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NRBS - Home Table of Contents		Northern River Basins Study Final Report 7.0 Appendices 7.7 Recommendations by the Science Components Impacts of Flow Regulation on the Aquatic Ecosystem of the Peace and Slave Rivers PEACE-ATHABASCA DELTA ACTION PLAN Effects of Contaminants on Aquatic Organisms in the Peace, Athabasca and Slave River Basins Distribution of Contaminants in the Water, Sediment and Biota of the Northern River Basins: Present Levels and Predicted Future Trends Nutrient Enrichment in the Peace, Athabasca and Slave Rivers: Assessment of Present Conditions and Future Trends Dissolved Oxygen Conditions and Fish Requirements in the Athabasca, Peace and Slave Rivers: Assessment of Present Conditions and Future Trends A Review of Population Health Status in Northern Alberta Use of Aquatic Resources in the Northern River Basins: Synthesis Report Assessment of Drinking Water Quality in the Northern River Basins Study Area: Synthesis Report Ecosystem Health and Integrated Monitoring in the Northern River Basins Cumulative Impacts within the Northern River Basins A Report of Wisdom Synthesized from the Traditional Knowledge Component Studies Synthesis of Fish Distribution, Movements, Critical Habitat and Food Web for the Lower Slave River North of the 60th Parallel: A Food Chain Perspective Impacts of Flow Regulation on the Aquatic Ecosystem of the Peace and Slave Rivers By: T. D. Prowse and M. Conly National Hydrology Research Institute Saskatoon, Saskatchewan
NRBS - Home Table of Contents Top of Page		Primary Recommendations [1] "Naturalized" Flow Modelling Evaluating the effects of regulation on the overall flow regime is hampered by the brevity of the pre-regulation period data set. One method to extend the "un-regulated" period is to model flow conditions since regulation without the effect of the dam. Such a model has been under development by Alberta Environment in conjunction with British Columbia Hydro. It was originally hoped to incorporate the results of this model into some of the NRBS studies but at the completion of this synthesis report, the modelling results remain in draft form and not yet available to scientists attempting to evaluate ecosystem impacts resulting from flow regulation. It is recommended, therefore, that a priority be placed by Alberta Environmental Protection and B.C. Hydro on finalizing this work, and releasing it to the public and scientific communities through official publications so that it can be used in related impact studies. Based on the normalized data set, a re-evaluation should also be made of the summary flow statistics presented in this report. Integral to this evaluation, should be an assessment of the significance of hydro-climatic variations in affecting the post-regulation flow characteristics. [2] Hydro-climatic Studies of Tributary Flow Given the importance of tributary flow in producing downstream peaks on the Peace and Slave River systems, a hydro-climatic study needs to be conducted of inter-annual variations in tributary flow. Special attention should be placed on spring snowmelt events that are known to enhance sediment contributions and be a driving force in producing break-up floods. A companion study should also be undertaken of the apparent climatic signal in the snowpack record. Temporal anomalies need to be evaluated relative to atmospheric circulation and synoptic climatic variations. The network of snow survey stations must also be improved/expanded to permit more accurate snowmelt modelling of critical tributary basins. No data, for example, is currently collected within the Wabasca catchment, a tributary known to be important to break-up conditions near the Peace-Athabasca Delta. [3] Linking of Hydraulic Models The current one-dimension hydraulic model of the Peace-Athabasca Delta needs to be coupled with the new hydraulic flood-routing model of the Peace and Slave Rivers. The focus of the Peace-Athabasca Delta model should be expanded beyond water levels within the Peace-Athabasca Delta to include explicitly full-season modelling of discharge to the Slave River, including the dynamic freshet period. Obtaining reliable modelled discharge from the Peace-Athabasca Delta is the only way by which flow can be modelled accurately through to Great Slave Lake and by which pre-regulation and "naturalized" flows can be calculated for the Slave River. The one-dimensional flow model of the Peace-Athabasca Delta should also be integrated with ice-jam models currently being developed in the PADTS for the reach of the Peace River that controls spring flooding of the Peace-Athabasca Delta. [4] Ice Break-up Modelling The importance of ice-jam floods on the Peace River (negative impacts to settlements and positive to riparian ecosystems) presents an excellent reason for developing and testing a river-ice break-up model. The Peace River hydraulic flood routing program, developed for the NRBS, offers the ideal building block for the development of such a break-up model. Testing and validation of the model will require more extensive monitoring of break-up conditions in the lower portions of the Peace River. This could be accomplished by extending downstream the current ice observation program conducted near the town of Peace River. [5] Ice Jam Enhancement Although break-up modelling and forecasting is still in a state of early development, it is recommended that the current regulation scheme be modified to increase the chances of creating a break-up jam near the Peace-Athabasca Delta. Relying solely on the reservoir to produce a major break-up near the Peace-Athabasca Delta would require an enormous release of water from the Williston reservoir. Notably, this could also lead to unpredictable ice-related backwater flooding at other upstream and downstream locations. Some success could be achieved, however, if minor adjustments are made to the regulation strategy in years where tributary inflow is forecast to be large. In some years, the only modification might be a delay in the retarding of spring flows. Current ice jam modelling by the PADTS should provide an idea of the size of combined flow needed to initiate flooding of the Peace-Athabasca Delta. Furthermore, PADTS water-balance modelling will provide guidance on how frequently such intervention might be required. A single agency is needed to co-ordinate these scientific activities. [6] Changes to Morphology and Riparian Habitat Evaluation of morphologic/vegetative changes to the Peace River involved comparison of two sets of aerial photography: just prior to regulation in the mid-1960's and a recent set obtained by the NRBS in 1993. Additional sets of photography covering other decades before and after regulation were also assembled but insufficient time precluded their analysis. It is recommended that this additional photography be analyzed to provide a better long-term record of morphological and vegetative change, one that permits validation of predicted rates of change likely to result from flow regulation. Although morphologic studies of the Peace River included four representative reaches, the lack of aerial photography precluded an analysis of the lowest reaches, characterized by broad floodplains and numerous large islands. This zone represents a significant and productive riparian habitat consisting of a multitude of wetlands interspersed among old-growth boreal forest. Furthermore, it has been observed that the large number of split and side-channels located in this area (downstream of Peace Point) may contain backwater areas bedded with silt and clay sedimentóthe fine fractions known to be associated with industrial pollutants. It is therefore recommended that this reach be selected for long-term monitoring and that monumented cross-sections specifically include backwater areas that can be assessed for changes in bed sediment quality. Monumenting of sites should be conducted in collaboration with Parks Canada who have already established some permanent study plots to monitor vegetation succession within the floodplain. [7] Riparian Habitat Assessment Some of the most significant ecological impacts produced by altered flow and water level regimes are experienced along the flow margins. To evaluate the nature and spatial extent of habitat impacts within this zone, it is recommended that further quantification (following from experience gained from the test trials of multi-spectral imaging) be made of habitat availability, over the full range of flow conditions. This will provide the basis for establishing requisite seasonal sets of regulated flow conditions, specifically in terms of timing, duration and magnitude. There is also a need to more fully understand how vegetation changes on the river mainstem and particularly in the two deltas affect wildlife habitat and related species populations and diversity. It is recommended that wildlife habitat changes be assessed through such methods as Habitat Evaluation Procedures (HEP) and associated wildlife surveys. Because it is not practical to assess the habitat suitability for all affected wildlife species, representative species such as muskrat, moose and buffalo should be used. A recommendation should be made to the upcoming "Bison Research and Containment Program" for the Peace-Athabasca Delta to include a science component that focuses on developing linked hydrologic, vegetation-succession and wildlife-habitat models. [8] Peace-Athabasca Delta Lake Stabilization Effects Further investigations of the aquatic impact of stabilized water levels should be conducted for some of the large delta lakes, especially regarding changes in the nature and availability of waterfowl habitat. A special focus should be placed on fall and winter water levels that do not experience the natural seasonal drawdown as a result of both forms of regulation (weirs and upstream reservoir). [9] Slave River Delta To obtain a better understanding of the temporal and spatial effects of flow regulation in the Slave River Delta, further studies related to the changing dynamics of the Delta are recommended possibly similar to those of the PADTS. Integral elements of this ecological monitoring program should include assessments of: a) flood frequency, including open-water and ice-jam flooding, and the role of Great Slave Lake fluctuations; b) water-balance studies to determine the relative importance of flooding recharge; c) sediment regime changes including under-ice investigations; and d) vegetation succession, aided by remote-sensing assessments and the establishment of permanent transects through representative cover. 2 Secondary Recommendations The following recommendations stem from the results of studies conducted in response to NRBS Question #10 but are considered secondary to completing a first-order assessment of flow-regulation impacts. Aspects of some, however, relate directly to the primary recommendations. [i] A water temperature model should be applied to the Peace River so that the relative effects of variations in climatic conditions and regulated flow can be discerned. Ideally, the model should be integrated with the new hydraulic flood-routing model developed for the NRBS. [ii] A detailed ice-hydraulic study should be conducted of flow conditions leading to reductions in open-water zones associated with rapids such as the Vermilion Chutes. Such an evaluation should include other turbulent reaches that historically remained open under lower pre-regulation flow conditions and be coupled with hydro-ecological studies of the importance of open-water zones to aquatic life, especially fisheries. [iii] Studies should be conducted of the long-term effect of freeze-up staging on regional groundwater levels and of its more local effect on riparian zone habitats, such as in the recharging of backwater snyes or in the succession of seral vegetation. [iv] Studies should be conducted on the role of frazil deposition in modifying/eliminating winter aquatic habitat. [v] The ultimate adjustment time of a large river is extremely long but no system has been studied systematically for more than a few decades. The Peace River data set provides an excellent opportunity to evaluate fully the long-term effects of flow regulation. As part of a long-term study, it is recommended that monumented cross-sections for monitoring changes in channel morphology and riparian vegetation be established within the representative reaches used in the current NRBS studies. [vi] More detailed studies of sedimentation processes in the outer delta are required. These are essential to separate the effects of flow regulation from natural processes, such as isostatic rebound and the role of wave action from Great Slave Lake. Such work first requires completion of the hydraulic flood-routing model of the Peace-Slave Rivers, preferably with a delta-channel network component similar to that developed for the Peace-Athabasca and Mackenzie deltas. [vii] An attempt is being made by the PADTS to improve the understanding of how changes in the hydrologic regime of the perched basin environments control changes in the vegetation regime. It is recommended that further efforts be expended on such model development and that the model be applied and validated for conditions on the Slave River Delta. PEACE-ATHABASCA DELTA ACTION PLAN
NRBS - Home Table of Contents Top of Page		The following was produced in response to a request from the NRBS for an experimental action plan for the Peace-Athabasca Delta. It presupposes, based on groundwork conducted by the PADTS, that flooding of the PAD is the key to restoring the ecosystem health of the perched-basin environments. Many of the proposed actions also stem from the results of PADTS discussions about potential methods and, in some cases, actions that have already been field tested in the PAD. Prior to describing these, it is useful to review the PAD hydrology so that the recommendations can be placed in context. 1 Background Review As earlier described in Sections 2.6.2; 3.2; and 3.8.2, the PAD is composed of two different hydrologic regimes. The first includes the large shallow lakes and the major deep channels which link them to Lake Athabasca and the Peace, Athabasca and Slave Rivers. It is this flow system that has been affected by the construction of rockfill weirs. In general, the weirs have restored the summer mean-maximum water levels to near pre-regulation values but they have also reduced the seasonal amplitude in water levels. Although the decrease in amplitude should create an ecological impact on lake margins, research in this area has been meagre (see Section 4.8.1: Recommendation [8]). The second major regime is that of the "perched basins" which are to varying degrees disconnected from the main flow system. It is these basins that have experienced the most extensive drying and are not affected directly by water levels produced by the rockfill weirs. Notably, however, this perched-basin regime can be further subdivided according to source and frequency of flooding. For example, since the time of the last major flood of 1974, the Athabasca River has inundated some of the perched basins in the southern portions of the PAD. Similarly, some of the low-lying southern basins have been flooded by high lake levels. Perched basins that have experienced the most extensive drying exist in the northern portions of the PAD and are dependent on macro-scale flooding of the Peace River for filling. 2 Proposed Experimental Actions Given the above differences in hydrologic regime, it is useful to consider experimental actions that differ by scale and location. 2.1 Small-Scale Basin Specific The basic experimental approach here is to capture water in single basins during high flow events with the use of simple control structures. The structure is constructed within the levee of the basins and operated to permit the entry of water during periods of high stage and prohibit its exit when flow in the main channels and lakes decline. Since this method relies on the main flow network, it can only be conducted in basins with suitable levee/elevation characteristics. The results of such an approach (e.g., on vegetation succession or small mammal populations) are limited to the experimental basin. Results could provide, however, invaluable data for developing the requisite models for predicting vegetative response to large-scale wetting of the PAD. An alternative to the expensive construction of variable-height weirs is the use of pumps to recharge specific basins. Pumps offer the additional opportunity of flooding basins perched above the main flow network. 