Biodiversity enhances coral growth, tissue survivorship and suppression of macroalgae.

Coral reefs are declining dramatically and losing species richness, but the impact of declining biodiversity on coral well-being remains inadequately understood. Here, we demonstrate that lower coral species richness alone can suppress the growth and survivorship of multiple species of corals (Porites cylindrica, Pocillopora damicornis and Acropora millepora) under field conditions on a degraded, macroalgae-dominated reef. Our findings highlight the positive role of biodiversity in the function of coral reefs, and suggest that the loss of coral species richness may trigger negative feedback that causes further ecosystem decline.