Contributed by Stephen R. Palumbi, February 27, 2019 (sent for review December 11, 2017; reviewed by Andrew C. Baker, Les Kaufman, and Nancy Knowlton)
(Upper) Forty corals from the HVP (red border) and 40 from the MVP (orange border) colored by time spent above 31 °C from December 2014 to April 2015 (austral summer). (Lower) Thermal tolerance (relative chlorophyll retained after a single day, species-specific heat stress) tends to be higher in corals from the HVP. Corals are arranged in ascending order of chlorophyll retention for the four species. Error bars represent SD across four paired replicates per colony.
(A) Average temperature in the HVP, the MVP, and the transplant site in Sili with observed natural bleaching marked in the red box. The gray line marks the expected threshold bleaching temperature. (B) Visual bleaching severity of nubbins in the nursery partitioned using the three simplest proxies for predicted resilience. Labels on the predicted resilient or vulnerable stocks axis are as follows: (A, in blue lettering) corals from the HVP; (B, in blue lettering) top 10 experimental stress performers; (C in blue lettering) hottest extreme microclimates and the corresponding predicted vulnerable stocks: (a) corals from the MVP; (b) bottom 10 experimental stress performers; and (c) coolest extreme microclimates.
Correlations between the average bleaching severity of replicate nursery nubbins in Sili versus the average bleaching severity of their parent genotypes in their original habitats. Photograph demonstrates severely bleached A. gemmifera next to nonbleached nubbins.
Average percent bleaching across four species in the Sili nursery after the 2015 natural bleaching event. Bleaching of nubbins that came from parents from the HVP (red) was two- to threefold lower than for nubbins with parents from the MVP (orange).
