Coral reefs around the world are doing it pretty tough as they face an onslaught
of challenges, most of which are connected to human activity.
Warming seas can lead to bleaching events and carbon dioxide saturated oceans
are becoming acidic and eating away at coral structures in some regions.
Pesticides also take their toll, even when they are present in extremely small
levels. Back in 2007, I mentioned researchers had discovered some
pesticides
killed juvenile coral when present in water at just one part per
billion.
Another threat to emerge is human poop; or more accurately a bacterium called
Serratia marcescens sometimes present in human excrement.
Aside from coral reefs being an important part of tourism, injecting cash into
local communities, corals such as Elkhorn provide a valuable marine habitat and
used to be the Caribbean's most prolific reef builder.
The presence of elkhorn coral in the region has declined 90% over the past
decade, due in part to white pox disease. White pox disease results in lesions
that expose the coral's skeleton, ultimately killing it. Coral in the Florida Keys
region has also experienced outbreaks in the last decade.
In an experiment conducted by researchers from Rollins College and the
University of Georgia, when exposed to the human-specific strain of Serratia
marcescens, healthy elkhorn coral showed signs of white pox infection within as
little as 5 days.
What makes this finding even more disturbing is it's a case of "reverse
zoonosis". Zoonosis is a phenomenon where an infectious disease can be
transmitted from non-human animals to humans. Additionally, this human-to-coral
reverse zoonosis jumps the gap between land-based creatures and marine.
In the case of Florida Keys, septic tanks that leak sewage into the porous
bedrock are thought to be a source of the bacteria. The scientists behind the
research are hoping the conclusive results will encourage communities to upgrade
sewage treatment. They note Key West hasn't experience a case of white pox since
its community made the switch to an advanced wastewater treatment facility some
years ago.
Source:
Rollins
College and
University
of Georgia
Related:
Sewage wastewater treatment
Composting human waste - humanure
Your pee is precious
