[Coral-List] How many are corals ?

[Martin Pêcheux]

Dear all,

How many are adult corals ?

We can take the surface they inhabit multiplied by their number per
square metre.
Surface : the reef surface is 617 OOO km2 (Smith, 1978), 580-750 000 km2
(Kleypass, 1997). The equivalent surface occupied by corals is 6.5% of
that (Kinsey and Hopley, 1991 - 15% for GBR).
Number per m2: more delicate for me. Take half cover, and a diameter of
30-50 cm.
This give roughly 5-10 specimens/m2 (there are many monitoring data but
I suppose 
no synthesis).
So total round 200-500 billions.

Even more delicate, the total number, from settled planulae to adult.
May I multiply my previous estimate by 2 ? i.e. 10 settled planulae/m2
each year, almost all dying ? or is it 100 ?

Cheers,

Dr. Martin Pêcheux, Scientific Consultant/IPCC
Large Foraminifer Institute
3, allée des Elfes, 94260 Fresnes, France
Phone: +33 1 4237 4196
martin-pecheux at wanadoo.fr
-----------------------------------
Publications at www.reefbase.org, publication, Pecheux

References
Smith SV (1978) Coral-reef area and the contributions of reefs to
processes and ressources of the world's oceans. Nature 273:225-226
Kleypass JA (1997) Modeled estimates of global reef habitat and
carbonate production since the last glacial maximum. Paleoceanogr
13:533-545
Kinsey DW, Hopley D (1991) The significance of coral reefs as global
carbon sinks - response to greenhouse. Paleogeogr Paleoclim Paleoecol
89:363-377