2.2 Meso-Scale Basins Adjacent to Large Lakes and Channels Meso-scale flooding of the PAD requires the redirection of water flowing through the Delta onto the adjacent landscape. The best method to achieve this is to present an obstruction to the flow at a critical hydraulic node in the delta channel-lake system, thereby creating backwater which would inundate the surrounding perched-basin environment. The natural levels around such basins would retain the water after the backwater recedes. The best hydraulic node for the construction of a flow obstruction within the PAD is near the Quatre Fourches Dog Camp. Notably, this was the site of one of the early rockfill weirs; a structure that was successful in significantly raising lake water levels during a large spring-runoff event in 1971, but also one that proved to be ecologically unsuitable because it impaired the migration of fish. As part of the PADTS (see Section 3.8.2), an artificial ice dam was constructed overtop of the old weir. The objective was to use the temporary ice structure the passage of spring snowmelt runoff through the Delta, thereby creating backwater that would flood basins adjacent to the large delta lakes. Since construction of the early weirs, a significant percentage of the Athabasca flow has been diverted naturally into the Delta Lakes through development of the Embarras River breakthrough to Mamawi Creek. This has increased the possibility of obstructing spring flow in the delta lakes. Success of using an artificial ice dam at this site is dependent on the vagaries of winter climate (specifically the magnitude, rate and timing of spring snowmelt) and the winter flow strategies of B.C. Hydro. For example, it appears that sudden winter decreases in upstream flow over the winter of  1994/95 hampered the ability of the artificial ice dam to elevate water levels to flood stage. If such an attempt is undertaken again, agreements should be made regarding winter flow operations. An alternative to using an artificial ice dam would be to employ a gated structure. This, like the ice dam, would minimize problems associated with fish migration among the lakes and channels but problems may exist about the construction of such a permanent feature within a National Park. It should be stressed again, however, that the above medium-scale approaches still only have the possibility of affecting perched basins close to the backwater effect that could be established near the Dog Camp hydraulic node. Such flooding will not affect the northern perched basins close to the Peace Riveróones that are believed to have experienced the most drying since  1974. 2.3 Macro-Scale Flooding from the Peace River Introducing macro-scale flooding of the PAD is possible only through disruption of flow on the large Peace or Slave Rivers. Again, a permanent gated structure could be used but construction/engineering costs would be enormous. The possibility of constructing an artificial ice dam has also been considered by the PADTS. Recognizing the need for an environmental impact assessment of related effects, early community information meeting were also held by the PADTS. Similar to the meso-scale approach, the success of an artificial ice dam depends very much on the vagaries of climate, especially as they affect the magnitude of spring runoff produced by tributaries downstream of the Bennett Dam, such as the Smoky and Wabasca Rivers. Given this, the most practical recommendation is "[5] Ice Jam Enhancement" outlined in Section 4.8.1. The success of an artificial ice jam could be enhanced further if there was a concurrent attempt near the PAD to increase the resistance of the Peace  River ice cover to breakup. This could include increasing thickness using spray-ice techniques and/or the retardation of melt through the application of insulating materials. Effects of Contaminants on Aquatic Organisms in the Peace, Athabasca and Slave River Basins By: John H. Carey and Olga T. R. Cordiero National Water Research Institute Burlington, Ontario
NRBS - Home Table of Contents Top of Page		CONCLUSIONS AND RECOMMENDATIONS In summary, there was little evidence from the basin-wide survey of physiological parameters in wild fish or from either of the more new approaches to specific monitoring of regional effects on biota in the basins. The Sediment toxicity studies supported this statement. There was some limited evidence that pulp mills may be causing depressed sexual hormones in fish, but in light of the physiological responses observed in the lower Athabasca River area and in tributaries in this region, more attention needs to be devoted to understanding the long term effects of the tar sands and related petroleum pollution. To further improve our understanding of the responses there are several scientific studies that could be conducted both in the field and laboratory: The long-term response of fish in the lower Athabasca River to contaminants from the petroleum seeps, tar sands and other hydrocarbon related pollution needs to be investigated. In particular, the connection, if any, between the distribution of immature burbot in the downstream areas needs to be addressed. More information needs to be obtained concerning the ecology of burbot to determine if the anomalous distributions observed in this study were caused by contaminants or are the result of some previously unknown aspect of burbot lifestyle The apparent anomalous high concentrations of free retinols and depressed tocopherol in the lower Peace River needs to be further investigated. If the observation is replicated, it needs to be explained. Not enough information is available on the growth rates, reproductive strategies, or life history of these species to help plan monitoring programs based on forage fish to monitor impacts of industrial discharges in large rivers. Baseline data on life history characteristics of these species needs to be collected. Greater knowledge of the general biology would also improve the capture efficiency of small species. Due to higher levels of abundance associated with many forage species, the collection of adequate sample sizes would become very cost-effective. The NRBS studies demonstrated substantial variability in whole organism responses among reference populations of the small fish species studied, spoonhead sculpin and lake chub. More effort needs to be directed towards establishing the full range of variability associated with reference fish; both within a monitoring system and among a variety of similar aquatic systems. Interpretation of results of a small fish-based monitoring program will depend on a good understanding on the extent and causes of natural variability. More information is needed to further evaluate the mobility of smaller fish species. Although small species in this study were not as mobile as many of the large fish species, it is still necessary to increase our understanding of the degree and pattern of mobility, size of home range and habitat requirements associated with specific small species of interest. To further evaluate the suitability of small fish species, it would be of interest to compare responses between small and large fish species of the same monitoring system. If possible, it would be advantageous to monitor a system possessing habitat or man-made barriers that would restrict the movement of the larger fish species. The comparison would examine the consistency of responses between species and investigate the relative sensitivity of each species. Laboratory evaluations of the potential of Athabasca effluents to disrupt steroids and induce MFO activity need to be repeated. Preliminary work was during the current project, but the steroid exposure protocol was still under development and has just been recently finalized. The exposures should be repeated using the final protocol. This information would be valuable to evaluate whether the effluents show the potential to induce the physiological changes. work on developing the SPMD concept further should be encouraged so that a standardized protocol for their use in a monitoring program can be achieved Distribution of Contaminants in the Water, Sediment and Biota of the Northern River Basins: Present Levels and Predicted Future Trends By: John H. Carey, Olga T.R. Cordeiro, and Brian Brownlee National Water Research Institute Burlington, Ontario
NRBS - Home Table of Contents Top of Page		Monitoring and Reporting 1. Given the low levels of organochlorines in water, sediment and biota by the end of the study period, it is recommended that the design and purpose of existing water quality monitoring programs be reviewed based on the NRBS findings. There appears to be no need for intensive basin-wide monitoring for these contaminants. Periodic monitoring, on a two or three year cycle, for contaminants in relevant compartments only, for example PCBs and chlorinated dioxins/furans in fish and PAHs and resin acids in sediment, should be sufficient to detect changes in the basin. 2. Mercury levels in certain areas of the basin, for example the lower reaches of the Athabasca River, are high and likely exceed human health consumption guidelines. It is recommended that mercury levels continue to be monitored regularly, particularly in the lower Athabasca River and western Lake Athabasca. 3. Burbot or, failing that, one of the sucker species are likely the most suitable large fish for use as an indicator species for biological monitoring. It is recommended that whitefish not be used for biological monitoring in this system. 4. It is recommended that a combination of the NRBS results from the broad spectrum analysis and selected target compound analysis be used to establish a baseline finger-print pattern of contaminants in effluents and ambient waters against which future changes can be assessed through the use of pattern recognition techniques. 5. It is recommended that a data management system be established to allow storage and access of all contaminant data collected by governments, industry, etc. 6. In view of the unique character of the NRBS samples and their potential value to future generations, it is recommended that government agencies undertake to ensure that the NRBS samples are adequately stored so that they can be made available as a baseline reference for future studies. Fish Consumption/Water Quality Guidelines 7. In light of the dramatic decreases in chlorinated dioxin and furan concentrations in fish observed by the NRBS after bleaching changes by the pulp mills, it is recommended that these bleaching changes be permanent for the mills and that fish consumption advisories based on chlorinated dioxin/furan concentrations be reviewed. 8. It is recommended that better dietary intake information on subsistence fish consumers in the basin be collected. This information is needed to help establish fish consumption guidelines based on human health for these people. Research 9. It is recommended that the apparent local spots of PCB and metal contamination identified during the study be further documented and where the elevated levels are confirmed, that small site specific studies be conducted to identify the sources. Nutrient Enrichment in the Peace, Athabasca and Slave Rivers: Assessment of Present Conditions and Future Trends> By: P.A. Chambers National Hydrology Research Institute Saskatoon, Saskatchewan
NRBS - Home Table of Contents Top of Page		SCIENTIFIC AND MANAGEMENT RECOMMENDATIONS 1 MONITORING, DATA HANDLING AND REPORTING Regular monitoring and reporting of nutrients from sewage treatment plants should be license requirements, particularly the larger sewage treatment plants such as Grande Prairie and Fort McMurray. These larger sewage treatment plants have nutrient loads similar to that of pulp mills in the basins. Yet under the 1993 Alberta Environmental Protection and Enhancement Act, operators of continuously-discharging sewage treatment plants need only report exceedances (within 24 h) to Alberta Environmental Protection. Compliance with sampling and analytical procedures should be mandatory for all licensed dischargers. Demonstration of QA/QC for sampling and analytical procedures and adequate detection limits should be a license requirement and conducted at regular intervals. While all licenses stipulate that sample analysis must be done following the latest edition of Standard Methods for the Examination of Water and Waste Water (APHA 1995), some samples have been analyzed incorrectly. In addition, some laboratories are not analyzing to current detection limits (i.e., TP detection limits are reported as 0.05 mg/L). Standard reporting requirements for water quality parameters should be established. For example, the units of reporting are not consistent (e.g., reporting of nitrite as nitrogen rather than nitrite) or misleading (e.g., nitrite reported as nitrogen but "as N" left off data sheet). Phosphate is reported when the analysis (digestion) would appear to be TP. TDP concentrations are greater than TP concentrations. Provision is needed for ensuring trained personnel to collate laboratory results and prepare data reports. Reporting proper water quality data should be a license requirement Provisions are needed to ensure training of certified operators to measure (and record) flows and discharge volumes and for enforcement of reporting requirements. At present, sewage treatment plant operators often supply missing, unreliable and/or ambiguous discharge data that then become incorporated in effluent databases (e.g., the Towns of Peace River, Barrhead and Wabasca have not reported reliable flow data). Reporting accurate discharge data should be a license requirement A properly-maintained central database should be established for: (a) effluent monitoring data (discharge and water quality parameters for all industries and municipalities with licensed monitoring requirements), and (b) environmental data collected by industries. These databases should be linked with the provincial surface-water quality database. The bioavailability of nutrients in industrial and municipal effluents should be characterized. At present, pulp mill licensing requirements include monitoring of NH4, NO3, NO2, total Kjeldahl N, TDP and TP in weekly grab samples; there is not a monitoring requirement for nutrients by municipal dischargers. Analysis of SRP concentrations and/or algal bioassays for N and P availability in effluents would allow better assessment of instream impacts. Artificial streams and nutrient diffusing substrata developed for NRBS should be considered as a promising tool for environmental effects monitoring by the pulp and paper industry. Artificial streams allow investigation of cause and effect scenarios and development of ecological indicators for Riverine biota under experimentally controlled dose-response regimes. They also facilitate the development, parameterization and testing of water quality models for predicting ecosystem-level responses to nutrient and contaminant addition. Nutrient diffusing substrata permit in situ assessment of the effect of effluents on river nutrient status. These approaches would assist in defining the effects of pulp mill effluent on benthic biota. Limited data are collected on nutrient concentrations during fall, which is the time of maximum biological productivity. Environmental monitoring by industries should be undertaken in fall and, in the case of the Athabasca River, should be coordinated such that a comprehensive longitudinal survey of the river is obtained each fall. 2 MODELLING The scope of nutrient and biotic data collected to date is too limited for simulation modelling. The season of concern is fall and nutrient concentrations are not usually monitored at this time of year. The limitations in the nutrient, periphyton and benthic invertebrate data could likely be addressed if industries coordinated their environmental monitoring. However, there is still no information on rates of nutrient uptake and cycling for the Northern Rivers. Given the limited database and the problems identified in attempting to model other less complex parameters in the Northern Rivers (Chambers and Mill 1996; McCauley 1996), simulation modelling of nutrient dynamics and associated biological responses is not recommended at this time. At present, predictions of changes in benthic communities can better be made from studies conducted in artificial streams or through empirical modelling. 3 RESEARCH In situ experiments have identified nitrogen limitation of periphyton growth in the 230 km reach of the Athabasca River from downstream of Alberta Newsprint Co. to the Lesser Slave River and in the Smoky River downstream of the Wapiti River confluence. Controlled experiments are required to evaluate the effects of nitrogen addition on biota in these river reaches. Data are almost entirely lacking on the contribution of non-point sources to nutrient loads in the Northern Rivers. While contributions can be estimated from the limited data for Alberta and other parts of the world, the large changes in land use patterns that have taken place and continue to occur (e.g., agricultural land clearing, timber harvesting, oil and gas activities) warrant closer examination of the impacts of changing land use on nutrient loading. 