Experiment design
Twelve acclimated coral nubbins (6 from each reef zone) were exposed to the high temperature treatment for one week while the remaining nubbins were maintained at ambient temperatures. Productivity and respiration rates and photochemical efficiency were measured the day before the heat treatment started (post-acclimation or pre-treatment) and on day 6, which is the final day of the experiment (post-treatment). The coral mucus was collected at the end of each incubation for respirometry using a two-way 50 ml syringe that is filled with 0.02 µm filtered seawater (Lima et al. 2020, 2022). The filtered seawater is flowed across the coral surface, dislodging the mucus and associated microbes, which are then sucked up via the recirculating tube, and resulting sample pushed through a 0.22 µm sterivex for DNA extraction.