![(a) Relationship between concentrations of 28 PAHs in the Muskeg River upstream and downstream of industrial oil sands development (raw data from [21]). Some points overlap; axes are log10 transformed. (b) Ratio of downstream : upstream alkylated PAH concentrations. (c) Difference in concentration for alkylated PAHs between downstream and upstream sites (n = 17).](https://www.researchgate.net/profile/Kevin-Timoney-2/publication/228662176/figure/fig1/AS:671514777120777@1537113007297/Fig-2-a-Relationship-between-concentrations-of-28-PAHs-in-the-Muskeg-River-upstream_Q320.jpg)
![Trend in mean mercury concentration (+/-1 SE) in muscle of mature walleye of the lower Athabasca River. Raw data: 1976, n = 59, from [94]; 1992, n = 12, from [95]; 2005, n = 25, from [21].](https://www.researchgate.net/profile/Kevin-Timoney-2/publication/228662176/figure/fig2/AS:671514777112584@1537113007361/Fig-4-Trend-in-mean-mercury-concentration-1-SE-in-muscle-of-mature-walleye-of_Q320.jpg)
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Does the Alberta Tar Sands Industry Pollute? The Scientific Evidence
Abstract and Figures
The extent to which pollution from tar sands industrial activities in northeastern Alberta, Canada affects ecosystem and human health is a matter of growing concern that is exacerbated by uncertainty. In this paper we determine whether physical and ecological changes that result from tar sands industrial activities are detectable. We analyze a diverse set of environmental data on water and sediment chemistry, contaminants in wildlife, air emissions, pollution incidents, traditional ecological observations, human health, and landscape changes from the Athabasca Tar Sands region, Canada. Increases in contaminants in water, sediment, and fishes downstream of industrial sources; significant air emissions and major pollution incidents; and the loss of 65,040 ha of boreal ecosystems are documented. Present levels of some contaminants pose an ecosystem or human health risk. The effects of these pollutants on ecosystem and public health deserve immediate and systematic study. Projected tripling of tar sands activities over the next decade may result in unacceptably large and unforeseen impacts to biodiversity, ecosystem function, and public health. The attention of the world's scientific community is urgently needed.
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... If the CAPP (2013) assertion that 80% of tailings water is recycled is accepted at face value, then ~ 131 million m 3 of tailings were added to the tailings ponds each year (as of 2008). If the local Morton's shallow lake evaporation (1980( -2009( , AESRD, 2013 of 590 mm/yr is combined with the 2008 Fort McMurray precipitation (420 mm), the net evaporative loss from the 2008 tailings pond footprint of 120.6 km 2 (Timoney & Lee, 2009), approximated 20 million m 3 in 2008, yielding a net annual addition to the tailings pond volume of 111 million m 3 . At that time, escaped seepage from the then 14 tailings ponds in the bitumen sands region was estimated to be in the range of 4-9.5 million m 3 /year (Environmental Defence, 2008). ...
... If the CAPP (2013) assertion that 80% of tailings water is recycled is accepted at face value, then ~ 131 million m 3 of tailings were added to the tailings ponds each year (as of 2008). If the local Morton's shallow lake evaporation (1980( -2009( , AESRD, 2013 of 590 mm/yr is combined with the 2008 Fort McMurray precipitation (420 mm), the net evaporative loss from the 2008 tailings pond footprint of 120.6 km 2 (Timoney & Lee, 2009), approximated 20 million m 3 in 2008, yielding a net annual addition to the tailings pond volume of 111 million m 3 . At that time, escaped seepage from the then 14 tailings ponds in the bitumen sands region was estimated to be in the range of 4-9.5 million m 3 /year (Environmental Defence, 2008). ...