4 WATER QUALITY AND EFFLUENT GUIDELINES Effluent permit limits should be assessed and should be based on environmental effects rather than on technology design standards. The 1 mg/L TP level for most municipal permits is a technology-based limit since tertiary sewage treatment plants can usually achieve P removal to less than 1 mg/L. Similarly, the 3 kg BOD5/air-dried tonne for most pulp mill permits is a technology-based limit. All industries and municipalities should be licensed on the basis of environmental effects. In the case of no perceptible environmental effects, industries and municipalities should be regulated to a designated technology standard. It should be noted, however, that while phosphorus (and, in some locations, nitrogen) are important factors controlling periphyton abundance in the Athabasca and Wapiti-Smoky Rivers, we still lack quantitative relationships between phosphorus concentrations and periphyton biomass for any given site. Thus, it is not possible to set effluent permit limits for phosphorus so as to control periphyton abundance at a specific level. Alberta Water Surface Quality Objectives (Alberta Environment 1977) are frequently exceeded for TP and occasionally exceeded for TN in the Athabasca, Wapiti, Smoky and Peace Rivers. With the exception of the Wapiti River, many of these exceedances are attributable to high particulate loads associated with high flows. In the Wapiti River, many of the exceedances appear attributable to effluent discharge from Weyerhaeuser Canada Ltd. and, in the case of TP, to the Grande Prairie sewage treatment plant. Many regulatory agencies are moving away from numeric guidelines for nutrients but, instead, are evaluating or implementing qualitative or numeric guidelines based on aquatic plant abundance in the receiving water. At present, increased periphyton biomass is observed downstream of all mill and large sewage treatment plant (Fort McMurray and Grande Prairie) discharges. There is no evidence that this increased periphyton biomass has impaired spawning habitats, contributed to DO declines during winter or caused consistent long-term changes in benthic invertebrate taxonomic composition. However, if these reaches are deemed to be of recreational or aesthetic value, then a site-specific guideline for plant biomass may be desired. The British Columbia Ministry of Environment has recommended a criterion based on periphyton biomass of < 50 mg/m2 chlorophyll a to protect uses related to recreation and aesthetics in streams and < 100 mg/m2 chlorophyll a to protect against undesirable changes in aquatic life. However, before adopting a guideline based on a quantitative nutrient response (i.e., a specific level of aquatic plant abundance), a quantitative relationship between periphyton biomass and its environmental controls must be established. Dissolved Oxygen Conditions and Fish Requirements in the Athabasca, Peace and Slave Rivers: Assessment of Present Conditions and Future Trends By: P.A. Chambers1 and T. Mill2 1National Hydrology Research Institute Environment Canada Saskatoon, Saskatchewan 2Policy and Planning Branch Alberta Environmental Protection Regina, Saskatchewan
NRBS - Home Table of Contents Top of Page		SCIENTIFIC AND MANAGEMENT RECOMMENDATIONS 1 MONITORING, DATA HANDLING AND REPORTING Regular monitoring and reporting of BOD5 from sewage treatment plants should be license requirements. Some of these larger sewage treatment plants, such as Fort McMurray, have BOD5 loads approaching that of pulp mills in the basins. Yet under the 1993 Alberta Environmental Protection and Enhancement Act, operators of continuously-discharging sewage treatments plants need only report exceedances (within 24 h) to Alberta Environmental Protection. Compliance with sampling and analytical procedures should be mandatory for all licensed dischargers. Demonstration of QA/QC for sampling and analytical procedures should be a license requirement and conducted at regular intervals. While all licenses stipulate that sample analysis must be conducted following the latest edition of Standard Methods for the Examination of Water and Waste Water (APHA 1995), some samples have been analyzed incorrectly (e.g., some BOD5 samples) and other methodologies (e.g., for BODu analysis) vary between laboratories. Provisions are needed to ensure training of certified operators to measure (and record) flows and discharge volumes and for enforcement of reporting requirements. At present, sewage treatment plant operators often supply missing, unreliable and/or ambiguous discharge data that then become incorporated in effluent databases (e.g., the Towns of Peace River, Barrhead and Wabasca have not reported reliable flow data). Reporting proper discharge data should be a license requirement. A properly-maintained central database should be established for: (a) effluent monitoring data (discharge and water quality parameters for all industries and municipalities with licensed monitoring requirements), and (b) environmental data collected by industries. These databases should be linked with the provincial surface-water quality database. Concern has been raised about DO concentrations in mixing zones. DO concentrations in mixing zones have never been explicitly studied although the Alberta Environmental Protection winter water quality surveys usually sample from both banks in reaches of effluent mixing. At low flow conditions, effluents to the Athabasca and Wapiti River are usually fully mixed by approximately 10 km downstream of the outfall. Since there have been no reports of impairment to fish in the mixing zones, further field work on mixing zones with respect of DO conditions is not recommended at this time. DO monitoring and modelling must be more closely tied to the distribution of fish and fish habitat and fish DO requirements. 2 DO MODELLING 2.1 Modelling Deficiencies Modelling goals need to be clearly defined. There appear to be two goals with respect to DO modelling in the Northern River basins: (1) short-term compliance assessments (i.e., predicting DO levels during the upcoming winter), and (2) long-term basin management (i.e., establishing license requirements with respect to changing industrial operations). Dynamic models (i.e., allowing for temporal and downstream variability in DO) may be better suited for addressing the short-term goal because early DO winter data could be used in predicting DO concentrations during late winter. Modelling for long-term basin management focuses on average or low-flow conditions and, hence, could be accomplished using a deterministic approach. For both approaches, a probabilistic model should be employed so as to allow assessment of the effect of variances in model input parameters on the confidence of the model predictions. Implementation of a dynamic model such as WASP (Water Quality Analysis Simulation Program) will address questions regarding temporal variability in the decrease in DO in the Athabasca River with distance (i.e., the changing relationship between upstream and downstream DO concentrations as the winter progresses). However, basic issues such as validating the ice-cover Leopold-Maddock coefficients used in calculating reach velocities (see Section 8.2.2) need to be resolved before more complex modelling is attempted. If WASP or any other DO simulation model is implemented, the model rates established and validated by Chambers et al. (1996) should be employed rather than calibration values. Concerns about DO concentrations in mixing zones could be addressed by moving to a model capable of 2-dimensional simulation (i.e., changes across the channel as well as longitudinally down the channel). However, there are currently only limited data on DO concentrations within mixing zones. Modelling of temporal DO patterns in the Athabasca River and the cumulative impacts on populations of mountain whitefish, bull trout and burbot should be attempted. Modelling of effluent discharge timing and seasonal DO sagging in the Athabasca River should be conducted whenever industrial operations change or unusually low winter flows are forecast, and a schedule developed to minimize increases in chemical and biological oxygen demand during late winter. Modelling needs to be undertaken by one group and independently reviewed by another group with modelling expertise to validate the assumptions and subjectivity that comes into play when modelling complex systems with parameter-rich (sometimes data-poor) models. 2.2 Data Deficiencies Additional measures of STP BOD5 decay rates and BODu:BOD5 ratios are required to verify the values currently used in the modelling. Currently this information is limited to data from Grande Prairie STP on one date. Cross-channel variability in SOD should be examined and the relationship between sedimentation and SOD should be assessed, particularly below mill outfalls and tributary inflows. Ice-cover Leopold-Maddock coefficients, which are used to establish reach velocities and to convert areal SOD to volumetric SOD rates, should be re-evaluated for discharges similar to the long-term average discharge at Hinton. Comparisons of time-of-travel by Thompson and Fitch (1989) and Andres et al. (1989) showed discrepancies particularly in the reach downstream of Hinton (Chambers et al. 1996). An additional under-ice time of travel study should be conducted to verify the results of Andres et al. (1989) and provide further data for re-assessing the ice-cover Leopold Maddock coefficients. Temperature correction coefficients for correcting laboratory measurements of BOD decay made at 20oC to the river temperature of 0oC in winter must be validated. Photosynthetic rates below ice and snow cover of differing thicknesses should be measured during years when this is deemed significant and the influence of this parameter on DO modelling should be evaluated. With respect to two-dimensional modelling (i.e., changes in DO over time and with distance downstream), little or no temporal data exist on parameters such as SOD, the size of open-water leads, photosynthetic rates (both temporally and diel), and BOD5 sedimentation. The use of "balanced", "estimated" or "measured" river and tributary flows should be standardized. What discharge should be used for tributaries that are not gauged? How is discharge calculated on the mainstem between gauged stations? Data are not available on groundwater inputs, diffuse loading, the size of open-water leads, nitrification (i.e., nitrogenous oxygen demand), and the applicability of SOD rates measured near shore to the entire channel. The concentration of DO upstream of Hinton is an important factor determining downstream concentrations in the Athabasca River. Between 1990 and 1993, DO concentrations in the Athabasca River upstream of Hinton ranged from 11.5 to 12.5 mg/L approximately 3-4 weeks after freeze-up. Concern about forecasting DO concentrations upstream of Hinton could be resolved by recognizing that modelling for: (1) long-term basin management must focus on average or worst-case scenarios (thereby eliminating the need to predict headwater DO concentrations for any particular year), and (2) short-term compliance assessments could be initiated in early winter using headwater DO concentrations measured in early winter (December or January) and average winter variance of headwater DO, or could incorporate a model relating headwater DO concentration to ice development. 3 RESEARCH In situ measurements of DO levels in the substratum during winter and their relationship to water-column DO concentrations are necessary to assess the DO status of fish and benthic invertebrate habitat and to predict substratum DO concentrations from the more routine measurements of water-column values. Studies of the combined effects of effluent and low DO levels should be expanded to include other fish species and important benthic invertebrates and to assess how impacts may be modified by differences in developmental stage or in acclimation time to low DO levels. In fish, contaminant-DO interactions should be examined, specifically the relationship between various hormonal and enzyme induction indicators of stress and seasonally low DO. Sedimentation rates should be measured below all mills to determine if settling rates are the same for different effluent types. Also, a determination of whether the sedimentation rates measured for all material (organic and inorganic) applies to only oxygen-consuming material is needed. The cause of elevated SOD rates below pulp mill discharges needs to be established. These higher SOD rates may be due to organic carbon loading or enhanced periphyton growth due to nutrient loading from pulp mills. In situ bioassays with eggs of mountain whitefish, bull trout and burbot should be conducted at key sites in the Athabasca River in conjunction with measurements of DO, BOD5, contaminant occurrence and effects, and ice cover effects. In addition, laboratory studies are required to determine a dose-dependent relationship between individual embryonic development stages and DO concentration for each of the major fish species. This work should include incubation trials at 0 to 1oC to more closely simulate natural winter temperature regimes. 4 WATER QUALITY AND EFFLUENT GUIDELINES Effluent permit limits should be assessed and based on environmental effects rather than technology design standards. The 3 kg BOD5/air-dried-tonne limit for most pulp mills and the 25 mg/L BOD5 limit for most municipal discharge permits is a technology-based limit. The Towns of Peace River, Fort Smith and Fort Chipewyan have continuous sewage discharges that often exceed the permit limit of 25 mg/L BOD5. In the case of Peace River and Fort Smith, these high discharges may not have biological consequences due to the large volumes of water in the Peace and Slave Rivers. In addition, 26 periodic municipal dischargers (i.e., discharge from wastewater stabilization lagoons) exceeded the 25 mg/L BOD5 limit (based on 1990-1993 data). An assessment of the environmental impacts of these exceedances is recommended. Regulatory standards for DO need to be reviewed to ensure that they are consistent with the minimal requirements known to be important for the native fishes of the northern river basins. Laboratory studies on effects of lowered DO levels (3 mg/L) at low temperature (2-3 oC) showed that mountain whitefish eggs took longer to hatch and bull trout alevins were less well developed than at higher DO concentrations. DO concentrations of 6 mg/L may also extend the time required to hatch by some burbot. The commonly-occurring mayfly in the Northern Rivers (Baetis tricaudatus) was also found to have decreased survival and reduced feeding rates at a DO concentration of 5 mg/L. Given the fact that mayflies and the early life stages of fish live at or in the surface layers of the riverbed and that DO concentrations can differ by 3 mg/L DO between the water column and the sediment-water interface (Chapman 1986), DO concentrations in the Athabasca River could already be at levels that could have chronic effects on these animals at localized sites. Based on the fact that many fall-spawning fish species in the Northern River basins are in the salmonid family, the more conservative Canadian Water Quality Guideline (CCREM 1987) of 6.5 mg/L DO for salmonids is recommended as a policy-based guideline to be used in setting effluent license conditions for periods of ice-cover. A Review of Population Health Status in Northern Alberta By: Dr. S. Gabos Environmental Health Services Alberta Health Edmonton, Alberta
