Athabasca River Basin Research Articles

Development of an effects‐based approach for watershed scale aquatic cumulative effects assessment

Environmental impacts can manifest themselves in a cumulative manner over very large spatial (watershed) and temporal (decadal) scales. In response to these challenges, scientists have been developing methods that attempt to assess the complex interactions between our environment and the current and future demands of society. This article proposes a framework for quantifying cumulative changes in water quality and quantity and demonstrates its implementation in an entire watershed, the Athabasca River Basin in Alberta, Canada. The Athabasca River Basin is an ideal watershed for this study as it has undergone significant increase in urban and industrial developments that have the potential to impact this aquatic ecosystem. This framework addresses the problems of setting a historical baseline and comparing it to the current state in a quantitative way. This framework also creates the potential for predicting future impacts by creating thresholds specific to the study area. The outcome of this framework is the identification and quantification of specific stressors (dissolved Na, chloride, and sulfate) showing significant change across the entire Athabasca River Basin, as well as the development of thresholds for these parameters. This information can be used in future assessments of proposed development and possible mitigation in the basin.

Assessing large spatial scale landscape change effects on water quality and quantity response in the lower Athabasca River basin

Increased land use intensity has been shown to adversely affect aquatic ecosystems. Multiple landscape stressors interact over space and time, producing cumulative effects. Cumulative Effects Assessment (CEA) is the process of evaluating the impact a development project may have on the ecological surroundings, but several challenges exist that make current approaches to cumulative effects assessment ineffective. The main objective of this study was to compare results of different methods used to link landscape stressors with stream responses in a highly developed watershed, where past work has shown that the river has experienced significant water quality and quantity changes to improve approaches to CEA. The study site was the lower reaches of the Athabasca River, Canada that have been subjected to a diverse range of intense anthropogenic developments since the late 1960s. Linkages between landscape change and river response were evaluated using correlation analyses, stepwise, multiple regression, and regression trees. Notable landscape changes include increased industrial development and forest cut-blocks, made evident from satellite imagery and supporting ancillary data sets. Simple regression analyses showed water use was closely associated with total phosphorus (TP) and Na(+) concentrations, as well as specific conductance. The regression trees for total organic carbon (TOC), TP, and Na(+) showed that the landscape variables that appear as the first characteristic were the same variables that showed significant relations for their respective simple regression models. Simple, stepwise, and multiple regressions in conjunction with regression trees were useful in this study for capturing the strongest associations between landscape stressors and river response variables. The results highlight the need for improved scaling methods and monitoring strategies crucial to managing cumulative effects to river systems.

Fish tainting in the Alberta oil sands region: a review of current knowledge

The Athabasca oil sands in northeastern Alberta, Canada represent the second largest petroleum reserve in the world. The process of extracting bitumen from the oil sands uses huge volumes of water, drawn from sources in the Athabasca River basin, and numerous mining companies operate adjacent to the river. Oil sands process-affected water (OSPW) from open pit mining is placed in large settling basins or tailings ponds that have the potential to leak. The goal is to eventually reclaim the tailings ponds to become functional ecosystems. Natural outcrops of oil sands in contact with surface waters also occur, and there are anecdotal reports in the media that fish caught near the Athabasca oil sands have an unusual flavor or odor. Several analytical and sensory studies have been undertaken to address this issue. Two major questions related to fish tainting arise: (1) Do the current oil sands mining, extraction and upgrading processes cause fish tainting in surrounding waters? (2) What is the tainting potential for fish that become established in reclaimed waters in the future? This review examines the types of compounds in OSPW that might contribute to tainting and the sensory science literature available related to fish tainting and the oil sands.

