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，干扰前污染物水平的实时测量是未知的，也不能追溯。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）开发和应用科学严谨的古湖泊学方法，以提供阿萨巴斯卡河和和平河所携带的有关金属污染物工业化前基线水平的关键缺失信息。该方法是15年前期研究的产物，将分析工业发展前河流洪水沉积到洪泛区湖泊的沉积物中的污染物，以确定河流中沉积物污染物浓度的自然范围，作为评估长期河流监测数据的基线，以寻找油砂开发和其他人类活动污染的证据。一个新的方面是利用洪水易发湖泊的扰动前沉积物来评估河流的污染。一个关键的成果将是产生可用于当前和未来河流质量监测的方法和数据，以确保油砂开发对下游的累积影响最小。最终，我们的目标是使用该方法确定自然过程与工业活动对加拿大和世界其他河流污染物水平的相对作用，这些河流的影响前数据不足阻碍了检测污染的能力，并使该方法适用于其他类型的污染物（例如，多环芳香族化合物）。3名博士和12名本科生将接受环境评估方面的技能培训。

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, real-time measurements of pre-disturbance contaminant levels are not known and cannot be produced retroactively. 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 develop and apply a scientifically-rigorous paleolimnological approach at three strategically-selected locations (Athabasca River downstream of oilsands, Peace-Athabasca Delta, lower Peace River) to provide key missing information on pre-industrial baseline levels of metal contaminants of concern carried by the Athabasca and Peace rivers. This approach, a product of 15 years of prior research, will use analyses of contaminants in sediments deposited into floodplain lakes by river floodwaters before industrial development to determine the natural range of sediment contaminant concentrations in the river, as baseline' to evaluate long-term river monitoring data for evidence of pollution by oilsands development and other human activities. A novel aspect is use of pre-disturbance sediments from flood-prone lakes to assess pollution of rivers. A key outcome will be generation of methods and data that can be used in ongoing and future river-quality monitoring to ensure there are minimal downstream cumulative effects from oilsands development. Ultimately, we aim to use the methodology to determine relative roles of natural processes versus industrial activity on contaminant levels at other rivers in Canada and elsewhere in the world where insufficient pre-impact data impede an ability to detect pollution, and to adapt the methodology for other types of contaminants (e.g., polycyclic aromatic compounds). Three PhD and 12 undergraduate students will be trained in sought-after skills in environmental assessment.