Development and application of paleolimnological methods to assess pollution of aquatic ecosystems downstream of the Alberta oilsands

近年来，阿萨巴斯卡河下游流域快速增长的油砂开发对下游生态系统的累积影响引起了社会的关注。根据专家小组的报告，目前的监测计划不足以解决人们对油砂开发通过空气和水释放污染的日益担忧。重点地点包括阿萨巴斯卡河下游、阿萨巴斯卡湖、和平-阿萨巴斯卡三角洲和奇佩温堡社区，人们对这些地方的人类和生态系统健康表示担忧。特别值得关注的是金属和有机污染物。对积雪和湖泊沉积物的研究表明，油砂开发正在通过空气污染半径至少50公里的地区。然而，由于系统监测是在油砂开发30年后才开始的，因此，要弄清自然过程与工业发展对阿萨巴斯卡河污染物供应的影响仍然是一个关键的科学挑战。因此，干扰前或基线污染水平是未知的。此外，这条河流自然侵蚀了100公里的河岸含油地层，这进一步混淆了对现有监测数据的解释。拟议的研究将通过在三个战略选择的地点（油砂下游的阿萨巴斯卡河，和平-阿萨巴斯卡三角洲，和平河下游）应用一种新的“古湖泊学”方法，提供有关阿萨巴斯卡河所携带的金属污染物基线水平的关键缺失信息。

In recent years, societal concerns have escalated over cumulative effects of rapidly-growing oilsands development on downstream ecosystems in the lower Athabasca River watershed. Based on expert-panel reports, current monitoring programs are inadequate to address the growing apprehension about releases of pollution from oilsands development via air and water. Key locations include the lower Athabasca River, Lake Athabasca, Peace-Athabasca Delta and community of Ft. Chipewyan where worries have been expressed for human and ecosystem health. Of particular concern are metals and organic pollutants. Studies of snowpack and lake sediments show that oilsands development is polluting at least a 50-km radius via the air. However, disentangling the roles of natural processes versus industrial development on contaminant supply via the Athabasca River remains a key scientific challenge, because systematic monitoring began 30 years after oilsands development. Thus, pre-disturbance, or baseline, contaminant levels are not known. Also, the river naturally erodes oil-bearing strata along >100 km of riverbank, which further confounds interpretation of existing monitoring data. The proposed research will provide key missing information on baseline levels of metal contaminants of concern carried by the Athabasca River by applying a novel ‘paleolimnological’ approach at three strategically-selected locations (Athabasca River downstream of oilsands, Peace-Athabasca Delta, lower Peace River).