Climate impacts are triggering a host of novel bio- and geoengineering interventions to save coral reefs. This Comment challenges heroic scientific assumptions and advocates for a more systemic, evidence-based approach to caring for coral reefs.

For example, evidence shows that resilience and recovery are an inherent feature of natural ecosystems. The assumption that human intervention can deliver a better outcome is not supported by data: a synthesis of 400 studies of post-disturbance recovery shows no consistent benefits with human restoration compared to natural recovery⁹. Disturbed ecosystems undoubtedly display recovery debt, that is, “deficits in biodiversity and functions”¹⁰. But passive recovery as a natural process supports continued functioning and, most importantly, avoids further human disturbance.

Recent evidence from the northern Great Barrier Reef supports nature’s un-aided capacity to recover in the short term, with coral cover jumping from 10%, the lowest ever recorded, to a record high of 36% in just six years following the last major bleaching event. It was not coral reseeding or biophysical interventions that delivered this outcome over vast spatial scales, but natural recruitment and regrowth. Unfortunately, current and future heatwaves will continue to kill these regrown corals, rendering this natural success ephemeral. Yet to date, there is little evidence that the ecological dynamics that enabled this regrowth will cease to exist, or that active interventions — which have the stated goal of increasing cover of the same fast-growing corals — can have any population-wide impact¹¹.

(…)Therefore, rather than being preoccupied with how to intervene, the scientific community can prudently step back and consider how to have less, not more, influence on nature.

A deliberate reduction of human influence on natural systems is not careless withdrawal, but a radical acceptance of our limited capacity to predict and influence specific outcomes within complex natural systems. (…)