information regarding plague type II

[Jeff Miller]

Hello,

I recently recieved a message about a virulent outbreak of plague type II
in Puerto Rico, and that message has prompted this response to let people
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 Tropical 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.  We've observed the conventional
signs of plague type II at depths ranging from <10 feet to >80 feet.  
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, near 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.)

There are photos depicting some of the effects that we have been
observing at the following address:

http://www.coral.noaa.gov/coral_list/coral_list_photo_legends.html

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


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