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As part of a larger survey on cumulative effects within the Saint John River basin (Canada), a fish survey was conducted near Edmundston (NB, Canada) in the fall of 1999 using slimy sculpin (Cottus cognatus) and white sucker (Catostomus commersoni). The discharge environment receives effluent from the pulp mill, a paper mill, three sewage discharges, and tributaries receiving agricultural runoff. Sculpin collected downstream of the sewage discharges and pulp mill effluent had greater growth, condition, and liver size but no significant differences in gonad size. Stable isotope data indicated slimy sculpin did not move between sites. Female sculpin collected downstream of the paper mill showed no significant differences in length, body weight, age, condition factor, liver size, and gonad size compared to fish from reference sites. Female white sucker collected downstream of the pulp mill did not differ significantly in any measured parameter compared to reference fish. Liver sizes of white sucker from the Saint John River were outside the range considered to be indicative of uncontaminated riverine sites. In 2000, sculpin collected downstream from a poultry-processing facility had larger livers and lower condition factors, suggesting that the site is contaminated. We found no significant differences in sculpin length, weight, condition (except for males), and liver size in sculpin collected downstream from the pulp mill in October 2001. The responses of slimy sculpin and white sucker differed, perhaps in relation to differences in life history characteristics. Results from this study indicate the slimy sculpin is a suitable fish species for monitoring rivers that receive multiple industrial and municipal effluents. [ABSTRACT FROM AUTHOR]

River Ganga covers around 26% of India's land area and sustains diverse ecosystems in this overly populated area. The globally accepted coherent approach of water quality indices (WQIs) and multivariate statistical models (principal component analysis (PCA) and cluster analysis (CA)) were applied on the dataset to evaluate the spatial-temporal variation and pollution source identification and apportionment. Twenty-two hydro-chemical parameters were analyzed by collecting the samples from 20 different vertically elevated monitoring locations for different seasons. The CA evaluation of data, grouped the monitoring locations into five clusters of varied water quality with human perturbations and geo-genic inputs. The PCA analysis of an extensive dataset indicated the seven significant principal components (PCs) explaining 93.0% of the total variance and finalized 8 water quality parameters out of preselected 22 to represent good aspects of the water quality. The seasonal variation in river water quality by the Canadian Council of Ministers for Environment Water Quality Index (CCMEWQI) showed the quality class at a marginal level in summer (62.16), monsoon (59.96), and post-monsoon (60.20) season, whereas in winters (71.18), water quality was in fair condition. The response of National Sanitation Foundation Water Quality Index (NSFWQI) classified the river water in medium quality class for summer, monsoon, post-monsoon, and winter season, respectively. The present observations contribute in the usefulness of these statistical methodologies to interpret and understand large dataset and also provide reliable information to reduce the tedious and cost of water quality monitoring and assessment programs., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

There has been much written about the negative social and environmental impacts of large hydropower dams, particularly the impacts on people and the environment caused by flooding linked to the creation of large reservoirs. There has also long been recognition of the importance of Indigenous and local knowledge for understanding ecological processes and environmental impacts. In this paper, however, we focus on a topic that has received insufficient consideration: the downstream impacts of dams, and the role of Indigenous and local knowledge in assessing and addressing these impacts. Using examples from three river basins in different parts of the world: the Peace-Athabasca in Canada, the Mekong in mainland Southeast Asia, and the Amazon in Brazil, we demonstrate that the downstream impacts of hydropower dams are often neglected due to the frequently long distances between dams and impacted areas, jurisdictional boundaries, and the less obvious nature of downstream impacts. We contend that Indigenous or local knowledge, if applied consistently and appropriately, has important roles to play in understanding and addressing these impacts, with the goal of avoiding, reducing, and appropriately compensating for the types of environmental injustices that are frequently associated with the downstream impacts of dams.

Beavers (Castor canadensis and C. fiber) build dams that modify catchment and pond water balances, and it has been suggested that they can be a nature-based solution for reducing flood hydrographs, enhancing low flow hydrographs and restoring hydrological functioning of degraded streams. How water moves through a beaver dam is determined by its flow state (e.g., overflow, underflow). However, current conceptual models only consider flow state as changing over the beaver site occupation-abandonment cycle. To assess whether flow state changes at shorter timescales and identify possible triggers (e.g., rainfall, animals), we integrated camera trap imagery, machine learning, water level measurements, and hydrometeorological data at beaver dams in a montane peatland in the Canadian Rocky Mountains. Contrary to current models, we found that flow states changed frequently, changing a maximum 12 times during the 139-day study period, but that changes had limited synchronicity amongst the dams in the same stream. More than two-thirds of the changes coincided with rainfall events. We observed no changes in flow state in response to beaver activity or wildlife crossings perhaps due to the camera positioning. Our findings augment the long-term oriented framework, which links changes to the occupancy cycle of a beaver pond and frequent and hydrological-driven changes. To develop realistic predictions of hydrological impacts of beaver dams, ecohydrological models should update their representation of the influence of beaver dams to include short-term dynamism of flow states and potential triggers. Our study advances the understanding of the important, yet understudied, role of beaver dams in stream restoration and climate change initiatives., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Rapid changes in the volume and sources of discharge during the spring freshet lead to pronounced variations in biogeochemical properties in snowmelt-dominated river basins. We used daily sampling during the onset of the freshet in the Fraser River (southwestern Canada) in 2013 to identify rapid changes in the flux and composition of dissolved material, with a focus on dissolved organic matter (DOM) and mercury (Hg) dynamics. Previous time series sampling (at twice monthly frequency) of dissolved inorganic species in the Fraser River has revealed smooth seasonal transitions in concentrations of major elements and tracers of water and dissolved load sources between freshet and base flow periods. In contrast, daily sampling reveals a significant increase in dissolved organic carbon (DOC) concentration (200 to 550 µmol L-1) occurring over a matter of days, accompanied by a shift in DOM optical properties, indicating a transition towards higher molecular weight, more aromatic DOM composition. Comparable changes in DOM composition, but not concentration, occur at other times of year, underscoring the role of seasonal climatology in DOM cycling. Concentrations of total and dissolved Hg also varied during the spring freshet period, although dissolved Hg dynamics appear to be driven by factors beyond DOM as characterized here. The time series records of DOC and particulate organic carbon (POC) concentrations indicate that the Fraser River exports 0.25-0.35% of its annual basin net primary productivity. [ABSTRACT FROM AUTHOR]

