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NRBS - HomeTable of Contents |
Northern River Basins Study Final Report
3.0 Major Findings
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Ecosystem HealthIn this report, cumulative effects are categorized into several key issues relating to ecosystem health: the effects of chemicals, changes to flow regimes, the effects of nutrients and dissolved oxygen, the health of aquatic biota, and effects and implications for human populations. Cumulative Effects of Chemicals
Major findings related to cumulative effects of chemicals are illustrated in figure 3.14.1. A priority of NRBS research was to collect information regarding levels of organochlorines and other contaminants in the aquatic environment. Environmental concentrations of chlorinated organic compounds, such as dioxins, furans, chlorinated resin acids, and chlorophenols, have declined overall since the late 1980s, but are still found in detectable levels in sediments and fish in the basin. Traces of pulp mill-related compounds in sediments from Great Slave Lake confirm that these compounds are transported great distances downstream. The reductions are partly due to improved mill technologies that have reduced effluent loadings of certain contaminants, especially organochlorine contaminants. Environmental processes have also influenced the distribution of contaminants within the ecosystem; for instance, the annual influx of sediment tends to bury previously contaminated sediments.
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Generally, highest concentrations of chlorinated compounds still tend to occur in reaches immediately below pulp mill effluent inputs. The highest levels of organochlorine compounds (dioxins and furans) associated with sediments and aquatic life were measured in the reach between Hinton and the Emerson Lakes sampling site on the upper Athabasca River. Levels of specific contaminants in sediments from this reach exceed guidelines developed by the Canadian Council of Ministers of the Environment. Higher frequencies of physical abnormalities in aquatic invertebrates confirm that this reach of the Athabasca River has been subjected to the cumulative effects of development. Research has confirmed that the atmosphere is a source of contaminants (including PCBs) However, the variation in PCB concentrations across the basins suggests the existence of additional point-sources. Higher PCB levels in burbot were found in the Wapiti / Smoky Rivers, the Peace River and the Athabasca River downstream of Hinton and Whitecourt. Elevated PCB levels in sediments were found in the Wapiti / Smoky Rivers and in the Peace River upstream of the Smoky River confluence. Higher PCB concentrations in some reaches of the Wapiti / Smoky and Athabasca River basins may be related to point-source inputs into the environment, such as those occurring from spills. In three locations within the Peace River drainage, observed levels of PCBs in burbot doubled between 1992 and 1994. The reason for this is unclear, but deserves further investigation. Higher PCB concentrations in some fish species may be partly related to different eating habits. Mercury contamination of fish is a concern among basin residents. In contrast to the downward trend of organochlorine contaminants, mercury concentrations in sediments and fish tissues throughout the basins has not changed since the late 1980s. However, one concern relates to walleye, which sometimes exceed Health Canada mercury guidelines in the lower Athabasca. Existing fish consumption restrictions in the Study area extend to walleye in the mainstem Athabasca River. Current health advisories for all fish species should be re-evaluated and adjusted based on fish consumption patterns within the basins. For more information related to mercury and fish consumption refer to Section 3.13.
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Cumulative Effects of Hydrology and Climate
Major findings related to the cumulative effects of hydrology and climate change are illustrated in figure 3.14.2. NRBS research has furthered knowledge of how flow regulation has changed the natural river flow of the Peace River system. A detailed discussion of these changes is found in Section 3.5 of this report. To summarize, within the Peace River:
Many of these effects are dampened with distance from the Bennett Dam in British Columbia. These alterations, combined with climate variability, have had a dramatic impact on the ecology of the Peace basin, including drying of the Peace-Athabasca Delta perched basins, changes to vegetation of wildlife, and alterations to the geomorphology of the mainstem Peace River. Further information regarding the impact of the Bennett Dam can be found in Section 3.5.
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On a human scale, one of the cumulative impacts of these changes is related to residents' lifestyles. Residents contacted by the Traditional Knowledge Component reveal that traditional basin residents rely on the rivers for their culture and lifestyle (Section 3.4). Not surprisingly, these hydrological changes have had a pronounced affect on their perceptions of ecosystem health and their quality of life, and have caused them to change their use of the basin resources. Many of the perceptions and commonly held beliefs of basins residents regarding the state of the basins ecosystem were corroborated by NRBS research. Some of these observations include reduced flooding in the Peace-Athabasca Delta, changes in sediment patterns along the Peace River, increased turbidity in certain river reaches and alterations to aquatic and nearshore habitats. Cumulative Effects of Nutrient Addition and Dissolved Oxygen
Zones of concern for nutrients and dissolved oxygen are illustrated in figure 3.14.3. Nutrient discharges into the northern rivers have been shown to enrich aquatic communities immediately downstream of point sources, such as pulp mills and municipalities (see Section 3.7). Currently, the cumulative effect appears to be primarily aesthetic—related to an increase in the amount of algae in reaches immediately downstream of nutrient discharges.
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During winter, dissolved oxygen levels tend to decrease naturally along the length of ice covered rivers such as the Wapiti / Smoky and Athabasca Rivers. In addition, there are noticeable "sags" below major effluent discharges from communities and certain pulp mills. Oxygen concerns exist in the Athabasca River upstream of Grand Rapids, and in the Wapiti / Smoky River system downstream of Grande Prairie to the confluence of the Peace and Smoky Rivers (see Section 3.8 for further detail). In these areas, the number of developments, combined with ice cover, significantly reduces winter dissolved oxygen levels in specific reaches. The Wapiti / Smoky system has lower flows and the oxygen depletion is much greater than in the affected Athabasca River reaches. Pulp mills are one of the larger man-made sources of oxygen-demanding substances being directed to the aquatic ecosystem. To reduce their discharge of these substances, pulp mills will often add nutrients to improve their effluent treatment process. These nutrients are intended to enhance bacterial breakdown of organic compounds in the effluent prior to its release into the environment. In such cases, any excess nutrients enter the aquatic environment and further enhance aquatic productivity, which can contribute to the use of dissolved oxygen in the aquatic environment. The cumulative effect of continued or increased nutrient loadings to these systems is currently unknown and requires further investigation.
