Article " Global Warming Not Only Danger to Corals"
howzit at turtles.org
Thu Nov 15 16:51:12 EST 2001
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.
"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
"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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