This work addresses the last 20 years' evolution of the suspended particulate matter (SPM) concentrations in the Beaufort Sea (Canadian Arctic Ocean) directly influenced by the Mackenzie River discharge. The SPM variations in the coastal zone are highlighted and related to the freshwater and solid discharges of the river measured in situ at the Arctic Red River station (150 km upstream of the river delta). The correlation between the variations of the river discharge and SPM concentration within the surface layer of the coastal waters is obvious. Rather unexpectedly, both have been slightly but significantly decreasing from 2003 to 2018-2019 and started to increase very recently (2019-2022). This change of regime could be explained by changing winter precipitation and groundwater distribution, progressively accumulating sediments within the thawing permafrost layer and its recent release into the groundwater together with thermokarst lakes' rapid drainage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Shortened hospital stays have shifted the burden of care for older adults to community, informal (ie, family, caregiver) and formal post-acute care and services, highlighting the need for effective post-hospital stay services and programs. As there is a dearth of information related to community-based, slow-stream rehabilitation program models for older adults transitioning from hospital to home in the Canadian context, the paper describes a mixed methods evaluation of such a program., Materials and Methods: A mixed methods program evaluation, with process- and outcome-related elements, included 1) review and analysis of program documents; 2) observations to examine fidelity. Observation data were coded and summarized using descriptive statistics. Coded information and data were compared to document review data; 3) quantitative assessment of pre-post changes in physical, social, and psychological outcome measure and instrument scores using descriptive statistics, paired t -tests and confidence intervals ( p = 0.05); and 4) exploration of acceptability through interviews and focus groups with 41 of the older adult participants and 17 family caregivers. Thematic analysis was used to examine focus group and interview transcripts., Results: Observational data indicated alignment with the program document information overall. Statistically and clinically significant positive trends in improvement for physical outcome measure scores were observed (6-minute Walk Test, Life Space Assessment, Short Physical Performance Battery, Rapid Assessment of Physical Activity). Participants and family caregivers identified several positives and benefits of the program, ie, improvement in physical, social and mental well-being, decreased caregiver burden; and areas for improvement ie, need for more information about the program prior to enrollment and individualization, several of which aligned with the observation and quantitative data., Discussion/conclusion: This mixed methods program evaluation provided a detailed description of a community-based, slow-stream rehabilitation program for older adults who are transitioning to home post-hospital stay and its participants. Evidence of program fidelity, acceptability, and positive trends in improvement in physical outcome measure scores were found. Information about program strengths and areas for improvement can be used by stakeholders to inform program refinement and enhancement., Competing Interests: Dr Vanina Dal Bello-Haas reports grants from Hamilton Community Foundation, outside the submitted work. The authors report no other conflicts of interest in this work., (© 2023 Dal Bello-Haas et al.)

Abstract: Anadramous Atlantic salmon (Salmo salar L.) returning to Exploits River, Newfoundland, Canada, to spawn encounter low concentrations of thermomechanical pulp (TMP) effluent as they migrate upstream past an integrated newsprint mill. Various physiological responses of adult Atlantic salmon from the Exploits River were studied under laboratory conditions. The effects of a 6-h exposure to 0%, 6%, 12%, or 25% (v/v) TMP effluent or an increasing concentration gradient of effluent (0–25%) on cardiac output , critical swimming performance (U crit), hematocrit, and blood glucose, cortisol, lactate, and osmolality were examined. Relative to other treatment groups, during routine and low-level activity was 7–10% higher in fish exposed to at least 12% effluent. The 25% exposure group had a distinctly lower U crit and scope for increase in than the other treatment groups. These findings suggest that effluent exposure elevates physiological maintenance and repair costs, resulting in a reallocation of energetic resources. [Copyright &y& Elsevier]

Many sediment attributes have been proposed as proxies for determining salinity conditions under which sediment is deposited, and six attributes (Sr/Ba-HAc, Sr/Ba-NH 4 Ac, δ 13 C org , C/N, and the relative abundances and concentrations of dinoflagellate cysts) are compared here. In this paper, sediment attributes from the Fraser River Delta, Canada and surrounding coastal areas are compared by depositional position along the fluvial-to-marine transition, by salinity, and by sedimentological characteristics. Along the fluvial-to-marine transition, most attributes exhibit distinct trends between parts of the river that experience sustained marine water (saltwater) influence over seasonal and tidal timeframes, and parts that experience only freshwater or periodic saltwater influence. No attributes are reliable indicators of depositional position where saltwater incursion is short lived or where water is fresh. Where marine influence is sustained, Sr/Ba-HAc and Sr/Ba-NH 4 Ac are the most reliable positional indicators along the fluvial-to-marine transition. When compared strictly to salinity, Sr/Ba-HAc, Sr/Ba-NH 4 Ac, and δ 13 C org all correlate predictably except in delta front and prodelta settings. Our data show that all six sediment attributes are heavily impacted by river-derived sedimentation, and it is not appropriate to compare values from strongly river-influenced settings (e.g., deltas) with those from weakly river-influenced settings (e.g., bays and estuaries)., (© 2022. The Author(s).)

