The sound of recovery: Coral reef restoration success is detectable in the soundscape

Pantropical degradation of coral reefs is prompting considerable investment in their active restoration. However, current measures restoration success are based largely on cover, which does not fully reflect ecosystem function or reef health. Soundscapes an important aspect health; loud and diverse soundscapes guide the recruitment organisms, but this process compromised when denudes soundscapes. As such, acoustic recovery a functionally component recovery. Here, we use recordings taken at one world's largest projects to test whether successful benthic fish communities accompanied by restored soundscape. We analyse simultaneously healthy, degraded (extensive historic blast fishing) (restoration carried out for 1–3 years previously reefs). compare using manual counts biotic sounds (phonic richness), two commonly used computational analyses (acoustic complexity index [ACI] sound-pressure level [SPL]). Healthy exhibited similar diversity was significantly higher than This pattern replicated some automated others; ACI same qualitative result as phonic richness low-frequency, high-frequency bandwidth, there no significant difference between SPL values either frequency bandwidth. Furthermore, low-frequency scores were only weakly correlated despite showing qualitatively equivalent overall result, suggesting that these metrics likely be driven different aspects Synthesis applications. These data show can lead soundscape recovery, demonstrating return function. They also suggest passive monitoring (PAM) might provide ecosystem-level recovery—but PAM ecological status, those did soniferous animals. Recording represents potentially valuable tool evaluating across ecosystems, caution must exercised choosing interpreting results.