Alberta’s Oil Sands: Hard Evidence, Missing Data, New Promises

Pitched battles are a regular occurrence in northern Alberta, Canada, as development of the province’s oil sands continues to expand. One ongoing battle—with another salvo launched in February 2011 with the leak of a European Commission report1—concerns how dirty oil sands are, relative to other fuels. Another concerns the influence of the oil sands industry in monitoring its own activity.2 In an effort to cut through the rhetoric of health advocates, industry representatives, environmentalists, government officials, and local residents, the Royal Society of Canada (RSC) selected and covered expenses for an expert panel to winnow out the facts. In a report issued 15 December 20103 the panel cited substantial evidence that efforts to extract oil from the Alberta deposits have degraded air, land, and water quality to varying degrees. The extent of the degradation is sometimes controversial; water quality data, in particular, are subject to differing interpretations and attributions of causality. However, the panel says that, based on publicly available evidence, there appear to be no significant human health threats to the general population either now or from development anticipated in the next decade or so. But the panel also warns that their conclusions come with a major caveat: there are major gaps in health and environmental data, risk assessments, government oversight, information transparency, industry efforts, and disaster preparedness. The health of the region could hinge on these gaps being addressed, particularly since, according to Travis Davies, a spokesman for the Canadian Association of Petroleum Producers, 97% of projected oil extraction and processing is still to come. After the RSC panel reviewed reams of publicly available information on factors such as health status, air and water pollution, greenhouse gas emissions, land disturbance, and energy and water consumption, it concluded that “[t]he claim by some critics of the oil sands industry that it is the most environmentally destructive project on earth is not supported by the evidence. However, for Canada and Alberta, the oil sands industry involves major environmental issues on many fronts which must be addressed as a high priority.”3p293

Differences and sensitivities in potential hydrologic impact of climate change to regional-scale Athabasca and Fraser River basins of the leeward and windward sides of the Canadian Rocky Mountains respectively

Sensitivities to the potential impact of Climate Change on the water resources of the Athabasca River Basin (ARB) and Fraser River Basin (FRB) were investigated. The Special Report on Emissions Scenarios (SRES) of IPCC projected by seven general circulation models (GCM), namely, Japan’s CCSRNIES, Canada’s CGCM2, Australia’s CSIROMk2b, Germany’s ECHAM4, the USA’s GFDLR30, the UK’s HadCM3, and the USA’s NCARPCM, driven under four SRES climate scenarios (A1FI, A2, B1, and B2) over three 30-year time periods (2010–2039, 2040–2069, 2070–2100) were used in these studies. The change fields over these three 30-year time periods are assessed with respect to the 1961–1990, 30-year climate normal and based on the 1961–1990 European Community Mid-Weather Forecast (ECMWF) re-analysis data (ERA-40), which were adjusted with respect to the higher resolution GEM forecast archive of Environment Canada, and used to drive the Modified ISBA (MISBA) of Kerkhoven and Gan (Adv Water Resour 29(6):808–826, 2006). In the ARB, the shortened snowfall season and increased sublimation together lead to a decline in the spring snowpack, and mean annual flows are expected to decline with the runoff coefficient dropping by about 8% per °C rise in temperature. Although the wettest scenarios predict mild increases in annual runoff in the first half of the century, all GCM and emission combinations predict large declines by the end of the twenty-first century with an average change in the annual runoff, mean maximum annual flow and mean minimum annual flow of −21%, −4.4%, and −41%, respectively. The climate scenarios in the FRB present a less clear picture of streamflows in the twenty-first century. All 18 GCM projections suggest mean annual flows in the FRB should change by ±10% with eight projections suggesting increases and 10 projecting decreases in the mean annual flow. This stark contrast with the ARB results is due to the FRB’s much milder climate. Therefore under SRES scenarios, much of the FRB is projected to become warmer than 0°C for most of the calendar year, resulting in a decline in FRB’s characteristic snow fed annual hydrograph response, which also results in a large decline in the average maximum flow rate. Generalized equations relating mean annual runoff, mean annual minimum flows, and mean annual maximum flows to changes in rainfall, snowfall, winter temperature, and summer temperature show that flow rates in both basins are more sensitive to changes in winter than summer temperature.

Unconditional uncertainties of historical and simulated river flows subjected to climate change

► Observed and simulated river flows exhibit similar multifractal behavior. ► Multifractal characteristics have significant implications for uncertainty estimates. ► Climate Change can alter the multifractal character of river flows. ► Uncertainty due to multifractal variation is on the order of +/- 50%. ► Uncertainty due to emissions scenarios and GCM selection is on the order of +/- 20%. The objective of this study was to estimate the unconditional sample uncertainty of observed streamflows and streamflows simulated from a hydrologic model (MISBA) for the Fraser River Basin (FRB) and the Athabasca River Basin (ARB) of Canada under historic conditions and under future conditions simulated by General Circulation Models (GCMs). For each basin, the multifractal properties of 54 simulated hydrographs based on the predictions of seven GCMs and four climate scenarios over three 30-year periods of the 21st century were evaluated and used to generate extended artificial time series by the randomized generalized multifractal cascade model. Uncertainty estimates derived from this multifractal approach were compared with classical statistics, Hurst exponent, and autocorrelation methods. The multifractal approach resulted in greater departures from statistical independence, higher skewness, and a wider range of flows over a 30-year time scale than the other methods. Under climate change, the multifractal strength of streamflows of FRB increased with temperature as the snow fed character of the basin weakened, but in the colder ARB, a decrease in multifractal strength resulted under rising temperatures because of declined snow packs. The estimated unconditional sample uncertainty was compared with uncertainty associated with model and emissions scenario selection. Among four major sources of uncertainty, uncertainty associated with two different hydrologic models (MISBA and SAC-SMA) and global emission patterns in the 21st century were relatively small (20% or less) even though for the latter, the range of SRES climate scenarios may not be representative of future economy and the seven GCMs may not accurately represent actual physical processes. The uncertainties associated with multifractal variation were the largest, on the order of ±50%.