NRBS - Home Table of Contents Top of Page		RECOMMENDATIONS Develop better health information related to environmental contaminants. People living in the Northern River Basins are concerned about the subtle impact of environmental changes and contaminants on their health. At present, our knowledge about the potential human health risks and the environmental contaminants is extremely limited. Developing better heath information related to contaminants should be a major direction for future research and monitoring. Particularly, the long term effects of low levels of exposure to contaminants should be investigated. Since one time health studies are not likely to yield results (in spite of the associated costs), this should strategically be accomplished through the ongoing monitoring and surveillance of both environmental and human health indicators including exposure, biological markers of exposure and effect, and health outcomes. Undertake periodic and systematic health risk assessments of contaminants in fish (and other traditional foods). The presence of contaminants in the food chain is a concern for many local people who rely extensively on traditional foods for subsistence. A thorough health review of the data on contaminants gathered by the Northern River Basins Study should be a priority issue. Existing fish consumption advisories should be re-evaluated based on the new information. New health based standards should be developed as opposed to the current mechanistic approach. The approach should include periodic and systematic health risk assessments to detect trends and emerging issues. The provincial, territorial, federal and first nations governments should work together toward developing a common integrated process to share resources and provide accurate and timely information for the communities. Human health assessment be included in the future development projects. Local people are concerned about the health impacts of major development projects. In making sustainable development a fundamental value in our society, the governments and corporations should ensure that health is being given appropriate consideration in all major development projects. Use of Aquatic Resources in the Northern River Basins: Synthesis Report By: R. Bruce MacLock and John P. Thompson 1Network Center of Excellence University of Alberta Edmonton, Alberta 2Corporate Management Service Alberta Environmental Protection Edmonton, Alberta
NRBS - Home Table of Contents Top of Page		Recommendations The socio-economic component of the NRBS represents a departure from the conventional, technical approach to water management studies. In mapping out public perceptions on water issues, the study has yielded information that allows water and environmental managers to better differentiate between technical and perceived management issues. Perceived problems are real problems, regardless of whether or not there is a technical cause, and still need to be dealt with by resource managers. However, the management approaches used to address perceived problems are substantially different from the technical solutions often considered. The socio-economic studies also provide a rare, quantified summary of public views and understanding of current issues that can only be attained through surveys. This study shows that there are often very large differences between public and stakeholder values and opinions. It demonstrates that what industry wants or what local government wants, is not always what the general public wants. This study is also a landmark in that no comparable research on water use and management issues has been attempted to date in the NRBS area. The social, economic, environmental, legal, jurisdictional and institutional views of northerners from both sides of the NWT-Alberta border will be of considerable value to the legislators and regulators of the three jurisdictions involved. Some basin residents who responded to the survey also mentioned that this type of survey provides a valuable means of monitoring River health and public perceptions of river management, and recommended that it be repeated on a regular basis. In response to these suggestions it is recommended that assessments of public perceptions of river health should be undertaken at regular intervals as a way of monitoring change. These assessments should follow the survey approach used by the NRBS in order to allow direct comparison of results. This approach, which was based on a combination of telephone and mail surveys from a stratified random sample of basin residents, proved to be quite satisfactory and cost effective. The surveys and related analysis conducted for the Northern River Basins Study were undertaken at a modest expenditure (approximately $150,000). It is also recommended that the same regional boundaries (based on telephone prefix regions or nearest equivalent) be used in future surveys. The NRBS surveys showed few regional differences in public opinion at the present time. However, some regional differences in perceptions and issues may evolve in the future, and these should be monitored so that water management can be responsive to regional needs. Finally, it is recommended that future river or resource management studies be undertaken using an ecosystem approach. This approach involves: defining the area to be studied in terms of river basin or other ecoregion boundaries; using an integrated approach to examine the interactions among land, water and other resources; supplementing technical, biophysical information with socio-economic information that include perceptions and values; and, considering transboundary effects. Within this process, surveys of the general public and stakeholder groups can be used to provide decision-makers with quantitative, representative data on public perceptions and values. In addition, surveys offer a structured opportunity for public involvement. They can be used to solicit input from a broad range of interests, and present a less intimidating and more user-friendly method for personal involvement in resource management decisions. Assessment of Drinking Water Quality in the Northern River Basins Study Area: Synthesis Report By: Tanya F. Armstrong, Dennis S. Prince, Stephen J. Stanley and Daniel W. Smith Environmental Engineering and Science Program University of Alberta Edmonton, Alberta
NRBS - Home Table of Contents Top of Page		SCIENTIFIC AND MANAGEMENT RECOMMENDATIONS Public Health As has been stated, drinking water quality and public health are closely related. The assessment of public health should continue with special attention given to the correlation of public health with drinking water quality and drinking water supplies in the study area. This would require additional monitoring of health records in conjunction with water quality data if possible. Also, in terms of public health, the Drinking Water Component perceives that there is a need for some public health educational programs in the NRBS area, particularly in communities where there is a large objection to chlorination. This would be beneficial to those that turn to other supplies of drinking water as a result of their distaste for chlorine, to know why chlorine is used, and the risks and benefits associated with chlorinated versus unchlorinated water. Educational programs would also be beneficial for individuals who are involved in living off the land expeditions or other wilderness activities, so that they are provided with information with which they can make the best decisions regarding drinking water, sanitation and hygiene during activities such as these. Since all of these have an effect on health, good decisions in these regards would have a positive impact on public health protection. Aesthetics Since the aesthetic quality of water is generally the basis of evaluation by which consumers judge the safety of their drinking water, it is important that the aesthetic quality of the water in the northern river basins continues to be monitored and assessed. In this manner, an historical database with baseline information would be compiled. Furthermore, additional scientific studies are required to characterize influences that affect the aesthetic quality of water. Drinking Water Supplies The main recommendation in terms of the conventional drinking water facilities in the study area is that the existing facilities in the study area are optimized so that the best quality drinking water is supplied to consumers. This involves action at several levels. First, the existing monitoring practices should be improved so that they are more representative of the plants performance. Samples of raw, treated and distributed water should be analyzed in order to assess the overall quality of treatment and distribution. Second, based on this monitoring, proper remedial actions should be practised for parameters that do not meet recommended guidelines. Third, the operation and maintenance of the existing facilities is critically important for the assurance of good quality drinking water. Therefore, continuing educational programs and monitoring are necessary for plant operators. A fourth recommendation regarding conventional drinking water supplies in the study area has to do with some of the distribution systems that are currently in place. Although piped distribution systems are ideal, they are not financially or technically feasible for many of the remote areas typical in the NRBS area. Where trucked delivery of water is supplied, the water should be delivered to water cisterns rather than water barrels which are still in use by some NRBS residents. Furthermore, the state of the distribution system, piped and trucked, should be monitored. An effective water supply system will involve the community in all aspects of decision making. Although this is especially important during the design stages, it is also important for the maintenance of an existing water supply system. Figure 24 (provided in the synthesis report) illustrates a simple approach that can be used in communities in the NRBS area in the maintenance of a successful drinking water system. According to this figure, there are three main components involved in the maintenance of a community water supply system. Community involvement is of paramount importance to the success of any project in the community. If an outside expert is to be involved in the project, then that person should spend time in the community getting to know the residents. During this time in the community, public forums can be held where questions, concerns and ideas can be discussed. The forums would also be a good time to educate residents regarding drinking water quality and general public health. Educational programs such as these comprise the second important component in this model. The third main component in the maintenance of an effective water supply program is the proper operation and maintenance of the system implemented. This is done through appropriate selection of community members to operate the designed system and through continued community involvement in future decisions. If a mode such as this is followed in the design of a water supply system in the study area, a safe and sustainable supply of potable water is possible. Further scientific studies on non-conventional drinking water supplies in the study area and elsewhere are necessary. More drinking water quality data is needed, as well as the extent of consumption of non-conventional supplies. As part of the scientific investigation into non-conventional drinking water, an epidemiological study could be carried out which would look at waterborne disease rates in selected areas and potential links with non-conventional drinking water consumption and/or quality. If a significant relationship was found, the results could then be used for educational programs and determining possible solutions. Remote access to good quality drinking water is a challenge. When possible, the best source of drinking water for people living in remote areas away from conventional facilities is from a protected groundwater well. If groundwater is unavailable, then other supplies should be tapped and treated appropriately. If the safety of a given water supply is unknown or questionable, then the water should be boiled. Finally, it is vitally important that all present and future drinking water sources are protected from physical, chemical and bacterial contaminants. In doing so, additional precautions are taken in the maintenance of safe drinking water supplies in the Northern River Basins. Ecosystem Health and Integrated Monitoring in the Northern River Basins By: Kevin J. Cash1, Fred J. Wrona1, William D. Gummer2 1National Hydrology Research Institute Environment Canada Saskatoon, Saskatchewan 2Environmental Conservation Branch Environment Canada Regina, Saskatchewan
NRBS - Home Table of Contents Top of Page		Recommendations 1. We recommend a basins' Integrated Ecosystem Monitoring Committee (IEMC) be established to coordinate all ecosystem monitoring in the northern river basins. Governments, industries, some municipalities and to a lesser extent other organizations conduct various types of monitoring. This committee should play a key role in overseeing all aspects of monitoring within these basins (e.g., scientific implementation and assessment of societal goals/objectives, evaluate protocols for design, data collection, analyses, quality assurance and data management). 2. We recommend that the IEMC adopt the ecosystem approach to environmental monitoring and the Integrated Ecosystem Monitoring framework described in this report. This synthesis report has provided in some detail the basis for the design and implementation of a holistic and integrated ecosystem monitoring program and should be considered at the starting point for future monitoring in the basins. 3. We recommend a panel of scientific experts (including representatives of Traditional Knowledge) be established to advise the IEMC. A scientifically rigorous IEM program requires expert advice on its design, implementation, data interpretation, and scientific recommendations. Similar to the Science Advisory Committee of the NRBS, this committee would serve as an independent and objective reviewer of the IEM program. 4. We recommend current and future monitoring activities within the basins be integrated following the framework developed in this report. Particular attention must be given to standardization of monitoring activities and the adoption of appropriate quality assurance / quality control protocols. There is a need to ensure that monitoring within the basins is coordinated and avoids duplication. Appropriate priority needs and scientifically acceptable protocols must be identified and applied across agencies. Quality assurance and quality control practices as well as procedural standardization must incorporated into all aspects of monitoring activities. 5. We recommend an IEM database for the basins be established and maintained. A critical component to an effective integration of monitoring data is the existence of a standardized database that will allow for interpretation of monitoring information at a variety of scales (spatial and temporal). A process is required by which this database can monitored, updated and made publicly available. 6. We recommend a process be established whereby the integration of monitoring data collected in the basins be subject to scientific interpretation by an independent group. The individual agencies contributing to the IEM database are responsible for the interpretation of their own monitoring data. However, there is also a need for interpretation of the integrated data. Such an interpretation should be scientifically-based and consider a broader range of issues that would any single monitoring agency. It is also necessary that the scientific validity of monitoring activity be assessed by independent experts. 7. We recommend that volunteer organizations and individuals be incorporated into the IEM implementation strategies. Community involvement in the implementation of basin-wide monitoring provides a unique opportunity. The involvement of volunteers (including schools) in monitoring results in a more holistic consideration of ecosystem health. A major challenge will be to adapt community-based monitoring to the scale of the northern river basins. Paramount in any decision to introduce community-based participation in monitoring will be the development of appropriate manuals, other educational material and the adoption of an ongoing training plan. 8. We recommend that future management programs recognize that the aquatic ecosystem is directly related to the adjacent terrestrial ecosystem and that the evaluation of aquatic ecosystem health must include considerations of land use activities (forestry, agriculture, urban development, mining, etc.). The Study Board deliberated at length about the inclusion of terrestrial components within the research program of the NRBS. Due to its restricted mandate and limited budget, NRBS was unable to incorporate such issues as forestry management and other land uses, climate change and biodiversity. The science components responsible for the design and implementation of the NRBS science program also recognized the need to focus primarily on the aquatic ecosystem, but expressed concerned over the limited research pertaining to terrestrial issues. Future IEM in these basins should extend beyond the mainstems of the major rivers and tributaries to consider importance of terrestrial activities and processes. 9. We recommend a process of public consultation be undertaken every 3-5 years to assess and re-evaluate societal priorities and to identify emerging issues. An essential component of an effective IEM is the requirement to assess periodically and re-evaluate societal priorities, goals, and objectives for these basins and to incorporate this information in the refinement of monitoring activities. As discussed in this synthesis report, the identification of appropriate ecosystem indicators is dependent on the development of precise statements of ecosystem goals and objectives. Cumulative Impacts within the Northern River Basins By: Fred J. Wrona1, William D. Gummer2, Kevin J. Cash1 Kenneth T. Crutchfield3 1National Hydrology Research Institute Branch Environment Canada Saskatoon, Saskatchewan 2Environmental Conservation Environment Canada Regina, Saskatchewan 3Fisheries Management Division Alberta Environmental Protection Edmonton, Alberta