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Health of Aquatic Biota
Several independent NRBS investigations confirm that some fish in certain areas of the northern river basins are being affected by the cumulative effects of development discharges to the aquatic ecosystem. Traditional peoples have expressed a concern over the observed decline in the quantity and quality of fish from the lower Peace and Athabasca Rivers, the Peace-Athabasca Delta and the Slave River. The cause for these changes remains largely unknown. Using a suite of biomarkers, NRBS researchers determined that some fish in select river reaches are exhibiting signs of environmental stress (see Section 3.9). Certain fish captured downstream of pulp mills displayed higher frequencies of physical abnormalities (i.e., scars, lesions, tumours, etc.) and depressed levels of sex hormones. There were also higher numbers of sexually immature fish captured immediately downstream of pulp mills. The oil sands regions located near Fort McMurray in the Athabasca River and in the Wabasca River are also sites where fish are exhibiting signs of stress. It should be noted, however, that NRBS biomarker research is currently insufficient to fully describe the nature and extent of these problems. Further research is required to understand the link between biomarker responses in individual fish and population / community level effects. A critical knowledge gap exists with regard to the availability of fish habitat, particularly in the mainstem rivers. Fish habitat in the delta regions has also been affected by changes in flow patterns and flooding frequency. These changes have greatly reduced the availability of spawning habitat for spring spawning fish and have physically isolated certain lakes and streams within the Peace - Athabasca Delta. These flow regulation effects may also be true for the Peace River.
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NRBS studies show that fish species spawn in tributaries and the mainstem rivers. They are most vulnerable to point source pollution on the mainstem systems where industry and municipalities are dominant. One critical feature of mainstem river habitat is the availability of sufficient levels of dissolved oxygen. Since low dissolved oxygen levels can impair the development and survival of fish and other aquatic organisms, it is imperative to ensure that human activities do not critically reduce these levels within the river, particularly during the winter. As with fish, benthic invertebrates are sensitive to pulp mill effluent and municipal discharges. There is evidence that nutrients in pulp mill and municipal effluent are enhancing the density of invertebrates that inhabit substrates downstream of the mills—a common enrichment response. While on a basin-wide scale substrate quality appears to be acceptable, there is some evidence indicating that the Athabasca River reach between Hinton and Whitecourt is ecologically impacted. Deformities in fish occur naturally, but NRBS studies found a slightly higher than the normal incidence of deformities immediately downstream of pulp mills in this reach. Incidences of deformities returned to normal as the river progressed downstream. Cumulative Effects and Implications to Human Use
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The NRBS generated information on topics that may be related to human health, such as drinking water quality. Furthermore, the Other Uses and Traditional Knowledge components have collected a large amount of information regarding human perceptions, values and concerns with regard to the environment, as well as their use of basin resources now and into the future. Generally speaking, other scientific findings within the NRBS have served to confirm many commonly held beliefs by basins residents regarding the quality of the basins' ecosystem. The large majority of residents received high quality drinking water from municipal treatment facilities. However, NRBS studies found several instances where the quality of treated water from small facilities failed to meet guidelines (see Section 3.10). A number of these facilities failed to meet guidelines for turbidity or microbial content. In addition, a small number of facilities exceeded guidelines for trihalomethanes—by-products of chlorine disinfection. Industrial contaminants in drinking water do not appear to be a public health issue at this time. However, some residents believe that waters downstream of pulp mills are tainted with effluent. NRBS has confirmed that tainting substances can be chemically detected hundreds of kilometres below point sources. However, concerns regarding these substances are primarily aesthetic, and levels of these compounds have decreased due to improved pulp mill technologies on the Athabasca River. Less is known on the topic of fish tainting. Anecdotal evidence suggests that fish are tainted downstream of pulp mills and in the oil sands region near Fort McMurray. Research has been unable to identify the specific tainting compounds.
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Communities situated on the lower Peace, Athabasca, and Slave Rivers insist that they are on the receiving end of pollution originating from upstream developments or industrial plants. The distance that contaminants travel downstream is a function of their specific chemical and physical characteristics within water. Traces of contaminants that are commonly associated with pulp mills can be found as far downstream as Great Slave Lake. Some aboriginal people have expressed concern regarding the quality and quantity of fish and wildlife they consume and how these species may be affected by contaminant exposure. Levels of mercury, dioxins and furans were usually at barely detectable or non-detectable levels in wild foods, including fish, waterfowl, muskrats and mink. One exception exists in the lower Athabasca River, where mercury levels in walleye often exceeded Health Canada guidelines. Fish consumption advisories are currently in place in this region. At present, there is no information that allows the NRBS to comment on long-term implications to either human or ecological health caused by long exposure to low levels of contaminants. A companion study to the NRBS (the Alberta Northern River Basins Human Health Study) will shed further light on health-related issues in the basins. Summary Of Cumulative Effects By River Reach
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As shown in the Key Findings and Cumulative Effects Assessment sections of this report, cumulative environmental effects manifest themselves at a variety of spatial, temporal, and organizational scales within the ecosystem. Although it is important not to lose sight of cumulative effects occurring at a basin-wide level and the inter-relatedness among river reaches, we now summarize our understanding of cumulative impacts on a reach-by-reach basis. This approach provides the opportunity to focus on characteristics which are unique to reaches and identify related management considerations. A summary of scientific findings is provided, as is a social perspective which was developed from input obtained at community gatherings, science fora, and through the household and traditional knowledge surveys. In addition to the individual reach profiles, a basin-wide profile is included to highlight those factors that apply throughout the basins. While this summary is inclusive of NRBS and companion investigations, we remind the reader that investigation of some facets of the ecosystem including: climate change, agriculture practices, forestry management, biodiversity and human health were beyond the scope of this study. While these issues were not investigated directly, they will almost certainly have implications for cumulative effects within the basins and should not be ignored in any future ecosystem management program.