An approach for assessing cumulative effects in a model river, the Athabasca River basin

Novel approaches addressing aquatic cumulative effects over broad temporal and spatial scales are required to track changes and assist with sustainable watershed management. Cumulative effects assessment (CEA) requires the assessment of changes due to multiple stressors both spatially and temporally. The province of Alberta, Canada, is currently experiencing significant economic growth as well as increasing awareness of water dependencies. There has been an increasing level of industrial, urban, and other land-use related development (pulp and paper mills, oil sands developments, agriculture, and urban development) within the Athabasca River basin. Much of the historical water quantity and quality data for this basin have not been integrated or analyzed from headwaters to mouth, which affects development of a holistic, watershed-scale CEA. The main objectives of this study were 1) to quantify spatial and temporal changes in water quantity and quality over the entire Athabasca River mainstem across historical (1966–1976) and current day (1996–2006) time periods and 2) to evaluate the significance of any changes relative to existing benchmarks (e.g., water quality guidelines). Data were collected from several federal, provincial, and nongovernment sources. A 14% to 30% decrease in discharge was observed during the low flow period in the second time period in the lower 3 river reaches with the greatest decrease occurring at the mouth of the river. Dissolved Na, sulfate, chloride, and total P concentrations in the second time period were greater than, and in some cases double, the 90th percentiles calculated from the first time period in the lower part of the river. Our results show that significant changes have occurred in both water quantity and quality between the historical and current day Athabasca River basin. It is known that, in addition to climatic changes, rivers which undergo increased agricultural, urban, and industrial development can experience significant changes in water quantity and quality due to increased water use, discharge of effluents, and surface run-off. Using the results from this study, we can begin to quantify dominant natural and man-made stressors affecting the Athabasca River basin as well as place the magnitude of any local changes into an appropriate context relative to trends in temporal and spatial variability.

Hydrodynamic and physical assessment of ice-covered conditions for three reaches of the Athabasca River, Alberta, Canada

Water is needed for oil sand developments in the lower Athabasca River basin of northern Alberta, Canada, and is also a key consideration from an ecological and fish habitat perspective, particularly in winter when river flows are at their lowest. Efforts to establish an appropriate flow management regime for the lower Athabasca included revision of River2D, a fixed bed, depth-averaged finite element model, available from www.river2d.ca, to predict hydraulics with a partial or total ice cover. Hydrometric surveys from three reaches of the Athabasca River were used to test the model, assess different model calibration methods, and simulate hydrodynamics for ice-covered conditions. Calibrating bed roughness from ice-free data, assuming the same bed roughness for ice-covered conditions, or the reverse, provided a close fit to the surveyed water surface elevations. The applied ice and composite roughness heights differed according to the applied method of calibration. This may have implications for local velocity estimates possibly affecting fish habitat suitability. A range of bed and composite grain roughness heights, corresponding to different bed substrates and ratios of bed and composite roughness heights to water depths, are provided for model calibration purposes. Key words: hydrodynamics, hydraulics, ice, ecology, environment, fish habitat, winter, oil sands.

