[Coral-List] Evidence that ocean warming has caused most Caribbean, coral loss
Eugene Shinn
eugeneshinn at mail.usf.edu
Mon May 8 14:06:48 EDT 2017
More on African dust. Those of you who were active coral researchers in
the 1980s will remember that 1983 was a banner year and also a strong El
Nino year. It was the year /Diadema/ populations collapsed throughout
the Caribbean, It was the Year Sea fan disease began and /Acroporid/
coral diseases peaked throughout the Caribbean including the Florida.
Keys. In addition I have been told the scallop industry along the
northeast USA collapsed that year. I recall corals on the Pacific side
of Central America bleached but do not recall 1983 being a particularly
warm year elsewhere in the Caribbean especially at San Salvador Island
which is surrounded by 4,000 meter deep oceanic water flushed by the
Antilles current. Significantly /Acroporid /corals, both Staghorn and
Elkhorn, corals along with /Diadema/ died within a few months around the
island in 1983. The corals growing at San Salvador was monitored by
researchers at the Finger Lakes Marine laboratory (now Gerace lab). When
the corals abruptly died from disease their demise was not preceded by a
bleaching event. I supposed there must be water temperature records from
that time taken by lab workers. I do not recall anyone at the lab
wondering if coral disease had been related to unusual SST. But there is
more.
San Salvador Island supports a thin rich red soil called Pineapple Loam.
The soils red color is due to iron rich clay minerals that overlie
limestone. Deep core borings in the Bahamas show the limestone is about
15,000 ft., thick. Normally iron rich clay soils are sourced from upland
mountainous areas and spread by river systems. There are no rivers in
the Bahamas and no high ground. I well remember an archeologist I met on
San Salvador in 1984 who provided me with shards of red/brown clay pots
he had recovered during his digs. To make such pottery requires clay.
Clay is mixed with water, shaped and then fired to make it harden. One
cannot make pottery from calcium carbonate mud. The archeologist
explained to me that the pottery was made from soil dust scraped from
smooth rock surfaces. Gee I wonder where it came from way out there in
the Atlantic surrounded by deep oceanic depths? Of course the pottery
was hundreds of years old but corals had flourished there before 1983.
The mystery deepens. Gene
--
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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