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As well, because of the higher level of industrial pressure, primarily existing pulp mills, the NRBS science program placed a greater emphasis on the Athabasca River than on the Peace and Slave Rivers. The reader is therefore cautioned that not all issues were equally investigated in all reaches, and this reflects perceived impact priorities at the outset of NRBS. Issues not investigated (e.g., nutrient enrichment studies on the Peace River), should not be interpreted to mean that these issues are not important, rather they reflect the research and funding priorities of the NRBS. Figure 3.14.4 summarizes overall cumulative effects with the northern river basins on a reach-specific basis. This figure provides a mechanism for illustrating priority areas for environmental management and identifies issues of concern based on a weight-of-evidence approach. Within each reach a histogram, consisting of five stacked boxes, is provided. Each box represents one of the five major issues in the basins (i.e., dissolved oxygen, nutrient enrichment, hydrologic regime, human health implications and contaminants) and the shading of the box reflects the level of concern for that issue in that reach. A completely dark box indicates significant concern and a need for action. A partially shaded box indicates caution and a need for ongoing monitoring and / or further investigation. A clear box indicates that, based on current information, the issue is of minimal concern. In most cases ongoing routine monitoring should be adequate for those issues designated as being of minimal concern; however, further investigation may result in a change in designation for some of these issues. The purpose of figure 3.14.4 is to provide a general overview of cumulative effects in these basins. A more detailed description of these effects is provided on a reach-by reach basis in the following section. The histograms presented in figure 3.14.4 are provided again in this Section along with the criteria and rationale used to determine the levels of cumulative effects concern. Basin-wideScientific Summary
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The basin-wide fish surveys and other fish collections by NRBS have confirmed that dioxins and furans occur in the food web at low levels across the basins, relative to other areas in Canada. The highest detection frequencies for all 2,3,7,8-substituted dioxin / furan congeners were observed immediately downstream of bleached kraft mills. NRBS corroborates other investigations which have reported a recent decline in concentrations of dioxins and furans in fish, commensurate with improvements in pulp mill treatment technologies. Although there is evidence of PCB contamination in both the Athabasca and Peace River systems, PCDD/Fs, rather than PCBs or organochlorine pesticides, are the chemicals of concern for human exposure. Levels of TCDD and TCDF, the major contributors to toxicological concerns in these groups of compounds, are expected to decline further because of technology improvements. Low level contribution of several contaminants from the atmosphere have been demonstrated by NRBS. Fish health investigations have raised concerns about exposure of fish to contaminants, hormone disruptors and delayed sexual maturation. The vulnerability of fish to anthropogenic contaminants remains uncertain because of the general deficiency of information on fish ecology within the basins. However, the level of knowledge for larger fish in the Slave River basin is good. Natural sources and processes contribute to some of the perceived environmental problems (e.g., mercury levels in fish, eutrophication, low dissolved oxygen, taste and odour of drinking water, hydrocarbons and turbidity). The primary human health concerns related to contaminants need to be assessed by health authorities, and include dioxins, furans and mercury in fish, and trihalomethanes and bacteria / pathogens in treated drinking water (especially in communities of less than 500). Dietary information (e.g., fish consumption) obtained as part of NRBS should be useful in reviewing health implications. Science findings to date do not establish thresholds related to ecosystem health or to pollution loadings. There is a lack of long-term monitoring data related to contaminants in edible fish tissue.
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Enrichment of river reaches below pulp mill and municipal sources is observable and quantifiable. It is recommended that nutrient regulations should be developed which are ecosystem based, not technology based. Hydrologic regimes influence the state of aquatic ecosystems. The ecology of the Peace and Slave River delta systems are particularly vulnerable on account of the Bennett Dam. The quality of the Athabasca River ecosystem, although not influenced significantly by river impoundments, is highly influenced by natural variability of flows coupled with the use of the river for handling treated effluent. Climate variability is potentially a factor in explaining some of the water issues in the deltas but more research is required to expand on the NRBS findings. The ecological knowledge of traditional peoples is highly relevant and valuable to understanding the behaviour and distribution of wildlife, ecosystem functions and ecosystem responses over space and time. Current monitoring in the basins is not designed to address cumulative effects assessment needs. There remain inconsistencies across agencies with regard to scientific design, collection-analysis-data handling / storage and reporting protocols that would benefit from coordination, integration and standardization. Societal Perspective
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Overall, the public recognizes the high quality of water within the northern basins and their uniqueness relative to other areas of Canada and the world. For this reason, the public favour tight controls to protect this asset over the long-term. They are, however, concerned about the contaminants from industries and they frequently perceive fish and water to be unsafe to consume. Fish are a valued resource of the basins. As indicators of ecosystem integrity, society has indicated the need to protect fish health, population, distribution, migration and spawning behaviour and critical habitat. The public surveys of NRBS clearly reflect a need for public involvement in the decision-making affecting the sustainability of the basins' resources as well as a role in the monitoring of ecosystem health. There appears to be a general lack of public trust for industries to self-regulate and conduct their own monitoring. Management philosophies of no further degradation and zero discharge frequently surfaced in community discussions. Key Management Considerations Applicable to all Basins
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Athabasca River: Athabasca Falls to HintonScientific Summary
The Athabasca River between Athabasca Falls and Hinton reflects a unique river / tributary system (e.g., Snaring, Snake-Indian, Rocky Rivers) which is vitally important to the survival of the remnant pygmy whitefish population and the spawning movement of mountain whitefish, bull trout, and lake whitefish. Because of large populations of mountain whitefish that spawn in these areas, major habitat disruptions could have significant impacts on these species. NRBS has reported that lake whitefish likely spawn on the mainstem in the area upstream of Jasper Lake. Fish containing contaminants associated with downstream developments are known to seasonally frequent the waters of Jasper National Park. Sources of pollution in this reach are mainly municipal. Nutrient enrichment below the townsite of Jasper is readily evident in the river by the increased abundance of algae, the main impact of which appears to be on the aesthetic / recreational value of the river. The potential effects of contaminants from landfill sites have not been investigated nor have the effects of deforestation. Societal Perspective
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Public views expressed at community gatherings, science fora, past public hearings, and views expressed by the Study Board members would suggest that this reach is generally viewed as being pristine and deserving of a high level of protection. The presence of a National Park in the headwaters of the river is seen as providing a high level of protection by virtue of its non-degradation policies. Key Management Considerations Unique to Reach
Athabasca River: Hinton to Whitecourt
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Scientific Summary
The quality of water entering this reach is generally excellent (natural) but deteriorates upon receiving effluent from the town of Hinton and the Weldwood of Canada Ltd. pulp mill. With the addition of the Hinton combined effluent (HCE), there is evidence immediately downstream of nutrient enrichment in the benthic community, but no evidence in this community of acute toxicological effects; certain contaminants (e.g., dioxins, furans, PCBs and mercury) are bioaccumulated in the aquatic food chain. Depressed steroids in fish have been observed as having, what appears to be an abnormally high ratio of sexually immature to mature fish.
