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McRae C.J.,University of Northern British Columbia | McRae C.J.,National Dong Hwa University | Warren K.D.,University of Northern British Columbia | Warren K.D.,Rescan Environmental Services Ltd. | Mark Shrimpton J.,University of Northern British Columbia
Endangered Species Research | Year: 2012

Understanding habitat requirements for spawning is important for species at risk of extirpation to define areas for protection of this critical life stage. Interior Fraser coho salmon (IFC) Oncorhynchus kisutch spawn in tributaries of the upper Fraser River, British Columbia, Canada. They are regionally isolated, genetically distinct, and have been listed as endangered. Recent enumeration efforts have shown declining escapement and range contraction. IFC spawn in snow-dominated watersheds, yet much of our understanding of spawner habitat requirements is based on information for coho from coastal rain-dominated systems. Consequently, we examined the relative influence of habitat features on spawning site selection. Our sampling focused on why fish chose particular locations and not others in what seemed to be suitable habitat. We defined several logistic regression models, including various combinations of physical, chemical and hydrological microhabitat features, and used an information-theoretic approach to evaluate the relative plausibility of these models. Models combining intragravel measures of electrical conductance, dissolved oxygen, temperature and specific discharge were the best models associated with spawning microhabitat selection, and jackknife validations showed that these models had good predictive abilities. Intragravel variables, therefore, appear to play a prominent role in spawning site selection for IFC. Understanding the influence of the intragravel environment on spawning site selection will help identify habitat requirements as well as potential threats to fish populations and will contribute to the development of comprehensive conservation initiatives. © Inter-Research 2012. Source


Gustavson K.,Rescan Environmental Services Ltd. | Kennedy E.,Stantec Consulting Ltd.
Wetlands | Year: 2010

Development of a reliable and practical approach for quantifying values of wetlands in Canada is essential to support full cost accounting in resource management decisions. Information on wetland values can: demonstrate the magnitude and range of existing values; assist in tradeoff analysis; and guide wetland management and public investments to protect and enhance benefits. Our approach to valuation focuses on identifying the wetland types, attributes and services, types of economic values, and appropriate valuation procedures. Functional assessment offers the best means to link wetland attributes to services and values. To identify economic values, information regarding ecosystem services is placed in the context of the study site. Additionally, the scales and increments of scientific data collection are chosen to suit the economic valuation tools being employed. Valuation must make an important distinction between strategic level and detailed site valuation. Clear identification of the policy question is the critical first step in analysis, as it determines whether a measure of total economic value will suffice, or if information is required on marginal values. Before wetland valuation can be implemented broadly in Canada, additional baseline inventory information must become available. Preferably, regionally-calibrated models of wetland function should be developed. © Society of Wetland Scientists 2010. Source


Muttray A.,Environment Canada | Muttray A.,Rescan Environmental Services Ltd. | Reinisch C.,Environment Canada | Miller J.,Environment Canada | And 4 more authors.
Science of the Total Environment | Year: 2012

Intensive farming of potatoes in Prince Edward Island (PEI) relies on the repeated and widespread application of fertilizers and pesticides. In PEI the main potato farming areas are in close proximity and drain directly to estuaries. Runoff from high agricultural activity watersheds could impact benthic organism health in the depositional zone of downstream estuaries. The estuarine filter feeder Mya arenaria (soft-shell clam) could be particularly vulnerable to both particle-adsorbed and water soluble contaminants. M. arenaria is susceptible to haemocytic leukemia. In May 2009, we established that heavily proliferated leukemia (HPL) prevalence was generally higher in PEI estuaries located downstream of high intensity potato farming (Dunk and Wilmot estuaries) watersheds than in estuaries downstream of lower intensity areas. Using Mab-1E10 based immunocytochemistry we observed that leukemic haemocytes from the Dunk and Wilmot estuaries were 1E10 negative whereas those from the Ox/Sheep estuary (low potato farming intensity) were 1E10 positive. The expression of genes in the p53 tumour suppressor pathway enabled us to differentiate groups of leukemic and normal M. arenaria, validating our diagnoses. In October 2009, we confirmed that HPL prevalence was elevated in the Dunk and Wilmot estuaries compared to reference (Souris River). Moreover, leukemia prevalence declined with distance from the river mouths along transects through the Dunk and Wilmot estuaries. The pesticides ß-endosulfan and α-endosulfan were detected in surface sediments from the Dunk and Wilmot estuaries, but not in sediments from either the Souris River or several other lower intensity potato farming watersheds. Our study provides evidence of an association between intensity of potato farming and prevalence of clam leukemia at downstream estuaries in PEI. © 2012. Source