Based on analysis of documents obtained in public databases and under freedom of information requests, this study assessed the Alberta Energy Regulator’s (AER) monitoring and management of bitumen tailings spills. The AER’s claims of no environmental impacts at any tailings spills lack corroborative environmental data. Claims of perfect spill recovery in 75% of tailings spills are not supported by credible evidence. AER’s spill footprints are unrealistically small relative to the spill volumes. The reported number of spills and total spill volumes are underestimates of the true rates. Reported spill locations are imprecise and inaccurate. For many spills, incident dates are not being accurately reported. The AER claim of routine inspections of spills is not supported by data; only ~ 3.2% of reported tailings spills are inspected. The AER’s tailings spill data lack the ecological, biological, and chemical data required to assess and manage the environmental impacts of tailings spills. Approximately 41–54% of tailings spill sites with photographic documentation showed evidence of environmental harm. If similar rates of harm in relation to tailings spill volumes apply to spills lacking photographic evidence, environmental harm would be inferred in 23–36% of those spills. The AER’s failure to gather credible and relevant environmental data, conduct routine on-site inspections, and protect ecosystems from harm is inconsistent with its regulatory responsibilities. As a result of chronic mismanagement since 1967, ecological risks will persist for decades. The true magnitude of the ecological impacts of tailings spills may never be known.
... Studies have demonstrated that oil sands industrial activities have resulted in environmental impacts inside the region, as well as in areas beyond the specific oil sands deposit footprint (Kelly et al. 2009(Kelly et al. , 2010Schwalb et al. 2015). The effects of contamination on ecosystem health and biodiversity (Hebblewhite 2017;Timoney and Lee 2009), including wildlife of subsistence, livelihood, and traditional and cultural importance (Schindler 2013;Timoney and Lee 2009), have been an enduring concern among Indigenous groups living within or near the region (Natcher et al. 2020b). However, despite the long-standing public expression of these concerns, and the establishment of government and industry funded multidisciplinary environmental research and monitoring, it is only recently that environmental research programs involving Indigenous peoples have become more common in the oil sands region (Beausoleil et al. 2021). ...
... Studies have demonstrated that oil sands industrial activities have resulted in environmental impacts inside the region, as well as in areas beyond the specific oil sands deposit footprint (Kelly et al. 2009(Kelly et al. , 2010Schwalb et al. 2015). The effects of contamination on ecosystem health and biodiversity (Hebblewhite 2017;Timoney and Lee 2009), including wildlife of subsistence, livelihood, and traditional and cultural importance (Schindler 2013;Timoney and Lee 2009), have been an enduring concern among Indigenous groups living within or near the region (Natcher et al. 2020b). However, despite the long-standing public expression of these concerns, and the establishment of government and industry funded multidisciplinary environmental research and monitoring, it is only recently that environmental research programs involving Indigenous peoples have become more common in the oil sands region (Beausoleil et al. 2021). ...
The braiding of Indigenous knowledge systems and Western-based sciences offers insights into ecology and has emerged as a way to help address complex environmental issues. We reviewed the publicly available ecological research involving the braiding of Indigenous knowledge systems and Western-based sciences to support collaborative work in the Alberta oil sands region of Canada. We conducted a systematic review, coding for 78 questions in six categories: (1) literature search and bibliographic information; (2) research themes; (3) study setting and design; (4) knowledge systems; (5) power relationships, colonization, and ethical considerations in research; and (6) benefits and challenges of braiding. We identified six articles that braided knowledge, with those articles focusing on environmental management and monitoring for impacts of industrial activity in northern Alberta. Researchers used a broad range of approaches to gather Indigenous knowledge and scientific data and identified multiple challenges (e.g., asymmetries of power, resource availability, and funding) to research. Our findings show that more support is needed to foster, promote, and disseminate interdisciplinary collaborative work involving braiding. Additional support is also required to address Indigenous community research needs related to the assessment of environmental impact and reclamation, as well as the understanding of ecological threats across the region.
... The northern boreal ecoregion of Canada and its freshwater habitats are exposed to both development stress, mainly through resource extraction, and recreational activities including fishing [1,20,34,35]. Approved anthropogenic impacts like logging or mining in the northern boreal ecoregion are often compensated for by creating new lakes either from the ground up or by repurposing mining pits [36]. These newly created ecosystems rely on expert knowledge to ensure trophic and community stability in the long run [36][37][38]. ...
