Intervention of stony coral tissue loss disease in Utila, Honduras using Base2B and amoxicillin treatments

Introduction. Coral diseases are on the rise due to anthropogenic stressors, and treatment is challenging due to the complexity of replicating natural reef environments. Stony coral tissue loss disease (SCTLD), detected in 2014 off the coast of Florida, has become one of the most lethal modern coral diseases, spreading throughout the Caribbean to Utila, Honduras. Methods. Monthly monitoring and in-situ treatments for SCTLD on 97 coral colonies over 12 months were carried out using amoxicillin and Base2B in two sites of Utila, Honduras. The paste is applied around the margins of the lesion with careful attention to application technique to maximize efficiency. Results. Of the 97 monitored corals 91.75% (n=89) of the colonies survived, with the two sites having survival rates of 97.96% and 85.42%. A total of 842 lesions were treated with only 45 lesions remaining active by the end of the monitoring period. Although treatment intervention halted the lesions it was directly applied to, it did not stop the appearance of new SCTLD lesions on coral colonies. Conclusion. It was found that the treatments themselves are highly effective. Previously infected and healed corals were observed spawning indicating that the treatment works in keeping the corals healthy enough to reproduce. This treatment is suggested as early-stage intervention to help keep as many genotypes of highly susceptible species viable as possible.