Coral health and disease in the Pacific : vision for action

Diseases occur globally in most coral reef habitats whether near human population centers or remotely offshore. They generally affect a low proportion of the susceptible species, although localized outbreaks have produced significant mortalities to scleractinian corals, gorgonians, sea urchins, reef fish, sponges, algae and other coral reef organisms (Peters, 1993; Harvell et al., 1999; Williams and Bunkley-Williams, 2000). There are now over 30 named diseases in the Caribbean basin affecting 45 zooxanthellate scleractinian corals, three hydrozoan corals, ten octocorals, two zoanthids, nine sponges and two crustose coralline algae (Green and Bruckner, 2000; Weil et al., 2006), and at least seven major diseases from the IndoPacific, along with about 30 additional conditions that are associated with compromised health in scleractinian corals. While an apparently unprecedented increase in disease occurred in the Caribbean since the 1980s, much less is known about the status of disease in the IndoPacific and Red Sea. Surveys over the last decade in Australia, Palau, East Africa, the Philippines and other locations have revealed new diseases, suggesting a rapid emergence of disease, or at least a realization of their presence, throughout the Indo-Pacific. Between 1972 and 2005 coral diseases were reported on 39 genera and 148 species worldwide, with observations in 63 countries. Although Pacific reefs have a higher diversity of reef-building corals than the Atlantic and harbor 92% of the world’s coral reefs (Spalding and Greenfell, 1997), only 14% of the global observations of coral disease were from the Indo-Pacific during this period (Green and Bruckner, 2000, Sutherland et al., 2004, GCDD, 2007), and 58% of all coral disease records are for BBD, WBD and WP. The Caribbean has historically been referred to as a “hotspot” for disease, largely because of the rapid emergence, high prevalence, wide distribution, large numbers of host species, and virulence of diseases in this region. There are eight major diseases (BBD, WP, WBD, YBD, DSD, WPX, ASP and tumours) that have been reported from throughout the western Atlantic along with another 32 conditions (including different “types” of the major diseases) that have been reported since 1972. WBD, BBD and WP were first reported from the Caribbean in the 1970s from a small number of countries, with observations expanding to new locations during the 1980s including reports of WBD from about half of the Caribbean nations. During this period, BBD and WP caused localized mortality, while WBD contributed to a