The antidepressant, sertraline, impacts growth and reproduction in the benthic deposit feeder, Tubifex tubifex.

Among emerging contaminants, pharmaceuticals are considered one of the most pertinent substances that may threaten aquatic ecosystems. Pharmaceuticals are designed to be directed at specific metabolic- and molecular pathways. Thus, they are assumed to be still biologically active when entering the ecosystem and may result in unpremeditated impacts on non-target organisms. One of the most widely used selective serotonin reuptake inhibitors, sertraline (an antidepressant), is regularly found in aquatic environments. However, knowledge about the effects, and in particular, of sediment-associated sertraline in benthic invertebrates is limited. We examined the impacts of chronic exposure (28 d) to sediment-associated sertraline (3.3, 33, 330 μg/g dw sed.) on survival, growth and reproduction in the deposit-feeding oligochaete, Tubifex tubifex. Sertraline significantly decreased T. tubifex survival and growth. Worms exposed to high sertraline concentrations (330 μg/g) had a lower growth rate and reproduction, as indicated by a significantly lower number of cumulated cocoons. Worms exposed to an environmentally relevant concentration (3.3 μg/g) decreased growth but maintained a reproduction rate similar to that of the control. The implications are that adult worms exposed to high sertraline concentrations presumably required more energy for maintenance and detoxification, thereby reducing available energy for reproduction and growth. This represents a trade-off between survival, reproduction and growth. In contrast, T. tubifex exposed to environmentally relevant concentrations allocated more energy to reproduction by slightly increasing the number of cocoons produced and reducing growth. However, the quantity and quality of offspring may be impacted as we observed fewer juveniles in the environmentally relevant treatment than in the control. Overall, the results indicate that sediment-associated sertraline is bioavailable and negatively impacts T. tubifex survival, growth, and reproduction even at environmentally relevant concentrations.