In 1994, Craig Quirolo reported a disease characterized by yellowish lightening of tissue in a band around sediment patches on mountainous star corals in the lower Florida Keys. It was first called yellow-band disease (YBD). A major outbreak of YBD was discovered in the Caribbean off Panama in the summer of 1996 and another was noted off the Netherlands Antilles in the summer of 1997. In these outbreaks, it appeared that the earliest change in the coral was the yellowish lightening of a patch of tissue, prompting Jim Porter to call this condition yellow-blotch disease. In 1997, Jan Korrubel and colleagues reported yellowish tissue changes and loss of tissue affecting several species of corals in the Arabian Gulf, usually in a band pattern, which they called yellow-band disease. Presently, the disease in the Caribbean is referred to as yellow-blotch, the one in the Arabian Gulf as yellow-band, since tissues are affected in different patterns and different species of corals are affected in each locality.

Yellow-blotch disease on mountainous star coral, Montastraea faveolata, in Panama. Photo by N. Bianchi.
Appearance	Yellow-blotch disease begins as an irregularly-shaped blotch of lightened yellow-colored tissue on the surface of the coral. As the disease progresses, the tissue in the center of the patch dies and the area fills with sediment and algae, resulting in a band of yellow tissue around the enlarging sediment patch (thus, it was first called yellow-band disease). The disease has been found most commonly on Montastraea faveolata, the massive keeled species, and less frequently on the columnar lobed star coral, Montastraea annularis. In the disease affecting corals in the Arabian Gulf at Jebel Ali in Dubai, United Arab Emirates, the tissue is discolored yellowish and moves in a broad band with tissue loss and fouling of the skeleton with filamentous algae. Species affected are in the genera Acropora, Porites, Turbinaria, and Cyphastrea.
Close-up of yellow-blotch disease on a mountainous star coral, Panama. Photo by E. C. Peters.
Cause	Unknown. Several scientists are studying this disease in both the Caribbean and Arabian Gulf.
Distribution	Florida Keys and Caribbean (yellow-blotch disease). Arabian Gulf (yellow-band disease).
Impact	Massive, 200- to 300-year-old colonies of star coral have been found to be severely affected by yellow-blotch disease, especially on reefs off the Netherlands Antilles and Panama, and in the Florida Keys. Serious loss of coral tissue due to these diseases is occurring throughout the Caribbean and in the Arabian Gulf.