A Bioenergetic Model Of Food Chain Uptake And Accumulation Of Organic Chemicals Athabasca River

Describes a study to construct and calibrate a steady-state food chain model to simulate the uptake and bioaccumulation of selected organic chemicals, with different physical and chemical properties, in the mountain whitefish, longnose sucker, and northern pike food web of the Athabasca River. The model is based on the WASP 14, Thomann-Connolly and Gobas food chain models. The modelling effort involved review and interpretation of sediment transport dynamics, contaminant distribution and concentration in sediment, water, and biota, and the refinement of the existing models. Results are presented from model simulations and compared to observed concentrations of such compounds as furans, resin acids, and chlorinated phenolics. The appendix includes a discussion of food chain modelling theory and its application to the present study.

Describes and presents simulation results using a revised model simulating the fate of contaminants in the Athabasca River. The revised fate model allows predictive sediment transport simulation within the WASP4 model framework, predicts resuspension from hydraulic information supplied by WASP4 and from user-supplied sediment characteristics, and can be applied to different flow conditions without having to re-describe sediment transport rates. Several simulations were run using input files from the original model calibration. Program listings of subroutines are included.

Presents results of contaminant analyses of bottom sediments collected from the Peace and Athabasca river basins 1988-90 and 1992. Contaminant groups represented are the polychlorinated dibenzo-p-dioxins and dibenzofurans, resin acids, chlorophenolic compounds, and polycyclic aromatic hydrocarbons. Contaminant concentrations were correlated with percent organic carbon of the fine fraction (the fraction on which analysis was performed. Correlations between concentrations of bleached kraft mill related contaminants were also investigated and results are presented.

Report to the federal ministers of Environment and Indian & Northern Affairs, Alberta's Minister of Environmental Protection, and NWT's Minister of Renewable Resources. Summarises the main scientific findings of the Northern River Basins Study, which was established to examine the relationship between industrial, municipal, agricultural, and other development and the Peace, Athabasca, and Slave River basins. Reviews the characteristics of the northern river basins and their peoples, the organisation of the Study, and major findings in the areas of environmental overview, use of aquatic resources, traditional knowledge, flow regulation, fish distribution and habitat, nutrients, dissolved oxygen, contaminants, drinking water, ecosystem health, modelling, human health, and cumulative effects. Recommendations by the Study Board, First Nations, and scientific advisors regarding such issues as basin management, monitoring, research, public participation, and a successor organisation are then presented. Also includes a summary of opinions, suggestions, and recommendations expressed at 17 community workshops held throughout the northern river basins area.

Describes and presents simulation results from numerical models of the transport and fate of environmental chemicals in northern Alberta rivers. The models were developed using the USEPA WASP modelling system and were structured as one-dimensional (longitudinal) models with separate, interacting water column and bed sediment compartments. Seven selected organic chemicals were simulated over 1992-93 for the Athabasca River and over 1990-91 for the Wapiti/Smoky River system. Chemicals simulated included 2,3,7,8-tetrachloro dibenzofuran, dehydroabietic acid, and phenanthrene. The models were first calibrated for sodium and total suspended solids. Organic chemicals were simulated using a set of environmental fate constants developed from a literature search, numerical estimation software, and estimation from field data. Results of initial simulations were compared to observed data and adjustments made to selected constants to improve the calibration.

Summarizes levels of polychlorinated dioxins and furans in fish observed in various studies on the Peace and Athabasca rivers in Alberta and assesses temporal trends in these contaminants by comparison with previously published data. Begins with background information on chlorinated dioxins and furans, and describes site locations, sampling, and field and laboratory methodologies used. Spatial trends in relation to industrial pollution sources are also noted and risks to humans, fish, and wildlife are evaluated. Fish species analyzed include longnose sucker, burbot, mountain whitefish, and northern pike.

Summarizes the major modelling projects undertaken to model water quality in the Peace, Athabasca, and Slave river systems. The first section describes the scope of the problem of modelling water quality in large complex systems that are relatively oligotrophic, located at relatively high altitudes, and experience highly seasonal environmental fluctuations. It also provides a summary of the models used to predict key water quality variables. Section 2 gives a general overview of the utility and shortcomings of water quality models, with the goal of establishing key criteria for assessing the successes of models developed by the Northern River Basins Study (NRBS). Section 3 summarizes key findings of the NRBS models and evaluates the results against criteria outlined in section 2. Section 4 presents a series of recommendations for modelling dissolved oxygen, transport and fate of contaminants, and distribution of contaminants in the food chain, along with strategic suggestions for future work.