A critical review of the ecological status of lakes and rivers from Canada's oil sands region

Abstract

We synthesize the information available from the peer‐reviewed literature on the ecological status of lakes and rivers in the oil sands region (OSR) of Canada. The majority of the research from the OSR has been performed in or near the minable region and examines the concentrations, flux, or enrichment of contaminants of concern (CoCs). Proximity to oil sands facilities and the beginning of commercial activities tend to be associated with greater estimates of CoCs across studies. Research suggests the higher measurements of CoCs are typically associated with wind‐blown dust, but other sources also contribute. Exploratory analyses further suggest relationships with facility production and fuel use data. Exceedances of environmental quality guidelines for CoCs are also reported in lake sediments, but there are no indications of toxicity including those within the areas of the greatest atmospheric deposition. Instead, primary production has increased in most lakes over time. Spatial differences are observed in streams, but causal relationships with industrial activity are often confounded by substantial natural influences. Despite this, there may be signals associated with site preparation for new mines, potential persistent differences, and a potential effect of petroleum coke used as fuel on some indices of health in fish captured in the Steepbank River. There is also evidence of improvements in the ecological condition of some rivers. Despite the volume of material available, much of the work remains temporally, spatially, or technically isolated. Overcoming the isolation of studies would enhance the utility of information available for the region, but additional recommendations for improving monitoring can be made, such as a shift to site‐specific analyses in streams and further use of industry‐reported data. Integr Environ Assess Manag 2022;18:361–387. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Exploring the Influence of Industrial and Climatic Variables on Communities of Benthic Macroinvertebrates Collected in Streams and Lakes in Canada’s Oil Sands Region

“…Particulates were also emitted after installation of the precipitator at SBM and following the opening of the Syncrude Mildred Lake (SML) mine [5]. Since the opening of the SBM and SML facilities, they have been expanded and new operations have also opened [8]. As the industrial development intensified, studies also expanded and identified the influence of a broader set of sources affecting the environment, including haul road, petroleum coke, and other fugitive dust emissions associated with SBM and SML, but also with the opening of the new mines, technological differences among the facilities, including the opening of in situ operations, and changes at facilities over time [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”

“…Since the opening of the SBM and SML facilities, they have been expanded and new operations have also opened [8]. As the industrial development intensified, studies also expanded and identified the influence of a broader set of sources affecting the environment, including haul road, petroleum coke, and other fugitive dust emissions associated with SBM and SML, but also with the opening of the new mines, technological differences among the facilities, including the opening of in situ operations, and changes at facilities over time [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. The work also shows the greatest loading of CoCs to the environment typically occurs in the minable region within ~25 km of the original bitumen upgrading facilities at SML and SBM, e.g., [10,25,28], but the influence of industrial activity on CoCs is not always apparent [8].…”

“…However, identifying causes may not always be straightforward in areas such as the OSR which are (1) rich in geological resources where exposures to CoCs from natural and industrial sources may co-occur, (2) where industrial activities can affect ecosystems through multiple effect pathways, (3) other anthropogenic stressors are present, and (4) predevelopment exposure scenarios may not be well-characterized [3,[31][32][33][34][35][36][37][38]. For example, in the OSR differences at sites adjacent to mines compared to upstream reference areas are often observed, but natural confounding effects can obscure the identification and tracking of any potential impacts of industrial development on biological indicators [8,34,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53]. Although studies also suggest the ecological conditions are generally good [42,48], separating natural and industrial influences remains both a priority and a substantial challenge in many monitoring studies in the OSR [8,34].…”

“…For example, in the OSR differences at sites adjacent to mines compared to upstream reference areas are often observed, but natural confounding effects can obscure the identification and tracking of any potential impacts of industrial development on biological indicators [8,34,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53]. Although studies also suggest the ecological conditions are generally good [42,48], separating natural and industrial influences remains both a priority and a substantial challenge in many monitoring studies in the OSR [8,34].…”

“…First, examining sites over time may overcome the interpretative challenges of comparing reference and exposure locations in the OSR [30,54]. The approach has been used successfully to document changes in both chemical and biological status in lakes and bogs [7,9,22] and in some studies of streams [8,[55][56][57]. Second, while changes may be documented at a site over time, data on natural covariates, including temperature and precipitation [58,59], and descriptors of potential industrial influence, including mining intensity [8] and land disturbance [55] can also be included to identify potential drivers.…”