An important top-down predator, the northern pike (Esox lucius), faces harsh environmental conditions in the northern boreal ecoregion. They are often managed for recreational fishing and, more recently, to create environmental offsets; strategies aimed at balancing ecological impacts by enhancing or restoring habitats. Our study examines northern pike populations in two remote boreal lakes in northern Alberta: Steepbank and Wappau. The lakes differ in size, vegetation cover, and trophic status, providing a natural experiment for investigating northern pike growth, condition, diet, and population density. Over three years (2018–2020), northern pike were sampled using gill nets. Population metrics, including growth, condition, and stomach contents, were compared between the lakes. Steepbank, a smaller, oligotrophic lake with low vegetation cover, showed lower prey fish densities compared to the larger, eutrophic Wappau, but it did not differ in northern pike catch per unit effort. Growth rates and body condition varied significantly between the lakes, with the northern pike in Wappau exhibiting faster growth and a better condition in the older age groups, while the younger northern pike in Steepbank had higher relative weights. A diet analysis revealed significant differences in prey consumption: Steepbank northern pike displayed higher rates of conspecific predation and invertebrate consumption, particularly in the younger age classes. These findings highlight how lake characteristics and prey availability shape northern pike population dynamics, offering valuable insights for lake management approaches in northern Alberta.
... During the following two decades, periodic environmental reassessments reiterated this need (PADIC 1987;PADTS 1996), but a long-term delta-wide lake monitoring program has remained elusive even as concern has grown over aquatic ecosystem degradation (e.g., Prowse and Conly 1998;Schindler and Donahue 2006;Schindler and Smol 2006;Schindler 2010). Primary concerns include observed and recorded drawdown of lake and river water levels, variably attributed to hydroelectric regulation of Peace River flow and climate (e.g., PADPG 1973;Prowse and Conly 1998;Peters and Prowse 2001;Peters et al. 2006b;Wolfe et al. 2012Wolfe et al. , 2020Beltaos 2014Beltaos , 2018Beltaos , 2019Hall et al. 2019;Timoney et al. 2019;Lamontagne et al. 2021;Kay et al. 2024), and the potential for pollution of aquatic ecosystems by contaminant emissions from upstream oil sands development (e.g., Timoney and Lee 2009;Schindler 2010;Hebert et al. 2013Hebert et al. , 2019Evans et al. 2016). In 2014, MCFN formally petitioned that UNESCO inscribe Wood Buffalo National Park (WBNP) on the List of "World Heritage In Danger", in part because industrial activities pose serious threats to "Outstanding Universal Values" of the PAD's aquatic ecosystems (note that ∼80% of the PAD lies within WBNP), and "provincial and federal monitoring of the effects of upstream activities and climate change on WBNP and the PAD has been wholly inadequate" (MCFN 2014;page 34). ...
In a multistressor world, evidence-based stewardship of aquatic ecosystems requires long-term monitoring data to understand the timing and magnitude of environmental change and potential causes. At the Peace-Athabasca Delta (PAD; northeastern Alberta, Canada), concern for aquatic ecosystem degradation has triggered renewed and urgent calls by Indigenous, national, and international governance bodies for implementation of a long-term lake monitoring program capable of tracking changes in hydrological conditions and contaminant deposition attributable to major energy projects located upstream, climate change, and other unnatural and natural processes. Challenges imposed by the delta's size, hydrological complexity, inaccessibility of lakes, and other factors, however, have long impeded implementation of a delta-wide lake monitoring program. To address this pressing need, here we review and synthesize results obtained during 7 years (2015–2021) of intensive, multifaceted research at 60 shallow lakes spanning the delta's broad hydroecological gradients to inform an integrated hydrology, water chemistry, and contaminants monitoring program. The research involved systematic, repeated measurements of water isotope composition, water depth variation, water chemistry and turbidity, and metal(loid) concentrations in lake surface sediment and periphytic biofilm. Results reveal marked spatial and temporal variation of hydrological processes and their affects on lake water balance and depth, strong association between hydrological processes and lake water chemistry, and that concentrations of nickel and vanadium (key oil sands indicators) remain within the range of natural variation. Correspondence of generalized additive model trendlines for isotope-derived lake evaporation-to-inflow ratios and water chemistry with climate indices (Pacific Decadal Oscillation, Oceanic Niño Index) demonstrates the sensitivity, and predictability, of lake ecosystem processes in the delta to large-scale climatic patterns. We provide recommendations for field sampling, sample analysis, data display, and integration of information for ongoing monitoring at the PAD. These approaches are readily transferable to other complex landscapes with abundant shallow waterbodies threatened by multiple stressors that may alter hydrological regimes and contaminant delivery.
