More Information:  White Plague
Date: Thu, 2 Aug 2001
 
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

 

August 24, 2001

Hello,
I recently received a message about a virulent outbreak of plague type II in Puerto Rico, and that message has prompted this response to let folk know what we've seen and are doing here in St. John.  Researchers at Virgin Islands National Park (VINP) and the US Geological Survey field station in St. John, USVI have been monitoring the presence and progress of the coral disease plague type II in St. John on a monthly basis since December 1997.  (This work was recently presented in La Pagurea at the AMLC meeting, and a paper was submitted to Revista de Biologia Tropica as part of the proceedings to that meeting.)  We have observed the more typical occurrences of plague type II characterized by the sharp line differentiating apparently healthy tissue from diseased tissue.  In this form, the disease starts from the bottom of colonies, especially near sand or within depressions in corals (e.g., where sand and turf or macroalgae exist).  We have also observed virulent form of the disease in which mortality seems to progress much faster, cover a much larger area, and not necessarily start near the bottom of the colony.  This was observed in 1997 in a shallow (<10 feet) backreef environment, and also in 2000 on a reef slope (25-30 feet).  Both sites are located in undeveloped watersheds, one within the boundaries of VINP and the other outside the park.  The coral most commonly affected is Montastraea annularis (complex), although we've seen similar virulence in Colpophyllia natans  where the disease races through the colony.  The entire colony may be consumed or partial live coral may remain.  Currently, we have a list of 14 species being affected by plague type II: Montastraea annularis (complex), Montastraea cavernosa, Colpophyllia natans, Siderastrea siderea, Dendrogyra cylindrus, Mycetophyllia lamarckiana, Agaricia agaricites, Eusmilia fastigiata, Madracis mirabilis, Madracis decactis, Porites porites, Porites astreoides, Leptoseris cucullata, and Stephanocoenia michelinii.  Tissue samples were taken from five species for lab analysis which verified the disease pathogen.  We have also observed plague type II in the British Virgin Islands, and on Buck Island, off the island of St. Croix.

In consultation with Dr. Laurie Richardson, we have conducted some in situ experiments to "smother" this aerobic bacteria by applying a two part epoxy to the margin between the apparently healthy and diseased tissue (extending about an inch into both sides).  The disease line stopped advancing in 3 of 4 cases, but given the sporadic nature of the disease response, it is impossible to say whether the epoxy had any affect.  (We plan to conduct more experiments along these lines.)

Feel free to share this with anyone that might be interested, and I can be contacted by return e-mail or at 340-693-8950, ext 227.

All the best,

Jeff Miller
 

Photo legends:

1) plague II, 1997: photos of rapid, extensive mortality in 1997
2) plague II, 2000a: initial outbreak of rapid, extensive mortality in 2000.  Yellow dot marks "horseshoe-shaped" lobe for reference.
3) plague II, 2000b: six week post 2000a photo.  Yellow dot for reference.  Dotted, yellow box denotes the approximate boundaries of the 2000a photo.  White quadrat is 1 meter2.
4) plague II, epoxy not working: Mortality progressed beyond the epoxy on C. natans.
5) plague II, epoxy working: Mortality contained within epoxy boundary on C. natans.
 



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