NRBS - Home Table of Contents Top of Page		Recommendations These recommendations are a result of an interpretative, integrated synthesis of results from the eight study components. The analysis also considered advice received from public gatherings and science fora held during the study. These recommendations are science-based and not reflective of societal values. It is the challenge of the Study Board with its multi-stakeholder representation to incorporate societal values in the final NRBS recommendations. Each of the Component synthesis and project reports contain a number of issue- and discipline-specific scientific recommendations, too many to list here. We recommend that management authorities review and consider these recommendations as the issues and concerns warrant. The recommendations which follow are divided into four primary issue areas: I Environmental Contamination II Aquatic Ecosystem Health III Environmental Management and Monitoring IV Cumulative Effects Within each of these areas, recommendations are presented in order of priority. I Environmental Contamination Given the prevailing concerns about the presence, concentration and distribution of contaminants in the aquatic ecosystems of the Peace, Athabasca and Slave River systems, the following monitoring and research recommendations should be considered immediately by governments: 1. We recommend that a basin-wide monitoring program be undertaken at least once every three years to assess fish health and levels of contaminants in fish tissue. NRBS research has identified that although the health of fish is generally believed to be good across the basins there are indications that some fish may be showing early signs of stress and possibly exposure to contaminants. For instance, there is a high incidence of abnormalities reported in fish below Whitecourt, and higher than normal incidence of abnormalities in fish below other pulp mills. As well, our findings indicate depressions in sex steroids in fish from these same locations. Together, there is a body of evidence which suggests that there may be sub-lethal toxicological concerns. There is no active fish contaminant monitoring program in the basins. Given the concerns related to human consumption of fish containing mercury, dioxins, furans, PCBs and toxaphene (various fish consumption advisories exist now in the basins), and given that fish contamination is changing over time and space due to improvements in technologies and due to biological and ecological processes, periodic assessments would provide governments, public and other stakeholders with current information. It is our view that a three year monitoring cycle reflects a reasonable time frame over which one could expect fish and other organisms to respond to changing conditions within the basins. 2. We recommend that the federal and provincial governments and industry consider further optimization of the Environmental Effects Monitoring (EEM) protocols for pulp mills based upon the NRBS findings. NRBS undertook investigations to assess the state of aquatic ecosystems, and in particular, the health of fish and the benthic communities upstream and downstream of pulp mills. The most in-depth work was conducted on the Athabasca River. Considerable effort went into the selection of appropriate fish species, sampling design and selection of assessment protocols. We anticipate that the fish information concerning contaminants, fish movement and distribution, fish health (biomarkers) and indicator development, and sampling design could be used to optimize the Environmental Effects Monitoring (EEM) protocols. Consideration should be given to coordinating the industry collections (timing, species, number of samples, etc.) of all the mills so that data can be comparable and integrated on a larger basin scale. 3. We recommend that all levels of government actively support and encourage ongoing research investigating ecosystem structure and function within these basins. An explicit objective of the NRBS was to acquire a baseline data set pertaining to the basic ecology of the Peace, Athabasca, and Slave River basins. The importance of understanding the structure and function of the ecosystem cannot be over emphasised. It is this understanding which determines our view of the system and provides a context within which all management priorities and objectives are developed. Gaps in this understanding could result in a failure to identify key issues or in the misdirection of time and effort. Unfortunately, there are considerable gaps in our current knowledge of the ecology of the Peace, Athabasca, and Slave River basins. These knowledge gaps are reflective of the difficulties associated with working in these systems and of a more general lack of information on the ecology of large rivers, particularly large northern rivers. Additional research on ecological structure and function is required to determine more precisely the distribution and fate of contaminants in the environment and to further parameterize analytical models developed to predict the consequences of discharging contaminants to the environment. Governments should participate directly in such research, particularly when the research question falls within their mandate. In addition, governments should actively encourage, and perhaps subsidize, ecological research conducted in these basins by other groups such as universities, colleges, community groups and international agencies. 4. We recommend that the governments of Canada, Alberta, and Northwest Territories and the key Industries investigate the feasibility and implementation of an integrated environmental information system. There is a continuing problem, not unique to these basins, of access to environmental data and information. Virtually every industry, certainly the senior governments, all have computerized systems for handling their own data. For purposes of facilitating the sharing of information, protocols could be developed which would outline the basic standards for handling, storing and reporting of environmental data. Furthermore, protocols could be developed which would link the many databases together so as to permit the transfer of data between them, or at the very least, could direct the user to where the data could be obtained. The five private laboratories and the several provincial and federal laboratories used by NRBS all had different analytical method codes, methods of reporting detection limits, quality assurance methods, and reporting protocols. Considerable human intervention was needed to ready the laboratory data for NRBS use. We believe that a concerted effort by the partners could be successful at reconciling these sorts of problems and the product ultimately developed could be marketable nationally and internationally. This multiplicity of approaches and techniques amongst agencies can be reduced but not eliminated because differing methods are often justifiable. Opportunities exist to make advances now through such organizations as the Canadian Association of Environmental Laboratories, using the INTERNET, and through existing informatics initiatives of governments. Bibliographic inventories of studies and reports undertaken in the basins, land and water use, monitoring data, etc. could be incorporated. II Aquatic Ecosystem Health 5. We recommend further research be undertaken to address the observation of endocrine disruption and increased numbers of sexually immature fish in reaches immediately below pulp mills. Preliminary NRBS data concerning endocrine function and sexual maturity of at least two fish species (burbot and longnose suckers) suggest that pulp mill effluents may adversely affect the reproductive ecology of individual fish; however, there is as yet no evidence for an effect at a population level. Using a weight-of-evidence approach, we recommend using the precautionary principle as the basis to initiate more detailed studies examining the linkages between reproductive ecology and exposure to pulp-mill effluent before further developments, singularly or in combination, cause additional ecological stress on the fish populations. 6. We recommend investigations be undertaken to determine the linkages between exposure to environmental stresses and sub-lethal effects on fish and other aquatic biota, including physical abnormalities and biomarker responses. NRBS studies reveal basin-wide variation in the frequency of physical abnormalities and in the extent of biomarker response. In some cases the measured response appears to be associated with specific point-source discharges (e.g., increased incidence of fish abnormalities below pulp mills); however, in other cases the measured response is not as obviously associated with a particular environmental stress, this is particularly true in some of the tributaries not intensively studied by the NRBS (e.g., elevated levels of metallothionein response in fish collected from the Pembina River and MFO induction in fish from the Wabasca River). The consequences of long-term exposure to contaminants takes on added significance in light of NRBS data indicating the presence, usually at low levels, of environmentally persistent contaminants (e.g., dioxins, furans and PCBs) throughout the basins. 7. We recommend investigations be undertaken to identify the sources of PCBs to the upper portions of the Peace River Basin, including the Smoky and Wapiti River systems, in the upper Athabasca River between Jasper and Athabasca and the extent to which PCBs are concentrated in the food web. PCBs are known to bio-concentrate and in some cases higher measured levels of PCBs in fish tissue (e.g., burbot) may be a consequence of changes in the fish foraging behaviour (e.g., large burbot feeding on other fish will concentrate PCBs to a greater extent than those feeding on macroinvertebrates) rather than a consequence of exposure to a PCBs spill. The role of food web interactions in observed tissue concentrations of PCBs could be investigated using stable isotope analysis. NRBS has identified that PCBs are one of the major contaminants in the tissue of biota from these basins. Importantly PCBs are not produced by pulp mill activities and are not uniformly distributed throughout the basins. In particular, PCBs concentrations have doubled in several locations in the Peace River Basin between 1992 and 1994, although the explanation for this increase is unknown. 8. We recommend the development of ecologically rather than technologically-based endpoints for the regulation of nutrient discharges from industries and municipalities. Current levels of nutrient discharge from both industry and municipalities have been demonstrated to change patterns of nutrient limitation and hence primary and secondary productivity. At present issues associated with these changes are largely aesthetic, but continued and or additional loadings have the potential to dramatically impact the trophic structure in these basins. Current guidelines focus exclusively on technology-based endpoints and do not incorporate ecological responses. Technologically-based effluents guidelines and regulation should be viewed as a means to preserve adequate ecological structure and function, and not as an end in themselves. Implicit in this approach is the recognition that regulatory levels may vary from reach to reach as a function of river size, cumulative effects and unique ecology of each reach. 9. We recommend further research into the dissolved oxygen requirements of the most sensitive life-history stages of fish species and their invertebrate prey. We further recommend the development of ecosystem / reach specific dissolved oxygen guidelines. Much of the available information on dissolved oxygen is not representative of the aquatic species and conditions existing in these northern rivers. NRBS review of under-ice river dissolved oxygen levels reveal an enhanced diminishment of dissolved oxygen in the Wapiti-Smoky Rivers, and the Athabasca River between Hinton and Grand Rapids. These river reaches receive major inputs of municipal and pulp mill effluent. In a river channel fish and other riverine biota focus much of their life processes, close to the river bed or bank. Current dissolved oxygen monitoring practices record dissolved oxygen levels away from the streambed. Consequently, the dissolved oxygen data does not accurately reflect conditions existing within habitats utilized by fish and other biota. Available scientific knowledge indicates that an average three mg/L differential exists between dissolved oxygen levels within the water column and those existing in the streambed. The availability of sufficient dissolved oxygen influences the aquatic community composition within a river reach. Fish and other biota exposed to diminished dissolved oxygen will respond by altering life processes. NRBS work into the embryonic development of three fall-winter spawning fish species: mountain whitefish, bull trout, burbot, and the feeding behaviour of an invertebrate species provided insightful information. The information indicated a need for further research and the establishment of reach specific dissolved oxygen guidelines. More specific information is needed to manage effluent for the protection of sensitive life stages in biota likely to be subjected to diminished dissolved oxygen levels. Research must be done to find out the acceptable limits of northern river aquatic biota to lowered dissolved oxygen levels, and the relationship between water column and substrate-water/substrate interface dissolved oxygen levels. 10. We recommend that research be undertaken by Environment Canada and partners to develop an understanding of the inter-relationship between climate variability and hydrologic regimes of the mainstem rivers and major tributaries in the basins. The NRBS has determined that variability in precipitation and reduced winter snow pack have reduced the magnitude of recent (up to 1995) spring run-off in the Peace River drainage and the probability of ice-jam formation in the delta area. Reductions in the spring runoff volumes in recent years are therefore not just a result of the Bennett Dam. The implications of climate change on the regulated flow regime of the Peace River and on the ecology of the delta must be understood, especially if solutions for the long term are to be sought for alleviating the ecological problems in the Peace-Athabasca Delta. Eventually, scenarios of climate variability could be factored into water management strategies and the operational plans for Bennett Dam. 11. We recommend that current human health advisories for the consumption of fish, including the "recommendation" issued by the Government of the Northwest Territories, be reviewed, revised and/or developed, based upon human dietary and fish contaminant information reported by NRBS. Further, we recommend starting an ongoing contaminant monitoring effort for fish consumed as food by domestic and sport fisherman. Similar to previous investigations, NRBS has identified contaminants in the fish flesh and organs (liver) that are the subject of current provincial human health consumption advisory ( e.g., mercury, dioxin-furan) or territorial recommendation (e.g., toxaphene). NRBS sampled fish from the mainstem rivers of Peace, Athabasca and Slave Rivers and major tributaries (e.g., Wapiti-Smoky Rivers). Many of these sampled fish species are eaten for domestic and sport purposes. Currently, aside from the monitoring associated with the export of commercial fish products (Freshwater Fish Marketing Corporation), a program does not exist for the regular collection and analysis of fish obtained for domestic and/or sport purposes. The current guideline utilized by Health Canada in preparing human health assessments has provision to incorporate the unique dietary information of the human population consuming the contaminated fish product. Often this dietary information on the human population consuming the contaminated fish product are scant. There are there are instances where an advisory or recommendation can be in force within one jurisdiction and not an adjoining jurisdiction when but for a line on a map the same fish population is being considered, e.g., dioxin-furan advisory on the upper Athabasca River downstream of Jasper National Park but not in the Park, toxaphene recommendation for burbot liver in the NWT portion of the Slave River but not in Alberta. The public perception of the risk is at best confusing. The current human health consumption advisory or recommendation should be reviewed in light of the NRBS findings. As well, the traditional users who rely or used to rely on fish for a significant portion of their dietary protein source, require special consideration in preparation of the advisories and/or recommendation that takes note of their consumption use patterns. A need also exists for a semi-regular monitoring program that acknowledges the likely variation in contaminant levels as effluent standards are modified. 