Six priorities to advance the science and practice of coral reef restoration worldwide

Abstract

Coral reef restoration is a rapidly growing movement galvanized by the accelerating degradation of the world's tropical coral reefs. The need for concerted and collaborative action focused on the recovery of coral reef ecosystems coalesced in the creation of the Coral Restoration Consortium (CRC) in 2017. In March 2020, the CRC leadership team met for a biennial review of international coral reef restoration efforts and a discussion of perceived knowledge and implementation bottlenecks that may impair scalability and efficacy. Herein we present six priorities wherein the CRC will foster scientific advancement and collaboration to: (1) increase restoration efficiency, focusing on scale and cost‐effectiveness of deployment; (2) scale up larval‐based coral restoration efforts, emphasizing recruit health, growth, and survival; (3) ensure restoration of threatened coral species proceeds within a population‐genetics management context; (4) support a holistic approach to coral reef ecosystem restoration; (5) develop and promote the use of standardized terms and metrics for coral reef restoration; and (6) support coral reef restoration practitioners working in diverse geographic locations. These priorities are not exhaustive nor do we imply that accomplishing these tasks alone will be sufficient to restore coral reefs globally; rather these are topics where we feel the CRC community of practice can make timely and significant contributions to facilitate the growth of coral reef restoration as a practical conservation strategy. The goal for these collective actions is to provide tangible, local‐scale advancements in reef condition that offset declines resulting from local and global stressors including climate change.

Colouring coral larvae for tracking dispersal

“…From an experimental perspective, the ability to use different colour stains can allow differentiation between larval cohorts to examine fine scale behavioural responses and interactive processes. At larger scales, the approach may be useful to help validate simulation studies of local coral connectivity (Hock et al 2017, Doropoulos and Babcock 2018, Mumby et al 2021) and differentiate between targetted larval releases and background settlement during large-scale restoration programs (Doropoulos et al 2019, Harrison et al 2021, Vardi et al 2021) with a view to optimising management strategies for conservation planning of coral reefs.…”

“…Like many benthic invertebrates, most corals (~84%) reproduce by broadcast spawning (Baird et al 2009), whereby eggs and sperm are released into the water column where fertilisation, larval development and dispersal occurs (Babcock and Heyward 1986). Due to the ecological and economic importance of corals, coupled with the impacts of local stressors and climate change (Hughes et al 2017), research efforts have shifted towards the scaling of larval restoration (Doropoulos et al 2019, Harrison et al 2021, Vardi et al 2021), with larval connectivity and conservation planning (Hock et al 2017, Doropoulos and Babcock 2018, Mumby et al 2021) at the forefront of research for management strategies to maintain the long-term resilience of coral reefs. This research has been hindered by the lack of direct methods to quantify larval connectivity and source-sink dynamics, with studies instead relying on indirect methods such as particle dispersal models and genetic correlation that operate at broader spatial and temporal scales.…”

Horizon scan of rapidly advancing coral restoration approaches for 21st century reef management

“…Within a 21st century reef management framework, acceleration of coral reef restoration practices will undoubtedly be fuelled via the UN Decade of Ecosystem Restoration [ 15 , 106 ], which launched in June 2021. However, translating this acceleration of practices into tangible and valid management aids still rests on ensuring three key inter-dependent factors (adapted from [ 11 , 103 ]): (1) Advancing the scale of practice to achieve ecological outcomes. Whilst scalable and cost-effective coral propagation and planting activity is increasingly evident (e.g.…”

“…To develop more standardised practice as well as catalyse innovative tools, activities have become increasingly networked via regional or global bodies (e.g. the Coral Restoration Consortium) with goals to more systematically and collectively build knowledge [11], whilst also adopting core principles from more well established terrestrial and coastal restoration fields [12][13][14] (Box 1). In doing so, building a more robust scientific process has galvanised this movement to transform the scale, feasibility and hence cost-effectiveness needed to solidify reef restoration as tangible management action [7,15].…”

“…Box 1. General principles for viability and development of coral reef restoration: ten 'key rules' for reef restoration programs ( [14]; see also [11,12,105]) identifying barriers slowing natural recoveryis essential where possible. 6.…”