... By 2014 the major industrial sources of PAHs to the AOSR remained unknown, and new emission pathways were still being proposed, including off-gassing from tailings (Parajulee and Wania, 2014a). Wildfires were known to make a background contribution (Schuster et al., 2015), while prospective anthropogenic sources included upgrader stack emissions, exhaust from diesel and gasoline vehicles, wind-blown particles from oil sands ore, haul road dust, and fine tailings dust (Ahad et al., 2014;Wania, 2014a, Parajulee andWania, 2014b;Timoney and Lee, 2009). In 2016, the major by-product material from the coking process, called petroleum coke (petcoke), was considered as a source of PAHs to the region for the first time. ...
Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) has increased in northern Alberta, Canada, due to industrial development in the Athabasca oil sands region (AOSR). However, the sources, summertime deposition fluxes and associated spatial patterns are poorly characterized, and the magnitude of contamination has not been directly contrasted with comparable measurements around large Canadian cities. PAHs were measured in Sphagnum moss collected from 30 bogs in the AOSR and compared with reference moss collected from various remote, rural and near-urban sites in Alberta and Ontario. At all 39 locations, strong correlations between depositional fluxes of PAHs and accumulation rates of ash (n = 117, r = 0.877, p < 0.001) implied that the main source of PAHs to moss was atmospheric deposition of particles. Average PAH concentrations at near-field AOSR sites (mean [SD], 62.4 [24.3] ng g-1) were significantly higher than at far-field AOSR sites (44.9 [20.8] ng g-1; p = 0.038) or the 7 reference sites in Alberta (20.6 [3.5] ng g-1; p < 0.001). In fact, average PAH concentrations across the entire AOSR (7,850 km2) were approximately twice as high as in London, ONT, or near petroleum upgrading and major traffic corridors in Edmonton, AB. A chemical mass balance model estimated that both delayed petcoke (33% of PAHs) and fine tailings (38% of PAHs) were the major sources of PAHs in the AOSR. Over the 2015 summer growing season, we estimate that 101 - 110 kg of PAHs (on 14,300 - 17,300 tonnes of PAH-containing dusts) were deposited to the AOSR within a 50 km radius of surface mining. Given that the highest PAH deposition was to the northern quadrant of the AOSR, which includes the First Nations community of Fort MacKay, further dust control measures should be considered to protect human and environmental health in the region.
... Since then, periodic government-led reassessments of environmental conditions at the PAD have reiterated this need but a long-term delta-wide aquatic ecosystem monitoring program has remained elusive, even as concern has grown over environmental degradation of the delta's aquatic ecosystems. This primarily includes observed and recorded drawdown of lake and river water levels, variably attributed to hydroelectric regulation of Peace River flow and climate [32,[35][36][37][38][39][40][41][42][43][44][45], and the potential for pollution of lakes via transport of substances of concern from upstream oil sands development along the Lower Athabasca River [46][47][48]. In 2014, the MCFN petitioned that WBNP be inscribed on UNESCO's List of World Heritage in Danger, in large part because of the threats of industrial activities to the delta's aquatic ecosystems [49]. ...
