Title: Adaptive strategies of carbon transformation amongst coral symbionts (Symbiodinium spp.)
Supervisors: A/Prof David Suggett, Dr Emma Camp (co-supervisor)
Tropical coral reefs are amongst the most productive and biologically diverse marine ecosystems on Earth. At the heart of their success is the symbiosis of reef forming corals with dinoflagellate algae, Symbiodinium sp., which live within their tissues and provide corals with the bulk of their required energy. Mutualistic association between corals and their symbiotic dinoflagellates largely explains the ability of corals to build the framework of coral reefs, which serve as a habitat for millions of other species. Pioneering genomic studies continue to uncover immense phylogenetic diversity of Symbiodinium sp., allowing us to build strong taxonomic and evolutionary relationships. Yet, we still know little of the fundamental physiological properties that define the ecological success of Symbiodinium’s extensive genetic diversity. Adaptive differences in how Symbiodinium can transform light into energy through photosynthesis may explain ecological patterns of symbiotic associations in the environment but also can help us to understand the fitness (sensitivity or tolerance) of coral reefs towards climate change.
My project investigates the fate of inorganic carbon uptake by a wide array of symbiosis-relevant Symbiodinium genotypes into organic carbon (for their growth and/or translocation to the host), to resolve the potential costs-benefits of symbiotic associations. Novel fast repetition rate fluorometry approach will support these metabolic rates, endorsing differences in factors modulating photosynthetic performance, whilst advanced biochemical assays will be used to better define processes of cellular carbon uptake, incorporation and utilisation. As part of this suite of measurements, I will characterise the metabolites differentially produced by Symbiodinium in response to thermal stress, unravelling potential biomarkers related to coral bleaching and thus benefiting management of coral reef resources.