Caribbean Coral Catch Disease From Sewage

Healthy elkhorn coral is found on Sombrero Reef in the Florida Keys National Marine Sanctuary. In the past 15 years, almost 90 percent of elkhorn populations in the Florida Keys have died, landing this once-common coral on the endangered species list.

Human beings occasionally get diseases from animals, such as swine flu, rabies and anthrax. A new study finds that humans can also spread disease to wildlife, with grim results. A bacterium from our guts is now rampaging through coral reefs in the Caribbean.

Those reefs were already in slow decline, but they took a huge hit starting in 1996, when a disease called white pox appeared in the Florida Keys.

“Since that time, elkhorn coral — the species it affects — has declined 88 percent in the Florida Keys,” says Kathryn Sutherland, a reef ecologist at Rollins College in Florida. “And we’ve seen similar declines elsewhere in the Caribbean.”

The coral is named for its resemblance to elk antlers, and is among the most important reef-building species in the Caribbean. Sutherland and her colleagues soon found a culprit for the die-off — a bacterium called Serratia marcescens. It also happens to cause disease in human beings, notably hospital infections. But the scientists couldn’t prove cause and effect.

“In 2002, we could only speculate that human waste was the source of the pathogen because the pathogen is also found in the guts of other animals,” such as deer, Sutherland says.

So she and some colleagues exposed the coral in the laboratory to bacteria extracted from sewage. As they report in the journal PLoS ONE, the coral got the pox within days.

“That gave us definitive evidence that white pox disease is caused by a pathogen found in human sewage.”

An ‘Evolutionary Triple Jump’
Traditionally, we think of diseases moving from animals to us, but “this is almost a man-bites-dog story,” says James Porter at the University of Georgia, a co-author of the study.

“This is a very rare and unusual evolutionary triple jump,” Porter says. The bacterium “went from humans to the lower invertebrates — coral. It went from the terrestrial environment to the marine environment. And then it went from the anaerobic [low oxygen] conditions of our stomach to the fully oxygenated conditions on the reef.”

Porter says they are still trying to explain exactly how the bacterium makes coral sick, and why white pox appeared so suddenly and viciously. The good news is those answers aren’t needed to protect coral. You can just keep the germ away. And, happily, that’s been happening along the Florida Keys.

Jay Gewin, utilities manager in the city of Key West, says residents there voted to upgrade their leaky sewer system. It was not done to save coral per se, but to get rid of health warnings that were keeping the tourists away.

“In the early 2000s when this was such a problem, every single beach in the city of Key West would have an advisory,” Gewin says.

Those health warnings on the beach are now rare, thanks to a sophisticated new wastewater system that cost the city more than $70 million.

“The wastewater is treated to the highest level in the state of Florida, and then it goes into a deep injection well, where the treated final water product is sent thousands of feet down into the ground,” Gewin says.

Eventually it may seep back up into the ocean, but he says by then it’s clean. The biologists say that since the new system was installed, there haven’t been any further die-offs of elkhorn coral around Key West. Other towns along the Keys are now in the process of cleaning up their act, too.

“But this is a problem Caribbean-wide,” Sutherland says, “and there’s a widespread lack of wastewater treatment in the wider Caribbean region.”

And that’s bad news for the elkhorn coral. Due largely to the disease spreading from humans, it’s been tagged as vulnerable on the endangered species list.

Puerto Rico aims to protect newly discovered reefs


By DANICA COTO, Associated Press Danica Coto, Associated Press
Thu Jan 13, 9:29 pm ET
SAN JUAN, Puerto Rico

As the ocean floor plunges off southwestern Puerto Rico, it reveals coral reefs dotted with bright-blue sea squirts and a multitude of other organisms whose existence has given hope to scientists who strive to save the island’s threatened ecosystems.

The organisms are an integral part of a group of reefs discovered to be thriving near an area where most shallow coral reefs and the fish that depend on them are in poor health overall.

The reefs — at a depth of up to 500 feet (152 meters) in an area 12 miles (19 kilometers) across — were recently discovered as part of a federally funded mission to conduct research on deep-water corals, according to the U.S. National Oceanic and Atmospheric Administration.

“We stumbled across this area,” Richard Appeldoorn, a professor at the University of Puerto Rico in Mayaguez who was involved in the mission, told The Associated Press on Thursday.

