Zonation (Reef)

Reef zonation is the predictable cross-reef pattern of distinct biological and physical zones set by depth, wave energy, light, and substrate. From shore seaward a typical fringing or barrier reef runs through a back-reef lagoon, the reef flat, the reef crest exposed to the strongest wave action, and the fore-reef or reef slope descending to depth. Each zone holds characteristic coral growth forms: branching and tabular corals on the sheltered flat, robust encrusting and crustose coralline algae on the high-energy crest, and plating corals adapted to low light on the deeper slope. Zonation governs habitat partitioning, accretion rates, and resilience to bleaching and storm damage.