Coral Disease Handbook: Guidelines for Assessment, Monitoring & Management
(2008)
Please find an excerpt of the full PDF below
Coral Disease Handbook: Guidelines for Assessment, Monitoring & Management
Our research careers began in Discovery Bay, Jamaica, in the mid 1970s, where we both studied the behavior of coral reef organisms, rather than the corals themselves. At that time, living coral covered 70 percent of the bottom, and no one worried about the long term persistence of the reefs, even though the reefs were clearly impacted by people via severe overfishing. Quite simply, we took the reefs for granted.
That sunny confidence turned out to be totally unfounded. In 1980, Hurricane Allen, a category five storm, struck and turned much of the reef into a rubble ground. However, reefs routinely get hit by hurricanes and typhoons, so they should have recovered. But in 1982 the sea urchin Diadema antillarum was decimated by an as yet unidentified pathogen, and losing this last remaining major grazer contributed to the overgrowth of corals by seaweeds throughout the region. By 1995, coral cover stood at less than 10 percent.
But the loss of grazers was not the only thing happening to these reefs. A more subtle and gradual but no less important killer was also taking its toll – the white band disease of the branching staghorn and elkhorn corals. These two species used to be so common that as students we were taught about the “Acropora cervicornis zone” and the “Acropora palmata zone”. Now both species are listed as endangered under the Endangered Species Act, having lost over 90 percent of their numbers in the ensuing decades. Like the elms and chestnuts of US forests, they have largely vanished due to disease.
And they are not alone – white plague, yellow band, black band, and many others have since been documented as major reef killers, not only in the Caribbean but in the Pacific as well. For most of these diseases we still do not know the causative agent – nor the extent to which pollution and increased sea surface temperatures may be contributing to disease outbreaks or affecting the ability of corals to recover from infections. Yet progress is being made, and simply reliably recognizing and documenting these syndromes and their patterns of infection are important first steps in addressing this problem.
This handbook makes it much easier to do just that. Designed for managers, it outlines procedures for describing signs, measuring disease impacts, monitoring disease outbreaks, assessing causes, and managing reefs to minimize losses due to disease. As the authors note, information and expertise on coral disease are inadequate relative to the scale of the problem. This handbook helps managers not only to document and manage disease on the reefs they are responsible for, but also allows them to contribute to our scientific understanding of this grave threat.