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Glaciers provide cold, turbid runoff to many mountain streams in the late summer and buffer against years with low snowfall. The input of glacial meltwater to streams maintains unique habitats and support a diversity of stream flora and fauna. In western Canada, glaciers are anticipated to retreat by 60-80% by the end of the century, and this retreat will invoke widespread changes in mountain ecosystems. We used a space-for-time substitution along a gradient of glacierization in western Canada to develop insights into changes that may occur in glaciated regions over the coming decades. Here we report on observed changes in physical (temperature, turbidity), and chemical (dissolved and total nutrients) characteristics of mountain streams and the associated shifts in their diatom communities during de-glacierization. Shifts in habitat characteristics across gradients include changes in nutrient concentrations, light penetration, temperatures, and flow, all of which have led to distinct changes in diatom community composition. Importantly, glacial-fed rivers were 3-5 °C cooler than rivers without glacial contributions. Declines in glacial meltwater contribution to streams resulted in shifts in the timing of nutrient fluxes and lower concentrations of total phosphorus (TP), soluble reactive phosphorus (SRP), and higher dissolved inorganic nitrogen (DIN) and light penetration. The above set of conditions were linked to the overgrowth of the benthic diatom Didymosphenia geminata. These changes in stream condition and D. geminata colony development primarily occurred in streams with marginal (2-5%) to no glacier cover. Our data support a hypothesis that climate-induced changes in river hydrochemistry and physical condition lead to a phenological mismatch that favors D. geminata bloom development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Nowadays, urban rivers play an important role in city development and make great contributions to urban ecology. Most urban rivers are the drinking water sources and water quality is extremely critical. The current assessment method in national standard of China has multiple limitations; therefore, this paper introduces an advanced assessment, that is, Canadian Water Quality Index (CWQI). This method can help to provide comprehensive and objective water quality assessment for the urban rivers. Moreover, CWQI can prevent waste of the water resource, since current assessment is pessimistic and tent to underestimate water samples to a lower grade. Linyi development area is selected as study region and CWQI method is applied to assess two major urban rivers within the area. The water monitoring data from 2014 to 2017 is acquired in 24 parameters. Since the CWQI calculation is still based on traditional water quality measurement in parameters, there will be a huge cost when increasing research scale and accuracy. In this paper, remote sensing technique is employed to develop models of CWQI scores from satellite data. By utilizing 23 selected monitoring instances and matching satellite data, linear regression analysis shows that red band data has highest correlation with CWQI in both two urban rivers in the study region. In addition, two testing datasets with five instances for each river are used to validate the RS-based CWQI models and the results show that testing datasets can be fitted well. With the models, CWQI distribution diagrams are generated and assist both spatial and temporal analysis. Experimental results show that the proposed approach can indicate actual water quality pattern which is validated by field visit. The proposed approach in this paper has satisfying effectiveness and robustness.

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In cold region environments, any alteration in the hydro-climatic regime can have profound impacts on river ice processes. This paper studies the implications of hydro-climatic trends on river ice processes, particularly on the freeze-up and ice-cover breakup along the Athabasca River in Fort McMurray in western Canada, which is an area very prone to ice-jam flooding. Using a stochastic approach in a one-dimensional hydrodynamic river ice model, a relationship between overbank flow and breakup discharge is established. Furthermore, the likelihood of ice-jam flooding in the future (2041–2070 period) is assessed by forcing a hydrological model with meteorological inputs from the Canadian regional climate model driven by two atmospheric–ocean general circulation climate models. Our results show that the probability of ice-jam flooding for the town of Fort McMurray in the future will be lower, but extreme ice-jam flood events are still probable. [ABSTRACT FROM AUTHOR]

Scotty Creek, Northwest Territories (NWT), Canada, has been the focus of hydrological research for nearly three decades. Over this period, field and modelling studies have generated new insights into the thermal and physical mechanisms governing the flux and storage of water in the wetland-dominated regions of discontinuous permafrost that characterises much of the Canadian and circumpolar subarctic. Research at Scotty Creek has coincided with a period of unprecedented climate warming, permafrost thaw, and resulting land cover transformations including the expansion of wetland areas and loss of forests. This paper (1) synthesises field and modelling studies at Scotty Creek, (2) highlights the key insights of these studies on the major water flux and storage processes operating within and between the major land cover types, and (3) provides insights into the rate and pattern of the permafrost-thaw-induced land cover change and how such changes will affect the hydrology and water resources of the study region. [ABSTRACT FROM AUTHOR]

Water temperature is a key determinant of biological processes in rivers. Temperature in northern latitude rivers is expected to increase under climate change, with potentially adverse consequences for cold water-adapted species. In Canada, little is currently known about the timescales or magnitude of river temperature change, particularly in large (≥104 km2) watersheds. However, because Canadian watersheds are home to a large number of temperature-sensitive organisms, there is a pressing need to understand the potential impacts of climate change on thermal habitats. This paper presents the results of a study to simulate the effects of climate change on the thermal regime of the lower Saint John River (SJR), a large, heavily impounded, socio-economically important watershed in eastern Canada. The CEQUEAU hydrological-water temperature model was calibrated against river temperature observations and driven using meteorological projections from a series of regional climate models. Changes in water temperature were assessed for three future periods (2030-2034, 2070-2074 and 2095-2099). Results show that mean water temperature in the SJR will increase by approximately ~1 °C by 2070-2074 and a further ~1 °C by 2095-2099, with similar findings for the maximum, minimum and standard deviation. We calculated a range of temperature metrics pertaining to the Atlantic Salmon and Striped Bass, key species within the SJR. Results show that while the SJR will become increasingly thermally-limiting for Atlantic Salmon, the Striped Bass growth season may actually lengthen under climate change. These results provide an insight into how climate change may affect thermal habitats for fish in eastern Canadian rivers. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper provides an overview and summary of United States and Canadian federal, state, and provincial laws that offer some form of legal protection for environmental flows. Special attention is given to the new “second generation” law established in Texas and to ways western states are beginning to encourage transactions that help restore dewatered streams. Progress in the eastern states and some Canadian provinces to provide environmental flow protection is addressed. Based on this review, this paper presents recommended elements of a “model” environmental flow policy. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: In this paper, a novel modeling approach is applied to assess the unique transport characteristics of hydrophobic (bitumen containing) cohesive sediment for the Ells River, AB, Canada. The modeling offers a new way of treating the transport and fate of fine sediment in rivers and points to the importance of including a sediment entrapment process in the modeling of the Ells River sediment dynamics. Materials and methods: The modeling approach involves combining two existing models (RIVFLOC and MOBED). Using fine sediment transport parameters derived from laboratory flume experiments (e.g., settling velocity of sediment as a function of floc size and the critical shear stresses for deposition) and the calculated flow field from the MOBED model (using field survey data such as, cross-sectional geometry, river slope, grain size of bed material, and discharge), the RIVFLOC model is used to predict the transport characteristics (including entrapment) of the hydrophobic Ells River sediment. Results and discussion: The application of the connected RIVFLOC and MOBED models, demonstrated the unique hydrophobic sediment dynamics of the Ells River. The model showed no deposition (in the classical sense) of the hydrophobic sediment as the bed shear stresses, even at base flow, are well above the critical bed shear for deposition (flocculation is shown to occur, but its impact on settling is negligible given the high shear stresses). However, the model showed the possibility of fine sediment ingression into the river bed (interstitial voids) due to the entrapment process which is known to occur at bed shear stresses well above the critical shear stress for deposition. Conclusions: The salient features of RIVFLOC and MOBED models and their applications for understanding the transport and fate of unique hydrophobic fine sediments are presented. The models are shown to be useful for the understanding and projection of flow characteristics and sediment dynamics (including entrapment), and will be of benefit for the adaptive management of riverine monitoring programs given various flow scenarios including extreme events and climate change. [ABSTRACT FROM AUTHOR]

