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Some of you may have read about a disease that is devastating coral populations throughout the Caribbean. As if these populations hadn't already been through enough, between runoff, overfishing, and warming -- now they're facing yet another disease outbreak.
The following image, from a publicly available article at www.secore.org, illustrates the symptoms of this disease.
Researchers are calling this Stony Coral Tissue Loss Disease, or SCTLD. There is an excellent description in this article on Science News. I'd urge you to pay attention to the language these researchers are using. One of the leading scientists studying this disease, Dr. Marilyn Brandt, describes it this way:
A recent study using DNA sequencing identified five bacteria associated with this disease. You can read more in this open-access article (I warn the reader, this is a technical article and its pretty dense). The researchers stop short of calling these pathogens, since some of the requirements for formally making this designation have not been established. But the evidence in this study is pretty compelling, and several of these same bacteria have previously associated with coral disease.
Here's an image from the publicly available article, showing symptoms of the disease from this study
The five bacteria identified in this study were present in many or all of the diseased tissues and absent in most or all of the healthy tissue samples. (Further details are available in the article). These are really strong associations -- you could reliably determine whether a sample came from diseased or healthy tissue based entirely on the presence of these bacteria.
Since the researchers used exactly the same genetic marker for this study that I do for AquaBiomics testing of home reef tanks, I couldn't resist asking: are any of these recently described bacteria present in our samples?
The answer is absolutely yes -- I've found perfect, 100% matches to four of these SCTLD-associated bacteria in samples from a small number of home reef tanks. Each of these likely pathogens was found in about 2 to 14% of tanks. Some tanks had more than one. This figure shows the percentages of each type in the tanks I've sampled so far (79 different tanks are included in this dataset).
I will be working to further document effects of these likely pathogens, since I have access to some tanks containing one or more of these. And I'll be contacting the owners of these tanks to let them know!
For now, I wouldn't draw any conclusions beyond what the researchers who wrote the study have claimed. They said,
My contribution here is simply to bring your attention to these recently described bacteria of interest in the study of SCTLD, and to point out that exactly the same bacteria are starting to show up in home aquariums.
I will be looking into the information on those tanks to see what we can learn about the possible origins and effects of these bacteria in our tanks... for now, I'll take the researchers' conclusions at face value that these are prime candidates in the search for the cause of SCTLD. And probably not something I would like to have in my tank (so far, my home tanks appear free of most of them /knock on wood)
The following image, from a publicly available article at www.secore.org, illustrates the symptoms of this disease.
Researchers are calling this Stony Coral Tissue Loss Disease, or SCTLD. There is an excellent description in this article on Science News. I'd urge you to pay attention to the language these researchers are using. One of the leading scientists studying this disease, Dr. Marilyn Brandt, describes it this way:
Dr. Brandt said:It marches along the reef and rarely leaves corals behind... we’re pretty scared.
A recent study using DNA sequencing identified five bacteria associated with this disease. You can read more in this open-access article (I warn the reader, this is a technical article and its pretty dense). The researchers stop short of calling these pathogens, since some of the requirements for formally making this designation have not been established. But the evidence in this study is pretty compelling, and several of these same bacteria have previously associated with coral disease.
Here's an image from the publicly available article, showing symptoms of the disease from this study
The five bacteria identified in this study were present in many or all of the diseased tissues and absent in most or all of the healthy tissue samples. (Further details are available in the article). These are really strong associations -- you could reliably determine whether a sample came from diseased or healthy tissue based entirely on the presence of these bacteria.
Since the researchers used exactly the same genetic marker for this study that I do for AquaBiomics testing of home reef tanks, I couldn't resist asking: are any of these recently described bacteria present in our samples?
The answer is absolutely yes -- I've found perfect, 100% matches to four of these SCTLD-associated bacteria in samples from a small number of home reef tanks. Each of these likely pathogens was found in about 2 to 14% of tanks. Some tanks had more than one. This figure shows the percentages of each type in the tanks I've sampled so far (79 different tanks are included in this dataset).
I will be working to further document effects of these likely pathogens, since I have access to some tanks containing one or more of these. And I'll be contacting the owners of these tanks to let them know!
For now, I wouldn't draw any conclusions beyond what the researchers who wrote the study have claimed. They said,
They also caution thatthe article said:A single potential pathogen was not identified; however, five unique ASV sequences were enriched in the SCTLD lesions of M. cavernosa, D. labyrinthiformis, and D. stokesii, and all but one of these sequences were exact matches to sequences previously associated with coral disease.
the article said:The enrichment of disease-associated bacteria in the lesions of corals with SCTLD is not definitive proof that the pathogen is bacterial. However, disease progression in laboratory and field trials appears to slow or stop with the application of antibiotics, strongly suggesting that bacteria are involved with disease progression.
My contribution here is simply to bring your attention to these recently described bacteria of interest in the study of SCTLD, and to point out that exactly the same bacteria are starting to show up in home aquariums.
I will be looking into the information on those tanks to see what we can learn about the possible origins and effects of these bacteria in our tanks... for now, I'll take the researchers' conclusions at face value that these are prime candidates in the search for the cause of SCTLD. And probably not something I would like to have in my tank (so far, my home tanks appear free of most of them /knock on wood)
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