The coral reef ecosystems play a vital role in the world. Coral reefs provide humans with a consistent source of food, eco-tourism which stimulates Hawaii’s economy, and protection from large waves and tsunamis. This study uses an organism that utilizes symbiotic algae much like coral, but due to the importance of coral to marine ecosystems a similar organism was used. The main goal of this study was to determine if Homosalate, an active ingredient in sunscreen, can impact the photosynthetic process of symbiotic algae called Zooxanthellae found in Aiptasia pulchella (Glass Sea Anemones).

Eighteen similar sized (approximately 2.5 cm) A. pulchella were collected and was distributed into tanks, six anemones in a controlled settings, six anemones in a high concentration treatment, six in a low concentration treatment. After a 56 hour acclimation period. Zooxanthellae abundance, photosynthetic yield (Y(II)) and qualitative health assessments were collected, then homosalate at the appropriate concentration was added to each tank.

This study shows that the zooxanthellae photosynthetic yield at both high concentrations (approximately 19 μg/100 L) and low concentrations (approximately 5 μg/100 L) have net losses in zooxanthellae abundance. The only treatment in this study that did not see a net loss of zooxanthellae was the control treatment. These net loss of zooxanthellae were also seen in the recorded data for photosynthetic yield. The control treatment had the highest percentage yield of all the treatments, while the high concentration treatment had the lowest yields of all the treatments. Percentage photosynthetic yields (Y(II)) were used because each organism had different initial zooxanthellae counts. This study supports the hypothesis that the introduction of homosalate negatively impacts the symbiont in A. pulchella which impacts the overall health of the organism.