Metabolomic Analysis of Hexagenid Mayflies Exposed to Sublethal Concentrations of Naphthenic Acid

The oil sands region in northeastern Alberta, Canada contain approximately 165 billion barrels of oil making it the third largest oil reserves in the world. However, processing of extracted bitumen generates vast amounts of toxic byproduct known as oil sands process waters. Naphthenic acids and associated sodium naphthenate salts are considered the primary toxic component of oil sands process waters. Although a significant body of work has been conducted on naphthenic acid toxicity at levels comparable to what is observed in current oil sands process waters, it is also important to understand any impacts of exposure to sublethal concentrations. We conducted a microcosm study using the mayfly Hexagenia spp. to identify sublethal impacts of naphthenic acid exposure on the survival, growth, and metabolome across a concentration gradient (0–100 μg L−1) of sodium naphthenate. Nuclear magnetic resonance-based metabolomic analyses were completed on both the polar and lipophilic extracted fractions of whole organism tissue. We observed a positive relationship between sodium naphthenate concentration and mean principal component score of the first axis of the polar metabolome indicating a shift in the metabolome with increasing naphthenic acid exposure. Eleven metabolites correlated with increased naphthenic acid concentration and included those involved in energy metabolism and apoptosis regulation. Survival and growth were both high and did not differ among concentrations, with the exception of a slight increase in mortality observed at the highest concentration. Although lethal concentrations of naphthenic acids in other studies are higher (150–56,200 μg L−1), our findings suggest that physiological changes in aquatic invertebrates may begin at substantially lower concentrations. These results have important implications for the release of naphthenic acids into surface waters in the Alberta oil sands region as an addition of even small volumes of oil sands process waters could initiate chronic effects in aquatic organisms. Results of this research will assist in the determination of appropriate discharge thresholds should oil sands process waters be considered for environmental release.

Potential Influence of Sewage Phosphorus and Wet and Dry Deposition Detected in Fish Collected in the Athabasca River North of Fort McMurray

The health of fish is a primary indicator of ecosystem response in the Oil Sands Region of northeastern Alberta. However, industrial activity is accompanied by other stressors, such as the discharge of sewage, municipal activity, forest fires, and natural weathering and erosion of bitumen. To combat the spatial confounding influences, we examined white sucker (Catostomus commersonii) captured in the Athabasca River at sites over time (2011–2019) and included covariates to account for the possible sources of influence. The analyses suggest spatially heterogeneous influences of natural factors on fish, such as discharge and air temperature, but also the influence of sewage phosphorus and precipitation. Among the stressors examined here, precipitation may be the most complex and may include a mixture of sources including inputs from tributaries, urban activity, industrial development, and forest fires. Although suggestive, the attribution of variance and detection of changes are affected by sample sizes in some years; these analyses may have missed effects or misspecified important relationships, especially in males. Despite these limitations, the analyses suggest potential differences may be associated with precipitation and highlight the need to integrate robust information on known and suspected stressors in future monitoring of aquatic ecosystems in the oil sands region and beyond.

Opportunistic wetland formation, characterization, and quantification on landforms reclaimed to upland ecosites in the Athabasca Oil Sands Region

Surface mine operators in the Athabasca Oil Sands Region (AOSR) of northeastern Alberta are required by regulation to mitigate habitat impacts resulting from their operations, including impacts to wetlands. To date, most land reclamation efforts have focused on recreating upland forestlands that resemble the surrounding natural (dry) boreal forest. However, the surficial conditions on these reclaimed upland sites can also promote spontaneous wetland development. At Suncor’s Base Plant mine, opportunistic wetlands occurring on reclamation sites have not been formally included in the current inventory of reclaimed wetland areas and remain largely unquantified. We characterized and delineated an estimated 210 ha of opportunistic wetlands (consisting of shallow open water, marshes, and swamps) using aerial photo interpretation and remote sensing analysis in combination with follow-up field verifications. The remote-based (desktop) delineations consistently underestimated actual wetland extents, due mainly to underestimations in the extent of non-inundated vegetation zones (e.g., wet meadow) as well as shrubby swamp. After field corrections, opportunistic wetland habitat was estimated to constitute ~ 17% of the total study area (1209 ha), representing more than a fourfold increase in aerial wetland extent associated with reclaimed landforms over that delineated prior to this study. The interspersion of opportunistic wetlands with upland reclaimed landforms, although unintended, more closely reflects the pre-disturbance landscape, which was characterized by a matrix of forestlands, peatlands, and mineral wetlands (in contrast to the more peatland-dominated lowlands). At Suncor, wetland vegetation composition varied significantly across the study area and was influenced by topographic variation (e.g., in elevation and % slope) in combination with the reclamation substrates (soils) that were placed prior to seeding/planting. Thus, the inclusion of opportunistic wetland delineation in reclamation tracking and closure planning merits consideration as does the opportunity to manipulate current reclamation practices to promote the establishment and persistence of wetlands on reclaimed landforms.