Systematic and sustainable monitoring approaches capable of tracking the status and trends of keystone characteristics are critical for detecting aquatic ecosystem degradation, identifying the influence of multiple potential stressors, informing environmental protection policy and anticipating future change. At remote lake-rich landscapes, ability to implement and maintain long-term monitoring is often challenged by logistical and financial constraints. At the Peace-Athabasca Delta (PAD; northeastern Alberta, Canada), an internationally recognized remote freshwater landscape threatened by climate change and upstream industrial development (hydroelectric regulation of river flow, oil sands mining and processing), the need for an integrated aquatic ecosystem monitoring program has long been recognized to track changes to the flood regime, water balance, water quality, and contaminant deposition in the abundant shallow lakes. The remoteness and hydrological complexity of the landscape, among other factors, have hindered the implementation of such a program. In recent years, concern over aquatic ecosystem degradation has led to renewed and urgent calls by international and national governance agencies for implementation of a long-term monitoring program. Here, we report on intensive, multi-faceted research performed during 2015-2021 at 60 lakes spanning the delta’s broad hydroecological gradients to develop, evaluate, and apply a framework for integrated assessment of status and trends in water balance, water chemistry and contaminant enrichment. We present the design and approaches used, synthesize the knowledge gained from data collected during the 7-year-long research phase, and provide a foundation for a long-term aquatic ecosystem monitoring program that addresses several recommendations stemming from assessments by UNESCO and key priorities within the Wood Buffalo National Park Action Plan. We suggest the monitoring framework is readily transferable to other remote shallow lake- and pond-rich landscapes threatened by multiple potential stressors.
... Contemporary contamination from the Alberta Oil Sands activities can enter the environment through several pathways, e.g. spills during transport, tailing ponds, pipeline leaks, and stack emissions (Timoney and Lee, 2009). There are numerous reports of sediment contamination linked to extraction in the Fort McMurray area and the erosion of natural exposures (e.g. ...
Oil spills and natural oil seeps are sources of petrogenic hydrocarbons in soils and sediments. To determine the source of hydrocarbon contamination in the environment the geochemical signature of the contaminant needs to be characterised. Here, we present biomarker and other molecular marker diagnostic ratios of Alberta Oil Sands using gas chromatography-mass spectrometry to characterise the deposits and detect their incorporation in surficial sediments. Diagnostic ratios of steranes, terpanes, and aromatic steroids (e.g., C27, C28, and C29 regular sterane abundance, Gammacerane Index, Ts/Tm, TAS/(TAS+MAS), and MPI-2) were measured in samples of Alberta Oil Sands providing a set of criteria for their identification. Seven surficial sediment samples from central and southeast Alberta were then analysed using these criteria to detect Alberta Oil Sands contamination and other petrogenic and pyrogenic source inputs. Geochemical signatures consistent with Alberta Oil Sands hydrocarbons were identified in surficial sediments in Lamont County and glacial sediments from a moraine in Beaver County. Both sites are in Central Alberta, ~300 km south of any oil sands extraction sites and natural exposures in northern Alberta, indicating long-distance sediment transport processes mobilised the deposits. These results show that the oil sands have been eroded and transported beyond the boundaries of their current known limits. This is important for understanding sediment transport processes as well as for remediation and reclamation purposes.
Oil sands development in the Athabasca and Cold Lake oil sands regions of Alberta has raised concerns about potential impacts to groundwater and groundwater dependent ecosystems. This review summarizes the current state of understanding as to how oil sands mining and in situ activities can affect groundwater systems using a stressor-mechanism-response framework. Specific oil sands activities and practices are reviewed, and where possible, described in terms of how they can impact hydraulic head, the hydraulic properties of aquifers, recharge and transport of constituents of concern and linked to observed or potential impacts to groundwater quantity and quality. Groundwater is an important component of the water balance in boreal ecosystems, and specific vulnerabilities related to development are reviewed, including water use, landscape disturbance, groundwater withdrawals, tailings pond seepage, deep well disposal and thermal impacts. Knowledge gaps include lack of baseline data and monitoring of the quantity and quality of groundwater discharge to rivers, lakes and wetlands. One key monitoring challenge is attribution of hydrogeologic responses to specific oil sands stressors given the range of other natural and anthropogenic factors contributing to their variability. Quantitative groundwater exchange mapping, regional-scale isotope mass balance assessment, and broader incorporation of isotopic and geochemical tracers for fingerprinting water sources and incorporation of Indigenous Knowledge appear promising for improved effectiveness of monitoring.
