[Coral-List] Porites Line Disease - Red Sea Photos

Douglas Fenner dfenner at blueskynet.as
Sat Jan 12 19:23:01 EST 2008

    I just looked at your photos.  I see dead areas, I see a thin white edge 
on the living coral in some photos, but I don't see signs of active disease 
that kills coral.  Active disease that kills coral moves across the coral at 
some speed.  Thus, the dead area near the edge of the living coral has been 
killed more recently than dead areas farther from the edge of the living 
coral.  Turf algae colonize dead surfaces over a period of days to weeks 
after it is killed.  As a result, when you see a disease like white 
syndrome, you see a white dead area near the edge of the living coral which 
grades into a light green then a dark green then perhaps a nearly black 
area, which reflects the increasing growth of the turf algae with time after 
a particular area of coral was killed.  In your photos, the dead areas do 
not show this kind of zonation.  In most of them the dead areas have uniform 
heavy turf filled with sediment.  The dead area was killed quite a while 
before the photo, and there is no active disease at the edge of the living 
coral.  The white line then is most likely some kind of irritation, as are 
pink edges.  Something definately killed that dead area, but it happened 
long ago enough that it will likely not be possible to determine what killed 
it, and there is no currently active disease.  At least one of your photos 
shows an area killed much more recently, but again there is no color 
gradient and no evidence of active disease moving across the coral. 
Something certainly killed it, I don't know what.  I suppose you can call 
anything that kills a disease (state of ill health), including fish bites, 
but I see no evidence of an infective microbial disease killing coral at the 
time of the photo.  I'll let Laurie comment on the white spots.   -Doug

----- Original Message ----- 
From: "Zaki Moustafa" <zakimou at comcast.net>
To: <Coral-List at coral.aoml.noaa.gov>
Cc: <goreau at bestweb.net>
Sent: Friday, January 11, 2008 4:55 AM
Subject: Re: [Coral-List] Porites Line Disease - Red Sea Photos

> Dear Coral-Listers,
> I just got around to posting some of my coral disease photos taken from
> a fringing reef in the Gulf of Suez.  With the generous assistance of
> Dr. Goreau, I was able to identify and subset some examples of what
> we are referring to as Porites Line Disease.  The last two photos showing
> white pox marks may be the Porites Ulcerative White Spot Disease
> Laurie Raymundo mentions.
> Photos are posted at the following link:
> http://i258.photobucket.com/albums/hh263/zakimou/Red%20Sea%20Gulf%20of%20Suez%20PLD
> Regards,
> Zaki Moustafa

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