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The highest levels of contaminants in sediments of the Athabasca River exist in this reach, specifically below the pulp mill to below Emerson Lakes. The HCE was found (1992 / 93) to have the highest levels of TCDD/F of any effluent sampled on the Athabasca River. All mean levels of TCDD (and their toxic equivalents) in fish muscle or liver were below the Health Canada limit for commercial fish sale. A few individual fish tissues, mainly burbot liver, downstream of Hinton, exceeded the 20 pg.g-l guideline. Tainting compounds (chlorophenolics) are introduced by the effluent, and affect the palatability of water. In 1992/1993, odour causing compounds from Hinton were detected 1,200 km downstream indicating the large spatial influence of the effluent. In the 1994 survey, Hinton-related odours, although present, were not distinguishable from other influences such as from Alberta Newsprint and Millar Western pulp mills at Whitecourt. Biomarkers, bioindicators and gross pathology indicate sub-lethal influence of contaminants in this reach. The frequency of deformity is above background in the chironomid community below Hinton. Relative to elsewhere in Canada, this reach is considered to be lightly impacted by contaminants but the implications of long-term exposure to sub-lethal concentrations is still unknown. Although dissolved oxygen is not an issue in the reach, the cumulative effect of the HCE and sources in the next river reach combine to become an issue further downstream. As with all mills, there is a concern that mill effluent can, under extreme hydrologic conditions of low flows and high summer temperatures or winter ice cover, deplete oxygen to levels where the instream and / or streambed dissolved oxygen levels may threaten various life stages of fish and other biota. Societal Perspective
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Public input at community gatherings, science fora, past hearings, and household surveys suggest that this reach is generally viewed as being impacted by the HCE. Public opinion seems to favour tighter effluent regulation and monitoring and public views have included philosophies of zero discharge and capping of pollution loads. To many, no level of dioxins and furans is acceptable in effluent or the environment and the quality of the system is worth protecting from further degradation. Particular concern has been expressed about high levels of phosphorus from the HCE and the need for reduction to protect river water quality. The McLeod River has been identified as a water quality concern due to sewage effluent releases. Other concerns include: scum on surface water, garbage dumping along the river, pesticides, forestry (clear cutting) impacts, point source controls, impacts on song birds, use of chlorine, handling of toxic wastes, contamination of wildlife, and safety of drinking water. Key Management Considerations Unique to Reach
Athabasca River: Whitecourt to AthabascaScientific Summary
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The Athabasca River has naturally occurring low flows and low oxygen levels under ice conditions. The loading of organic wastes to the river are known to further reduce oxygen levels. Oxygen sags have been recorded under ice conditions immediately below Millar Western at Whitecourt. Since 1989, the minimum winter dissolved oxygen levels appear to have not fallen below 6.8 mg/L. A concern is the progressive longitudinal downstream decline in dissolved oxygen in the river until it is enhanced by the entry of the Lesser Slave River. The minimum mid water column level indicates that the oxygen level at the sediment-water interface could be as low as 4 mg/L. In order to ensure the survival of fish eggs and other biota, this level should not fall below 3 mg/L. The Pembina River displays naturally low oxygen levels during the winter and summer. Ground water is important to the base flow of the Pembina River.
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The benthic community downstream of the town of Whitecourt is reflective of nutrient enrichment. The pulp mill practice of adding phosphate to encourage biological breakdown of organic wastes prior to release into the river should be reviewed and controlled. Coal development on the upper Pembina River was not investigated; fish collected from the lower Pembina River show unusually high metallothionein induction indicating possible exposure to metals in this system. Optimal mountain whitefish spawning habitat exists in this reach. Fish health is suspect in this reach based on a high incidence of abnormalities below Whitecourt pointing to the need for in-depth investigations of the causes. Levels of dioxins, furans, PCBs, chlorinated resins acids and chlorophenols in fish and / or sediments are lower than in the reach immediately upstream but tend to be highest below Whitecourt. None of the contaminants investigated were detected at levels thought to cause acute toxicology in aquatic life. Taste and odour compounds in the river improve longitudinally throughout this reach. Societal PerspectiveStatements of concern from the public relate to issues arising during the AlPac hearings including: dissolved oxygen requirements of fish; fish quality and health; nutrient enrichment; dioxins and furans; drinking water quality; land use impacts; etc. Members of the public have identified the Pembina River as having nutrient, turbidity and dissolved oxygen problems. Other concerns include: deforestation effects on water quality, drainage of muskegs and wetlands, long-term monitoring, edibility of fish, quality of fish, mink and other wildlife, abundance of fish, spills, sewage discharges, and effluent treatment.
