In July 2016, a Husky Energy pipeline spilled 225,000 L of diluted heavy crude oil, with a portion of the oil entering the North Saskatchewan River near Maidstone, SK, Canada. This event provided a unique opportunity to assess potential effects of a crude oil constituent (namely polycyclic aromatic hydrocarbons, PAHs) on a possible sensitive indicator of freshwater ecosystem health, the gut microbiota of native fishes. In summer 2017, goldeye (Hiodon alosoides), walleye (Sander vitreus), northern pike (Esox lucius), and shorthead redhorse (Moxostoma macrolepidotum) were collected at six locations upstream and downstream of the spill. Muscle and bile were collected from individual fish for quantification of PAHs and intestinal contents were collected for characterization of the microbial community of the gut. Results suggested that host species is a significant determinant of gut microbiota, with significant differences among the species across sites. Concentrations of PAHs in dorsal muscle were significantly correlated with gut community compositions of walleye, but not of the other fishes. Concentrations of PAHs in muscle were also correlated with abundances of several families of bacteria among fishes. This study represents one of the first to investigate the response of the gut microbiome of wild fishes to chemical stressors.

2016年7月，赫斯基能源公司的管道泄漏了225,000升稀释的重质原油，其中一部分油进入了加拿大梅德斯通附近的北萨斯喀彻温省河。该事件为评估原油成分（即多环芳烃，PAHs）对淡水生态系统健康的可能敏感指标即本地鱼类的肠道菌群的潜在影响提供了独特的机会。在2017年夏季，金眼鱼（Hiodon alosoides），角膜白斑鱼（Sander vitreus），北部派克（Esox lucius）和短头红马（Moxostoma macrolepidotum））收集在泄漏上游和下游的六个位置。从单个鱼中收集肌肉和胆汁以定量PAHs，并收集肠道内容物以表征肠道微生物群落。结果表明宿主物种是肠道菌群的重要决定因素，跨站点的物种之间存在显着差异。背肌中PAHs的浓度与角膜白斑的肠道群落组成显着相关，而与其他鱼类无关。肌肉中PAHs的浓度也与鱼类中几个细菌家族的丰度相关。这项研究代表了第一个研究野生鱼类肠道微生物组对化学胁迫的反应的研究。