: Agricultural and residential activities are key non‐point sources of nitrogen pollution in urban‐rural fringe areas. A GIS‐based watershed approach was used to compare land use indicators (septic system and animal unit densities), to streamwater nitrate‐N in the Salmon River near Vancouver, B.C., Canada. The density of septic systems was used as an indicator of residential development while animal unit density was used as an indicator of the intensity of agricultural activity. Nitrate‐nitrogen (nitrate‐N) concentrations as high as 7.1 mg·L−1 were found in the mid‐portion of the watershed during the summer months, when streamflow is low and groundwater comprises a large proportion of water in the stream. The major aquifer supplying water to the midsection of the watershed is contaminated with nitrate‐N. A comparison of the relationships between septic system and animal unit density and nitrate‐N in the upstream to downstream direction provided evidence that both residential and agricultural activities contribute to elevated nitrate‐N in the Salmon River mainstem. In contrast, only septic system density corresponded to the pattern of streamwater nitrate‐N in Coghlan Creek, the main tributary to the Salmon River.

Wabamun Lake (Alberta, Canada) has been subject to ongoing contamination with polycyclic aromatic hydrocarbons (PAHs) from multiple sources for decades and in August 2005 was exposed to ca. 149 500 L of bunker C oil following a train derailment. We compared the pattern, frequency, and severity of deformity in larvae of lake whitefish (Coregonus clupeaformis) incubated in situ in areas of Wabamun Lake exposed only to "background" PAH contamination and in areas additionally exposed to PAHs from the oil. All sites in the lake (including reference areas) showed incidences of deformity higher than are typically observed in laboratory studies. A small number of oil-exposed sites showed higher incidences of some teratogenic deformities and a tendency to exhibit deformities of higher severity than sites not exposed to oil. The frequency of moderate to severe deformities in 8 of 16 classes was correlated with PAH exposure. Nonmetric multivariate ordination of deformity data revealed a general pattern of increasing incidence and severity of several skeletal (lordosis, scoliosis) and craniofacial (ocular, jaw) deformities at sites with relatively high exposure to oil-derived PAHs. A simultaneous consideration of incidence, severity, and pattern of deformity enabled us to detect a consistent (overall approximately 5% above background) response to the oil despite high variability and high background deformity rates in this historically contaminated environment.

A weight-of-evidence (WOE) framework was developed to evaluate potential effects on the aquatic ecosystem of Wabamun Lake (Alberta, Canada) associated with the release of Bunker "C" oil after a train derailment. The wide variety of stakeholders and interested regulatory agencies made it necessary to develop a consistent and transparent approach to assessing ecological effects on multiple ecosystem components within the lake with the use of a large number of lines of evidence (LOEs). Consequently, a scalable WOE framework was necessary to integrate the findings of 38 different LOEs. A priori and a posteriori weighting factors were applied to each individual LOE, and a combination of numeric and nonnumeric rating systems was used to integrate LOEs into an overall WOE conclusion for 5 different ecosystem components. We provide guidance regarding the development of a WOE framework and emphasize techniques that enhance the application of best professional judgement during the WOE process.

The Southeast False Creek (SEFC) lands in Vancouver, Canada, had a long history of industrial use and filling prior to their redevelopment first for use as the 2010 Winter Olympic Village and now as a continuation of the residential community along highly-sought-after city waterfront lands. Soil and sediment concentrations of metals and hydrocarbons exceeded regulatory benchmarks in and around a man-made embayment that supported ship building and steel fabrication. As well, the shoreline was highly disturbed with debris, erosion, and non-native vegetation, and consequently limited in its ability to support intertidal species typically expected in coastal waters of Western Canada.The Official Development Plan prepared by the City of Vancouver for SEFC incorporated shoreline improvements to public access, fish habitat, and safety and health objectives in response to community values expressed during an extensive public consultation process. Remediation and reconfiguration of the SEFC shoreline was thus a significant component of redevelopment which included removal of contaminated sediment and soil; filling of a portion of the embayment; stabilization, re-dressing, and planting of the remainder of the existing shoreline; and construction of an island in compensation for the partial filling of the embayment.Three annual surveys of a five-year post-construction monitoring program have been undertaken to date to evaluate the function of the constructed habitat and reconfigured shoreline. Both continue to be colonized by macroalgae and sessile invertebrates, and coverage and community structure is becoming more Environmental Impact 401

Following a train derailment in August 2005, Wabamun Lake (Alberta, Canada) was exposed to approximately 149,500 L of bunker "C" oil, much of which became entrained in the abundant Schoenoplectus tabernaemontani (= Scirpus validus) beds in the eastern basin of the lake. We assessed the regrowth of emergent macrophytes during the subsequent two growing seasons. Postspill measures of productivity, including transect length, total cover, and biomass were within the variability of prespill data collected in 2001, with the exception of a few specific areas in which biomass appeared to be affected. We conclude that exposure to oil during the late growing season in August 2005 and through the winter senescent period and regrowth in the summers of 2006 and 2007 did not cause large-scale changes to S. tabernaemontani communities. Physical factors such as cleanup activities and vegetation management appeared to be responsible for the reduced regrowth observed at some locations. Few previous studies have been published on the effects of oil spilled into freshwater on macrophyte communities; thus, the results of this study are expected to provide useful information for the assessment of future freshwater oil spills.