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Key Management Considerations Unique to the Reach
Athabasca River: Athabasca to Fort McMurrayScientific Summary
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This reach includes the AlPac pulp mill near the town of Athabasca. Dissolved oxygen levels sag below the town of Athabasca and conditions in this reach likely reflect the cumulative organic loading from upstream sources. Based on NRBS research, it is recommended that the provincial water quality objective for dissolved oxygen be increased to provide a greater safety margin for the protection of aquatic life. The influence of oil sands deposits begin to show in this reach with the natural occurrence of PAHs and other organic compounds. Overall, concentration of organochlorine contaminants in sediments and biota decline throughout this reach relative to upstream sites.
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Mercury was detected in all fish however the levels were highest in the larger-older fish, particularly walleye, a predator known to accumulate this contaminant. These results corroborate those which lead to the existing fish consumption advisories. The highest level observed was in walleye collected from above Grand Rapids. Taste and odour compounds are evident in this reach originating from upstream pulp mills and possibly enhanced by municipal wastes. The synergistic effects of these and oil sands hydrocarbons remain unknown. Critical spawning habitat for fish exists in the vicinity of Mountain and Cascade rapids upstream of Fort McMurray. Upwards of 1,000,000 lake whitefish (fall spawners) and large numbers of longnose suckers (spring spawners) that originate from Lake Athabasca spawn in this area. Walleye are also believed to spawn in this reach. Reaeration of the river by Grand Rapids significantly improves the instream dissolved oxygen levels thus providing optimal conditions for whitefish egg development. Societal PerspectiveStatements of concern from the public relate to issues arising during the AlPac hearings including: dissolved oxygen requirements of fish; fish quality and health; nutrient enrichment; dioxins and furans; drinking water quality; and land use impacts. Key Management Considerations Unique to the Reach
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Athabasca River: Fort McMurray to Peace-Athabasca DeltaScientific Summary
This reach includes the massive oil sand complexes and the municipal effluent from Fort McMurray. Natural hydrocarbon seeps are evident along the Athabasca River and contribute PAHs and other hydrocarbons to the river. The effect of these hydrocarbons on the ecosystem have not been extensively investigated but NRBS has obtained presumptive evidence that suggests that naturally occurring substances may be responsible for the MFO inductions in fish. The Clearwater and Steepbank Rivers also provided evidence of MFO induction. Further investigations into the causes of induction and its implications are required. Of the chemi-thermomechanical pulp mill and sewage treatment plant effluent, the Fort McMurray effluent is the largest source of PCDD/Fs, based on concentration and discharge to the entire river during a one-time sampling in April 1993. These same oil sands sources with their associated metals may also be linked to higher metallothionein in the lower Athabasca River and this requires investigation as well. Recent evidence submitted by Suncor indicates that the cause of mercury contamination of the Athabasca River benthic community has been remediated. Preliminary benthic invertebrate data, also provided by Suncor, suggest that the problem has been cleaned up. NRBS did not investigate mercury levels in benthos in this reach. Mercury levels are high in large walleye in this reach of the Athabasca River. Human consumption advisories are in effect.
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Nutrient enrichment is apparent in the benthic community immediately below Fort McMurray reflecting the addition of the municipal effluent. Unlike the two reaches immediately upstream, dissolved oxygen is not an issue in this reach. The Clearwater River influences the flow and quality of the Athabasca River. NRBS research has confirmed that the Clearwater River and the municipal discharge from Fort McMurray contribute to increased productivity in the Athabasca River. Taste and odour compounds are evident in this reach originating from upstream pulp mills. The synergistic effects of these and oil sands hydrocarbons remain unknown. Societal PerspectiveAt public gatherings, science fora and through surveys, statements of public concerns included: the lack of involvement of traditional knowledge in decision making and local people in monitoring; pulp mills are contaminating and fouling our fish and drinking water; oil sands developments are affecting wildlife; fish populations have declined; river looks dirtier and there are more weeds now; applicability of consumption guidelines for fish containing high levels of mercury; little or no warning provided to downstream interests when spills occur; effects of contaminants on human health and way-of-life.
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Other concerns expressed include: safety of tailing ponds and leachates, presence of carcinogens and linkages to human health, fish health and quality, drinking water quality, turbidity, taste and odour, hydrocarbon seeps, uncertainty in cumulative impacts and reliability of industry data. The Clearwater River is perceived as having become polluted in recent years and contains high levels of nutrients. Non-point source pollution was raised as regards the Clearwater River. Spill notification times and responses are a concern to citizens. Key Management Considerations Unique to Reach
Athabasca River: Peace-Athabasca Delta
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Scientific Summary
Science has demonstrated significant ecological changes in this area during the last two decades. Drying of the delta is related to the Bennett Dam and it is hypothesized that this may be exacerbated by climate variability. Ecological changes in the delta have resulted in impacts on fisheries habitat, fish movement and spawning behaviour, changes in waterfowl migration routes, decline in populations of ungulates, muskrats and other wildlife, and changes to way-of-life of people living in the delta. The PAD supports abundant fish populations of a number of species (walleye, northern pike, lake whitefish and goldeye) and a commercial fisheries operation. A subsistence fishery exists in the delta. Critical spawning areas are: Mamawi, Claire and Richardson Lakes. Spawning does occur throughout the delta. Contaminants such as dioxins, furans and mercury exist in burbot liver and the muscle and liver of other fish species. Levels need to be assessed relative to the unique dietary intake of aboriginal people. Radionuclide research confirms the fish collected at the delta and west end of Lake Athabasca have not been contaminated by mining operations in the basin.