Global increases in consumption of chemical nutrients, application of pesticides, and water withdrawal to enhance agricultural yield have resulted in degraded water quality and reduced water availability. Efforts to safeguard or improve environmental conditions of agroecosystems have usually focused on managing on-farm activities to reduce materials loss and conserve habitat. Another management measure for improving environmental quality is adoption of environmental performance standards (also called outcome-based standards). This special collection of six papers presents the results of four years of research to devise scientifically credible approaches for setting environmental performance standards to protect water quantity and quality in Canadian agriculturally dominated watersheds. The research, conducted as part of Canada's National Agri-Environmental Standards Initiative, aimed to identify Ideal Performance Standards (the desired environmental state needed to maintain ecosystem health) and Achievable Performance Standards (the environmental conditions achievable using currently available and recommended best available processes and technologies). Overviews of the papers, gaps in knowledge, and future research directions are presented. As humans, livestock, and wildlife (both terrestrial and aquatic) experience greater pressures to share the same limited water resources, innovative research is needed that incorporates a landscape perspective, economics, farm practices, and ecology to advance the development and application of tools for protecting water resources in agricultural watersheds., (Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.)

This paper presents the first characterization of aquatic particles and particulate organic matter (POM) by attenuated total reflectance infrared spectroscopy (ATR-FTIR) using particles deposited on filters. Particles from 30 water samples from the St. Lawrence System (Canada) were analyzed. ATR-FTIR spectra revealed changes in numerous organic and inorganic functional group contents. Particles from marine waters contained POM enriched in amide, N-H, and aliphatic groups, while terrigenous POM had more COO(-)/COOH and aromatic groups. The spectra showed the selective degradation of amide, N-H, aliphatic, and carbohydrate-like structures during the sinking of the particles. Partial least-squares (PLS) regression of the ATR-FTIR spectra was used to quantify 12 important elemental and molecular parameters, such as amino acids, bacterial biomarkers, and degradation indices. Most parameters were quantified with good accuracy compared to conventional methods (<15% error). The spectral regions leading to the best quantifications and the PLS loadings revealed that aromatic cycles, other unsaturated structures, and COO(-)/COOH groups were degraded at a much slower rate than N-molecules, such as amino acids, and carbohydrates. Marine POM was enriched in CH(3) groups. CH(3) groups appeared highly labile and abundant in bacterial POM. ATR-FTIR represents a new and powerful method for a rapid, inexpensive, and nondestructive characterization of particles collected by filtration revealing important biogeochemical processes involving POM.

Records of natural processes, such as gradual streamflow fluctuations, are commonly interrupted by long or short disruptions from natural non-linear responses to gradual changes, such as from river-ice break-ups, freezing as a result of annual solar cycles, or human causes, such as flow blocking by dams and other means, instrument calibrations and failure. The resulting abrupt or gradual shifts and missing data are considered to be discontinuities with respect to the normal signal. They differ from random noise as they do not follow any fixed distribution over time and, hence, cannot be eliminated by filtering. The multi-scale resolution features of continuous wavelet analysis and cross wavelet analysis were used in this study to determine the amplitude and timing of such streamflow discontinuities for specific wavebands. The cross wavelet based method was able to detect the strength and timing of abrupt shifts to new streamflow levels, gaps in data records longer than the waveband of interest and a sinusoidal discontinuity curve following an underlying modeled annual signal at ±0.5 year uncertainty. Parameter testing of the time-frequency resolution demonstrated that high temporal resolution using narrow analysis windows is favorable to high-frequency resolution for detection of waveband-related discontinuities. Discontinuity analysis on observed daily streamflow records from Canadian rivers showed the following: (i) that there is at least one discontinuity/year related to the annual spring flood in each record studied, and (ii) neighboring streamflows have similar discontinuity patterns. In addition, the discontinuity density of the Canadian streamflows studied in this paper exhibit 11-year cycles that are inversely correlated with the solar intensity cycle. This suggests that more streamflow discontinuities, such as through fast freezing, snowmelt, or ice break-up, may occur during years with slightly lowered solar insolation. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Conventional design and evaluation procedures usually classify steel through-truss bridges as single-load-path structures; however, their historic performance has demonstrated considerable structural resiliency. This paper presents a study of the Grand River Bridge, a Pratt through-truss bridge in Cayuga, Ontario, Canada, that systematically investigates the load paths not conventionally assumed in design and evaluation. The bridge with individual truss members removed was analyzed using nonlinear finite-element analyses to investigate the alternative load paths and associated critical members and responses. A system reliability analysis was conducted to evaluate the failure probabilities of the bridge accounting for the member resistance uncertainties. The bridge was found to be sufficient to carry its nominal dead load, even for the worst case of removal of an end post. The end bottom chord and hanger vertical were found to be the critical tension chord and web member, respectively. If multiple alternative load paths exist, the variability of the system collapse load is much less than that of the critical member resistance. [ABSTRACT FROM AUTHOR]