Divers enrolled in a one-year training course to depths of up to 100 feet (31 meters) noticed the thriving reefs and large predators lurking nearby, said Appeldoorn, who oversees the university’s fisheries, biology and coral reef studies program.

The deep underwater landscape they encountered was populated by lettuce coral, the lace-like star coral and several species of sponges, as well as groupers, snappers and reef sharks, said Appledoorn, who is calling for the protection of the reefs and nearby shallower areas where fish spawn and later retreat to deeper waters.

“Any large fish is always neat to see, not having seen them on top of the (ocean) platform for decades, or not at all,” he said.

The reef’s existence means that struggling, shallow ecosystems in the U.S. Caribbean territory may have a better-than-believed chance at survival, because fish species thriving at a deeper level can help replenish stocks in more shallow reefs, said Appeldoorn and Ernesto Diaz, director of Puerto Rico’s Coastal Zone Management Program.

“It’s a pleasant surprise to know that species you thought you wouldn’t see again exist,” Diaz said.

The discovery — first announced by NOAA last week — comes as officials in Puerto Rico and the U.S. Virgin Islands seek to create the Caribbean Regional Ocean Partnership, an endeavor that aims to better coordinate the use of coastal waters and the implementation of conservation programs.

The two islands recently submitted a proposal for the partnership to NOAA, which also financed the mission that led to the discovery of the new reefs.

Among the partnership’s proposed goals is the creation of a zoning map for waters surrounding Puerto Rico and the U.S. Virgin Islands. The map would designate certain areas for conservation, recreation or commercial purposes, Diaz said.

The project also would allow researchers to explore how the ocean could be harnessed for energy or for the development of fish farms or the installation of underwater fiber-optic cables, Diaz said.

Officials decided to launch the project shortly after the administration of President Barack Obama approved a recent new policy that strengthens the way the U.S. manages its oceans and coasts.

“About 22 percent of Puerto Rico’s waters are protected,” Diaz said. “The other 78 percent, what potential do they have?”

Diaz said the partnership would eventually extend to the nearby Dominican Republic and the British Virgin Islands.

As Diaz awaits approval from NOAA, scientists including Appeldoorn are beginning to explore reefs off the nearby island of Mona, which is just west of Puerto Rico and is sometimes the unintended final destination of migrants from Cuba and the Dominican Republic.

New Ocean Acidification Study Shows Added Danger to Already Struggling Coral Reefs

ScienceDaily (Nov. 13, 2010)

Over the next century, recruitment of new corals could drop by 73 percent, as rising carbon dioxide levels turn the oceans more acidic, suggests a new study led by scientists at the University of Miami Rosenstiel School of Marine and Atmospheric Science. The research findings reveal a new danger to the already threatened Caribbean and Florida reef Elkhorn corals.

“Ocean acidification is widely viewed as an emerging threat to coral reefs,” said Rosenstiel School graduate student Rebecca Albright. “Our study is one of the first to document the impacts of ocean acidification on coral recruitment.”

Albright and colleagues report that ocean acidification could compromise the successful fertilization, larval settlement and survivorship of Elkhorn corals. The research results suggest that ocean acidification could severely impact the ability of coral reefs to recover from disturbance, said the authors.

Elkhorn coral, known as Acropora palmata, is recognized as a critical reef-building species that once dominated tropical coral reef ecosystems. In 2006, Elkhorn was included on the U.S. Endangered Species List largely due to severe population declines over the past several decades.

The absorption of carbon dioxide by seawater, which results in a decline in pH level, is termed ocean acidification. The increased acidity in the seawater is felt throughout the marine food web as calcifying organisms, such as corals, oysters and sea urchins, find it more difficult to build their shells and skeletons making them more susceptible to predation and damage.

Recent studies, such as this one conducted by Albright and colleagues, are beginning to reveal how ocean acidification affects non-calcifying stages of marine organisms, such as reproduction.

“Reproductive failure of young coral species is an increasing concern since reefs are already highly stressed from bleaching, hurricanes, disease and poor water quality,” said Chris Langdon, associate professor at the Rosenstiel School and co-author of the study, published in the Proceedings of the National Academy of Sciences.