including those in Panama, Cuba, Puerto Rico, Florida and Barbados. The Bajan situation was said to be "terrible".
Dr Hazel Oxenford, Senior Lecturer at the Centre for Resource Management and Environmental Studies (CERMES) at the University of the West Indies Cave Hill Campus in Barbados, told me: "We are seeing bleaching of almost all coral species on all reefs. The values (affected areas) are around 65-70 per cent for our deep reefs and up to 86 per cent for shallow reefs. Water temperatures are exceptionally high at depth and have been in excess of 30oC, even at 22 metres deep."
Owen Day, who has been personally monitoring Tobago's sea temperatures and videoing horrific scenes of an alien transformation of the rainbow-hued coral sculptures, told me: "The sea surface temperatures have been about two degrees above average for the time of year. In the last 20 years, the dramatic increases in the reported incidences of mass coral bleaching events has been undisputable. I can't understand why the international media hasn't picked up on this," he said of the Caribbean's current crisis.
In Tobago the bleaching started with fire corals losing their vibrant warning colours in early September. A few weeks later it spread to the brain corals and in October began crossing to new species, affecting many different varieties. Day said reefs on the Caribbean coast "seem particularly badly affected", notably Buccoo Reef, Mt Irvine, Arnos Vale, Culloden, Castara and Englishman's Bay. The reefs at Speyside and south of Crown Point are also showing signs of bleaching, he added. Corals appear to be affected down to a depth of about 50 feet.
When coral bleaches it does the same as your laundry and turns "brilliant white". It occurs because of environmental stress, said Day; specifically, "high or low temperatures, sediment, excessive sunlight, exposure to air, freshwater or pollutants".
Think of bleaching as the coral equivalent of HIV/AIDS: species weakened and highly vulnerable to stresses and infections. When the phenomenon happens, said Day, the corals expel their symbiotic microscopic algal cells (zooxanthellae) in response to the environmental stress. The condition turns coral colonies white as their calcium carbonate skeletons become visible through their unpigmented tissue (bleached). Day explained that zooxanthellae typically provide the coral with around 90 per cent of the energy required for a healthy life, the remaining 10 per cent being obtained from mostly nocturnal filter feeding.
But unlike today's terrestrial AIDS patients, there are no life-prolonging wonder drugs available for corals, only a death sentence once the sources of the stresses persist for more than about eight to ten weeks or so, said Day. The exact length of time it takes before they die is dependent on various factors, such as the severity of the bleaching, the type of coral species, and the depth at which they live. Corals can recover once favourable conditions return in time.
Day pointed out that this week's heavy swells through the Caribbean will have resuspended the sediment in the seawater, brought there by unsustainable land practices. When corals are bleached they are unable to produce the mucous needed to clean themselves, and they die beneath their newly-settled, grainy blanket.
They also need sunlight to survive, but that becomes temporarily filtered out by swirling silt clouds in such conditions. Cloudy water through tidal action is also exacerbated by the rainy conditions that accompany weather systems: surging outflows of silt and polluted run-off from the land.
The importance and fragility of coral reefs cannot be overstated: they cover just 0.02 per cent of our planet's entire ocean floor-but a quarter of all known marine species call them home. A reason, no doubt, why Dr Oxenford was "very happy" someone was reporting this "Caribbean-wide mass bleaching event".
She told me: "It certainly will have some devastating consequences if the coral we are seeing bleached now, does not recover. We are hoping against hope that it will, but the longer it remains bleached the greater the chance of widespread coral mortality.
"Of course, if the living hard corals die, then the reef structures (built by living hard corals) will continue to erode without repair and will become less and less effective in protection of our coastlines, production of white sand for our beaches, and in harbouring a myriad of coral reef fish species, many of which are of commercial importance to fisheries," she said.
"The economic consequences will be severe-with huge implications for tourism (loss of beaches, loss of quality snorkelling and diving); for coastal property owners (reduced natural protection, coastal erosion, loss of beach sand); and for fishers (loss of livelihood for coastal reef fishers). There will also be a loss of recreational opportunity and aesthetic value; a huge loss in biodiversity and increased vulnerability to other impacts of climate change such as sea level rise and increased severity of storms,"she warned.
