Ships May Be Fueling a Coral-Killing Epidemic

For some time, researchers have speculated that infected ballast water, which ships take on in one region to keep it stable and then release at a different port, may contribute to the spread of stony coral disease. A recent study by scientists at the University of Miami seems to confirm that. The disease has spread throughout the Caribbean, especially to those islands with significant cruise ship traffic, such as Jamaica, St. Maarten, the U.S. Virgin Islands, Grand Cayman, and Belize.

The UM Rosenstiel School researchers conducted two disease transmission experiments of simulated ship's ballast water in their experimental reef lab. "The results suggest that ships' ballast water poses a threat to continued spread and persistence of SCTLD throughout the Caribbean and potentially to reefs in the Pacific, and that the established treatment (UV) and testing standards may not mitigate the risk of disease spread," said Michael Studivan, the study's lead author.

The solution is to find a means to treat the transported pathogens before they are dumped and the reefs are destroyed, as well as to require ships to dump ballast water far at sea, which is only an interim measure.

Reference: "Transmission of stony coral tissue loss disease (SCTLD) in simulated ballast water confirms the potential for ship-born spread" by Michael S. Studivan, Michelle Baptist, Vanessa Molina, Scott Riley, Matthew First, Nash Soderberg, Ewelina Rubin, Ashley Rossin, Daniel M. Holstein, and Ian C. Enochs, 10 November 2022, Scientific Reports. DOI: 10.1038/s41598-022-21868-z