Coral Persistence to Ocean Warming: Phenotypic Plasticity and Symbiont Selection

Grant Winners

Dean

Abstract

The ability of coral reef ecosystems to survive global warming will largely depend on the ability of scleractinian corals, the primary engineers of coral reefs, to acclimatize and adapt to increased temperature extremes. Here we propose to explore the within-generation capacity of corals to acclimate to environmental change through the combination of two processes: developmental phenotypic plasticity and symbiont selection. Developmental phenotypic plasticity, i.e. permanent responses to the environment that are established during ontogeny, is widespread among animals and has been shown to allow species to acclimate to new environmental conditions. Concomitantly, corals can associate with different clades of zooxanthellae of the genus Symbiodinium, and because the association with a thermally-resistant clade certainly has fitness trade-offs, it remains unknown if this association could be perpetuated through the entire life cycle. In this study, we will first expose embryos of the species Montastrea cavernosa to warmer conditions and later manipulate the larvae to make associations with a diverse pool of Symbiodinium clades, including thermally tolerant clades. Secondly, we will assess if the resulting juvenile corals survive and grow better than juveniles that were not exposed to higher temperatures. Additionally, we will determine if juveniles, when kept under warmer conditions, can maintain the thermally resistant clades as the colony grows. Experiments will be performed at the NSU Oceanographic Center. This study will allow us to determine M.cavernosa's capacity to acclimate to increased temperatures through developmental phenotypic plastic and symbiontselection, and thus contribute to a better understanding of how coral reef populations and communities may respond to global warming.