Areal symbiont densities under light and temperature treatments behaved according to scientific expectations, confirming that light and temperature experimental conditions were rigorously set up. Areal symbiont densities were significantly higher at low light and low temperatures, compared to high light and high temperatures. This conforms to expectations established in a large number of published experimental studies (Ban et al., 2014). In addition, light and temperature had an interactive effect on areal Symbiodinium densities, with the combination of low light and low temperature having a greater than additive effect in raising Symbiodinium areal densities than expected from the effect of each factor in isolation.