[Coral-List] Has the death of the Great Barrier Reef been greatly, exaggerated??

[Eugene Shinn]

I recall that coring and seismic profiling showed the linear  great 
barrier reef (like the outer reef in the Florida Keys) is quite thin 
(only a few meters) and underlain is by terrigenous sediment. Like the 
Florida reef tract it has only been submerged for between 6 and 7 
thousand years (not 25 million years as the article states). The barrier 
reefs has been in and out of water many times during the past 25 million 
years and suffered mortality each time it was left high and dry.  The 
present reef was dry land between 6 and 7 thousand years ago. The 
thickest coral accumulations are the patch reefs (composed of corals and 
Halimeda) that lie in the deeper lagonal area landward of the great 
barrier reef. Same is true in the Florida Keys. Our USGS Fisher Island 
group presented a paper  titled /Autopsy of a Dead Reef/ at the annual 
SEPM meeting in the 1970s. It was about Hens and Chickens reef in the 
Keys which had suffered near total mortality caused by a cold front 
during the winter of 1969-70. The time of death was clearly preserved in 
annual growth bands of both living and dead coral heads. One may wonder 
if similar periodic paleo cold fronts  kept the linear outer reef in 
check during the previous 6,000 years. Gene

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No Rocks, No Water, No Ecosystem (EAS)
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E. A. Shinn, Courtesy Professor
University of South Florida
College of Marine Science Room 221A
140 Seventh Avenue South
St. Petersburg, FL 33701
<eugeneshinn at mail.usf.edu>
Tel 727 553-1158
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