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Biological, sediment and water transport processes move contaminants from the headwaters of the basins to the delta. When the sediment contaminants reach the delta they become dispersed through particle size partitioning processes and are deposited throughout the delta, Lake Athabasca and / or transported into the Slave River system. Deep core investigations have confirmed this and the dilution effect of these processes. NRBS has confirmed that pulp mill contaminants have reached the perched basins. Weak PCDD/F signatures were evident in muskrat and canvasback ducks collected from perched lakes and Flour Bay. Health Canada reviewed the NRBS mammal and waterfowl contaminant data and concluded that consumption of these muskrats and canvasback ducks would not pose a hazard to humans. Societal PerspectiveAt public gatherings, science fora and through surveys, statements of public concerns included: pulp mills are contaminating and fouling our fish, increasing abnormalities in fish, and affecting wildlife, vegetation and drinking water; oil sand developments are affecting wildlife; uranium mining; fish populations have declined; spawning beds have dried up and migration patterns affected through infilling of channels; fish nets are now covered with weeds; applicability of consumption guidelines for fish containing high levels of mercury; little or no warning provided to downstream interests when spills occur; and effects of contaminants on human health and way-of-life. Major concerns were expressed related to the effects of the Bennett Dam including the loss of a way-of-life. Several elders noted that their concerns and views seem to be often ignored and they recommend that traditional knowledge be incorporated into decision-making related to resource management and approval of developments.
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Key Management Considerations Unique to Reach
Athabasca River: Lake Athabasca
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Scientific Summary
Lake Athabasca traps some of the sediments which move through the Athabasca River system. Sediments also deposit directly in the delta and / or move into the Slave River system and Great Slave Lake. Investigations have confirmed that pulp mill contaminants have reached the lake over very long time periods. Concentrations are close to the analytical detection limits, organochlorine contaminants in fish are near reference levels. Atmospherically derived contaminants are apparent in the cores as are PAHs originating with forest fires and hydrocarbon development. Some fish from the lake have high concentrations of mercury. A survey of subsistence fish in 1994 / 1995 indicated that mercury in burbot, walleye and pike are below the commercial guideline of 0.5 mg/kg (parts per million). Given the subsistence use of fish from the lake, the Alberta consumption advisories should be reviewed for relevancy to the traditional peoples. Radionuclide concentrations in fish are well within the guidelines provided by Health Canada. There is evidence of radionuclides moving out into Lake Athabasca at the east end of the lake from the Gunnar mine site although this has diminished in recent years due to lower mining activity and controls. Ongoing and increased mining in response to international pressures is a significant concern of the people who live along the shores of the lake and downstream in the Northwest Territories.
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Fish health assessments were not undertaken on fish from the lake. However, local people and commercial fisherman report fish abnormalities (external and internal) which should be investigated further. Societal PerspectivePeople from the delta area have expressed fears that the lake is vulnerable to contaminants from uranium mining, pulp mill developments, oil sands and other pollution sources. Commercial fisherman have noted an increased incidence of poor quality fish (livers) but this has not been confirmed. Water quality is generally seen as vulnerable to industrial development and poorest at the mouth of the Athabasca River. There have been observations that fish nets are now becoming covered by algae and a perspective is, that this is man-induced pollution from upstream developments. Other concerns include: incomplete environmental impact assessments, atmospheric contaminants, contaminants in fish and most of the concerns noted for the delta. Key Management Considerations Unique to Reach
Peace River: Many Islands to confluence with Smoky River
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Scientific Summary
An altered flow regime is an obvious consequence of the Bennett Dam. Winter flows tend to be higher than normal, summer flows and the spring peaks lower on average. Changes in channel geomorphology, aquatic vegetation and riparian habitat are evident throughout this reach and could take decades or centuries to stabilize. The effect of open water winter conditions, higher winter water temperatures and geomorphological changes on fish, habitat use and on other biota have not been quantified. Snow pack and spring runoff in tributaries have been lower in recent years.
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This Section of the Peace River is of generally good water quality although there is some evidence of industrial contamination as determined by the presence of certain contaminants in sediments and fish. Levels of PCBs, resin acids, and PAHs are higher than reference locations in sediments above the confluence with Smoky River and in this area. PCB levels in the sediments exceed the interim Canadian sediment quality guidelines for the protection of aquatic life. The concentration of PCBs in burbot liver are an order of magnitude higher than found in burbot from the Wabasca River, a tributary to the Peace River but still well below PCB guidelines for the commercial sale of fish. The extent to which observed PCB levels in fish are a function of their concentration in the food web as opposed to point source release is unclear; however, the PCB data should be reviewed from the point of view of traditional life styles. Levels of PCDD/Fs in sediments were low but detectable. The only sampling done for PCDD/Fs in fish was in 1994 when we tested burbot livers. All results were at or below the analytical detection limit. There are no data in this reach which could be used for assessing temporal trends in dioxins and furans. Mercury levels in fish of this reach are generally lower than elsewhere in the basins with the occasional larger fish having levels which exceed the commercial health guidelines of Health Canada. There is no fish consumption advisory in effect for this part of the Peace River and our data (for mercury, dioxins, furans and toxaphene) would seem to corroborate that none is required. The large river volume probably assimilates existing sources of nutrient and organic wastes effectively. NRBS did not investigate the effect of British Columbia pulp mills or municipalities on Peace River water quality. Dissolved oxygen levels are not an issue.
