Multigenerational consequences of antidepressant pollution: Effects of sediment-associated sertraline on life-history and behaviour in a marine deposit-feeding worm.

Pharmaceutical pollution is escalating worldwide due to increasing drug consumption and limited removal in conventional wastewater treatment plants. While low concentrations of SSRIs can already disrupt endocrine and behavioural functions in aquatic species, the long-term effects of sediment-associated SSRIs remain largely unexplored. In this study, we examined multigenerational effects of sediment-associated sertraline (SER; 0–15.6 μg/g dry weight sediment) on the polychaete Capitella teleta across three generations (f0–f2), assessing reproductive traits in all generations and behaviour only in f2. In f0, worms exposed to the lowest concentration (0.1 μg/g) produced ∼50% more mature individuals than controls after four weeks, but this stimulatory pattern reversed in f2. At the highest concentration (15.6 μg/g), maturation in f1 was delayed by one week relative to other concentrations. Worms exposed to 0.7 μg/g SER were consistently smaller across all generations, and in f2 they were ∼30% smaller than controls, whereas individuals in 15.6 μg/g were nearly 34% larger than controls. SER exposure delayed the onset of reproduction, particularly at higher concentrations, and caused subtle shifts in brooding intervals. Egg size and number were largely unaffected; however, worms in 15.6 μg/g increased egg production across generations, while those in 0–6.4 μg/g SER showed generational declines. Hatching success (quantified only in f2) decreased by ∼30% at both 6.4 and 15.6 μg/g. Behavioural endpoints in f2 revealed concentration-dependent effects: low SER enhanced negative phototaxis, intermediate concentrations increased burrowing activity, whereas high concentrations impaired burrowing and induced abnormal surface-rolling behaviour. Despite multigenerational exposure, worms did not avoid contaminated sediment in f2, suggesting no behavioural adaptation. Overall, our findings demonstrate that even environmentally relevant levels of sediment-associated SSRIs can elicit repro-toxic, neurotoxic, and multigenerational effects in C. teleta . Such multigenerational impacts in natural systems could alter population dynamics, potentially affecting ecological interactions. • Sertraline caused strong multigenerational effects on growth and reproduction; • Low doses suppressed size; high doses induced compensatory somatic growth; • Reproduction shifted across generations, reducing hatching success at high SER; • Behaviour showed dose-specific neurotoxicity, including impaired burrowing; • SSRI pollution may disrupt population stability in benthic fauna.