This project addresses the thermal biology of a common branching coral on the reefs of Moorea, which recently has been shown to represent a genetic complex of species and haplotypes (Edmunds et al. 2016), the abundances and distribution of which has played an important role in mediating reef-wide bleaching in 2019. While the ecological data are clear with respect to association between haplotype distribution and the mortality consequences of bleaching, currently there is no data supporting cause and effect in terms of physiology. In this study, Mr. Brown will conduct physiological contrasts to test the hypotheses that 1) Pocillopora haplotypes differ in their physiological response to temperature, and 2) the response of these haplotypes to temperature is mediated by crowding of branches within closely-spaced colonies (Fig. 1). The research will involve sampling coral nubbins (single branches of corals, ~ 2 cm diameter) and measuring their productivity as a function of temperature in singletons, and aggregates in which branch spacing will be matched to field data.

Approved