Exposure of wildlife to anticoagulant rodenticides from sewer baiting and bait application is poorly understood. We analyzed residues of eight anticoagulant rodenticides in liver samples of 96 great cormorants, 29 common mergansers, various fish species, and coypu, in different German regions. Results show that hepatic residues of anticoagulant rodenticides were found in almost half of the investigated cormorants and mergansers due to the uptake of contaminated fish from effluent-receiving surface waters. By contrast, exposure of coypu to rodenticides via aquatic emissions was not observed. The maximum total hepatic anticoagulant rodenticide concentration measured in waterfowl specimens was 35 ng per g based on liver wet weight. Second-generation anticoagulant rodenticide active ingredients brodifacoum, difenacoum, and bromadiolone were detected almost exclusively, reflecting their estimated market share in Germany and their continuing release into the aquatic compartment. Overall, our findings reveal that second-generation anticoagulant rodenticides accumulating in wild fish are transferred to piscivorous predators via the aquatic food chain.

人们对野生动物因下水道诱饵和诱饵应用而接触抗凝血灭鼠剂的情况知之甚少。我们分析了德国不同地区 96 只大鸬鹚、29 只普通秋沙鸭、各种鱼类和海狸鼠肝脏样本中 8 种抗凝血灭鼠剂的残留量。结果表明，由于从污水接收地表水中吸收了受污染的鱼类，几乎一半的调查鸬鹚和秋沙鸭体内都发现了抗凝血灭鼠剂的肝脏残留。相比之下，没有观察到海狸鼠通过水生排放物接触灭鼠剂。根据肝脏湿重，在水禽样本中测得的最大总肝脏抗凝血灭鼠剂浓度为 35 ng/g。几乎全部检测到了第二代抗凝血灭鼠剂活性成分溴鼠灵、苯敌灭灵和溴敌隆，反映了它们在德国的估计市场份额以及它们持续释放到水生区室中的情况。总的来说，我们的研究结果表明，野生鱼类中积累的第二代抗凝血灭鼠剂通过水生食物链转移到食鱼捕食者身上。