27 May 2007Trinidad Express
The bleaching of corals due to climate change may result in global economic losses of up to US$104.8 billion over the next 50 years, or 0.23 per cent of current global GDP.
These losses will occur in coral reef-dependent industries and services such as tourism and fisheries as well as shoreline protection and medicinal plants.
The findings were revealed by the World Conservation Union (IUCN), at the United Nations conference on climate change in November 2006.
"Mass coral bleaching events will have similar consequences on the lives of people as droughts and oil spills and require a similar response. This scenario is but one example of how people's lives may be threatened through climate change impacts on our environment," said Australian Senator and IUCN Vice President Christine Milne.
Milne said mass coral bleaching due to global warming has affected hundreds to thousands of kilometres of reefs simultaneously.
"It has caused stress, and in many cases extensive coral mortality, to nearly every coral reef region in the world. In 1997-98 alone, mass bleaching is estimated to have caused over 90 per cent coral mortality to 16 per cent of the world's coral reefs (Wilkinson 2002)," she said.
Milne noted analyses of coral reefs in the wider Caribbean region confirm major reef declines and they do not resemble the reefs of 30 years ago.
Milne added that phase shifts where a reef goes from coral dominated to algal dominated have already been documented in the 1990's by scientists studying the Caribbean (Hughes 1994).
"A distinct shift in fish community composition is likely as there will be an increase in herbivores, which benefit from enhanced algal growth on the dead corals and a decrease in fish that are heavily dependent on coral for food (coral polyps) or shelter (structural complexity) such as butterfly fish, gobies and blennies," she said.
The IUCN along with The Nature Conservancy (TNC) have released a report entitled "Coral Reef Resilience and Resistance to Bleaching" which shows that the fate of corals may not yet be sealed.
Milne said the guide is designed to provide pragmatic, science-based suggestions for adaptive management in time of change.
"Scientists agree that tropical seas will continue to warm over coming decades, increasing both the probability and severity of sea level rise, storms and mass bleaching events (Hughes et al. 2003)," she explained.
