WBD outbreak in Culebra Island, P.R.

[Hernandez Edwin]

Dear coral-listers:

During a field survey today (August 2, 2001) at
Culebra Island, Puerto Rico, we found that 60 out of
118 colonies or fragments of Acropora cervicornis were
infected with the White Band Disease (WBD).  Although
WBD has been observed previously in a sporadic
fashion, this is the first outbreak of the WBD we have
documented here since the beggining of our long-term
monitoring studies back in 1996.  

A total of 12/118 colonies were completely dead (10%).
Infected colonies were observed in depths ranging from
2 to 8 m.  All partially dead and completely-dead
colonies are starting to be overgrown by filamentous
algal turfs kept mostly by the three-spot damselfish,
Stegastes planifrons (Pisces: Pomacentridae).

Regarding the White Plague outbreak, colonies of
Montastrea annularis keep being infected, but at
apparentely a slower rate. However, spreading of the
disease appear faster than ever. One of the most
dramatic examples was a 3 m L x 2.5 W x 2 m H colony
of M. annularis which was completely wiped out by the
Plague in about a month or less.  In addition, we
documented, for the first time in Culebra Island, a
Mycetiophylia ferox colony infected by what appears to
be the White Plague.

Also, a few colonies of Montastrea annularis are
showing recent signs of Black Band Disease infections.
Sorry, no quantitative data yet.

In addition, there are new reports on coral bleaching.
A few isolated colonies of Montastrea annularis
(columnar and platy morphotypes) were showing
assimetric patches of pale yellow tissue in their
upper surfaces.  There were additional isolated
bleached colonies of Millepora alcicornis.

There were also a few additional blue-colored
Siderastrea siderea colonies showing tissue necrosis
at the edge of the colonies. One of them was
particularly affected showing a gradation of colors
from a brick-red, to lavender, to violet, to pink, to
white, followed by a recently dead area of exposed
skeleton a dark-green 0.5-cm wide thin filamentous
band which resembles a BBD infection, but
green-colored.  

The living areas of that colony showing lavender,
violet and pink colors barely produced mucous and were
covered by fine layer of silt.  About 50-60% of the
colony surface area was already dead.  

Sorry, I have no picture, but the colony was
georeferenced in an attempt to revisit it, take
pictures, take some measurements and do some
experiments. Has anybody else ever seen something like
that?

I'll keep you posted regarding the findings of our
ongoing studies there.

Regards,

Edwin

=====
Edwin A. Hernandez-Delgado, Ph.D.
University of Puerto Rico
Department of Biology
Coral Reef Research Group
P.O. Box 23360
San Juan, P.R. 00931-3360
Tel (787) 764-0000, x-4855; Fax (787) 764-2610

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