Accelerated climate change is increasing the frequency, duration, and severity of coral bleaching events while reducing recovery windows. To address this ecological crisis there is need for active coral restoration approaches. Chimerism in coral aquaculture has been shown to improve early survival, growth, and overall fitness; however, species-specific benefits and optimal fusion group sizes remain poorly understood. Furthermore, the interaction between chimerism and symbiont genetic identity has not yet been examined.
This research comprises two complementary studies using the common Great Barrier Reef species, Acropora kenti and Platygyra daedalea, inoculated with wild-type and heat-evolved symbionts (Cladocopium and Durusdinium). The first study investigates whether chimerism is beneficial on growth and survival in the early post-settlement phases, and if this is influenced by symbiont community composition. The second study assesses the performance of solitary (non-chimeric) recruits under ambient and ecologically relevant heat stress conditions to identify coral host–symbiont partnerships that confer the greatest thermal tolerance.
Data collection and analysis are ongoing. Differences in survival and growth between chimeric and solitary recruits are currently being assessed to determine how group size influences early performance. Preliminary visual observations from the heat stress experiment suggest minimal differences in survival among host–symbiont combinations; accordingly, analyses are being extended to additional metrics to detect potential sub-lethal effects of elevated temperature on coral performance and growth.
Together, this research will evaluate how host–symbiont combinations and chimeric group size influence early life-stage performance. The findings will inform coral aquaculture and restoration strategies by identifying approaches to enhance post-settlement survival and improve thermal resilience in coral juveniles under future ocean conditions.Together, this research will evaluate how host–symbiont combinations and chimeric group size influence early life-stage performance. The findings will inform coral aquaculture and restoration strategies by identifying approaches to enhance post-settlement survival and improve thermal resilience in coral juveniles under future ocean conditions.