Applying coral breeding to reef restoration: best practices, knowledge gaps, and priority actions in a rapidly‐evolving field

Abstract

Reversing coral reef decline requires reducing environmental threats while actively restoring reef ecological structure and function. A promising restoration approach uses coral breeding to boost natural recruitment and repopulate reefs with genetically diverse coral communities. Recent advances in predicting spawning, capturing spawn, culturing larvae, and rearing settlers have enabled the successful propagation, settlement, and outplanting of coral offspring in all of the world's major reef regions. Nevertheless, breeding efforts frequently yield low survival, reflecting the type III survivorship curve of corals and poor condition of most reefs targeted for restoration. Furthermore, coral breeding programs are still limited in spatial scale and species diversity. Here, we highlight four priority areas for research and cooperative innovation to increase the effectiveness and scale of coral breeding in restoration: (1) expanding the number of restoration sites and species, (2) improving broodstock selection to maximize the genetic diversity and adaptive capacity of restored populations, (3) enhancing culture conditions to improve offspring health before and after outplanting, and (4) scaling up infrastructure and technologies for large‐scale coral breeding and restoration. Prioritizing efforts in these four areas will enable practitioners to address reef decline at relevant ecological scales, re‐establish self‐sustaining coral populations, and ensure the long‐term success of restoration interventions. Overall, we aim to guide the coral restoration community toward actions and opportunities that can yield rapid technical advances in larval rearing and coral breeding, foster interdisciplinary collaborations, and ultimately achieve the ecological restoration of coral reefs.