Exposure to a common antidepressant alters crayfish behavior and has potential subsequent ecosystem impacts

Pharmaceuticals are ubiquitous in aquatic environments, yet little is known regarding their impacts on ecological processes. Selective serotonin reuptake inhibitors (SSRIs) frequently prescribed human antidepressants and have been shown to alter crayfish behavior. These behavioral alterations particularly relevant as play a central role freshwater ecosystems often reach high biomass anthropogenically influenced environments commonly exposed pharmaceutical contamination. Using 14-d artificial stream experiment, we spinycheek (Faxonius limosus) citalopram, common SSRI, at an environmentally realistic concentration (0.5 µg/L). We used Y-shaped flume quantify the effects of SSRI exposure behavior food/conspecific preference. also tested interacting citalopram habitat-specific whole-stream ecosystem functions biomass. Crayfish SSRIs exhibited increased boldness (time emerge from shelters; P < 0.05) spent more time orienting food resources than nonexposed crayfish. water column chlorophyll (P 0.01) benthic organic matter = 0.03). Furthermore, potentially respiration 0.09) decreased nitrate uptake 0.05). potential effect decreasing 0.07), but there were no significant CRAY+SSRI interactions. Neither nor treatments affected metabolism. results suggest that has affect algal did not functioning. However, driven by could lead subsequent ecosystem-level various response metrics. unable detect altered scale during our study, likely due short frame (2 weeks) experiment. Further work needed longer-term consequences sublethal pharmaceuticals, these show responses pharmaceuticals should consider entire ecosystem.