In response to a number of recommendations following the Northern Rivers Basin Studies (NRBS) contaminant program, the Northern Rivers Ecosystem Initiative (NREI) focused considerable attention on assessing contaminants from specific sources including pulp mill effluents, atmospheric transport of mercury and the Alberta oil sands operations. NRBS identified a number of major contaminants of concern including polychlorinated biphenyls, dioxins and furans, mercury and various hydrocarbons. Together, the NRBS and the NREI studies have demonstrated major declines in the levels of dioxins and furans over the last decade as pulp and paper mills have changed their process and treatment strategies in response to new Federal regulations. Polychlorinated biphenyls however, continue to be a concern for the region as their levels have not declined in fish and sediments over the course of these studies. Higher levels in sediments downstream of Grande Prairie and Hinton were identified, but the source of these contaminants remains unknown. Chlorinated pesticides were also investigated, and although toxaphene, DDT and other chlorinated organic pesticides were detected in fish tissue, they were present at very low levels. Studies on the oil sands industry in northern Alberta demonstrated limited impacts on the Athabasca River to date, although studies did identify slight to moderate impacts of natural oil seeps on fish and benthic communities in tributary streams. NREI studies also identified endocrine active compounds in the three pulp and paper mill effluents tested, but endocrine disruptive effects in wild fish were minimal. Municipal sewage effluents also contain endocrine active compounds and it is recommended that monitoring continue around these point sources.

If sustainable development of Canadian waters is to be achieved, a realistic and manageable framework is required for assessing cumulative effects. The objective of this paper is to describe an approach for aquatic cumulative effects assessment that was developed under the Northern Rivers Ecosystem Initiative. The approach is based on a review of existing monitoring practices in Canada and the presence of existing thresholds for aquatic ecosystem health assessments. It suggests that a sustainable framework is possible for cumulative effects assessment of Canadian waters that would result in integration of national indicators of aquatic health, integration of national initiatives (e.g., water quality index, environmental effects monitoring), and provide an avenue where long-term monitoring programs could be integrated with baseline and follow-up monitoring conducted under the environmental assessment process.

All six ecosystem initiatives evolved from many years of federal, provincial, First Nation, local government and community attention to the stresses on sensitive habitats and species, air and water quality, and the consequent threats to community livability. This paper assesses water quality aspect for the ecosystem initiatives and employs newly developed Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) which provides a convenient mean of summarizing complex water quality data that can be easily understood by the public, water distributors, planners, managers and policy makers. The CCME WQI incorporates three elements: Scope - the number of water quality parameters (variables) not meeting water quality objectives (F(1)); Frequency - the number of times the objectives are not met (F(2)); and Amplitude. the extent to which the objectives are not met (F(3)). The index produces a number between 0 (worst) to 100 (best) to reflect the water quality. This study evaluates water quality of the Mackenzie - Great Bear sub-basin by employing two modes of objective functions (threshold values): one based on the CCME water quality guidelines and the other based on site-specific values that were determined by the statistical analysis of the historical data base. Results suggest that the water quality of the Mackenzie-Great Bear sub-basin is impacted by high turbidity and total (mostly particulate) trace metals due to high suspended sediment loads during the open water season. Comments are also provided on water quality and human health issues in the Mackenzie basin based on the findings and the usefulness of CCME water quality guidelines and site specific values.

The International Joint Commission has recently completed a five-year study (2000-2005) to review the operation of structures controlling the flows and levels of the Lake Ontario - St. Lawrence River system. In addition to addressing the multitude of stakeholder interests, the regulation plan review also considers environmental sustainability and integrity of wetlands and various ecosystem components. The present paper outlines the general approach, scientific methodology and applied management considerations of studies quantifying the relationships between hydrology and wetland plant assemblages (% occurrence, surface area) in Lake Ontario and the Upper and Lower St. Lawrence River. Although similar study designs were used across the study region, different methodologies were required that were specifically adapted to suit the important regional differences between the lake and river systems, range in water-level variations, and confounding factors (geomorphic types, exposure, sediment characteristics, downstream gradient of water quality, origin of water masses in the Lower River). Performance indicators (metrics), such as total area of wetland in meadow marsh vegetation type, that link wetland response to water levels will be used to assess the effects of different regulation plans under current and future (climate change) water-supply scenarios.

Monitoring of stable water isotopes (18O and 2H) in precipitation and surface waters in the Mackenzie River basin of northern Canada has created new opportunities for researchers to study the complex hydrology and hydroclimatology of this remote region. A number of prior studies have used stable isotope data to investigate aspects of the hydrological regime of the wetland-dominated terrain near Fort Simpson, Northwest Territories, Canada. The present paper compares estimates of groundwater contributions to streamflow derived using the WATFLOOD distributed hydrological model, equipped with a new water isotope tracer module, with the results of conventional isotope hydrograph separation for five wetland-dominated catchments along the lower Liard River. The comparison reveals highly promising agreement, verifying that the hydrological model is simulating groundwater flow contributions to total streamflow with reasonable fidelity, especially during the crucial snowmelt period. Sensitivity analysis of the WATFLOOD simulations also reveals intriguing features about runoff generation from channelized fens, which may contribute less to streamflow than previously thought.

The article offers information on various aspects of temporary streams in Canada. It mentions that the Prediction in Ungauged Basins (PUB) Zeroflow workshop was held in Alberta in 2011 that focused on reconstruction, analysis and management of temporary streams in ungauged basins. It states that the temporary streams include ephemeral, intermittent and episodic channels and are common in the semi-arid areas of North America. The workshop revealed that Canada has distinct physio-climatic regions that influence the nature of temporary streamflow regimes.

