Advisor: Dr. Peter Fong
The release of pharmaceuticals and personal care products (soaps, shampoos, colognes) down the drain and into sewage treatment plants is an increasing environmental problem. The antidepressant fluoxetine (Prozac) has been detected in sewage influent and effluent, as well as in surface waters downstream from treatment plants and in fish (bluegills) living in such waters. I tested the effects of Prozac on the feeding behavior (daily ration) of the Siamese Fighting Fish (Betta splendens), a non-native species that has a well-documented set of behavioral characteristics. Feeding (# of bloodworms consumed) was measured three days before drug treatment and during 3 days of drug treatment (Prozac in the water while feeding), with a 7-day recovery period between exposures to different drug concentrations.
Preliminary experiments during the fall of 2008 showed that exposure of fish to a concentration of 3000 µg/L at room temperature (avg. 23° C) resulted in greatly reduced feeding followed by vertical (head up) posture. But, during the spring of 2009, this concentration was found to be lethal at higher temperature (controlled 30° C). Exposure to Prozac concentrations of 30 and 150 µg/L resulted in a significant increase in feeding (p<.001). However, a higher concentration (300 µg/L) caused a reduction in feeding (p<.001). These effects have potential implications for natural populations of aquatic animals living in water, which is contaminated with sewage effluent from a possibly over-medicated human population.