The impact of bitumen components on soil and groundwater resources is of environmental importance. Contaminants’ influx into the environment from bitumen components through anthropogenic activities such as exploration, mining, transportation, and usage of bitumen in all its forms have been reported globally. However, gaps exist in the geogenic occurrence of bitumen in the shallow subsurface such as in southwest Nigeria, contaminating the soil and groundwater resources. This review presents in situ bitumen seeps as a source of geogenic soil and groundwater contaminants in southwestern Nigeria. We conducted a systematic review of literatures based on defined selection criteria. We derived information on the state of knowledge about bitumen seep occurrences and distribution in southwestern Nigeria. Also, the processes that exacerbate bitumen contaminants’ influx into soil and groundwater were enunciated. At the same time, case examples highlighted areas for possible in situ bitumen contamination studies in Nigeria. The results of this review showed that a multidisciplinary approach has been employed to assess and monitor the contaminants resulting from the various activities involving the exploitation and application of bitumen in Nigeria. These studies emphasize bitumen contaminants as emanating from anthropogenic sources. The results also suggested that bitumen studies have been mainly exploratory to improve the understanding of the economic potential of the hydrocarbon reserve. Also, recent advances in bitumen contaminants studies accounted for the heterogeneous nature of the bitumen. This allows for the optimized categorization of the mechanism and processes undergone by the different bitumen components when released as environmental contaminants. However, a knowledge gap exists in characterizing and understanding the effects of in situ bitumen seeps as a geogenic source of soil and groundwater contamination. This review identifies the possibility of geogenic soil and groundwater contamination by in situ bitumen seeps in the coastal plain sand of the Dahomey basin in southwestern Nigeria. The impact of the bitumen contaminants on the environment was discussed, while methods for accessing the occurrence and distribution of the bitumen contaminants were highlighted.
Fort Chipewyan is a small community located approximately 600 kilometres north-east of Edmonton, Alberta, Canada. In 2006, Dr. John O’Connor, a physician working in Fort Chipewyan, reported a high number of cases of cholangiocarcinoma, a rare form of bile duct cancer, as well as high rates of other cancers.
Local residents echoed his concerns, attributing cancers in their community to environmental contamination from a range of industrial development including the oil sands 250 kilometres upstream, uranium mining and pulp mills.
An initial review of the Alberta Cancer Registry, the usual first step, did not confirm an increased incidence of cancer in Fort Chipewyan.
The community called for a further investigation, and after Dr. O’Connor submitted his list of cases in August 2007, a working group was formed to support the Alberta Cancer Board in doing a cluster investigation based on the guidelines of the U.S. Centre for Disease Control and Prevention.
The observed cases of cholangiocarcinoma and colon cancer during the period of investigation (1995-2006) are within the expected range of cancer occurrence.
The number of cancer cases overall was higher than expected. In particular, increases of observed over expected were found for biliary tract cancers as a group and cancers of the blood and lymphatic system. These increases were based on a small number of cases and could be due to chance or increased detection. The possibility that the increased rate is due to increased risk in the community, however, cannot be ruled out.
The increased number of cases of biliary tract cancers, cancers in the blood and lymphatic system and cancers of unknown primary seen in the most recent six years (2001-2006) compared to the years 1995-2000 of the investigation warrant closer monitoring of cancer occurrences in Fort Chipewyan in the coming years.
Further investigation is required to evaluate if there is a risk posed by living in Fort Chipewyan. This would be done by tracking a cohort of residents who have lived in the area within the past 20 to 30 years.
As part of an overall assessment of the health status of the community, further analysis should also be done of many potential risk factors, such as lifestyle risk factors, family history and occupational and environmental exposures.
Six international independent experts, chosen by the government, media, and the Aboriginal community peer reviewed the report.
