Figure 5. Coral thermal action spectrum.

Tissue surface heating is expressed as ΔT (°C), i.e., the difference between coral surface temperature and the temperature in the ambient water, and was normalized for an equal irradiance of 500 W m⁻² over each spectral band. Measurements were performed for (a) HF polyp, (b) NF polyp, (c) HF coenosarc and (d) NF coenosarc tissues (n = 3).