Electrical energy can be produced from the chemical potential difference of two liquids with dissimilar salinities. This source of energy is known as salinity gradient power. In this paper, the theory, the technologies used to exploit the power, the major challenges, and their development trends are first presented. Then a modeling of fluxes across semi permeable membranes is proposed and validated. Next, an energy balance study is done in order to estimate the power potential for a given salinity gradient system. By applying this study to several rivers in Quebec, the salinity power gradient potential is estimated to 45 TWh/yr based on the minimal flow rate of each river. [ABSTRACT FROM AUTHOR]

Abstract Reducing the cost of hydrokinetic turbines is an important step in the commer-cialization of the technology. One of the costs of the implementation of hydrokinetic turbines is the selection of potential hydrokinetic sites. In this paper, it is proposed that site selection for a hydrokinetic turbine can be improved in river environments in Canada by the use of winter imagery that is available at little or no cost. This is of particular value to remote communities who power their community using diesel fuel, as some pay over $1.00 per kWh. It is shown that river sections that do not freeze during the winter have higher velocity magnitudes than sections that are covered with ice. The average velocity magnitude for open ice locations is found to be 1.09 m/s, with a standard deviation of 0.48 m/s. Ice covered locations were found to have an average velocity magnitude of 0.301 m/s. The relationship between river depth and velocity magnitude is shown to have a low correlation, with an R2 value of 0.185. [ABSTRACT FROM AUTHOR]

There is widely documented evidence that rivers are one of the most degraded ecosystem types on the planet. As a consequence, concerted efforts have been made to improve the health of river systems in many parts of the world. Moves towards sustainable management approaches reflect transitions beyond the imposition of 'command-and-control' approaches towards ecosystem-framed applications. Although this transition is now well-understood in intellectual terms, there is little evidence of a genuine shift in practice and associated outcomes. Governance frameworks underpinning management practices have been identified as a key limitation in catalysing this transition. This paper provides an overview of governance frameworks and practices which underpin river management goals. Middle-ground governance frameworks that facilitate the interaction of top-down and bottom-up approaches are promoted as this structure allows for values and processes operating across multiple spatial and temporal scales to be included in management. Case studies from New Zealand, Canada and England are used to demonstrate the diversity of governance spaces that middle-ground initiatives can occupy, reflecting the unique socio-ecological and institutional trajectory of any given catchment. Middle-ground organisations at the catchment scale provide a focal meeting point to pool resources and set goals for decentralised, reflexive structures. This transition in practice is critical if contemporary top-down approaches are to be modified to foster adaptive ecosystem-based applications that incorporate participatory decision-making at a catchment scale. These considerations are vital if appropriate platforms are to be established to maximise efforts for sustainable river management. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: This special issue of the Journal of Cold Regions Science and Technology presents selected papers emanating from the 14th River Ice Workshop hosted by the Canadian Geophysical Union — Hydrology Section''s (CGU-HS) Committee on River Ice Processes and the Environment (CRIPE) in Quebec City, Canada in June 2007. Eight papers in total are presented in this issue, covering the complete ice season from freeze-up to breakup, encompassing field, experimental and numerical investigations, and representing the latest advances in knowledge of river ice processes and dynamics. As an introduction for those readers new to the field of river ice engineering, this introductory paper provides an overview of the river ice cycle, highlighting both the typical and the unusual phenomena encountered. From frazil ice to ice jams, this is truly a dynamic and fascinating research field and it is our hope that these papers will encourage readers to renew or initiate their own river ice research endeavours. The Committee on River Ice Processes and the Environment (CRIPE) extends its sincere thanks to the Journal of Cold Regions Science and Technology for making the Special Issue on River Ice possible. [Copyright &y& Elsevier]

Several oil sands mines and refineries are currently recovering oil from the Athabasca River region near Fort McMurray, Alberta. Planning and construction of additional oil sands mines are in various stages of completion. Due to environmental concerns for aquatic life in areas downstream from current and future oil sands activities, surveys were conducted between 1998 and 2000 to determine whether the quality of water and sediments in tributaries of the Athabasca River are affected by flowing through reaches with exposure to natural oil sand deposits. This paper presents the results for metals in bed and suspended sediments collected from the Mackay, Steepbank, and Ells rivers during those surveys. The suspended sediments had a clay content (n = 7) ranging from 36.2% to 65.0%, while bed sediments, which consisted of a predominant sand fraction, had percent clay (n = 39) ranging from 0.0% to 38.1%. A Mann-Kendall non-parametric analysis to assess the longitudinal trend of the metals in the bed sediments found no significant (α = 0.05) downstream trend in the Mackay or Steepbank rivers; however, the Ells River displayed a generally decreasing tend from upstream to downstream. The results provide no indication that metal concentrations in the bed sediments and/or suspended sediments of the Mackay, Steepbank, and Ells rivers increase significantly as the three tributaries flow through reaches that have natural oil sand exposures (McMurray Formation). [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a sampling design for monitoring spatial and temporal changes in forest health in the Upper Elbow River Basin, in Alberta, Canada. The procedure involved a combination of cumulative effects assessment and remote sensing techniques for selecting sampling sites based on physical and anthropogenic features. Normalized difference vegetation index (NDVI) was the indicator of forest health. Unique combinations of slope, aspect, soil moisture, NDVI, vegetation type, and the zone of influence of human activities were used to select pairs of sampling sites. Each pair consisted of a site within the zone of influence and one outside the zone. Spatial discrimination analysis was the method used for reclassification. The analysis suggested that 58 pairs would be appropriate for monitoring. NVDI was negatively correlated with dry soils and increased with the slope. To various extents, most of the species displayed NDVI values between 0.20 and 0.59. The density of linear disturbances (km/km2) was estimated and it showed that one of the three sub-catchments, the Bragg Creek, has levels of human disturbance above the value considered optimal for wildlife habitat suitability. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Earth Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We report in this paper major element and Sr isotopic ratio analyses for 19 rivers draining the Stikine Province in the Western Canadian Cordillera. Dissolved solutes, suspended sediments and river sands were analyzed. The aim of the paper is to calculate chemical denudation rates for this uplifted accretionary prism, mainly dominated by volcanics and volcanic-derived sedimentary rocks. The major chemical features of the Stikine rivers are their dilute character and the excess of Ca, Mg and Sr in the dissolved load with regards to Na. Molar Ca/Na ratios from 2 to 14, mean value of 5.4, are observed although the region is dominated by silicate rocks. Suspended sediments show Ca/Na ratios close to 0.4. Isotopically, most of the rivers investigated display lower Sr isotopic ratios in the dissolved load compared to the suspended load, which is very unusual. To account for the excess of cations, three different hypotheses are tested by an inversion method allowing us to determine the origin of each major solute. The first scenario assumes that the excess of Ca and Mg is due to the dissolution of unradiogenic carbonates. The second scenario supposes that the excess of base cations is derived from the preferential dissolution of Ca- and Mg-rich minerals, such as amphiboles. In the third scenario, all solutes are assumed to derived from silicate weathering. The cationic weathering rates of silicates, although imprecise, are in the order of 2–5 tons/km2/year for the two first hypotheses. If all solutes are taken into account, denudation rates are between 9 and 15 tons/km2/year. On a global scale, these numbers are among the lowest found for rivers draining basaltic rocks. They are however found to be consistent with the global law for chemical weathering rates established for basaltic rocks showing that chemical denudation rate are linearly correlated to runoff and depend on temperature according to an Arrhenius law. The rivers draining the complex assemblage of volcanic and volcanic-derived rocks in the subduction/collision geological context of the Stikine Province thus respond similarly to the other volcanic provinces of the world. This does not seem to be true for associated CO2 consumption rates. The abundance of sulfate ions in the dissolved load, possibly derived from oxidative weathering of sulfides, may indeed provide a non-negligible part of the protons necessary for chemical weathering. Within Canada, the Stikine geologic province is one whose silicates weather at a high rate. The order of chemical weatherabilty of Canadian geological province from the lowest to the highest is established as follows: granites