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Unique fish and riparian habitats exist within the Many Islands area downstream to the Montagneu River although they are unstable and undergoing change with evolving shorelines and shifting and new sand bars as evident in the Many Islands area. Societal PerspectiveThe Peace River is considered a valuable and precious resource. Flow regulation has been seen as self-serving to British Columbia with little consideration of the downstream ecosystem and human interests. Concerns have been expressed about the possibility of contaminants from British Columbia pulp mills and municipalities and mercury contamination of Peace River fish. Key Management Considerations Unique to Reach
Peace River: confluence of Smoky River to Rivière Des Rochers
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Scientific Summary
The most dominant stressor affecting the entire length of the Peace River is flow regulation by the Bennett Dam. Although hydrologic effects are attenuated downstream, there is concern related to reduced flooding of the Peace-Athabasca Delta. There is preliminary evidence that climate variability may be an important factor in explaining reduced tributary runoff in the upper basin and drying of delta lakes. The large water volume and high sediment load in the Peace River dilutes the contaminants discharged from pulp mills and municipalities. There is evidence of trace contaminants (PAHs and chlorophenolics) in sediments with tetrachlorodibenzo-p-dioxin (TCDD) levels below detection. Increases in chlorinated resin acids were not seen below Daishowa although total resin acids are as high in this reach as on the Athabasca River at Emerson Lakes. PCB levels doubled in fish from the Peace River near Notikewin, and near Ft. Vermilion between 1992 and 1994. Tetra-chlorodibenzodioxins and furans (TCDD/F) have decreased in burbot livers since 1992. Nutrient enrichment was not investigated by NRBS in the reach.
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Dissolved oxygen is not an issue. Depressed sex steroid levels (based on basin-wide analysis of near field sampling stations) occur in burbot and longnose sucker below pulp mills relative to reference samples and coupled with a low ratio of mature to immature fish is worthy of management follow-up. The levels of TCDD/Fs in fish have decreased by 50-80 per cent since 1992, probably as a result of technology improvements. The effects of agriculture on the Peace River or its tributaries has not been investigated. Examining the potential for non-point source pollution, NRBS scientists have noted that agriculture and forestry operations may be important considerations in the long-term management of the system. The oil sands which intersect the Peace River have not been found to cause any unusual water quality or ecosystem health effects. However, elevated levels of MFO induction in burbot collected in the Wabasca River are suggestive of natural contamination from oil sands seepage. This reach is critical winter habitat for goldeye which spend the spring and summer in the lower Athabasca River within Wood Buffalo National Park. Goldeye are the dominant fish species in this reach with an estimated population of one million. High level of free retinoids in burbot from the lower portion of this river reach suggests physiological stress but the cause is unknown. Societal Perspective
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The public fears river degradation by pulp mills, forestry, agriculture, mining, oil and gas, and municipal wastes. Frequent observations were made about past spills related to PCBs and other substances on the Smoky and Wapiti systems which may impact the Peace River. Observations of fiber, foam, odours, and tainted drinking water have been associated with pulp mills. Increased sediment and dirty ice, likely caused by increased winter flows, leaves an impression of degraded water quality. Changes in wildlife and fish populations are perceived to be linked to development on the river. Apparently uncontrolled agricultural activity, especially the clearing of land right down to the water's edge is a growing concern. Land clearing for forestry is increasing in the tributary watersheds (Notikewin, Cadotte, Buffalo, Wolverine, Ponton, Wabasca and Mikkwa) with concerns expressed about water quality and vulnerability of fish habitat. Key Management Considerations Unique to Reach
Smoky-Wapiti Rivers
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Scientific Summary
Based on the weight-of-evidence approach, the Wapiti / Smoky River system is currently the most heavily stressed in the northern river basins. Issues of concern include high levels of nutrient addition from the city of Grande Prairie and the Weyerhaeuser pulp mill, sharp declines in under-ice dissolved oxygen, and high PCB concentrations in sediment and fish. The extent to which observed PCB levels in fish are a function of their concentration in the food web as opposed to point source release is unclear. Whatever the factors responsible for these PCB levels, the issue clearly requires further investigation. Concerns relate to the rapid decrease in the river system's capacity to assimilate further organic wastes without implications to fish (dissolved oxygen) and long-term eutrophication on this system. Twenty-three per cent of annual TP loading in the Wapiti River is from Grande Prairie and Weyerhaeuser and is in excess of 40 per cent during low flow periods. The proportion of bio-available phosphorus in these effluent is higher than in the receiving water. Recent decreases in basin runoff related to decreased snowpack would further exacerbate the effect of nutrient / contaminant additions to the rivers.
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Contaminants related to dioxins, furans, PCBs and chlorophenolics are present in sediment, water and / or fish. Unexplained doubling of PCB levels in fish occurred between 1992 and 1994 on the Wapiti River. TCDD/Fs in biota appear to have declined by a factor of 10 since 1992 but are still relatively high relative to other locations in the basins. Depressed sex steroids coupled with an apparent anomalously high ratio of sexually immature fish (burbot and longnose suckers), and a higher than normal incidence of fish deformities below the mill give cause for concern and the need for further research. Although pulp mill effluent may have affected the reproductive ecology of individual fish, there is no evidence yet that populations have been affected. These small river systems provide critical spawning habitat for several fish species and therefore are particularly vulnerable to pulp mill and municipal wastes. NRBS has determined that variability in precipitation and winter snow pack has played a significant role in influencing observed levels of spring runoff in these tributaries to the Peace River. This has important implications for several areas of water management including flood forecasting and control, water licensing and apportionment, instream flow needs, pollution control and water quality. Societal Perspective
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Public statements about the state of the resource in this system include perceived impacts from coal mining (dust), power generation (transformers: PCBs), red snow, spills, deformed fish, air quality associated with oil and gas field flaring, aesthetics (such as foam, wood chips, and odours) and fish and water tainting. Key Management Considerations Unique to Reach
Slave River: Riviere Des Rochers to (including) Slave Delta
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Scientific Summary
Flow alterations in the Slave River may have implications to fish movement, distributions and the state of the delta. NRBS did not conduct in-depth investigations of the flow regulations effects on Slave River Delta ecology. Impacts of the flow regulation are therefore not adequately described except as related to understanding the hydrologic regime of the river itself. Research is needed to assess the state of the delta and its vulnerability to upstream flow regulations. Increased suspended sediment has been observed during winter with the higher than normal flows. The Rapids of the Drowned to Cunningham Landing is critical spawning habitat for inconnu and lake whitefish as is the lower-middle reach between Pointe Ennuyeuse and Grand Detour where inconnu spawn. The Slave River Delta is known to be a spawning and rearing habitat for burbot and northern pike.
