[Coral-List] Acropora recovery?

Eugene Shinn eshinn at marine.usf.edu
Wed Jan 25 14:18:43 EST 2012

The request for information on Acropora recovery caught my attention 
since I have been observing and photographing selected spots in the 
Florida Keys since 1960. You can get a sense of this at 
<http://gallery.usgs.gov/videos/334> Last summer I brought the count 
up to 51 years of observation. The photographic survey at my two main 
sites did not show  improvement. However, while cruising down the 
reef tract and ending at Dry Tortugas I made several stops and was 
surprised to see healthy clumps of Acropora cervicornis in a few 
places, especially the lower keys, where I did not expect to see any. 
I suspect , and hope, a recovery is taking place but can offer no 
statistical evidence. I will be doing the same cruise in the summer 
of 2012 and will be watching more critically. It would be great to 
document recovery at Grecian Rocks and Carysfort. Many of you know I 
have suggested that the 30 year decline is a natural cycle. That 
hypothesis is based on C14 analysis of buried A. cervicornis  that 
indicate two periods of  A. cervicornis absence during the past 6,000 
years. (Shinn, E.A., Reich, C.D., Hickey, T.D., and Lidz, B.H., 2003, 
Staghorn tempestites in the Florida Keys: Coral Reefs, v. 22, p. 
91-97.). One approximately 500-year hiatus is centered at 4,500 years 
before present and another is centered around  3,000 ybp. Earlier 
work (based on coring) also showed that death of the A. palmata that 
created the spurs at Molasses reef occurred over 1,000 years ago. At 
Looe Key the die-off was around 3.000 ybp. Those die-offs have long 
been attributed to rising sea level and creation of the tidal passes 
that allowed inundation of the lower keys reefs by muddy 
variable-temperature waters from Florida Bay and the Gulf of Mexico.
       The highlight of last years Keys cruise was a brief look at Ken 
Nedimyer's A. cervicornis nursery where around 2,500 individual 
healthy colonies are growing more rapidly in mid water (clothes 
line-like arrangement) than colonies on the bottom (according to 
Nedimyer). The nursery growth strongly suggests that water conditions 
are right for natural recovery throughout the keys. Keep your fingers 
crossed. Gene

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

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