For almost 25 years our laboratory has studied the impact of PAHs and related industrial contaminants on benthic fish, following an interdisciplinary approach involving chemical exposure assessment linked to synoptic detection of various effects at several levels of biological organization. These data demonstrate a cause-and-effect relationship between neoplastic and neoplasia-related liver lesions in English sole, and exposure to PAHs, and to a lesser degree, chlorinated hydrocarbons such as PCBs. In statistical analyses of data from multiple field studies conducted since 1978, exposure to PAHs measured in various compartments has consistently been identified as a highly significant, major risk factor for neoplasms and related lesions in this species, with PCB exposure shown to be a significant, but less consistent and less strong risk factor for these lesions. A cause-and-effect relationship between PAHs and toxicopathic liver lesions in this species is further supported by the experimental induction of toxicopathic lesions identical to those observed in field-collected fish, in sole exposed in the laboratory to model carcinogenic PAHs such as BaP or to PAH-rich extracts of sediments from Eagle Harbor, a severely PAH-contaminated site in Puget Sound. More recent field studies have identified significant associations between hepatic cytochrome P4501A (CYP1A) induction and xenobiotic-DNA adduct formation, and hepatic lesion prevalences in wild subadult English sole. Field studies in Eagle Harbor subsequent to capping of the most PAH-contaminated region of this harbor with clean dredge spoils have shown a decline in exposure to PAHs as assessed by biliary fluorescent aromatic compounds (FACs) and hepatic xenobiotic-DNA adducts. This decline in PAH exposure has been accompanied by a dramatic decline in risk of occurrence of toxicopathic hepatic lesions in English sole from Eagle Harbor. Further, laboratory studies have induced lesions in English sole by injections of extracts from PAHcontaminated sediments. Overall, these findings relating to exposure to PAHs and chlorinated hydrocarbons and the occurrence of hepatic neoplasms and neoplasiarelated lesions in English sole fulfill the classic criteria for causality in epizootiological or ecological risk assessment studies, including: (1) strength of association, (2) consistency of association, (3) specificity of association, (4) toxicological and biological plausibility, (5) temporal sequence/timing (i.e., exposure precedes disease, effect decreases when the cause is decreased or removed), (6) dose-response or biological gradient, and (7) supportive experimental evidence.
The oil sands operations in northern Alberta are among the most modern in the world. However, because the operations are extensive and lie on either side of the Athabasca River, there are concerns that they will adversely affect downstream environments such as the Athabasca River, its tributaries, the Peace-Athabasca deltas and Lake Athabasca. Research and monitoring programs are now investigating hydrocarbon sources, fate, and time trends in-these aquatic ecosystems. Natural hydrocarbon sources (oil sands) are numerous along the Athabasca River and its tributaries. Petrogenic hydrocarbons also are abundant in downstream lakes. Lower molecular weight compounds such as naphthalene and fluorene tend to increase in concentration from upstream sources to downstream depositional areas. There is little or no evidence of temporal trends of increasing PAH concentrations in sediment cores collected in Lake Athabasca and the Athabasca delta lakes, suggesting no or minimal impact from the oil sands operations. Some PAHs exceed interim sediment quality guidelines and some bioassay studies have showrr evidence of toxicity, particularly in the Athabasca delta. However, there is no evidence that this is associated with the oil sands industry. The RAMP monitoring program will continue to assess the potential impacts of the oil sands industry on river, tributary and delta ecosystems.
Gross examination of a spawning run of walleye (Stizostedion vitreum vitreum) showed a large proportion of fish to have tumors on the body and fins that appeared to be characteristic of lymphocystis disease. Light and electron microscopic examination revealed the presence of two distinct tumor types. One was characteristic of lymphocystis, consisting of typical enlarged nonneoplastic cells surrounded by hyaline layers and containing many 260 nm diameter lymphocystis virus particles in the cytoplasm. The other tumor, referred to as a dermal sarcoma, consisted of a solid mass of normal-sized cells and contained in the cytoplasm large numbers of 135 nm diameter virus particles referred to as walleye dermal sarcoma (WDS) virus. The WDS virus was similar in appearance to the leukoviruses and, with its outer layer sectioned tangentially, exhibited symmetry like a member of a leukovirus group designated by Fenner as subgenus C.
