Unexpected increasing trends in the concentration of contaminants in European perch (Perca fluviatilis) and in activity of ethoxyresorufin-O-deethylase (EROD) in European perch and eelpout (Zoarces viviparus) have been observed at a Swedish coastal reference site. This study uses data from different sources to investigate plausible explanations. The results showed that a change in diet and an improved overall condition coincide with an increase in mercury in European perch. Furthermore, an increase in several organic contaminants in European perch coincided with the introduction of an invasive deep-burrowing polychaete, which likely contributed to the release of contaminants through bioturbation. The increase in EROD-activity in both species seems to be related to contaminants that reach the fish through the water rather than the diet. The results show that for contaminants that are taken up via the diet, trends in contamination can be opposite for different species of fish in the same area.

欧洲鲈鱼（Perca fluviatili s）中的污染物浓度以及欧洲鲈鱼和鳗鱼（Eolpout）（Zoarces viviparus）中乙氧基试卤灵-O-脱乙基酶（EROD）活性的意外增加趋势）已在瑞典沿海参考点被观察到。本研究使用来自不同来源的数据来研究合理的解释。结果表明，饮食变化和整体状况的改善与欧洲鲈鱼中汞的增加相吻合。此外，欧洲鲈鱼中几种有机污染物的增加与侵入性深挖多毛cha的引入相吻合，这可能有助于通过生物扰动释放污染物。两种物种中EROD活性的增加似乎与通过水而不是通过饮食到达鱼类的污染物有关。结果表明，对于通过饮食摄取的污染物，同一地区不同鱼类的污染趋势可能相反。