marine species, provide coastal protection, wellbeing, food and economic security to millions of people globally through tourism and recreation. These are species diverse and productive ecosystems where the Western Indian Ocean coral reefs cover approximately 5% of the global coverage. Additionally, global estimates indicate that coral reefs contribute US$2.7 trillion per year in ecosystem service value, including US$36 billion in coral reef tourism. As a result of increased reef degradation, restoration efforts are widely applied on coral reefs through coral aquaculture to minimize the increase in threats to coral reefs and to meet the growing demand for their use in marine ornamental trade and pharmaceutical industry globally. Coral aquaculture offers an alternative to wild harvest and it has a considerable promise for restoring reefs and preserving biodiversity. In situ coral aquaculture involves cultivating corals within their natural habitats to enhance coral cover and health conditions while ex situ coral aquaculture involves controlled coral cultivation in aquarium or tanks to optimize coral production. Successful commercial coral aquaculture relies on qualitative and quantitative parameters such as shape, coloration and natural product content, as well as growth and volumetric productivity respectively. However, out-planted coral survival in restoration zones varies significantly where coral mortality can be a significant limitation to the success of restoration efforts. Further, despite its promising potential, coral aquaculture is challenged with sediment deposition, various types of emerging diseases and compromised health. The underlying causes of mortality, the potential for disease, and the role of infectivity associated with mortality events have not yet been widely determined. Studies have indicated coral mortality, coral disease prevalence and coral bleaching prevalence as indicators of coral condition. This far coral disease outbreaks are increasing in impact and frequency worldwide attributable to coastal water pollution and climate change. In the WIO region and East Africa, Black band disease (BBD), Fungal syndrome, white syndrome (WS), pink line syndrome (PLS), growth anomalies (GA), skeleton eroding band (SEB), Porites white patch syndrome (PWPS) and Bacterial Bleaching have been reported affecting Astreopora, Montipora, Echinopora, Acropora, Goniopora, Platygyra, massive Porites, Pocillopra, Goniastrea, Hydnophora, Cyphastrea and Oculina pategonica. While diseases affecting corals have increased there are few individuals throughout the world trained to diagnose diseases on coral reefs. There are limited studies on status of coral health and diseases in the Western Indian Ocean and by extension to Kenya. Thus understanding the underlying microbial, biological, and environmental drivers of mortality and disease in restoration programs provides a means by which to develop optimal strategies to support coral survival. Therefore, there is need for capacity building in coral identification, coral disease identification and management, enhanced regulatory frameworks on coral gardening investment and provision of adequate technical support.
Key words: coral health, disease, Western Indian Ocean, aquaculture