Bacterial attack of corals in polluted seawater

Coral heads of the genus Platigyra exposed to low concentrations of crude oil, copper sulfate, potassium phosphate, or dextrose were killed in periods of 5 to 10 days in aquarium studies. The chemicals stimulated the production of large quantities of mucus by the corals. In aquaria treated with antibiotics to prevent microbial growth, Platigyra survived the presence of these chemicals in the water, indicating a role of the microflora in the death of the corals. Evidence was obtained implicating predatory bacteria, Desulfovibrio and Beggiatoa, in the destruction of the stressed coral colonies.