Diseases are a natural aspect of populations, and are one mechanism by which population numbers are kept in check. Disease involves an interaction between a host, an agent, and the environment.
This section of the toolkit will focus on infectious biotic diseases; those that are caused by a microbial agent, such as a bacterium, fungus, virus, or protist, that can be spread between host organisms and negatively impact the host’s health.
Other forms of disease that impact corals may be considered abiotic diseases; they do not involve a microbial agent but still impair health. Examples of abiotic diseases may be those caused directly by environmental agents such as temperature stress, sedimentation, toxic chemicals, nutrient imbalance and UV radiation.
Coral diseases have not been thoroughly characterized and the causative agents remain uncertain. This is still an area of considerable research. This section of the toolkit provides current information on what is known about coral diseases in order to help managers predict impacts, to understand how current reef management practices and human impacts affect the spread and severity of diseases, and to guide management decision making.