Environment and Climate Change Canada, 867 Lakeshore Rd., Burlington, ON, L7S 1A1, Canada.
Environment and Climate Change Canada, 335 River Road, Ottawa, ON, Canada.
Environ Pollut. 2019 Aug;251:246-256. doi: 10.1016/j.envpol.2019.05.007. Epub 2019 May 2.
The aim of this study was to investigate the long-term effects of a short exposure to natural sediments within the Athabasca oil sand formation to critical stages of embryo-larval development in fathead minnows (Pimephales promelas). Three different sediments were used: Ref sediment from the upper Steepbank River tested at 3 g/L (containing 12.2 ng/g ∑PAHs), and two bitumen-rich sediments tested at 1 and 3 g/L; one from the Ells River (Ells downstream, 6480 ng/g ∑PAHs) and one from the Steepbank River (Stp downstream, 4660 ng/g ∑PAHs). Eggs and larvae were exposed to sediments for 21 days, then transferred to clean water for a 5-month grow-out and recovery period. Larval fish had significantly decreased survival after exposure to 3 g/L sediment from Stp downstream, and decreased growth (length and weight at 16 days post hatch) in Ells and Stp downstream sediments at both 1 and 3 g/L. Decreased tail length was a sensitive endpoint in larval fish exposed to Ells and Stp downstream sediments for 21 days compared to Ref sediment. After the grow-out in clean water, all growth effects from the bitumen-containing sediments recovered, but adult fish from Stp downstream 3 g/L sediment had significant increases in jaw deformities. The study shows the potential for fish to recover from the decreased growth effects caused by sediments containing oil sands-related compounds, but that some effects of the early-life sediment exposure occur later on in adult fish.
本研究旨在探究在阿萨巴斯卡油砂形成过程中，短时间接触天然沉积物对黑头软口鱼胚胎-幼虫发育关键阶段的长期影响。使用了三种不同的沉积物：取自上陡岸河的参比沉积物，测试浓度为 3 g/L（含有 12.2ng/g 总多环芳烃）；两种富含沥青的沉积物，测试浓度分别为 1 g/L 和 3 g/L；一种取自埃尔斯河（下游埃尔斯），另一种取自陡岸河（下游陡岸），浓度分别为 6480ng/g 和 4660ng/g 总多环芳烃。将卵和幼虫暴露于沉积物中 21 天，然后转移至清洁水中进行为期 5 个月的生长和恢复阶段。与参比沉积物相比，暴露于下游陡岸 3 g/L 沉积物中的幼虫存活率显著降低，在 1 g/L 和 3 g/L 时，埃尔斯和下游陡岸沉积物中的幼虫生长（孵化后 16 天的体长和体重）也有所下降。与参比沉积物相比，暴露于埃尔斯和下游陡岸沉积物 21 天的幼虫尾部长度明显缩短，这是一个敏感的终点。在清洁水中生长后，所有含沥青沉积物的生长效应都得到了恢复，但来自下游陡岸 3 g/L 沉积物的成年鱼的颌骨畸形显著增加。研究表明，鱼类有从含有油砂相关化合物的沉积物引起的生长效应中恢复的潜力，但早期生活中沉积物暴露的一些影响会在成年鱼中出现。
