Coral reef state influences resilience to acute climate‐mediated disturbances

Abstract

Aim The aim of this study was to understand the interplay between resistance and recovery on coral reefs, and to investigate dependence on pre‐ and post‐disturbance states, to inform generalizable reef resilience theory across large spatial and temporal scales. Location Tropical coral reefs globally. Time Period 1966–2017. Major Taxa Studied Scleractinian hard corals. Methods We conducted a literature search to compile a global data set of total coral cover before and after acute storms, temperature stress and coastal run‐off from flooding events. We used meta‐regression to identify variables that explained significant variation in disturbance impact, including disturbance type, year, depth and pre‐disturbance coral cover. We further investigated the influence of these same variables, as well as post‐disturbance coral cover and disturbance impact, on recovery rate. We examined the shape of recovery, assigning qualitatively distinct, ecologically relevant, population growth trajectories: linear, logistic, logarithmic (decelerating) and a second‐order quadratic (accelerating). Results We analysed 427 disturbance impacts and 117 recovery trajectories. Accelerating and logistic were the most common recovery shapes, underscoring non‐linearities and recovery lags. A complex but meaningful relationship between disturbance impact, the state of a reef pre‐ and post‐disturbance, and recovery rate was identified. Fastest recovery rates were predicted for intermediate to large disturbance impacts, but a decline in this rate was predicted when more than ~75% of pre‐disturbance cover was lost. We identified a shifting baseline, with declines in both pre‐ and post‐disturbance coral cover over the 50‐year study period. Main Conclusions We break down the complexities of coral resilience, showing interplay between resistance and recovery, as well as dependence on both pre‐ and post‐disturbance states, alongside documenting a chronic decline in these states. This has implications for predicting coral reef futures and implementing actions to enhance resilience.

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