Tailings ponds are an integral part of oil sands mining development in northeastern Alberta, but waterfowl and shorebirds often land in these ponds during spring migration where they may become covered with oil. For decades, managers have developed and implemented methods for deterring birds from landing in these ponds, yet no deterrent strategy is fully effective. Therefore, to enhance deterrence strategies, it will be important to understand the environmental conditions that influence bird use of tailings ponds. This study quantified waterfowl flights over, and use of, tailings ponds and compared this use to waterfowl activity at natural waterbodies in the region over a single spring migration period. Results suggest that waterfowl are most likely to land on tailings ponds before lakes have thawed, after which migratory ducks appeared mainly to use natural waterbodies for migratory stopover sites. Very high numbers of waterfowl were observed on one waterbody, Kearl Lake, suggesting that this lake may be of greater importance to spring staging waterfowl than previously thought. A small sample of birds oiled at tailings ponds were examined in relation to spring weather conditions. Logistic regression analysis demonstrated that the probability of birds being oiled tended to increase with precipitation levels. Results of this study suggest that (1) preservation of natural waterbodies may play an important role in minimizing bird use of tailings ponds, and (2) future bird deterrence efforts should especially aim to deter birds during rainy weather conditions when birds may be more likely to become oiled. These results were from a small sample size, are preliminary in nature, and should be interpreted with caution. A concerted and careful effort to collect and thoroughly analyze long-term records of oiled birds may reveal important environmental effects predicting bird oiling events.
Mercury is one of the most hazardous contaminants that may be present in the aquatic environment, but its ecological and toxicological effects are strongly dependent on the chemical species present. Species distribution and transformation processes in natural aquatic systems are controlled by various physical, chemical, and biological factors. Depending on the prevailing environmental conditions, inorganic mercury species may be converted to many times more toxic methylated forms such as methylmercury, a potent neurotoxin that is readily accumulated by aquatic biota. Despite a considerable amount of literature on the subject, the behavior of mercury and many of the transformation and distribution mechanisms operating in the natural aquatic environment are still poorly understood. This review examines the current state of knowledge on the physicochemical behavior of mercury in the aquatic environment, and in particular the environmental factors influencing its transformation into highly toxic methylated forms.
The aluminium, potassium, sulphur, titanium, and vanadium contents of the lichens Cladina arbuscula (Wallr.) Hale and W. Culb., Evernia mesomorpha Nyl., and Hypogymnia physodes (L.) Nyl. were determined for up to 69 sites in the Athabasca oil sands area in northern Alberta. The element accumulation by these lichens was related to both gaseous and particulate emissions from industrial sources and to a localized windblown dust component. The deposition of atmospheric emissions around an oil-extraction plant as measured by lichen thallus concentration closely followed the distribution patterns measured by physical and chemical methods. Visible changes in the thallus condition appeared to be related to the element concentrations.
Oil sands mining is one of several industrial activities that produces effluent that is dangerous to waterfowl. Such industries require effective systems to deter birds, but current deterrents are not always successful, presumably because wildlife ignore or habituate to them.
We tested a new radar‐activated on‐demand system of deterrence in the oil sands region of Alberta, Canada, by comparing the proportion of birds that landed on a tailings pond while it was activated with the proportion that landed during two other treatments: a continuous, randomly activated, deterrent system, and control periods with no deterrents. We also assessed the efficacy of different stimuli types within the on‐demand system.
Across several bird guilds, only the on‐demand deterrent system significantly reduced the probability of birds landing in comparison with the control treatment. In addition to treatment effects, birds were more likely to land earlier in the spring and when they flew at lower altitudes, and shorebirds were more likely to land than ducks, geese and gulls.
The comparison of stimuli revealed that cannons elicited significantly more response by birds in flight than mechanized peregrine falcon effigies with speakers broadcasting peregrine sounds.
Synthesis and applications. Our results promote the use of on‐demand systems for waterfowl deterrence at tailings ponds and recommend cannons over effigies as stimuli. We suggest that oil sands deterrence efforts should (i) be operational in the early spring, when tailings ponds appear to be most attractive to migrating waterfowl, (ii) target low‐flying waterfowl and shorebirds and (iii) be effective during both day and night. These results and recommendations have potential application for problems of bird deterrence at several other industrial sites.