The Tribune

RESEARCHERS have warned that coral is increasingly threatened by a disease that is taking a firmer hold of the nation.

Stony Coral Tissue Loss Disease (SCTLD) has been confirmed by the Perry Institute for Marine Science less than three months after its presence in Grand Bahama was revealed.

The disease has ravaged reef-building corals and endangered species alike, spreading through currents and likely in the ballast water from ships.

On June 4, a team led by scientist Dr Krista Sherman surveyed six sites between Columbus Cove on the northwest end of the island and Lighthouse Boulders, off the western end of Paradise Island.

Investigations were spurred by photos sent by Jenna Chaplin, a Nassau resident, which suggested stony corals surrounding New Providence were losing tissue, just like areas in Grand Bahama, whose infection was confirmed in March.

“Sixty-five percent of the corals assessed at Sandyport were infected with SCTLD and five percent of corals were recently dead. The greatest recent coral mortality was observed just off Caves Point, with 17 percent of corals dead,” said Dr Sherman.

“However, the shallow reef off Baha Mar had the greatest number of corals infected with SCTLD, other diseases and more recently dead corals than other sites.

“In contrast, reefs in the Traveller’s Rest area had the greatest number of healthy colonies, fewer corals infected with SCTLD and the lowest recent mortality compared to other sites.”

The institute says more detailed assessments are needed.

“For corals, this disease is as easy to catch and transmit as the common cold and has the mortality rate of Ebola,” said marine ecologist Dr Craig Dahlgren, the institute’s executive director.

Roughly half of coral species in The Bahamas are susceptible to SCTLD, which could potentially kill coral in a matter of weeks.

Of the 1,257 corals counted on the joint expedition conducted by the institute and the Bahamas National Trust this month, 37 percent were infected.

Another 719 or 57 percent were healthy and 78 individual colonies or six percent recently died. Thirteen coral species were represented in the surveys.

“It appears that the disease has more heavily impacted hard bottom/reef habitats between Paradise Island and Sandyport versus sites west of Sandyport,” said Dr Sherman.

“However, additional assessments to the east and west of surveyed sites including deeper reef sites are needed.”

Back in March, Dr Dahlgren’s report raised the alarm over the disease.

When sailing stopped in mid-March due to COVID-19, it served as a containment measure, albeit a temporary one.

The government has established a task force to help combat the disease.

Dr Lester Gittens, fisheries officer in the Science and Conservation Unit of the Department of Marine Resources, said: “The task force’s immediate priority is to detect where SCTLD is located in The Bahamas and determine how the spread can be contained in the shortest time period. This will take into account the situation at each site. For example, the disease might have limited spread in some locations versus being widespread as seen in Grand Bahama.”

Meanwhile, the institute plans assessments for New Providence, Grand Bahama and Abaco.

As COVID-19 restrictions on movement loosen, boat captains are urged to have ballast and bilge water treated while divers and snorkelers are asked to disinfect their gear to prevent the spread.