Coral Restoration Effectiveness: Multiregional Snapshots of the Long-Term Responses of Coral Assemblages to Restoration

Abstract

Coral restoration is rapidly becoming a mainstream strategic reef management response to address dramatic declines in coral cover worldwide. Restoration success can be defined as enhanced reef functions leading to improved ecosystem services, with multiple benefits at socio-ecological scales. However, there is often a mismatch between the objectives of coral restoration programs and the metrics used to assess their effectiveness. In particular, the scales of ecological benefits currently assessed are typically limited in both time and space, often being limited to short-term monitoring of the growth and survival of transplanted corals. In this paper, we explore reef-scale responses of coral assemblages to restoration practices applied in four well-established coral restoration programs. We found that hard coral cover and structural complexity were consistently greater at restored compared to unrestored (degraded) sites. However, patterns in coral diversity, coral recruitment, and coral health among restored, unrestored, and reference sites varied across locations, highlighting differences in methodologies among restoration programs. Altogether, differences in program objectives, methodologies, and the state of nearby coral communities were key drivers of variability in the responses of coral assemblages to restoration. The framework presented here provides guidance to improve qualitative and quantitative assessments of coral restoration efforts and can be applied to further understanding of the role of restoration within resilience-based reef management.

Effects of coral restoration on fish communities: snapshots of long‐term, multiregional responses and implications for practice

“…A previous study in Indonesia by Ferse () reported that fish abundance and diversity increased most (up to 8‐fold) in restoration plots where hard coral cover was initially very low (below 5%) and where complexity was substantially increased (using artificial structures) from zero or one (zero or sparse vertical relief) to three (moderately complex). In this study that degree of change in complexity only occurred at Koh Tao (Hein et al ).…”

Rebuilding relationships on coral reefs: Coral bleaching knowledge‐sharing to aid adaptation planning for reef users

“…Access to habitatspecific guidance at times of coral bleaching alerts may therefore begin to address conservation inequality, particularly if these efforts are coupled with effective local-scale mitigation, restoration, rehabilitation, conservation, and conservation strategies. [66][67][68][69] This would provide developing nations and areas with fewer resources access to the data and support needed to track and respond with greater specificity to bleaching risk and at a finer resolution than provided by current satellite alerts. As we enter an era of near-annual bleaching events it is increasingly evident that coral bleaching will continue to impact both coral reefs and coral reef users in profound and irrevocable ways.…”

Ecosystem design as an avenue for improving services provided by carbonate producing marine ecosystems

“…Second, coral reef restoration has largely centered on corals only, neglecting many species which contribute to the biodiversity and functioning of reef systems ( Rinkevich, 2021 ). Third, a large range of methodologies defining success hinders its evaluation ( Boström-Einarsson et al, 2020 ; Hein et al, 2020 ). Lastly, restoration efforts often focus on the ecosystem itself rather than on the services provided by this ecosystems as for example local fisheries pose a challenge in densely populated regions with high dependence on these services ( White et al, 2014 ).…”