Well before this bleaching event became evident, the stresses to Caribbean coral reefs had already become a wholly Caribbean-made epidemic through human activities; specifically, "land-based sources of pollution", often from the very tourism industry that profits from such attractions.
The Washington-based World Resources Institute have a map of threatened Caribbean reefs. The threat levels are illustrated as orange for "high" and red for "very high". The overall impression is of a region with coastlines painted like sunsets.
Two thirds of Caribbean coral reefs are under threat from humans, said the Institute in their 2004 publication "Reefs at Risk in the Caribbean". They advised: "Coral reefs are extremely important to the economies of Caribbean countries today, and they are the capital stock for future economic and political security ... Ensuring the vitality of the coral reefs and their ability to continue providing benefits to society is critically important ."
The Institute also warns of overfishing, leading to a change in the reefs' ecological balance; and of "poorly understood coral diseases that have spread rapidly throughout the region, devastating some of the main reef-building corals".
Many scientists concur that the major cause of bleaching is not Caribbean-made at all. It is the global pandemic to end all pandemics-Climate Change-in this case abnormal sea temperatures. While Caribbean nations alone cannot halt Climate Change, they can lessen the chances of the AIDS-like bleaching condition from becoming terminal , preventing land-based sources of pollution.
"Barbados is very aware of the importance of its reefs," said Oxenford. "It's put a great deal of effort (and money) over the last decade or so into mitigation of negative impacts on coastal water quality to ensure coral reef health. This includes sewage treatment, strict coastal building practices, effluent standards, and watercourse/coastal zone management."
"Also, direct protection is given through fisheries legislation which makes coral harvesting illegal island wide, and forbids the use of destructive fishing practices such as dynamite and use of toxins. Other efforts include the installation of mooring buoys and designated anchoring areas to prevent physical damage.
Like most islands, "improved agricultural practises to prevent soil erosion and pesticide contamination, and better drainage management to prevent land water runoff, needed attention", she added.
In Tobago's case, the Buccoo Reef Trust (BRT) isn't prepared to wait for the life-enhancing, self-administered medicine the island needs to save itself. It has formed an alliance with UK-based Coral Cay Conservation (CCC), a non-profit organisation based in the UK with "extensive experience in coral reef monitoring worldwide". They have offered to send out a team of four experienced divers to Tobago in mid-October to help establish and implement a bleaching monitoring programme.
Owen Day has sent a proposal to the Tobago House of Assembly (THA) for the monitoring programme called "Urgent Assistance for Monitoring of Coral Bleaching Event in Tobago", that BRT would coordinate. The THA have agreed to assist by providing some of the required funding for the immediate surveys, and a collaborative project is now being planned. But, "additional assistance will be required to fully assess the medium and long-term mortality associated with this bleaching event", Day said.
BRT's project aims to provide stakeholders with the "relevant information for the management and protection of Tobago's coral reefs". "In particular, the project will highlight the need to improve the management of Tobago's watersheds and coastal areas in order to reduce pollution and sedimentation - issues that are currently threatening the sustainability of the island's tourism industry," they say.
They want to find out the extent and severity of the bleaching; what the prospects are of medium and long-term recovery of the corals; and the effects of additional stresses of sedimentation and sewage pollution. BRT say it is essential to improve awareness "among all stakeholders of coral bleaching and other issues related to the conservation of Tobago's coral reefs".
As Day admitted, monitoring is all very well, but what really matters is action to reverse the human impacts. Deeds to defy the death sentence. The Caribbean bleaching event, he said, "is a dramatic reminder of the mantra of the environmental movement-'Think Globally and Act Locally'."
source: www.trinidadexpress.com/index.pl/article_news?id=110478347
- 87-88F here (just a scant few miles away from the BVIs too 
) Several beautiful reefa have that red and algae as well - choking off the coral