Coral Disease in Japan

While 40 different coral diseases have been described globally since the first report in 1973, the causative agents for most cases have yet to be identified. In Japan, a total of ten coral diseases, including black band disease, brown band disease, white syndrome, pigmentation response, and growth anomalies have been confirmed in the field by epidemiological surveys and monitoring projects. However, disease-induced coral mortality has yet to be reported. A national government-based monitoring project for coral reef conservation has recorded the three major diseases (black band disease, white syndrome, and growth anomalies) in ten areas (Kushimoto, Shikoku, Amakusa, Yakushima, Chichijima, Setouchi, Kerama, Miyako, Ishigaki, and Sekisei Lagoon/Iriomote) of Japan since 2003. Furthermore, a substantial number of studies have contributed to the understanding of coral diseases, identifying ten additional diseases in six coral genera, including a new disease discovered in the temperate coral Turbinaria peltata in 2009. In order to elucidate the causative mechanism of coral disease, researchers have utilized a variety of approaches including lipid measurements, molecular technique, and new histopathology methods. However, despite the efforts, further research is required to fully understand the mechanism and impacts of coral disease. This chapter summarizes current knowledge on coral pathogens and discusses the future of coral disease research in Japan.