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

Abstract

Identifying and tracking the influence of industrial activities on streams and lakes is a priority for monitoring in Canada’s oil sands region (OSR). While differences in indicators are often found in waterbodies adjacent to mining facilities, the confounding influence of natural exposures to bitumen and other stressors can affect the identification of industrial effects. However, recent work suggests metrics of industrial activity at individual facilities, including production and fuel consumption, may be used in site-specific analyses to identify influence of the industry as a whole as well as individual operations. This study further examined the potential relationships between industrial and climatic variables on benthic communities from 13 streams and 4 lakes using publicly available data from the minable region and the Elastic Net (EN) variable selection technique. From the full set of possible industrial and climate variables, the EN commonly identified the negative influence of plant and fuel use of petroleum coke at the Suncor Basemine on benthic communities in streams and lakes. The fuel/plant use of petroleum coke at Suncor likely reflects the emission and regional deposition of delayed coke fly ash. Among the other industrial variables, crude bitumen production at Syncrude Mildred Lake and other facilities, steam injection rates, and petroleum coke stockpiling were also selected for some benthic invertebrate indices at some sites. Land disturbance metrics were also occasionally selected, but the analyses largely support the predominant influence of industrial facilities via (inferred) atmospheric pathways. While climate variables were also commonly selected by EN and follow-up work is needed, this study suggests that integrating industrial performance data into analyses of biota using a site-specific approach may have broad applicability in environmental monitoring in the OSR. More specifically, the approach used here may both resolve the long-standing challenge of natural confounding influences on monitoring the status of streams in the OSR and track the influence of industrial activities in biota below critical effect sizes.

Incorporating Industrial and Climatic Covariates into Analyses of Fish Health Indicators Measured in a Stream in Canada’s Oil Sands Region

“…The correspondence between the GLMs and the regression diagnostics further supports the utility of the latter to identify large differences and prompting followup analyses or future field studies [72]. Additionally, the approach also highlights the potential sensitivity of these techniques to small influences and the likely utility of the temporal analyses irrespective of the results of spatial comparisons [39]. As discussed below, the site-specific approach also identified the potential influence of industrial activity at both locations, further supporting site-specific analyses.…”

“…Finally, analyses using both environmental and industrial covariates were performed. These analyses used the covariates described above, but also included additional 'mixture' variables to account for the potential cumulative industrial influence, the physical transport processes linking facilities with streams, and other seasonal effects (Supplemental Figure S4; [39,55]). These mixture variables included estimates of mean spring discharge (SP-SD) and air temperature (SP-MT; from Mildred Lake).…”

“…Contaminants of concern (CoCs) are emitted to the atmosphere from stacks and fugitive sources and many are deposited to the landscape [20,[32][33][34][35][36]. While the most intense deposition of materials often occurs within 10-20 km of the sources, e.g., [35], the deposition varies annually [20,32,37,38] and may also occur in areas used as references for studies in streams [39][40][41]. Additionally, in situ oil sand facilities may also be present upstream of reference sites [16,18], further altering the sensitivity of spatial designs to industrial influences.…”

“…Whereas some measurement types, such as chemical indicators in lake sediments and peat cores [47,52], may be less sensitive to these challenges, studies in streams require deliberate solutions. To overcome these challenges in flowing waters, generic covariates available from meteorological and hydrological stations can be incorporated to remove their influence on environmental indicators [32,39,53]. Although any residual variation could be qualitatively associated with extraneous sources, descriptors of industrial performance for individual facilities can also be included to identify any potential associations between the indicators and the local development.…”

“…Although any residual variation could be qualitatively associated with extraneous sources, descriptors of industrial performance for individual facilities can also be included to identify any potential associations between the indicators and the local development. Although not definitive, this approach may improve the utility of monitoring in the OSR, including identifying industrial influence without a pre-industrial baseline [20,32,39,[54][55][56] The purpose of this work is to evaluate the status of fish (lake chub; Couesius plumbeus) residing in the Ells River relative to industrial activity. To examine the potential effects of industrial influence, several approaches were used and were compared.…”