Key herbivores reveal limited functional redundancy on inshore coral reefs

摘要: Marine ecosystems are facing increasing exposure to a range of stressors and declines in critical ecological functions. The likelihood further loss functions resilience is dependent, part, on the extent functional redundancy (i.e. capacity one species functionally compensate for another species) within groups. We used multiple metrics; richness, generic abundance reserve relative number individuals available fulfil function if numerically dominant lost), as indicators assess potential four groups herbivorous fishes (browsers, excavators, grazers scrapers) two worlds' most intact coral reef ecosystems: Great Barrier Reef (GBR) Ningaloo Western Australia. found marked variations among habitats each system Despite negligible fishing fishes, coastal both systems had lower compared offshore locations all collectively independently. This pattern was consistent redundancy. vulnerability these highlighted by recent shifts from macroalgal dominance several reefs GBR. Our approach provides simple yet revealing evaluation Moreover, it highlights spatial variation systems.