Astrangia poculata (Northern star coral) is a common stony coral with an extensive range, reaching from southern Massachusetts to the Gulf coasts of Texas. It has been demonstrated that Northern populations of A. poculata are thermally tolerant and that populations from different regions show varying levels of thermal tolerance. These qualities make A. poculata an important model species for corals and their internal symbionts, primarily algae. However, no studies have been conducted to see how populations from the Gulf of Mexico react to thermal stress. 

To fill this knowledge gap, A. poculata specimens were collected off the West coast of central Florida before roughly half were exposed to known bleaching thresholds for other corals (32°C). Algal photosynthesis was measured via oxygen production rate before exposure and after two weeks of maximum temperature exposure. Colorimetric analysis was conducted to further differentiate algal concentrations before and after subjecting corals to bleaching conditions.

No significant differences in oxygen production or growth were found between the corals in ideal temperatures and raised temperatures. This suggests that, like the populations in the North, A. poculata populations in Florida are thermally tolerant, which strengthens its potential as a model species for understanding coral thermal tolerance. Using A. poculata as a model species to understand coral bleaching could help us determine what makes stony corals tolerant and susceptible to extreme temperatures, and possibly how to increase the thermal tolerance of endangered corals.