[Coral-List] Coral disease? Which one?

[Esther Peters]

Dear Jeff and Coral-List,

Good responses by Eric and the others.  I wanted to add that years ago, 
on the El Negro Reef off the west coast of Puerto Rico, I observed 1 
colony of Porites astreoides), and also 1 Diploria labyrinthiformis off 
Tague Bay, St. Croix, USVI, with a mat of fine white filaments on its 
surface, which I described as Beggiatoa net formation and discussed on 
p. 131 of this paper:

Peters, E.C.  1984.  A survey of cellular reactions to environmental 
stress and disease in Caribbean scleractinian corals.  Helgol. Meeres. 
   37:113-137.

I have not seen this since, although I have found an example of a small 
black band disease lesion on a coral at Looe Key with the entire central 
denuded skeleton covered by white filaments.  Beggiatoa is one of the 
sulfur-cycle bacteria associated with this disease.

I also wanted to point out that good observations are key to learning 
more about coral diseases and we still have much to learn.  Since The 
Coral Disease Page was set up by my husband and me, much has been 
learned and we now have a better understanding of most of the diseases 
that were illustrated on that Web site.  We have also been too busy to 
update it with all the information that has come out!  We have been 
planning to take it down because the Coral Disease and Health Consortium 
(CDHC) is planning to have a new Web site with continuous updating. 
However, like our site, it is still a largely volunteer effort and 
support has been limited for that project (one of many undertaken by the 
CDHC partners).  Through workshops sponsored by the CDHC and research 
conducted by various scientists, we have learned that more than one 
microbial pathogen can be responsible for what we now term the "white 
syndromes."  Like many human diseases, identifying the causal agent will 
probably require the use of multiple field and laboratory diagnostic 
techniques.

Please keep reporting coral health concerns to this list, which will 
help everyone!  And I apologize for the status of The Coral Disease 
Page, but our "spare time" was quickly taken up by growing family and 
other requests to help in the study of coral diseases!

Esther Peters


Jeffrey Low wrote:

> Thanks Ross, Ken, Melissa, Julian, James, Ernesto and Francesca for your prompt responses:
>    
>   It seems I know even less about coral disease than I thought. Not that I knew much anyway.
>    
>   The general consensus seems to be that it is not a disease, but possibly a secondary colonisation by microbes - Beggiatoa was suggested, as it forms the white film seen in the images.
>    
>   A dying sponge or something sitting on the coral could have been the original cause of death of the tissue. I'd rule out COTS because we don't have them.
>    
>   I will try to schedule a visit next week and find the corals again, but currents at the site typically follow a biweekly cycle, so it may be not safe to dive there again until the week after. Maybe I will look at other sites in the interim, as suggested.
>    
>   Just some replies to other observations:
>    
>   Melissa Keyes: I 'googled' Pulau Satumu and found it to be near Singapore.  I personally would not dive there.  But the coral does look diverse, and very ill.
>    
>   Jeff: LOL ... I dive in those conditions all the time, so much so I sometimes don't know what to do when I dive in clear waters! But yes, the diversity is quite high (about 200 species of hard corals at last count).
>    
>   Melissa Keyes: This series of photos shows a disease that does not resemble any that I have observed here in the Caribbean ... it looks as if it progresses at a very fast rate, much faster, and differently, from the White Plagues, seeing how there is apparent degradation of the structure of the calcarious structure of the coral.
>    
>   Ernesto Weil: White syndromes usually advance quickly leaving clear white skeleton behind and do not show the bacterial mats. The silty condition and heavy rains might be favoring the development of the bacterial mat quickly. 
>    
>   Jeff: Degradation can be very fast here in the tropics ... there is almost no way to identify "recently dead corals" based on the "whiteness" of its skeleton, simply because algal growth over the skeleton is quite rapid (how fast, I cannot say for sure, but a rough guess would be that within a week, it would be covered with algae and silt).
>    
>   
>   Francesca: Any possibility that you have collected a fragment of the colony?
>    
>   Jeff: I'd have no idea what to do with the fragment even if I had collected it, so I did not, but ... as Eric suggested below:
>    
>   Eric Borneman: .... contagion in terms of virulence would not be possible without experimentation...and DO NOT do any in the field .... if possible, send samples to the International Registry of Coral Pathology (contact them first for interest, availability of resources and proper fixation, storage and shipping protocols.)
>    
>   Jeff: I do not intend to experiment in the field (in fact I do not have facilities to do much, except observe, at this point). But I wanted a quick response so that I would know what to do next, like check with the International Registry of Coral Pathology.
>    
> Cheers, Jeff
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