Article " Global Warming Not Only Danger to Corals"

[Ursula Keuper-Bennett]

Greetings all,

Just found this and thought others would be interested.

I'm hoping too that someone might know what species of cyanobacteria was 
involved here.  I'd also be interested in any comments people might have 
about this article and the role cyanobacteria might play in disease 
expression of coral or any other marine organism.

Many thanks,
Ursula Keuper-Bennett
TURTLE TRAX
http://www.turtles.org



"Global Warming Not Only Danger to Corals
  EarthVision Environmental News


BOSTON, November 15, 2001 - Although scientists have warned that global 
warming was wreaking havoc with corals across the globe, a creeping 
bacterial infection that plagues corals, called black band disease, is 
caused by a combination of human sewage and shipyard discharge researchers 
say, which means corals are facing threats on more than one front. 
According to University of Illinois at Urbana-Champaign geologist Bruce 
Fouke and his colleagues, the corals are feeling the stress of 
environmental pollution, which in turn makes them more susceptible to 
bacterial infection.

"Black band disease is characterized by a ring-shaped bacterial mat that 
migrates across a coral colony, leaving dead tissue in its wake," says 
Fouke. "Like a tropical rainforest, a coral reef system is a cradle of 
biodiversity. If we
destroy the reefs, we destroy the ocean's ability to reproduce."

Fouke and his UI research team studied corals off the island of Curacao in 
the Netherlands Antilles, near the Venezuelan coast. To identify the 
microbes inhabiting the black band biomat, the researchers extracted the 
microbes' DNA and found several organisms that are human pathogens, which 
could be a direct link to raw sewage. Also present in the biomat was a ropy 
network of cyanobacteria, a unique group of photosynthetic bacteria that 
cannot live without light. In field experiments, the researchers used 
shields to block light from infected corals. Black band disease disappeared 
from the regions that were not exposed to light.

"This indicates that cyanobacteria are an important part of the disease 
development, but may not be the pathogen," Fouke said. "Perhaps the 
cyanobacteria form an apartment complex, allowing a variety of destructive 
anaerobic bacteria to take up residence in the low-oxygen microenvironment."

Although Fouke says more tests are needed to see exactly what is killing 
the coral, he notes that all the signs point to human pollution as playing 
a role in the destruction. Fouke presented the findings at the recent 
annual meeting of
the Geological Society of America."

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