A modified ISBA surface scheme for modeling the hydrology of Athabasca River Basin with GCM-scale data

A soil–vegetation–atmosphere transfer model (SVAT), interactions between the soil–biosphere–atmosphere (ISBA) of Météo France, is modified and applied to the Athabasca River Basin (ARB) to model its water and energy fluxes. Two meteorological datasets are used: the archived forecasts from the Meteorological Survey of Canada’s Global Environmental Multiscale Model (GEM) and the European Centre for Mid-range Weather Forecasts global re-analysis (ERA-40), representing spatial scales typical of a weather forecasting model and a global circulation model (GCM), respectively. The original treatment of soil moisture and rainfall in ISBA (OISBA) is modified to statistically account for sub-grid heterogeneity of soil moisture and rainfall to produce new, highly non-linear formulations for surface and sub-surface runoff (MISBA). These new formulations can be readily applied to most existing SVATs. Stand alone mode simulations using the GEM data demonstrate that MISBA significantly improves streamflow predictions despite requiring two fewer parameters than OISBA. Simulations using the ERA-40 data show that it is possible to reproduce the annual variation in monthly, mean annual, and annual minimum flows at GCM scales without using downscaling techniques. Finally, simulations using a simple downscaling scheme show that the better performance of higher resolution datasets can be primarily attributed to improved representation of local variation of land cover, topography, and climate.

A Comparison of Trends in Hydrological Variables for Two Watersheds in the Mackenzie River Basin

A study of trends and variability of hydrological variables was conducted for natural streamflow gauging stations within two watersheds that are important sources of flow within the Mackenzie River Basin. A comparison was made between trend results for the Liard River Basin and for the Athabasca River Basin. These basins represent a north-south transect of high elevation headwater basins within the Mackenzie River system and are significant since they produce 34% of the annual flow, while occupying only 24% of the total drainage area. Trend analysis was conducted using the Mann-Kendall test with an approach that corrects for serial correlation. The global (or field) significance of the results for each watershed was evaluated using a bootstrap resampling approach. The relationships between trends in hydrological variables and trends in meteorological variables were investigated using partial correlation analysis. The results reveal more trends in some hydrological variables than are expected to occur by chance. In general, both basins exhibit an increase in winter flows and some increase in spring runoff. These increased flows are somewhat offset by decreases (not field significant) in summertime flow. Almost 50% of the stations used in the analysis show an increasing trend in annual minimum flows. Other differences in trend responses are noted for the two watersheds and possible explanations for the differences are hypothesized.

Using reproductive endpoints in small forage fish species to evaluate the effects of Athabasca Oil Sands activities.

The main objective of this study was to evaluate the influence of naturally occurring oil sands-related compounds (OSRC) on reproductive function in fish in order to assess the impacts of anthropogenic point-source inputs. The health of slimy sculpin (Cottus cognatus) and pearl dace (Semotilus margarita) collected from the Alberta Athabasca Oil Sands (Canada) watershed were examined. Two rivers were selected for study: the Steepbank and the Ells. These rivers originate outside the oil sands formation, where fish are unexposed (Ref), exposed to naturally occurring oil sands-related compounds (Nat), or exposed to naturally occurring compounds as well as adjacent to surface mining activity (Dev). Assessment endpoints included gonadosomatic indices (GSI), fecundity, and in vitro gonadal steroid production. In vitro gonadal incubations demonstrated lower levels of steroid production at sites along the Steepbank River within the oil sands deposit. Hepatic 7-ethoxyresorufin-O-deethylase (EROD) activity, an indicator of exposure to OSRC, was elevated twofold at the site with natural compounds and up to 10-fold at the site adjacent to development compared to EROD activity in fish from the reference site. Fish collected in the Ells River had a threefold induction in EROD activity but no significant reduction in steroid production when compared to reference fish. No consistent alterations in gonadal development were seen in fish collected from sites within the oil sands deposit. This research in the Athabasca River basin provides baseline information of the health of fish populations within the oil sands deposit prior to further development in the area.

Preliminary characterization and source assessment of PAHs in tributary sediments of the Athabasca River, Canada

The Athabasca Oil Sands are one of four natural oil sands deposits in Northern Alberta, Canada. As a number of new mines are planned in the area, there is a need to establish background levels of natural hydrocarbon release prior to these developments. To this end, various environmental samples were taken from selected tributaries in the oil sands region of the Athabasca River Basin and analysed by gas chromatography/mass spectrometry (GC/MS) for polycyclic aromatic hydrocarbons (PAHs) and their alkylated analogues. Samples were collected over 3 years (1998–2000) to provide an increased understanding of the spatial distribution, nature and extent of natural hydrocarbon release to the environment. Results indicated that levels of total PAHs were elevated in the tributaries (up to 34·7μg/g) compared to the main stem Athabasca River (<2μg/g). As expected, samples from the oil sands deposits contained the greatest amounts of PAHs and alkylated PAHs. Profiles of the alkylated PAH distributions were very similar, indicating that all the samples tested were from a common petrogenic source.