Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.
Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Center, Ottawa, Ontario, Canada.
Environ Toxicol Chem. 2020 Dec;39(12):2516-2526. doi: 10.1002/etc.4876. Epub 2020 Oct 28.
The Alberta Oil Sands Region in Canada is home to one of the largest oil bitumen deposits in the world. The North American river otter (Lontra canadensis) is a top predator with a small home range and is sensitive to disturbances; it has been designated as a sentinel species for the potential impacts of the natural resource exploitation on freshwater ecosystems in the Alberta Oil Sands Region. With an increasing interest in noninvasive biomarkers, recent studies suggest that gut microbiota can be used as a potential biomarker of early biological effects on aquatic wildlife. The goal of the present study was to determine the river otter gut microbial structure related to environmental variables characterizing mining activities and metal body burden. We obtained 18 trapped animals from and surrounding the surface mineable area of the Alberta Oil Sands Region. The gut microbial community structure was characterized using high-throughput sequencing of 16S rRNA gene amplicon analyses. Trace metal concentrations in the liver were measured by inductively coupled plasma-mass spectrometry. Our study revealed that the gut bacteria of river otters in the Alberta Oil Sands Region clustered in 4 groups dominated by Peptostreptococcaceae, Carnobacteriaceae, Enterobacteriaceae, Clostridiaceae, and Nostocaceae. We show that arsenic, barium, rubidium, liver-body weight ratio, and δ N were associated with each cluster. When comparing affected versus less affected sites, we show that river otter gut bacterial community and structure are significantly related to trophic level of the river otter but not to Alberta Oil Sands Region mining activities. Our study reveals that the gut bacterial dynamics can provide insights into the diet and habitat use of river otters but that more work is needed to use it as a pollution biomarker. Environ Toxicol Chem 2020;39:2516-2526. © 2020 SETAC.
加拿大艾伯塔省油砂区是世界上最大的油砂沥青矿床之一。北美水獭（Lontra canadensis）是顶级掠食者，其活动范围较小，对干扰很敏感；它已被指定为监测艾伯塔省油砂区自然资源开采对淡水生态系统潜在影响的指示物种。由于对非侵入性生物标志物的兴趣日益浓厚，最近的研究表明，肠道微生物群可以用作水生野生动物早期生物效应的潜在生物标志物。本研究的目的是确定与表征采矿活动和金属体负荷的环境变量相关的水獭肠道微生物结构。我们从艾伯塔省油砂区的地表可开采区及其周围捕获了 18 只水獭。通过对 16S rRNA 基因扩增子分析的高通量测序来描述肠道微生物群落结构。通过电感耦合等离子体质谱法测量肝脏中的痕量金属浓度。我们的研究表明，艾伯塔省油砂区水獭的肠道细菌分为 4 组，主要由消化链球菌科、食烷菌科、肠杆菌科、梭菌科和念珠藻科组成。我们表明，砷、钡、铷、肝脏体重比和δ N 与每个聚类相关。在比较受影响和受影响较小的地点时，我们表明水獭肠道细菌群落和结构与水獭的营养水平显着相关，但与艾伯塔省油砂区的采矿活动无关。我们的研究表明，肠道细菌动态可以深入了解水獭的饮食和栖息地利用情况，但需要做更多的工作才能将其用作污染生物标志物。Environ Toxicol Chem 2020；39:2516-2526。©2020 SETAC。
