Dataset: Coral physiology data (chlorophyll a, symbiont densities) on four collected coral species from six sites in the Red Sea from 2018 to 2020

Data are from experiments performed across multiple sites in Israel, Saudi Arabia, and Djibouti. Multiple ramets from seven genets of Acropora hemprichii, Pocillopora verrucosa, Porites lobata, and Stylophora pistillata were collected from six sites along the Red Sea and used in an 18-hour acute thermal stress assay using the Coral Bleaching Automated Stress System (CBASS). 

Corals were subjected to 18-hour acute thermal profiles with four peak target temperatures (30°C, 33°C, 36°C, and 39°C). Experimental tanks were ramped up from the 30 degrees Celsius control treatment to temperature treatments reaching 33°C, 36°C, and 36.5°C in the prolonged experiment at rates of 0.5 and 1.5 degrees C per day. Each temperature treatment contained two replicate tanks (A and B).

Chlorophyll a and symbiont densities as physiological response metrics were recorded and at the end of the experiments. A MicroDisTec homogenizer 125 (Thermo Fisher Scientific), SpectraMax Paradigm Multi‐Mode Microplate Reader (Molecular Devices), and flow cytometer (BD LSRFortessa, BD Biosciences) were used.

'Chla_cm2' refers to chlorophyll a extracted from algal symbionts extracted in each ramet, normalized to the surface area of the ramet (µg per cm²). 'Sym_density' refers to symbiont densities measured in each ramet, normalized to the surface area of the ramet (cells per cm²).

Problems/Issues:
There are some missing data due to sample loss or mortality.