Overfishing, disease, degradation by human activities, and hurricane damage have brought about a dramatic shift in the ecology of coral reefs around Jamaica and in the Caribbean, according to Greenpeace. Most of the large predatory fish species, such as sharks and snappers, have almost disappeared as have sea turtles and manatees.
Coral disease and attrition have been observed since the 1970s. During the same period scientists noticed that desertification in the northern areas of Africa was moving sand and other particulate matter across the Atlantic Ocean in the form of dust.
A dust storm swirls off the northewestern coast of Africa on February 26, 2000. Image courtesy of US Geological Survey
Aspergillis, a common fungus normally found in soil has devastated one particular species of coral, and may be connected to some human respiratory problems as well. Since 1983, when Aspergillis first appeared, it has killed more than 90 percent of the Caribbean's sea fans. That same year, an unusually dusty year, the number of Diadema sea urchins drastically declined, which, in turn, triggered algal infestations in the reefs.
"It's a veritable soup of stuff," Shinn said. These dust clouds from Africa carry literally tons of spores similar to Aspergillis. Millions of dollars have been spent researching sedimentation, sewage, pollution, ship groundings, temperature, and other coral enemies. But none of these potential killers explain why coral disease and algal infestation occur at the same time throughout the Caribbean where there is little human activity.
This healthy star coral at Grecian Rocks as it was in 1988. Image courtesy of US Geological Survey.
One early theory had blamed this demise of coral on deforestation runoff. Shinn blames dust balls. "We looked at the dust," said Shinn. "That would explain howit could be all around the Caribbean, even in areas with no forests around." In fact, scientists have determined that the African dust so harmful to coral may have an upside, since it supplies most of the essential nutrients for the rain forest.
The same coral as it appeared in 1998. Image courtesy of USGS.
It is essential that we understand the relationship between African dust and the demise of coral reefs so that we can redirect research efforts. Scientists are analyzing dust trapped in coral skeletons.
|"It is essential that we understand the relationship between African dust and the demise of coral reefs so that we can redirect research efforts."|
In the meantime, what can be done? Plans are to collect new coral cores from the Caribbean reefs in the Virgin Islands. Older coral cores, stored in a Florida laboratory, will be analyzed for any correlation with the new cores. Other microbiologists will examine fresh dust collected in the Virgin Islands for fungal and bacterial spores. "All I'm trying to do is make people aware, because most don't even think of this," said Shinn. "And it does affect people's health, no doubt about it."
For more information visit coral.aoml.noaa.gov/agra/update.html
Status of Caribbean Reefs
Since June 1998, 13 large-scale AGRRA assessments have been completed and the results are being prepared for publication. Support for the initiative has come from the The Henry Foundation, Barcardi Family Foundation, Hachette Filipacchi Foundation, National Geographic Society Committee for Research and Exploration, Ocean Research Education Foundation, United Nations Environmental Program, United States Department of Interior, and the World Bank/Netherlands Environment Partnership Program. Below are some of the highlights from these surveys.
Many reefs of the Wider Caribbean are in relatively good condition:
Selected reef areas are showing signs of disturbance and decline:
There are currently additional assessments underway in Mexico, US Virgin Islands, Saba, Belize, Curaçao, and Brazil. Goals for the AGGRA Program over the next two years include collaboration of team leaders to synthesize data for regional comparisons of reef condition, developing a regional database accessible to all, and expanding assessments to additional areas in the region. The target date for completing the assessment of the Western Atlantic and Gulf of Mexico region is the end of the year 2001. AGRRA welcomes collaboration and partnerships with individuals and organizations interested in this large-scale effort.
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