Standard Presentation Australian Marine Sciences Association Annual Meeting 2023

Manipulating coral symbiosis: balancing symbiont community disruption, inoculum stability, and coral health while enhancing thermal tolerance (#43)

Corinne Allen 1 2 , Nadine Boulotte 2 , Matthew Nitschke 2 , Wing Yan Chan 1 , Madeleine van Oppen 1 2
  1. School of BioSciences, University of Melbourne, Melbourne, VIC
  2. Australian Institute of Marine Science, Townsville, QLD

To combat the rapid loss of corals due to climate change, coral thermal resilience may be enhanced through the introduction of heat-evolved algal symbionts (Symbiodiniaceae) into bleached corals. However, it is unknown whether artificially heat-evolved Symbiodiniaceae can establish symbiosis and proliferate in the presence of competing homologous Symbiodiniaceae occupying mildly bleached corals.  Here, I assess how the extent of bleaching in the coral Platygyra daedalea impacts a) host health and b) uptake of heat-evolved symbionts. Corals were differentially bleached using menthol and diuron, followed by re-inoculation with a heat-evolved symbiont strain. Throughout the recovery period, host pigmentation and tissue retraction was monitored alongside symbiont community composition and functional performance.  Sampling was completed at multiple locations across the coral surface to understand how symbiont communities vary within microenvironments of the host. Results will provide insight into competitive outcomes of Symbiodiniaceae communities and contribute to optimisation of this assisted evolution approach for implementation into reef restoration practices.