Structuring Symbiosis: Introducing Mixed Symbiont Communities into Laboratory-Bleached Scleractinian Corals
Róisín Hayden
Swire Institute of Marine Science, The University of Hong Kong, Hong Kong.
The global demise of coral reefs is a vivid reminder of how human activity is causing chaos in the natural world. As such, there is a large research effort directed towards mitigating the impacts of global climate change on these vital ecosystems. Central to this research is understanding the ecological processes that shape the symbiotic coral microbiome. As a dominant symbiont, the relationship between microalgal Symbiodiniaceae and their coral host plays a key role in structuring these processes. Through experimental bleaching and reinfection of the stony coral Galaxea fascicularis, we successfully introduced mixed communities of target symbiont species into a bleached coral animal. Colonies were artificially bleached and reinfected with one of two symbiont genera - Cladocopium sp. or Durusdinium sp. - or a combined treatment of both. Initial results show successful uptake of both genera into the coral microbiome, with Cladocopium appearing to be more dominant than Durusdinium. Subsequent studies will utilise stable isotope analysis (SIA) to investigate how these symbionts compete for nutrient access in hospite. This method provides significant potential to manipulate and study the coral microbiome, informing and improving novel approaches to coral reef conservation.
Keywords: symbiosis, microbial ecology, coral reefs, bleaching