Ground-based, interferometric, synthetic aperture radar (GB-InSAR) has been successfully implemented for the monitoring and assessment of both natural and man-made slopes. Its advantages include high-frequency data acquisition and high spatial density, providing maps of displacement. The implementation of this tool for civil projects in remote areas and under severe weather conditions present several challenges. This paper presents the implementation of GB-InSAR, particularly using discrete monitoring campaigns and temporal aggregation of data, for resolving logistical issues associated with power availability. This was implemented to monitor a very slow-moving (average displacement rate of ~10 mm/y) 2 to 3 million m3 bedrock landslide known as The Checkerboard Creek Rock Slope located within the Revelstoke dam reservoir, BC, Canada. GB-InSAR deployment has been successful as it confirmed the toppling-like deformation mode, improved definition of the most active area within the exposed slope cut, improved understanding of the seasonality observed in some instruments at the site, and identification of a potential unstable block north of the known active area. Further, the findings in this paper verify the feasibility of implementing GB-InSAR technology to monitor similar slopes associated with the safety of civil infrastructure and in challenging conditions characteristic of the Canadian environment. • Discontinuous ground radar slope monitoring in remote, challenging environments. • Successful implementation and update of rock landslide deformation patterns. • Valuable insight into slow rock landslides without base sliding surface. • Precedent and guide for ground radar deployment in remote, challenging weather. • Updated information on known Canadian landslide Checkerboard Creek Rock Slope. [ABSTRACT FROM AUTHOR]

We present in this paper a simple and computationally efficient numerical model that depicts a column of sublimating, blowing snow. This bulk model predicts the mixing ratio of suspended snow by solving an equation that considers the diffusion, settling and sublimation of blowing snow in a time-dependent mode. The bulk model results compare very well with those of a previous spectral version of the model, while increasing its computational efficiency by a factor of about one hundred. This will allow the use of the model to estimate the effects of blowing snow upon the atmospheric boundary layer and to the mass balance of such regions as the Mackenzie River Basin of Canada. [ABSTRACT FROM AUTHOR]

Facies relationships in Pleistocene braided outwash deposits in southern Ontario demonstrate the presence of a large braid bar with adjacent side channel. The core of the bar is up to 6 m high, and consists of crudely horizontally stratified gravels. Downstream from the core is the bar front facies, consisting of large gravelly foresets up to 4 m high, rounded off in many places by reactivation surfaces. Upstream from the core is the bar stoss side facies consisting of several sets (individually up to 35 cm thick) of tabular cross-bedding, arranged in coarsening-upward sequences. The stoss side-core-bar front relationships are continuously exposed in one 400 m long quarry face which is cut almost parallel to the palacoflow direction. A transverse quarry face shows the side channel facies, which consists if trough cross-bedded sands. Gravel layers can be seen to finger from the main gravelly bar into the sandy side channel, but they do not reach the base of the channel. This surprising relationship indicates that gravel moved only in the topographically higher parts of the system. After deposition in the side channel, and growth upstream and downstream from the bar core, the entire system aggraded. Crudely horizontally stratified, and imbricaled gravel sheets were laid down as a bar top facies. Grain size analyses indicate strongly bimodal distributions, implying that much of the sand in the spaces between pebbles and boulders filtered in after the gravel had been deposited. This interpretation is strengthened by velocity calculations—mean velocities in excess of 300 cm/s would be needed to roll the gravel as bed load, but at such a velocity, a large amount of sand would be transported entirely in suspension. In a final section of the paper, our results are combined with other work on braided systems in an attempt to formulate a more general facies model. [ABSTRACT FROM AUTHOR]

This study aims to untangle the knot of treaty-making, industrialization, and hydroelectric development in the Lake Abitibi region in northeastern Ontario by examining the extent to which industrialist discourses on waterways influenced changes to the physical and political landscape. An analysis of events leading up to the signing of Treaty No. 9 in 1906, and then the Abitibi River hydroelectric dams and concomitant flooding of Lake Abitibi in 1914–15 made possible by the treaty, is provided. Changes to Lake Abitibi during this period are evidence of a process of hydraulic imperialism whereby the Canadian state used waterways to exercise control of the James Bay watershed and encourage industrial and agricultural development in northeastern Ontario in the early twentieth century. This process not only contextualized the state’s understanding of Treaty No. 9 but is further evidence of inherent ambiguities concerning First Nations reserves around Lake Abitibi created by the treaty. [ABSTRACT FROM PUBLISHER]

