Evaluating the precariousness of coral recovery when coral and macroalgae are alternative basins of attraction

When coral and macroalgae are alternative attractors, the trajectory of benthic community following a major disturbance is shaped in part by whether herbivores keep suppressed, leaving reef surfaces state suitable for colonization. Because tend to colonize much faster than coral, an important issue how close ambient herbivory level where control lost, that is, precariousness coral-invasible relative switch-point macroalgae. In Moorea, French Polynesia, reefs dominated macroalga Turbinaria ornata remained so multiple population turnovers, whereas was removed simulated pulse free throughout 5-yr study. A field experiment revealed unable proliferate on disturbed until reduced more 50%. Low facilitated gradual transition because it allowed sufficient time repopulate. Accumulation 3.5 times greater undisturbed, Turbinaria-dominated reefs. Long-term persistence high abundances grazing prevent establishment macroalgae, reflected scarcity browsing consume mature By revealing processes foster bistability states, our work helps explain rich dynamical behavior exhibited communities Moorea elsewhere.