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

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).

History, overview, and governance of environmental monitoring in the oil sands region of Alberta, Canada.

Over the past decades, concerns regarding the local and cumulative impacts of oil sands development have been increasing. These concerns reflect the industry's emissions, land disturbance, water use, and the resulting impacts to Indigenous Rights. Effective environmental management is essential to address and ultimately manage these concerns. A series of ambient regional monitoring programs in the oil sands region (OSR) have struggled with scope and governance. In the last 10 years, monitoring has evolved from a regulatory-driven exercise implemented by industry into a focused, collaborative, multistakeholder program that attempts to integrate rigorous science from a multitude of disciplines and ways of knowing. Monitoring in the region continues to grapple with leadership, governance, data management, scope, and effective analysis and reporting. This special series, "A Decade of Research and Monitoring in the Oil Sands Region of Alberta, Canada," provides a series of critical reviews that synthesize 10 years of published monitoring results to identify patterns of consistent ecological responses or effects, significant gaps in knowledge, and recommendations for improved monitoring, assessment, and management of the region. The special series considered over 300 peer-reviewed papers and represents the first integrated critical review of the published literature from the region. This introductory paper of the series introduces the history of ambient environmental monitoring in the OSR and discusses historic and ongoing challenges with the environmental monitoring effort. While significant progress has been made in areas of governance, expanded geographical scope, and inclusion of Indigenous communities in monitoring in the region, significant issues remain regarding a lack of integrated reporting on environmental conditions, public access to data, and continuity of monitoring efforts over time. Integr Environ Assess Manag 2022;18:319-332. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Quantifying recent ecological changes in remote lakes of North America and Greenland using sediment diatom assemblages.

BACKGROUND: Although arctic lakes have responded sensitively to 20(th)-century climate change, it remains uncertain how these ecological transformations compare with alpine and montane-boreal counterparts over the same interval. Furthermore, it is unclear to what degree other forcings, including atmospheric deposition of anthropogenic reactive nitrogen (Nr), have participated in recent regime shifts. Diatom-based paleolimnological syntheses offer an effective tool for retrospective assessments of past and ongoing changes in remote lake ecosystems. METHODOLOGY/PRINCIPAL FINDINGS: We synthesized 52 dated sediment diatom records from lakes in western North America and west Greenland, spanning broad latitudinal and altitudinal gradients, and representing alpine (n = 15), arctic (n = 20), and forested boreal-montane (n = 17) ecosystems. Diatom compositional turnover (beta-diversity) during the 20(th) century was estimated using Detrended Canonical Correspondence Analysis (DCCA) for each site and compared, for cores with sufficiently robust chronologies, to both the 19(th) century and the prior approximately 250 years (Little Ice Age). For both arctic and alpine lakes, beta-diversity during the 20(th) century is significantly greater than the previous 350 years, and increases with both latitude and altitude. Because no correlation is apparent between 20(th)-century diatom beta-diversity and any single physical or limnological parameter (including lake and catchment area, maximum depth, pH, conductivity, [NO(3)(-)], modeled Nr deposition, ambient summer and winter air temperatures, and modeled temperature trends 1948-2008), we used Principal Components Analysis (PCA) to summarize the amplitude of recent changes in relationship to lake pH, lake:catchment area ratio, modeled Nr deposition, and recent temperature trends. CONCLUSIONS/SIGNIFICANCE: The ecological responses of remote lakes to post-industrial environmental changes are complex. However, two regions reveal concentrations of sites with elevated 20(th)-century diatom beta-diversity: the Arctic where temperatures are increasing most rapidly, and mid-latitude alpine lakes impacted by high Nr deposition rates. We predict that remote lakes will continue to shift towards new ecological states in the Anthropocene, particularly in regions where these two forcings begin to intersect geographically.