Diseases of coral reef organisms

Abstract

All coral reef organisms are susceptible to diseases, as are terrestrial organisms, but studying these diseases can be more difficult and much remains to be learned. Although health impairments of corals were first recognized only in the early 1970s, increasing numbers of infectious and non-infectious diseases, causing morbidity and mortality in numerous species of tropical marine organisms, have now been identified in diverse species of algae, plants, invertebrates, and vertebrates. Causes of diseases include biotic, as well as abiotic, factors, but identifying a primary pathogen has been reported in only a few cases, and some of those results have been questioned as additional diagnostic tools have been applied. The multitude of stressors affecting reef organisms, particularly along heavily urbanized coastlines, as well as introductions of species to distant reefs by global transport, are contributing to concerns about extinction risks and loss of biodiversity. This chapter presents an overview of diseases of reef organisms, how diseases have adversely affected coral reefs, and new developments in disease diagnoses. The application of concepts from the field of conservation medicine are aiding our understanding of diseases and their impacts on organisms of these shallow to mesophotic ecosystems.