[Coral-List] Coral Immortality

Eugene Shinn eshinn at marine.usf.edu
Tue Mar 15 13:12:48 EDT 2011

Dear Coral-Listers, Here is a stimulating break from the incessant 
job advertisements. See 
<http://planetearth.nerc.ac.uk/news/story.aspx?id=907>  It is 
interesting because the vast majority of head corals in the Florida 
Keys suffered mortality over the past 35 years, especially during the 
1980s at places like once-thriving Carysfort reef where there were 
hundreds in the 200 to 300 year-old range. More than a dozen of the 
living Montastrea sp heads there were cored and their growth rates 
measure and published by Hudson (1981). In addition brain corals also 
perished or are hanging on by a thread (see 
<http://gallery.usgs.gov/videos/334>). It is interesting to note that 
similar head corals grew during the Pleistocene and built the Florida 
keys when sea level was more than 20 ft higher than today. 
Interestingly those heads that built the reef grew no larger than 
those that recently died in the Florida Keys. Why do we not see head 
corals that grew 15 to-20-feet in height (or even 50 ft) back when 
there were no anthropomorphic influences? Does it mean corals are not 
immortal? Could it mean that corals die of old age like all other 
organisms on earth and we just happen to be living at the right time 
to observe the current age class of geriatrics demise?  Is that why 
more than 95 percent of what we call the Florida reef tract is less 
than 1 meter thick when it had the past 6 to 7,000 years to grow? I'm 
sure there are those who think today's corals should be immortal but 
why weren't they immortal in the past? Just something to think about! 

Reference: Hudson, J. H., 1981, Growth rates in Montastraea 
annularis, a record of environmental change in the Key Largo Coral 
Reef Marine Sanctuary, Florida. Bulletin of Marine Science, v. 31, 
pp. 444-459


No Rocks, No Water, No Ecosystem (EAS)
------------------------------------ -----------------------------------
E. A. Shinn, Courtesy Professor
University of South Florida
Marine Science Center (room 204)
140 Seventh Avenue South
St. Petersburg, FL 33701
<eshinn at marine.usf.edu>
Tel 727 553-1158---------------------------------- 

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