Acropora palmata

White-band disease (WBD) has affected elkhorn and staghorn coral populations throughout the Caribbean since the late 1970s, and has been the most significant cause of mortality to these corals. WBD has transformed thriving stands of living coral to graveyards of skeletons and rubble fields, many still in upright growth position.

Colonies affected by WBD have a distinct margin of slowly advancing tissue decay, which exposes a starkly contrasting bright white area of limestone skeleton adjacent to the dying tissue. The band of tissue that died most recently may be a few millimeters or up to 10 centimeters wide, but this is colonized by algae in a matter of days.

Tissue loss averages about 5 mm per day, but can occur much faster.

Some episodes of WBD begin in the middle of a colony, especially where a colony branches. Often, the entire colony is not killed, but colonies that recover from one episode of WBDcan suffer later episodes of tissue loss from WBD.

A second form of WBD (WBD type II) has been identified on staghorn corals in the Bahamas. Unlike WBD type I, the tissue adjacent to exposed skeleton bleaches prior to dying.