Biotactic Fisheries Research and Monitoring, Biotactic Inc., Kitchener, Ontario, Canada.
J Fish Biol. 2021 May;98(5):1410-1420. doi: 10.1111/jfb.14685. Epub 2021 Feb 15.
Anthropogenic effects on the aquatic environment are ever present and ever increasing and while a plethora of aquatic contaminants are known to affect fishes, one ubiquitous and increasingly prevalent world-wide urban runoff pollutant is frequently disregarded, and that is pet waste. While dog waste has been identified as a significant factor contributing to bacteria and nutrient loading within receiving waters and the associated water quality changes are known to affect fishes, the impact of uncollected dog faeces on urban fish populations has never been directly investigated. In this study we exposed creek chub (Semotilus atromaculatus), a widespread tolerant stream minnow, to various realistic concentrations of dog waste as simulated urban park runoff testing both fresh and dried dog faeces in both stagnant and aerated water for 96 h to investigate the impact on fish survival and behaviour. Creek chub percentage mortality increased significantly relative to controls and across an exposure gradient and was likely caused by anoxic conditions. Survivors were initially smaller while those that died were initially larger and presented with abnormal abdominal subdermal lesions post-exposure. Additional indicators of physiological stress included significantly increased rates of aquatic surface respiration and changes in flume test derived swimming motivation metrics with increased exposure concentrations. Both mortality and behavioural responses were alleviated by aeration. Furthermore, trials with fresh and dried faeces differed only in time-to-death and swimming metrics where results from dried trials were similar to those from aerated experiments. Results demonstrated the impact that the global dog waste management problem can have on aquatic communities with effects on creek chub likely to be more severe for less pollution-tolerant species and also likely to be exacerbated under future scenarios that consider climate change and increased urbanization.
人为因素对水生环境的影响一直存在且不断加剧，尽管已知大量水生污染物会影响鱼类，但有一种普遍存在且在全球范围内日益流行的城市径流污染物经常被忽视，那就是宠物粪便。虽然狗的粪便已被确定为导致受纳水体中细菌和营养物负荷的重要因素，并且已知这些水质变化会影响鱼类，但未收集的狗粪便对城市鱼类种群的影响从未被直接调查过。在这项研究中，我们将广泛分布且耐受能力强的溪流鲦鱼（Semotilus atromaculatus）暴露于各种现实浓度的狗粪便中，这些狗粪便模拟了城市公园径流，在静止和充气的水中分别测试新鲜和干燥的狗粪便 96 小时，以调查其对鱼类生存和行为的影响。溪流鲦鱼的死亡率相对于对照组和暴露梯度显著增加，这可能是由于缺氧条件造成的。存活的鱼最初较小，而死亡的鱼最初较大，暴露后腹部皮下出现异常病变。水生表面呼吸率的显著增加以及在增加暴露浓度时来自水槽试验的游泳动力指标的变化，这些都是生理应激的附加指标。曝气可缓解死亡率和行为反应。此外，新鲜粪便和干燥粪便的试验仅在死亡时间和游泳指标上有所不同，其中干燥试验的结果与充气试验相似。研究结果表明，全球狗粪便管理问题对水生生物群落的影响，对于污染耐受能力较弱的物种来说，影响可能更为严重，而且在考虑气候变化和城市化加剧的未来情景下，这种影响可能会加剧。