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Although contaminants (e.g., PCDD/F) have only been detected in fish (e.g., burbot) and lake sediments at or near analytical detection limits, this indicates upstream sources are beginning to show their presence many hundreds of kilometers downstream. Atmospheric sources of contaminants are implicated. Further research is needed to explain the cause and the significance of these findings. Fish health apparently remains exceptional throughout this reach. A recommendation by the Northwest Territories Government, similar in nature to the Alberta consumption advisories, exist for fish taken from the Slave River because of toxaphene. Due to analytical difficulties, NRBS data could not corroborate the toxaphene issue for fish from the Slave River. We heard from the people that wide use is made of drinking water using non-conventional treatment. Particular concern relates to the practice of using untreated water in back country locations and the possible consequences.
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Societal Perspective
Local people have indicated concerns related to: long-term sustainability of the white pelican colony; waste from Fort Smith, enhanced algal growth at the Rapids of the Drowned, increased turbidity in the winter, drinking water quality, buried landfill leachates, water level fluctuations, declining wildlife populations and fish quality. Key Management Considerations Unique to Reach
Relevant DocumentsPrimaryNRBS Synthesis Reports Wrona, F.J., Gummer, Wm., Cash, K.J. and K. Crutchfield. 1996. Cumulative Impacts within the Northern River Basins. Northern River Basins Study Synthesis Report No. 11.
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Supporting NRBS Synthesis Reports
Armstrong, T.F., Prince, D.S., Stanley, S.J. and D.W. Smith. 1995. Assessment of Drinking Water Quality in the Northern River Basins Study Area. Northern River Basins Study Synthesis Report No. 9. Carey, J.J. and O.T.R. Cordeiro. 1996. Effects of Contaminants on Aquatic Organisms in the Peace, Athabasca and Slave River Basins. Northern River Basins Study Synthesis Report No. 3. Carey, J.H., Cordeiro, O.T.R. and B.G. Brownlee. 1996. Distribution of Contaminants in the Water, Sediment and Biota of the Northern River Basins: Present Levels and Predicted Future Trends. Northern River Basins Study Synthesis Report No. 2. Cash, K.J., Wrona, F. and Wm. D. Gummer. 1996. Ecosystem Health and Integrated Monitoring in the Northern River Basins. Northern River Basins Study Synthesis Report No. 10. Chambers, P.A. 1996. Nutrient Enrichment in the Peace, Athabasca and Slave Rivers: Assessment of Present Conditions and Future Trends. Northern River Basins Study Synthesis Report No. 4. Chambers, P.A. and T. Mill. 1996. Dissolved Oxygen, Fish and Nutrient Relationships in the Athabasca River. Northern River Basins Study Synthesis Report No. 5.
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Flett, L., Bill, L., Crozier, J. and D. Surrendi. 1996. A Report of Wisdom Synthesized from the Traditional Knowledge Component Studies. Northern River Basins Study Synthesis Report No. 12. Gabos, S. 1996. The Human Health Synthesis Report. Northern River Basins Study Synthesis Report No. 6. Lyons, B. and B. MacLock. 1996. Environmental Overview of the Northern River Basins. Northern River Basins Study Synthesis Report No. 8. MacLock, B. and J. Thompson. 1996. Characterization of Aquatic Resources within the Peace, Athabasca and Slave River Basins. Northern River Basins Study Synthesis Report No. 7. Mill, T.A., Sparrow-Clark, P. and R.S. Brown. 1996. Synthesis of Fish Distribution, Movement and Critical Habitat, Slave River North of 60 . Northern River Basins Study Synthesis Report No. 13. Prowse, T. and M. Conly. 1996. General Hydrology and Effects of Flow Regulation on the Peace and Slave Rivers. Northern River Basins Study Synthesis Report No. 1. NRBS Technical Reports
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Alke, E. 1995. Executive Summary of a Workshop on the Impacts of Land Clearing on the Hydrologic and Aquatic Resources of Boreal Forests in Alberta, November 18 and 19, 1994. Northern River Basins Study Technical Report No. 63. Cash, K. 1996. Benthic Macroinvertebrate and Fish Community Structure Within the Northern River Basins: An Assessment of Their Utility in Biomonitoring. Northern River Basins Study Technical Report No. 123. Cohen, S.J. 1995. The Potential Effects of Climate Change in the Peace, Athabasca and Slave River Basins: A Discussion Paper. Northern River Basins Study Technical Report No. 65. Donald, D.B. et al. 1996. Indicators of Ecosystem Integrity: Peace-Athabasca Delta. Northern River Basins Study Technical Report No. 107. Hudson, E. 1996. Climate of the Northern River Basins. Northern River Basins Study Technical Report No. 124. McDonald, K. 1996. Analysis of Back Trajectories: Identification of Air Pathways. Northern River Basins Study Technical Report No. 109. |
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