Emerging pollutants, such as pharmaceuticals from human waste, are continuously released into aquatic systems. Although pharmaceuticals alone can adversely impact marine organisms, the bioavailability of many pharmaceuticals are dependent on ambient physical conditions, like pH. As few studies have considered the interactive effects of pharmaceutical pollution and anthropogenic ocean acidification, this study investigated the behavioral response of larval sea urchins (Heliocidaris crassispina) and ascidians (Styela plicata) to environmentally-relevant concentrations of fluoxetine (10 and 100 ng L-1) under ambient (pH 8.0) and acidified conditions (pH 7.7). Larval ascidians reared at pH 8.0 exhibited swam in slower, more directed paths with increasing fluoxetine. Interestingly, this effect was absent at pH 7.7. On the other hand, I only observed independent effects of fluoxetine and acidification on urchin swimming behavior. My findings highlight the importance of using behavioral endpoints when assessing the realistic sub-lethal organismal and ecological impacts of anthropogenic stressors, and that considering differences in species traits may allow for the generation of more realistic predictions of the impact of emerging pollutants under future climate scenarios.
Chua V. A., 2021. Ocean acidification modulates the impact of fluoxetine on larval behaviors of non-target organisms. Honors Program thesis, Department of Biology, Swarthmore College. 37 p. Thesis.