Dockrey J.W.,University of British Columbia | Dockrey J.W.,Lorax Environmental Services Ltd. | Lindsay M.B.J.,University of Saskatchewan | Mayer K.U.,University of British Columbia | And 5 more authors.
Minerals | Year: 2014

Microbial populations and microbe-mineral interactions were examined in waste rock characterized by neutral rock drainage (NRD). Samples of three primary sulfide-bearing waste rock types (i.e., marble-hornfels, intrusive, exoskarn) were collected from field-scale experiments at the Antamina Cu–Zn–Mo mine, Peru. Microbial communities within all samples were dominated by neutrophilic thiosulfate oxidizing bacteria. However, acidophilic iron and sulfur oxidizers were present within intrusive waste rock characterized by bulk circumneutral pH drainage. The extensive development of microbially colonized porous Fe(III) (oxy)hydroxide and Fe(III) (oxy)hydroxysulfate precipitates was observed at sulfide-mineral surfaces during examination by field emission-scanning electron microscopy-energy dispersive X-ray spectroscopy (FE-SEM-EDS). Linear combination fitting of bulk extended X-ray absorption fine structure (EXAFS) spectra for these precipitates indicated they were composed of schwertmannite [Fe8O8(OH)6–4.5(SO4)1–1.75], lepidocrocite [γ-FeO(OH)] and K-jarosite [KFe3(OH)6(SO4)2]. The presence of schwertmannite and K-jarosite is indicative of the development of localized acidic microenvironments at sulfide-mineral surfaces. Extensive bacterial colonization of this porous layer and pitting of underlying sulfide-mineral surfaces suggests that acidic microenvironments can play an important role in sulfide-mineral oxidation under bulk circumneutral pH conditions. These findings have important implications for water quality management in NRD settings. © 2014 by the authors; licensee MDPI, Basel, Switzerland. Source


Cowie N.M.,Rescan Environmental Services Ltd. | Cowie N.M.,University of British Columbia | Moore R.D.,University of British Columbia | Hassan M.A.,University of British Columbia
Earth Surface Processes and Landforms | Year: 2014

Proglacial stream development was studied in coastal British Columbia and Washington, focusing on reaches exposed by post-Little Ice Age (LIA) glacier retreat, to address three principal questions: (i) Does the legacy of LIA glaciation influence the evolution of channel morphology? (ii) How long does it take for riparian forest to establish following glacier retreat? (iii) Can newly exposed proglacial streams provide suitable fish habitat? Channel morphologies were identified by field surveys of 69 reaches in 10 catchments. Riparian forest development and potential fish habitat were characterized in those reaches and an additional 22 catchments using GIS analysis. The landscape template imposed by the Quaternary glaciation appears to override most of the modern effects of the LIA in controlling channel-reach morphology. Binary logistic regression analysis identified elevation and time since deglaciation as primary controls on the presence of riparian forest. At higher elevations, establishment of morphologically functional riparian forest could take several centuries, prolonged by channel instability associated with post-LIA sediment inputs. Of the recently deglaciated streams included in this analysis, the majority (86%) of the total length was of suitable gradient for fish and could be accessed either by downstream populations or from adjacent lakes. Predicted maximum weekly average stream temperature (MWAT) indicated that the post-LIA study streams were thermally suitable for cold-water fish. A future scenario of glacier loss would cause a 14% decline in accessible cold-water thermal habitat in post-LIA streams. Decreased summer flows due to glacier retreat could further limit usable habitat by reducing stream depths and wetted perimeters. © 2013 John Wiley & Sons, Ltd. Source

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