Herbivore Effects on Corals. In year 1, coral mortality was 0% in the mixed-herbivore treatment but was significantly higher (8–24% in 10 months) in the single- or no-herbivore treatments (Fig. 4A). Patterns were similar for growth (Fig. 4 B and C). There was a significant herbivore richness effect as coral cover increased 22% in the mixed-herbivore treatment but declined by 6–30% in all other treatments. Both absolute and relative change in coral area was negatively correlated with cover of upright macroalgae in our treatments (slope = −0.119, r2 = 0.150, P = 0.011; slope = −0.742, r2 = 0.278, P < 0.001, respectively), suggesting that coral decline was driven by treatment effects on macroalgal cover. For year 2, unexpected termination of the experiment by Hurricane Dennis prevented evaluations of treatment effects on coral survivorship and growth.