A human fecal bacterium kills coral, new research shows, and U.S. scientists say this is a warning to Florida and the Caribbean to protect prized reefs from sewage or face a    threat to a key pillar of their tourism.

Yesterday Tim Austin, Deputy Director of Research & Assessment at Cayman Islands Department of Environment (DOE) welcomed the findings and insisted Cayman Waters are on the whole very clean.

“The DOE works very closely with Cayman water authorities to monitor the waters around the Cayman Islands. Regulations on sewage discharge are very strict here and it is completely against the law to dispose of human waste into the sea. In turn our waters have a very low number of pollutants.

“Septic tanks are an issue but in particular, live aboard boats and boats without appropriate holding tanks are more of a concern. There are no pump out facilities or laws regulating boat sewage and so where the waste goes is anyone’s guess?”

In an article published by the PLoS ONE scientific journal, researchers said they had identified a bacterium from human fecal waste as a killer of common Caribbean elkhorn coral, whose spiky, layered, ochre-colored growths populate reefs off Florida and across the Caribbean.

The bacterium, Serratia marcescens, causes a coral disease known as “white pox,” producing leprosy-like lesions that eat away at, and kill, the coral, said the report by the scientists from Georgia and Florida universities.

“This strain that kills coral comes only from human beings,” James W. Porter of the University of Georgia’s Odum School of Ecology, one of the report’s authors, told Reuters.

Porter said the white pox disease caused by human waste, known scientifically as acroporid serratiosis (APS), had contributed heavily to an 88 percent decline of elkhorn coral in the Florida Keys over the last 15 years. Hurricanes and high temperature bleaching were other killers of coral.