12. We recommend the extent and causes of fish tainting be quantified and action taken as appropriate to remediate the problems. Although human health is not believed to be threatened by current levels of fish tainting, NRBS scientists learned that a widely held public perception is that fish are contaminated. This perception is based on fish odour and appearance; fish possessing oil and/or pulp mill odours are immediately perceived to be contaminated and unfit for human consumption. The occurrences of these observations is highest in the lower end of the basins but also occur in the Smoky and Wapiti systems, and some evidence exists (traditional knowledge) that suggests that the quality of fish livers has deteriorated. As long as these issues persist in the basin, the public will associate taste and odour with polluted fish and drinking water. In-depth assessment of tainting substances (synergistic effects of multiple effluent types) and alternatives for their control may be required to meet the public need to know. Insufficient data exist to address the issue of fish tainting and the particular substances responsible for tainting of drinking water supplies. The primary sources of tainting substances to the Athabasca River exist in the reaches between Hinton and Fort McMurray where dilution ratios are lowest and where there is a succession of industrial and municipal waste sources. 13. We recommend that provincial and federal authorities undertake, in accordance with their responsibilities, to ensure the ongoing training and certification of drinking water treatment plant operators, education of the public about their choices concerning drinking water sources and treatment, and timely reporting and corrective action for water quality problems. The vast majority of people within the basins receive excellent quality drinking water. The problems which have been most frequently observed are usually in communities of populations less than 500. Typical problems have included: high bacteria, turbidity, odours, and trihalomethane compounds. High levels of coliform bacteria indicate the potential risk associated with viruses and waterborne diseases. Although some of the facilities may be aging and therefore not capable of high performance, concern was expressed by some community members over the experience and dedication of treatment plant operators. Given the importance of quality water to the health of people, treatment plant operators should be recognized as critical assets to the community and afforded the best level of training and certification. Furthermore, monitoring protocols must be standardized and subject to quality assurance, and monitoring data regularly reported with timely corrective action taken, as needed. NRBS public surveys have confirmed that tainting substances (derived from pulp mill discharges and municipal disinfection with chlorine) are still an issue with respect to drinking water. Basin communities should be provided with documentation about the quality of their drinking water, explanations of why odours exist (natural occurrence included), and advice as to alternatives and choices people can make about their drinking water. III Environmental Management and Monitoring 14. We recommend the adoption of an integrated basin management and the assessment of cumulative effects of developments. Such an approach requires an integrated environmental monitoring framework to ensure ongoing scientific validity of results, and rationalization and optimization of monitoring and research conducted within the basins. It is further recommended that an Integrated Environmental Monitoring Committee (IEMC) be immediately established to coordinate basins' monitoring and research within this framework. Governments, industries, some municipalities and to a lesser extent other organizations conduct various types of monitoring within the basins. Individual agencies collect monitoring data for their own purposes, however, the total benefit realized would be greater if monitoring within the basins was coordinated so as to avoid duplication and provide the maximum return in information for each dollar invested. Such an approach would also allow for the consideration of a broader range of issues (e.g., basin-wide effects, cumulative effects) than would be considered by any one agency or industry. Appropriate priority needs and scientifically acceptable protocols should be identified and applied across agencies. Quality assurance and quality control practices as well as procedural standardization should be incorporated into all aspects of monitoring activities. A process is required by which this database can be maintained, updated and made publicly available. A scientifically rigorous integrated environmental management program requires expert advice on its design, implementation, data interpretation, and scientific recommendations. Similar to the Science Advisory Committee of the NRBS, this committee would serve as an independent and objective reviewer of the integrated environmental management program. The Synthesis and Modelling Component has presented a practical procedure for the development and application of ecosystem indicators and has recommended indicators for adoption by governments, industry and the public. Conformance with this monitoring and research template should be a condition of all monitoring and research undertaken in the basin. Government authorities may wish to consider the requirement of monitoring and research permits in order for agencies to conduct their work in the basins similar to what is done in the Northwest Territories. This would be a means of optimizing the monitoring and research in the interests of the basins needs. 15. We recommend that existing information on northern river fish movement, behaviour, and habitat use, must be compiled and interpreted. On completion, this work should be assessed for its support of cumulative effects assessment, deficiencies in knowledge identified and corrective action implemented. The composition and extent of fish species within the basins is generally known. A wide gap in knowledge continues to exist on seasonal distribution / abundance, habitat utilization and general biology of fish species, particularly for the non-domestic/sport/commercial varieties. NRBS, industry and government investigations since the start of the Study have further augmented the available knowledge but there remains a lack of interpretation on this existing body of knowledge. Consequently, the likelihood of redundant information being gathered at the expense of needed information remains high. NRBS investigations have identified significant freeze-up and morphological changes to the Peace River downstream of the Bennett Dam. The implications of these changes to the fish community reliant on the mainstem Peace River are unknown, particularly in the river reach downstream of Peace River and the lower portion of the Peace River within Wood Buffalo National Park. Without better understanding of fish movements and populations there is much difficultly in interpreting the significance of contaminant levels on the fish health effects documented by NRBS and others. It is also difficult to design effective monitoring programs to assess changes in fish health. This compromises the use of fish as reliable indicators of ecosystem health even though they remain the most obvious animal for the public to do their own evaluation of risks to human health. IV. Cumulative Effects 16. We recommend additional research and/or remediation in those areas of the basin identified as deserving of special attention by applying the weight of evidence approach to the assessment of cumulative effects. 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 basins-wide level and the inter-relatedness among river reaches, it is equally important to employ a weight of evidence approach to identify those portions of the ecosystem particularly deserving of attention. This approach provides the opportunity to focus on characteristics which are unique to reaches and identify related management considerations. What follows is a brief description of what we consider to be the five areas in the basins requiring priority consideration by managers at the federal, provincial and territorial levels. 16a. Protection of the Wapiti-Smoky River systems Based on the weight of evidence approach, the Smoky-Wapiti 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 PCBs loadings in fish. Dioxin and furan concentrations in biota have declined since 1992, but remain among the highest observed in the basins. Reduction in winter snow pack and subsequent declines in discharge levels will serve to further concentrate contaminants and nutrients in the system. Prevention of further deterioration should be a priority of both provincial and federal management authorities as should be the remediation of an already stressed aquatic ecosystem. These small and relatively shallow systems provide critical fish spawning habitat and are therefore particularly vulnerable to pulp mill and municipal wastes. 16 b. Remedial action plan for the Peace-Athabasca Delta The Peace-Athabasca Delta is internationally recognized as one of the most important and largest freshwater deltas in the world and has been designated as a Ramsar site under the international Ramsar Convention as well as a World Heritage Site. The NRBS has recognized that the Peace-Athabasca-Delta has been significantly impacted by flow regulation and climatic variability. Most significantly, a reduction in the frequency and extent of ice-jam flooding has resulted in the drying of perched basins and delta lakes. This in turn has had profound ecological consequences for the geomorphology of the delta and for the aquatic biota, terrestrial wildlife, and riparian vegetation in this region. Moreover, the ability of aboriginal peoples to pursue a traditional lifestyle has been significantly compromised. We believe that sufficient information now exists based on the previous studies in the delta, studies by Wood Buffalo National Park, research by NRBS, and the forthcoming results of the Peace-Athabasca Delta Technical Studies to develop and implement a remedial action plan. We further believe that options for remediation could include modifying the operation of the Bennett Dam so as to be more ecologically sensitive to the needs of the downstream ecosystem. Adaptive management strategies, whereby the best option (based on collective knowledge) can be implemented, and then modified based on the results, should be considered. To begin with, it will be necessary to have the stakeholders agree upon the ecosystem attributes (goals and indicators) which should guide the action plan. 16c. Intensify monitoring activity in the reach of the Athabasca River from Hinton to below Whitecourt Recent improvements in process technology at the Hinton and Whitecourt pulp mills have reduced levels of persistent organochlorine contaminants entering the environment. This improvement is reflected by declines in measured levels of certain contaminants (e.g., dioxins and furans) in sediment and biota. However, NRBS has identified contaminant-related concerns in the Emerson Lakes area below Hinton and has recorded a high incidence of fish abnormalities below Whitecourt. In addition, nutrient discharges from the Weldwood mill have resulted in nuisance growth of algae for up to 30 km downstream of Hinton. Improvements in pulp mill technology may serve to reduce these impacts, but given current conditions in this reach, we recommend that monitoring be particularly vigilant. 16d. Research into the ecological consequences of exposure to hydrocarbon-related contaminants in the oil sands area In the 1994 basin-wide fish survey, the only locations to produce significant MFO induction in burbot were located in the oil sands area (below Ft. McMurray and the Wabasca River). Moreover research using semi-permeable membrane devices supported this observation in the Athabasca mainstem as well as in the Steepbank and Clearwater Rivers. These observations point to the importance of environmental stress caused by exposure to natural sources of hydrocarbons in the oil sands area and to the need to distinguish and characterize the consequences of exposure to these natural sources and to effluent from oil sands refineries. 16e. Protection of the Slave River Delta ecosystem NRBS studies consistently found that fish in the Slave River Delta were the largest and in the best condition. However, these same populations also exhibited elevated biomarker responses (e.g., metallothionein). Although NRBS has obtained evidence that pulp mill contaminants are deposited in the delta and Great Slave Lake, observed levels are currently low and the actual exposure of these fish to contaminants, either from Great Slave Lake or from upstream sources remains unknown. Similarly, although there is little evidence to suggest that flow regulation on the Peace River is currently impacting the Delta there are suggestions that such impacts will become more apparent over time. The current state of the Slave River Delta thus provides an opportunity for conservation rather than remediation. An appropriate conservation strategy is particulary important in light of the fact that the Delta is downstream of all development in the basins. 17. We recommend that future management of these basins explicitly recognize and consider land use activities (forestry, agriculture, urban development, mining, etc.) occurring in the adjacent terrestrial ecosystem. The Study Board deliberated at length about the inclusion of terrestrial components within the research program of the NRBS. Due to its restricted mandate and limited budget, NRBS was unable to incorporate such issues as forestry management and other land uses, climate change and biodiversity. The science components responsible for the design and implementation of the NRBS science program also recognized the need to focus primarily on the aquatic ecosystem, but expressed concerned over the limited research pertaining to terrestrial issues. Future IEM in these basins should extend beyond the mainstems of the major rivers and tributaries to consider importance of terrestrial activities and processes. A Report of Wisdom Synthesized from the Traditional Knowledge Component Studies By: Lea Bill1, Jean Crozier2 and Dennis Surrendi2 Major Collaborators: Lloyd (Sonny) Flett, Danny MacDonald 1Carseland, Alberta 2Crozier Information Resources Consulting Ltd. Edmonton, Alberta
