The effects of naproxen sodium on the growth, reproduction, survival, and feeding of a freshwater pond snail

Over-the-counter drugs are emerging contaminants in the environment. These contaminants often affect aquatic communities, including freshwater invertebrates. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly found in aquatic ecosystems worldwide and have documented negative effects on aquatic organisms. Naproxen is often suggested as a more environmentally friendly alternative due to less bioconcentration in fish. However, studies have yet to test the effects of naproxen on freshwater molluscs. This study exposed pond snails, <i>Physa</i> spp., to three nominal levels of naproxen sodium, 100 µg/L, 1,000 µg/L and 10,000 µg/L, along with a control, over a month-long experiment. We measured snail growth, survival, reproduction, and feeding. Naproxen reduced snail survival across all levels of naproxen exposure and the rate that snails fed at the highest level of naproxen. However, we did not detect an effect of naproxen on snail growth or reproduction rates, even at pollution levels well above those observed in natural systems. Naproxen reduced the grazing of <i>Physa</i> spp. only at our highest concentration, but reduced survival by at least 50% across all concentrations.