The delivery and burial of terrestrial particulate organic carbon (OC) in marine sediments is important to quantify, because this OC is a food resource for benthic communities, and if buried it may lower the concentrations of atmospheric CO2 over geologic timescales. Analysis of sediment cores has previously shown that fjords are hotspots for OC burial. Fjords can contain complex networks of submarine channels formed by seafloor sediment flows, called turbidity currents. However, the burial efficiency and distribution of OC by turbidity currents in river‐fed fjords had not been investigated previously. Here, we determine OC distribution and burial efficiency across a turbidity current system within Bute Inlet, a fjord in western Canada. We show that 62% ± 10% of the OC supplied by the two river sources is buried across the fjord surficial (30–200 cm) sediment. The sandy subenvironments (channel and lobe) contain 63% ± 14% of the annual terrestrial OC burial in the fjord. In contrast, the muddy subenvironments (overbank and distal basin) contain the remaining 37% ± 14%. OC in the channel, lobe, and overbank exclusively comprises terrestrial OC sourced from rivers. When normalized by the fjord's surface area, at least 3 times more terrestrial OC is buried in Bute Inlet, compared to the muddy parts of other fjords previously studied. Although the long‐term (>100 years) preservation of this OC is still to be fully understood, turbidity currents in fjords appear to be efficient at storing OC supplied by rivers in their near‐surface deposits. Plain Language Summary: Plants on land use CO2 from the atmosphere to produce organic carbon, which promotes their growth. Rivers transport organic carbon to the sea, where it is either eaten by fauna or buried in the seafloor, thus decreasing atmospheric CO2 levels on Earth over thousands to millions of years. Fjords are recognized as global organic carbon sinks; trapping 18 million tons of organic carbon in their seafloor sediments each year. However, the complex morphology of fjord seafloors was not considered in the calculation of this organic carbon flux. In this study, we determine the distribution and abundance of terrestrial organic carbon across a fjord (Bute Inlet, Canada), which contains a submarine channel network terminating onto a large accumulation of sand (called a lobe). We show that 62% of the organic carbon supplied by the two rivers connected to the fjord is buried across the fjord; the majority of this carbon being held in the lobe. In total, Bute Inlet buries at least 3 times more organic carbon per unit of surface area than other fjords previously studied. Submarine channels in fjords thus appear to promote the storage of land‐derived organic carbon in the seafloor, potentially impacting CO2 levels and food resources for marine fauna. Key Points: Bute Inlet, a river‐fed fjord incised by turbidity currents, has a contemporary terrestrial organic carbon burial efficiency of 62% ± 10%Sandy surficial deposits are responsible for 63% ± 14% of the total terrestrial organic carbon burial budget in Bute Inlet, but only cover 17% of the seafloor areaGlobal estimates based only on the muddy parts of fjords may significantly underestimate organic carbon burial rates by a factor >3 [ABSTRACT FROM AUTHOR]

Abstract: Previous estimates of geothermal energy potential in Canada give an indication of available heat to be ‘farmed’ at depth with focus on Western Canadian Cordillera and Western Canadian Sedimentary basin as prime targets. This paper examines in more detail temperature–depth realtionships near large population centres in Québec, in order to provide a first order assesment of enhanced geothermal systems (EGS) potential for electrical and heat generation. Results show areas with significant EGS potential in the St-Lawrence River valley related to high heat flow density and thermal blanketing of thick sedimentary cover. At >120°C found to be a prospect for several areas in Québec (drilled to depths of over 4.5km in Trois-Rivières area, near 4.5km in the Eastern St-Lawrence River (Rimouski, Gaspé and Golf, including Anticosti Island) and just 4km in Quebec area) the potentially available geothermal power from EGS hydrothermal systems in deep sediments can be of significance. [Copyright &y& Elsevier]

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: We describe a decision support system that has been developed to inform management and planning in a portion of the St. Lawrence Estuary in Canada (covering the Saguenay-St. Lawrence Marine Park and the proposed St. Lawrence Estuary Marine Protected Area). The system is composed of a spatiotemporal, georeferenced database, a simulator (3MTSim) that reproduces the spatiotemporal movement of marine mammals and maritime traffic in the estuary, and data post-processing tools that can be used to analyse the output of 3MTSim. 3MTSim allows users to test different management scenarios for maritime traffic (e.g., area closures, speed limits, regulations concerning the observation of marine mammals) in order to assess their effects on navigational patterns which may influence marine mammal exposure to vessels. 3MTSim includes an individual-based model of marine mammal movement patterns that has been elaborated based on existing telemetry data on fin, blue, and beluga whales as well as on land-based theodolite tracking of humpback and minke whales. Observations recorded aboard research and whale-watching vessels have provided the spatial data necessary to estimate species’ abundances and distribution maps that are used to initialise the whale model. Different types of vessels, including cargo ships and commercial whale-watching boats are also modelled individually, using an agent-based approach. The boat model represents the decision-making process of boat captains as a function of environmental conditions, the contextual setting, and their respective goals. An extensive database of real-time tracking data available for the different types of vessels, coupled with observations and interviews, has served in the elaboration of the boat model. In this paper, an overview of the entire system is presented and its effectiveness as a decision support tool is demonstrated via the results from a sample of scenario-based simulations. [Copyright &y& Elsevier]

The article discusses an environmental controversy in northern British Columbia in the 1960s over log driving on the Stellako River. The conflict is seen on one level as a dispute between the federal government of Canada, which wanted to protect salmon spawning grounds, and the provincial government of British Columbia, which defended the interests of the forestry, logging, and pulp and paper industries. Also opposing the log drives were sportsmen, conservationists, and tourism interests. Debates over appropriate use of the river are seen as symbolic of changes in British Columbian society in the postwar era.