NRBS - Home Table of Contents Top of Page		7.0 RECOMMENDATIONS The Traditional Knowledge Component of the Northern River Basins Study recommends that: 1. Traditional knowledge research of the Northern River Basin Study be extended to include all Aboriginal communities within the NRBS study area, especially those in the southern portions of the area; these locations were not included in the present study due to fiscal constraints. 2. A comprehensive study be conducted to assess the economics of a traditional hunting/trapping economy within the Northern River Basin Study area. Comment: There currently prevails a "doctrine of inevitability" which is a powerful idea held by prominent and influential people that supporting and sustaining the hunting/trapping economy is a futile exercise. This doctrine is based on the myth that the human race has progressed by stages from hunting/gathering, to nomadic pastoralism, then to horticulture and agriculture, and finally to industrial society. This perspective is one with which we are so familiar that we take it as common sense. It is a basic cultural theme which biases the way in which, those who subscribe to this myth view the world. If one accepts this myth, it is clear that hunting and trapping cannot be taken seriously, because these activities are seen as an economic form that have historically been superceded. As such, those who partake in hunting and trapping are viewed as existing in an evolutionary backwater and they are thought, by those who subscribe to the myth, to have a need to move into a "more progressive," modern way of life. There is a dearth of comprehensive research on the true economics of a hunting and trapping economy. The only fact that can be stated with confidence is that the people who devote labour at hunting and trapping do so to secure sustenance for economic reasons. It is, therefore, imperative that the fiscal realities of such an economy be carefully assessed and understood, and that sound methodology be developed in order that the true value (ie. economic, social, cultural, spiritual, health, ecological, etc.) can be identified. This research will enable the hunting and trapping economy to be weighed more realistically, and to be reviewed in context with other development initiatives that may negatively impact on this life-style. 3. A "Handbook on Methodology for Traditional Knowledge Research" be developed for application on a local, national and international basis, and that the handbook be based on the experience gained by the Northern River Basin Study. 4. A comprehensive research and monitoring program be established, incorporating both traditional knowledge and conventional science, to assess the effects of land-use practices (eg. agricultural land clearing, logging, industrial development, municipal development, etc.) on the capacity of river basins to sustain ecologically desirable hydrologic regimes (surface and ground water) for future needs, and to recommend land-use management requirements to achieve this goal. 5. A water quality monitoring program be initiated throughout the Northern River Basin Study area, integrating traditional knowledge and conventional scientific methodologies. 6. Natural Resource Co-management Agreements (or cooperative management agreements) reflecting a partnership relationship between the Province of Alberta and the Aboriginal people inhabiting the Northern River Basin Study area be developed and implemented. Such agreements will integrate traditional knowledge and conventional science throughout the information-gathering processes, information interpretation, management, and decision-making processes on all matters relating to renewable natural resources within the region. 7. A comprehensive economic development strategy and implementation plan for the region encompassed by the Northern River Basin Study be developed, focusing on opportunities for local people using traditional knowledge as the key factor in pursuing economic development within the region. 8. A traditional knowledge transfer and extension program be developed and implemented to encourage the perpetuation of traditional knowledge from Aboriginal elders to the youth, as well as to other sectors of society. 9. An extensive literature search and information analysis be conducted to obtain the information that others have prepared, following analysis of specific aspects of archival and non-archival records relevant to this study. 10. Additional archival studies be undertaken to expand the present database, to ensure comprehensive coverage of relevant environmental information within the study area. 11. The Hudson Bay Company records of weather be studied and analyzed, then correlated with the data now included in the database(s) of Environment Canada; determine the extent to which decreased precipitation has been caused by developmental change factors. 12. Health-related issues that have been alluded to throughout the community research component, but for which no detailed documentation exists, be the subject of extensive studies. 13. Industrial sites such as the now-closed mine at Pine Point be forced to adhere to environmental regulations, and to not contravene the ecological wisdom of those who live in close liaison with the land. 14. The climatological effect of land stripped of trees and used for agricultural purposes, compared with farm land left with 30 to 50 foot strips of trees along road allowances or in rows throughout the land mass of the larger farms, be specifically studied and analyzed. 15. A protocol be developed jointly and immediately by the Province of Alberta and the First Nations/Metis, to ensure that the knowledge and the respectfulness of the First Nations/Metis peoples toward the land is incorporated into each industrial process now in existence or contemplated for future development. 16. An elder of the First Nations/Metis community be appointed to a senior consultancy position with each major industry now operating or being planned, to ensure that the wisdom of the ages is incorporated into the day-to-day operational practices of the industries. Support by the First Nations/Metis community, of the elder and his/her appointment, is implicit and essential. Synthesis of Fish Distribution, Movements, Critical Habitat and Food Web for the Lower Slave River North of the 60th Parallel: A Food Chain Perspective By: Ross F. Tallman1 Major Collaborators: W. Tonn, K.J. Howland, Alison Little2 1Department of Fisheries and Oceans Central and Arctic Region 501 University Crescent 2Department of Biological Sciences University of Alberta Biological Sciences Building Edmonton, Alberta
NRBS - Home Table of Contents Top of Page		SUMMARY CONCLUSIONS AND RECOMMENDATIONS The lower Slave River is a distinct habitat in the northern river basin in that it is connected hydrologically and chemically to the upper part of the watershed but isolated at the level of the fish community. There is virtually no interaction between the fish communities upstream of Rapids of the Drowned and those in the lower Slave River. Habitat requirements for fishes are unique in the lower Slave River because of the life cycles of the species and the surrounding abiotic and biotic environment. Three guiding questions were posed by NRBS that are relevant to fish ecology: #1a " How has the aquatic ecosystem including fish and / or other aquatic organisms been affected by exposure to organochlorines or other compounds?"; #6 "What are the distribution and movements of fish species in the Peace, Athabasca and Slave Rivers? Where and when are they most likely to be exposed to changes in water quality and where are their important habitats?"; #8 "Recognizing that people drink water and eat fish from these river systems, what is the current concentration of contaminants in water and edible fish and how are these levels changing by time and location?" To respond and / or provide supporting information to answer these questions I provided the following: 1) a review of the existing models for large rivers that could make predictions regarding the pathways contaminants and other anthropogenic effects might take to reach the fish food chain through hydrological regime and movements of the biota; 2) a general description of the major abiotic and biotic features of the environment surrounding the fish community in the lower Slave River; 3) a summary of the available knowledge (including NRBS studies) on the community composition, distribution and abundance of the fishes in time and space in the lower Slave River; 4) a synthesis of the available knowledge of geographic migratory patterns of fishes of the lower Slave River; 5) a summary of vital rates of major species; 6) a description of the pathways in the fish food web. 7.0.1 Theoretical Models and the lower Slave River Further research on the lower Slave River should be undertaken with a unifying theoretical model in mind. Such an approach will do more to preserve all ecosystem components than studies specializing in one or two species or aspects of fish biology in the river. On the other hand the present theoretical models which have been developed based on river systems in the southern temperate and tropical regions may not be sufficient to describe the sub-Arctic Slave River. As stated before, the river continuum concept is most appropriate for headwater streams and small rivers, whereas the flood pulse concept is limited to large floodplain rivers and the RPM is relevant to large rivers with constricted channels and firm substrates in the photic zone. Where does the lower Slave River fit in? The original concern from NRBS was probably partly based on a river continuum model - that what happens upstream profoundly affects function downstream. This is undoubtably true. However, the lower Slave River seems to fit better between the flood pulse and riverine productivity models because there is certainly a flood pulse and yet much of the river is a restricted channel with productive tributaries. The recommendations that follow, therefore, keep in mind that much of the focus in the NRBS has been dealing with the linear nature of riverine systems and that research into lateral inputs and local productivity must be undertaken. 7.1 Effects on the fish community Flow regulation from the Bennett Dam has produced a change to the seasonal hydrograph of the Slave River (Prowse and Conly 1996). By the lower Slave River the effects are diminished due to tributary flow becoming an increasing part of the total discharge. Contaminants have been found in some indicator fish (burbot) in the lower Slave River although at generally low levels (Brown 1996). The fish community could be affected by these changes in the environment in terms of vital rates, species composition and diversity. 7.1.1 Vital Rates Vital rates respond to changes in the environment by re-partitioning energy between maintenance, growth and reproduction (Roff 1992). Growth and reproduction are the basis for productivity in fish populations. Unfortunately, there is no general model predicting precisely how vital rates will respond to changes in the abiotic environment. Presumably, the first level that the above changes might affect fish is to increase their maintenance costs with a trade-off in reduced growth, delayed age at maturity and/or reduced fecundity. 7.1.1.1 Growth Ideally, one would like pre- and post-impact information with which to judge, but this is not the case, in general. Inconnu, burbot and lake whitefish have data of this type for growth but the other species do not. Therefore, the information presented in the report on the other species serves only as a bench mark of productivity indices to judge further changes. Inconnu in the lower Slave River has one of the highest growth rates in North America. The high growth rate is likely attributable to the normal response of the life history to fishing pressure and the fact that inconnu are at the southern end of their range. There appears to have been little change in growth patterns from 1983 to 1994. Burbot in the lower Slave grow more slowly than other populations but not substantially so. From the late 1970's to 1994 there may have been an increase in growth of the younger ages and a decrease in the growth rate of older ages. Based on data from the late 1970's and the early 1980's Slave River lake whitefish grow more slowly than surrounding populations. Between 1978 and 1984 there was little change in growth rate. Slave River goldeye also grow more slowly than other populations in the area whereas northern pike growth seems to be about average. Other than the changes observed in burbot there appears to be no unusual patterns in the growth of Slave River fishes that would suggest an impact. However, the conclusion is based on limited data. 7.1.1.2 Age at maturity There is no information to check for changes in age at maturity among Slave River fishes. Therefore, the limited age at maturity data will be considered as a bench mark for future assessment of impacts. Some populations were distinct compared to conspecifics. Inconnu had a low age at maturity compared to other North American populations. This is probably due to the rapid growth rate. Burbot in the lower Slave River matured about one year later than other burbot populations but this is not noticeably outside the inter-population variation one might expect. Lake whitefish and pike, age at maturities are similar to most other conspecific populations. Walleye, goldeye, and longnose sucker matured later than conspecific populations. Age at maturity does not appear to be outside the expected range for any of the major species in the Slave River. 7.1.1.3 Fecundity There was no information available to determine if fecundity has changed in fishes in the Slave River. Fecundity of inconnu, burbot and pike were comparable to other conspecific populations. Lake whitefish had a lower fecundity than most other lake whitefish populations. Fecundity levels were in the normal range and showed no evidence of impact. 7.1.1.4 Age Structure Inconnu had a narrow age structure compared to other populations. Burbot, goldeye longnose sucker, lake whitefish, walleye, and pike had broad age structures suggesting little impact from anthropogenic activities. The narrow age structure of the inconnu would make it less able to adjust to environmental changes than the other species. The major species are mainly in the two categories of large and medium sized fishes which Zaret (1980) described as being most vulnerable to anthropogenic activities and therefore the first to show any effects. The vital rates of these species given no indication that contaminants or flow changes have affected the Slave River fish community to any appreciable degree. However, the data is not sufficient to make conclusive judgements. RECOMMENDATION 1): Evaluating changes to the vital rates is limited by the lack of data prior to the construction of the Bennett Dam and other developments. Except for inconnu and burbot, most of the vital rates available are from 1978-79 collections by Tripp et al. (1981). Analysis of the current vital rates of other species should be undertaken especially goldeye, northern pike, walleye and lake whitefish. RECOMMENDATION 2): Future evaluations of the impact on fish productivity will require good data on vital rates. Key species, such as inconnu, northern pike, burbot, walleye and goldeye should be assessed on a regular basis. The Department of Fisheries and Oceans should continue collection and analysis of inconnu from the lower Slave River. Collections and analysis of the other key species should be made at least once every five years to assess changes in productivity. RECOMMENDATION 3): There is little information on the growth patterns of juveniles of the major species in the lower Slave River. Impacts from environmental degradation will probably affect juvenile stages first. Projects that focus on factors important to juvenile life history should be encouraged. RECOMMENDATION 4): There is almost no information on the vital rates of forage species such as emerald shiner, flathead chub, trout-perch. These species may be good indicators of changes that will ultimately affect the production of their predators, the harvested fish species. Studies that quantify the life history trajectory (growth, age at maturity, fecundity, longevity, mortality) of forage species in the lower Slave River should be undertaken. RECOMMENDATION 5): There are no models that can be used to predict the response of the life history trajectory (hence how fishes are affected) to environmental degradation in the lower Slave River. Existing life history trajectory models relate to mortality factors such as fishing. Quantitative models of the potential consequences to vital rates of flow changes and/or contamination should be developed for the lower Slave River. Such models would allow more precise hypothesis testing and prediction of the effects of habitat change. This recommendation is key because it may help to priorize Recommendations 1-4 and others. 