Accessing and Mobilizing “New” Data to Evaluate Emerging Environmental Impacts on Semi-Aquatic Mammals

This paper describes how knowledge mobilization evolved during a study that assessed a proposed increase in industrial water withdrawals from the Athabasca River in northern Alberta, Canada, and potential impacts on a suite of freshwater semi-aquatic mammals in the broader ecosystem. The oil sands region in northeastern Alberta faces various pressures that require rapid knowledge mobilization and decision making, while still acknowledging ecological sensitivities immediately downstream in the Peace-Athabasca Delta (PAD) in the Wood Buffalo National Park. Data were acquired using a multi-faceted approach, including literature reviews, acquisition and synthesis of raw data, and interviews with local knowledge holders. The final outcome of the study was then contextualized relative to elements of knowledge mobilization: (1) research, (2) dissemination, (3) uptake, (4) implementation, and (5) impact. Knowledge mobilization was easiest to quantify for the first two elements, yet was still present in varying forms in the latter stages. The cultural importance of beavers, muskrats, river otters, and mink for communities associated with the Athabasca River and the PAD allowed for increased engagement during all stages of the research process, which then facilitated the co-production of potential solutions among different organization and perspectives.

First recorded co-occurrence of Valvata lewisi Currier, 1868 and Valvata lewisi ontariensis Baker, 1931 (Gastropoda: Valvatidae) from Alberta, Canada, with notes on morphometric and genetic variability

Sympatric populations of Loosely Coiled Valve Snail (Valvata lewisi ontariensis Baker, 1931) and Fringed Valvata (Valvata lewisi Currier, 1868) are documented from Alberta, Canada, for the first time. Both forms have been identified concurrently in aquatic invertebrate survey samples collected from three wetlands in northeastern Alberta by the Alberta Biodiversity Monitoring Institute. Molecular analysis (DNA barcodes) indicates that there is no genetic distinction between V. lewisi (sensu stricto) and V. lewisi var. ontariensis. Morphometric measurements show that the degree of open coiling, the character that defines V. lewisi var. ontariensis, is highly variable in Alberta specimens. Our findings confirm that V. lewisi var. ontariensis is a phenotypic morph of V. lewisi.

Effects of linear features on resource selection and movement rates of wood bison (Bison bison athabascae)

Human-mediated disturbances can lead to novel environmental features that can affect native biota beyond simple habitat loss. In boreal forests of western Canada, linear features (LFs; e.g., pipelines, seismic lines, and roads) are known to alter behaviour, movements, and interactions among species. Understanding LF impacts on native species has therefore been a management priority. Here, we investigate how LFs affect the spatial behaviour of wood bison (Bison bison athabascae Rhoads, 1898), which are designated as “threatened” in Canada. Using data collected from the Ronald Lake population in northeastern Alberta, we assessed how LFs influenced habitat selection and movement of bison by testing support among three hypotheses explaining whether LFs (i) increased forage availability, (ii) enhanced movement efficiency, or (iii) increased predation risk. Results supported the movement efficiency hypothesis as bison were generally ambivalent toward LFs, showing weak selection or avoidance depending on land-cover type, but moved slightly faster when on them. These findings contrast with avoidance behaviours reported for sympatric woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)), which are also “threatened.” Our results should inform critical habitat decisions for wood bison, but we caution that further research is needed to understand the effects of LFs on bison demography.