Deadly coral disease in Florida and Caribbean may be transported in ship hulls, study finds

A brand new study means that ships may be spreading a lethal coral disease throughout Florida and the Caribbean. The findings by scientists on the University of Miami (UM) Rosenstiel School of Marine, Atmospheric, and Earth Science might assist set up testing and therapy strategies to mitigate the chance of additional disease unfold.

Stony coral tissue loss disease, or SCTLD, was first noticed close to Miami in 2014 and has since unfold all through all of Florida’s Coral Reef and into the Caribbean, together with in waters off Jamaica, St. Maarten, U.S. Virgin Islands, and Belize.

Researchers counsel that transport via ship hulls, the place the vessels tackle ballast water in one area to maintain it steady and launch it at a special port, may have contributed to disease unfold.

“Outbreaks in very distant locations suggests that disease transport was aided by means other than just ocean currents, such as through ship ballast water,” stated the study’s lead writer Michael Studivan, an assistant scientist on the UM Cooperative Institute for Marine and Atmospheric Studies (CIMAS) and NOAA’s Atlantic Oceanographic and Meteorological Laboratory.

In the Experimental Reef Lab on the Rosenstiel School, the researchers performed two disease transmission experiments of simulated ship’s ballast water and UV therapy of ballast water to find out whether or not SCTLD pathogens can be transported in this fashion, and whether or not established ballast water therapy approaches like UV can efficiently stop unfold of disease.

The first experiment uncovered wholesome corals to 3 forms of water: 1) disease-exposed, 2) disease-exposed and UV-treated, and 3) non-disease-exposed water in a flow-through tank system.

Over a six-week interval, the researchers noticed the onset of disease lesions and mortality to find out the variety of corals that grew to become diseased, how shortly, and whether or not UV therapy of disease-exposed water resulted in fewer affected corals.

In a second experiment, the researchers held the identical forms of water in containers to simulate a ship’s ballast tank for one and 5 days, then uncovered the water to wholesome corals to find out whether or not the SCTLD pathogens might survive over time, and whether or not they grew to become roughly infectious over time.

The researchers then examined the ballast water generated for each experiments in collaboration with the U.S. Naval Research Laboratory in Key West to quantify the microbial communities and their abundance in untreated and handled ballast water.

“The results suggest that ship’s ballast water poses a threat to continued spread and persistence of SCTLD throughout the Caribbean and potentially to reefs in the Pacific, and that established treatment and testing standards may not mitigate the risk of disease spread,” stated Studivan.

The study, titled “Transmission of stony coral tissue loss disease (SCTLD) in simulated ballast water confirms the potential for ship-born unfold,” was printed on November 1, 2022 in the journal Scientific Reports.