7.1.2 Fish Species Diversity A major problem with environmental degradation is the permanent loss of species. Lowering the diversity of ecosystems makes them less stable and able to withstand further environmental impacts. A total of 30 species have been reported in the Slave River and its delta. Twenty-seven of these species are confirmed from collection records. The other three are only reported in McCart (1986) but the references he provided do not confirm actual collections of these species. Within the confirmed group the most important family is the Salmonidae with 10 members. The Cyprinidae (5 species) is next followed by Percidae (2), Catostomidae (2), Cottidae (2), Percopsidae (1), Petromyzontidae (1), Esocidae (1), Hiodontidae (1), Gadidae (1), and Gasterosteidae (1). In the late 1970's 23 species were captured in the system compared to 18 in the mid-1980's and 19 in 1994/95. Different fish species are more or less vulnerable to capture depending on the gear used. When considering only one gear type common to all studies (gillnet) then there was no change in the number of species recorded (14) from the 1978-80 period to 1994-95. The NRBS funded study added two species not collected before to the lower Slave River list - Oncorhynchus nerka and O. tshawytsha. Overall, community composition differences were minor and are likely a result of chance in sampling. Therefore, there does not appear to be any affect of flow changes or contaminants on the fish species diversity in the lower Slave River. RECOMMENDATION 6): Fish species diversity is a fundamental indicator of ecosystem health. Collections by gillnet and other means should be made at least once every 5 years over the entire season to determine if fish species diversity has changed. RECOMMENDATION 7): A more formal analysis of the existing data using indexes of diversity should be undertaken. 7.1.3 Fish Species Abundance While some species have been a relatively stable percentage of the community others have shown fluctuations in their relative abundance between 1978 and  1995. Lake whitefish, white sucker, northern pike, flathead chub and walleye have remained relatively constant. Inconnu appears to have increased, probably due to reductions in fishing pressure. Burbot and longnose sucker appear to have decreased somewhat. Some of the differences may be due to sampling location the late 1970's samples were taken more heavily from the Slave River Delta than the recent samples. RECOMMENDATION 8): To validate the catch per unit effort method of estimating abundance and to get a benchmark estimate of the numerical abundance of each species it is recommended that mark-recapture studies be undertaken for each species. 7.1.4 Invertebrate Diversity In the flood-pulse and river continuum models all fish species in the Slave River would be considered predators. The basic medium of energy transfer is invertebrates. It is clear that maintenance of invertebrate populations is critical to the productivity of the fish populations. Effects of contaminants or flow changes may first affect the productivity of invertebrate populations. RECOMMENDATION 9): Studies to determine the species diversity, habitat requirements and productivity of invertebrates in the lower Slave  River should be undertaken. 7.2 Fish Distribution and Movement The lower Slave River fish community is seasonally dynamic, constantly changing throughout the year. Fish movements vary according to species from extensive to limited. The lower Slave River is an important habitat used for spawning, feeding, rearing of juveniles and for over-wintering of fishes and serves as a migratory corridor for all of these activities. All major species appeared to show seasonal aggregations and all seasons were important for spawning or feeding of at least one of the major species. 7.2.1 Distribution 7.2.1.1 Large Scale Patterns Goldeye were abundant in the Slave River, Slave River Delta and Salt River. Inconnu could be found near the outer Slave River Delta in the spring but generally used the Slave River, only, as a migration corridor and spawning area in the fall. Lake whitefish utilized the Slave River for feeding and spawning. The Salt River was an important nursery area for lake whitefish and juvenile pike. Northern pike adults were distributed throughout the system but were most abundant in the Slave River delta. Burbot were also widely distributed but had apparently much lower abundance. Longnose sucker inhabited the Delta and Slave River channel, while white sucker inhabited mainly the Salt River. Walleye had resident populations in the Salt and Slave Rivers but also had spawning and over-wintering runs from and to Great Slave Lake in the spring and fall, respectively. Some species like flathead chub, preferred the Slave River channel. A large number of others (Arctic lamprey, pearldace, lake chub, trout-perch, round whitefish, ciscos, Arctic grayling, emerald shiner, yellow perch, spoonhead sculpin and slimy sculpin) inhabit the Delta and the extreme lower reaches of the Slave River channel. 7.2.1.2 Micro-habitat Shallow, well vegetated areas were preferred by a greater diversity of species in greater numbers than other habitat types. However, the number of habitat types were limited to four defined by Tripp et al. (1981). RECOMMENDATION 10): Field and simulation studies to characterize the differences in fish habitat among the major areas of the lower Slave River drainage should be undertaken to determine what are the habitat characteristics that separate species in these areas. Particular attention should be made to develop a detailed scale of micro-habitat types and the preferences of fish to each. 7.2.1.3 Seasonal Variation in Community Structure The Slave River community changed greatly over the season. In the spring goldeye, flathead chub, walleye were numerically dominant. The high abundance was probably due to spawning aggregations. Longnose sucker, pike and lake whitefish were also present. Burbot and inconnu were absent. During the summer the community composition included most major species except inconnu. Goldeye was the most abundant but less so than in the spring. In the latter part of the summer the fall spawning species, inconnu and lake whitefish begin to dominate the biota. During the fall inconnu, lake whitefish and goldeye dominate but all species are present. Late in the fall ciscos enter the Delta in great numbers. In the winter there is a run of burbot downstream to spawn in the Delta. RECOMMENDATION 11): Little is known regarding the seasonal distribution under ice. Field studies over the entire ice on period should be undertaken to determine the fish community composition in different parts of the lower Slave River drainage and over- wintering habitat of each species. Sampling would necessarily be limited to the gillnetting techniques used by local fishermen unless new methodologies could be developed. RECOMMENDATION 12): Recognizing the seasonally dynamic nature of the Slave River fish community, geographic information system (GIS) analysis of relationship between probable point sources, fish distribution and contaminant concentrations in the fish over the seasonal cycle should be undertaken. 7.2.1.4 Distribution in side channels, tributaries and on floodplain              Studies to date (including the NRBS) have focussed on the main channel or the Delta of the Slave River. Much of the productivity, including fish production, must take place in still side channels, tributaries such as the Salt River, quiet backwaters and seasonally on the floodplain of the river. There is no information available on the fish distribution in these areas. Therefore, the importance of these areas to fish as habitat and the probability that fish might be exposed to contaminants while in these areas cannot be determined. The effects of hydrological changes on these areas must be considered, especially in the Delta, where the Bennett Dam effects may be or are ongoing. RECOMMENDATION 13): A study to determine the fish species composition in tributaries , backwaters and side channels throughout the season should be undertaken in the lower Slave River. RECOMMENDATION 14): A study of the distribution and activities of both juvenile and adult fish during the flood-pulse on the lower Slave River should be undertaken. 7.2.2 Movements The seasonally dynamic community composition in the Slave River is a result of fish migrations to feeding, spawning, rearing or over-wintering habitat. Movements can be extensive or limited depending on the season and species. The annual movement patterns of the adults of one of the most important harvested fishes, inconnu can now be described in detail. Inconnu spawn in the Slave River at sites near Fort Smith and near Cunningham Landing. The offspring apparently migrate directly to Great Slave Lake where they spend five or more years in the case of the males and seen or more years in the case of the females until they are mature. Once mature inconnu return to the Slave River to spawn, entering the river in the late summer and proceeding up-river to their spawning site. They aggregate at the spawning grounds for several days to weeks until spawning occurs, usually around the third week of October. After spawning the return to Great Slave Lake is rapid occurring over less than a week. Within the lake migrations are geographically extensive. The inconnu migrate in a large counter-clockwise gyre in the western basin of the lake bounded by the south and north shores, the Simpson Islands and the Mackenzie River outlet. In the spring the inconnu are located in the open water near the outlets and deltas of rivers on the south shore. After this they proceed along the shore to the Slave River. Therefore, inconnu have great potential to transport contaminants from the northern river basins area into Great Slave Lake. Similarly, they could also import contaminants into the lower Slave River from sources around Great Slave Lake. On the other hand, as adults they are the top predator among fishes and thus contaminant transfer would not be to the fish food chain but mainly to the next level of dogs and humans. In contrast, burbot migrate little, apparently holding small feeding territories in the river or delta. In the winter they migrate downstream in the Slave to spawn in the Delta probably in January or February and return back up river prior to the spring. Lake whitefish appear to follow a similar migratory pattern both seasonally and geographically to inconnu except that at least some of their juveniles may rear in the river and not migrate to the ;ake until they mature. As well, some lake whitefish may over-winter in the lower river. Goldeye, flathead chub and walleye migrate to the river near the Fort Smith area during the spring to spawn then disperse into the river for the rest of the year. Adult walleye may leave the river after spawning. Juveniles and some adult walleye remain in the river during the open water season. Lake ciscos migrate into the Slave River delta in late fall to spawn and spend the rest of the year in Great Slave Lake. Given the reliance of ciscos on the Delta for reproduction changes there may effect them the most. Northern pike, probably move into the Slave and Salt Rivers from the Slave River delta to spawn in the early spring prior to the completion of ice-out. Pike then re-distribute themselves along the Slave River and the delta for the rest of the year. The seasonal movement patterns of longnose and white sucker are uncertain as there has only been limited data collected. Most importantly, no fish have been observed to migrate above the Rapids of the Drowned. Thus, the lower Slave River populations are isolated from the conspecific populations upstream except when a fish slips downriver through the rapids. 7.2.3 Probability of exposure to water quality changes due to distribution and movements If the flow and water quality changes are transported from upstream then fishes undergoing critical phases of their life cycle near Rapids of the Drowned would be at greatest risk. Thus, lake whitefish and inconnu during spawning in the fall; pike, goldeye, flathead chub and walleye spawning in the spring near Fort Smith would most likely be exposed. However, if the change in water quality is strong enough to be transmitted from a great distance it is unlikely to attenuate at Rapids of the Drowned. Thus, species that rear or are resident in the Slave River Slave River Delta, or even Great Slave Lake since 85% of the water entering it comes from the Slave River, such as northern pike, lake whitefish, walleye, flathead chub, goldeye, burbot and longnose sucker would be most vulnerable. RECOMMENDATION 15): There is nearly no data on winter movements of fishes (inconnu movements in Great Slave Lake during winter are known) in the Slave River and delta. While it is assumed that most species are relatively inactive at this time it is not confirmed and remains a gap in the knowledge base. A study of winter ecology, including floy tagging and radio-tracking experiments on the major species excepting inconnu and ciscos should be undertaken. RECOMMENDATION 16): Other than inconnu and burbot there is only limited knowledge of the details of movement patterns of major species, such as northern pike, goldeye, lake whitefish, and walleye, in the lower Slave River. Radio-telemetry studies of these species' movement patterns throughout the year should be undertaken in order to determine their probability of exposure to contaminants and other effects of environmental degradation. RECOMMENDATION 17): There is almost no knowledge of the movements of forage species such as trout-perch, emerald shiner, lake chub, and flathead chub. The movement patterns of these species may determine whether or not contaminants enter the fish food chain. Studies of movement patterns using floy tags and dye markers should be encouraged.   RECOMMENDATION 18): Juvenile movements in the river have not been investigated to date. Studies of the movements of juvenile fish should be undertaken. RECOMMENDATION 19): If, when and how fishes migrate onto the floodplain of the lower Slave River has not been studied. Studies to determine the degree of flooding during the spring pulse and the movement patterns of fishes should be undertaken. This is a key recommendation given the present Bennett Dam and future hydrological impacts. RECOMMENDATION 20): A simulation model of the probable movement patterns of all species of fishes to feed, spawn, rear and over-winter should be constructed as a reference for habitat managers. The model could be checked against available data and modified as new data becomes available in the future. This is also key relative to assessing impacts from obstructions, such as dams. 7.3 Food Web All fishes in the lower Slave River are carnivorous and would be classified as predators by general models of large rivers. Those lower in the food web, such as suckers, goldeye, lake whitefish, flathead chub and shiners concentrated on invertebrate prey. The top predators, such as inconnu, northern pike, walleye and burbot ate exclusively fish. Three species played key roles in the food web. Pike consumed all other major species of fish present except inconnu. Of the fish species occupying the lower part of the food web, goldeye and lake whitefish consumed the widest variety of invertebrates. Of the invertebrate fauna the most important by far were the chironomids, followed by the corixids. In the Slave River delta the food web again revolved around pike, goldeye and lake whitefish. Corixids and chironomids were about equal in importance to invertebrate feeders and often composed 60 to 80% of the diet. Because all fish in the lower Slave River and Slave River delta are predatory they are all at risk of bio-accumulation of toxicants through the food chain. Clearly, the fish predator group, including inconnu, northern pike, walleye, and burbot are the most likely to concentrate contaminants to a high level. RECOMMENDATION 21): The importance of invertebrates to the productivity of the fish community and as potential conduits of contaminants is obvious. Detailed studies of the ecology and habitat requirements of the invertebrate community, especially the chironomids and corixids, should be undertaken in the lower Slave River. RECOMMENDATION 22): To determine the organisms most at risk a bio-energetic model of the food web should be constructed. 7.4 Priorization of Recommendations While all recommendations, above, should be carried out I believe it reasonable to emphasize some of the key ones in order to help researchers and habitat managers on the question of 'Where to proceed next?'. The key recommendations fall into three categories: critical gaps in the database, quantitative model development and long-term monitoring. There are serious knowledge gaps in the understanding of invertebrate ecology, winter ecology of the aquatic biota and the biological importance of side channels and the annual flood-pulse which are addressed in recommendations 13, 15, 19 and 21. Models to make predictions and quantitatively understand processes are completely lacking and therefore additional key recommendations are 5, 20 and 22. Finally, for the fish community there should be a monitoring effort that is ongoing, consistent and long-term in order to detect future changes, such as suggested in recommendation 6.

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