Pharmaceuticals entering aquatic ecosystems via wastewater effluents are of increasing concern for wild animals. Because some pharmaceuticals are designed to modulate human behaviour, measuring the impacts of exposure to pharmaceuticals on fish behaviour has become a valuable endpoint. While laboratory studies have shown that pharmaceuticals can affect fish behaviour, there is a lack of understanding if behaviour is similarly affected in natural environments. Here, we exposed sea trout (Salmo trutta) smolts to two concentrations of two pharmaceutical pollutants often detected in surface waters: temazepam (a benzodiazepine, anxiolytic) or irbesartan (an angiotensin II receptor blocker, anti-hypertensive). We tested the hypothesis that changes to behavioural traits (anxiety and activity) measured in laboratory trials following exposure are predictive of behaviour in the natural environment (downstream migration). Measures of anxiety and activity in the laboratory assay did not vary with temazepam treatment, but temazepam-exposed fish began migrating faster in the field. Activity in the laboratory assay did predict overall migration speed in the field. In contrast to temazepam, we found that irbesartan exposure did not affect behaviour in the laboratory, field, or the relationship between the two endpoints. However, irbesartan was also not readily taken up into fish tissue (i.e. below detection levels in the muscle tissue), while temazepam bioconcentrated (bioconcentration factor 7.68) rapidly (t_1/2 < 24 h). Our findings add to a growing literature showing that benzodiazepine pollutants can modulate fish behaviour and that laboratory assays may be less sensitive at detecting the effects of pollutants compared to measuring effects in natural settings. Therefore, we underscore the importance of measuring behavioural effects in the natural environment.

通过废水进入水生生态系统的药物越来越受到野生动物的关注。由于某些药物旨在调节人类行为，因此测量暴露于药物对鱼类行为的影响已成为一个有价值的终点。尽管实验室研究表明，药物会影响鱼类的行为，但人们缺乏对自然环境中行为是否同样受到影响的了解。在这里，我们暴露了海鳟鱼（Salmo trutta）会在地表水中经常检测到两种浓度的两种药物污染物：替马西（（苯二氮卓，抗焦虑药）或厄贝沙坦（血管紧张素II受体阻滞剂，降压药）。我们测试了以下假设：暴露后在实验室试验中测得的行为特征（焦虑和活动）的变化可预测自然环境中的行为（下游迁移）。在实验室测定中，焦虑和活性的测量值随替马西m的处理而变化，但暴露于替马西m的鱼开始在田间迁移更快。实验室测定中的活性确实预测了该领域的总体迁移速度。与替马西m相反，我们发现厄贝沙坦暴露不会影响实验室，田野或两个端点之间的关系。然而，_1/2 <24小时）。我们的发现增加了越来越多的文献，表明苯二氮卓类污染物可以调节鱼的行为，并且与在自然环境中进行测量相比，实验室分析对检测污染物的影响可能不那么敏感。因此，我们强调了在自然环境中衡量行为影响的重要性。