The objective of this study was to apply the WEND model, a nutrient mass balance model, to the Castor watershed in southern Quebec to evaluate phosphorus movement, storage and export over time. The WEND model was customized to run on a field-scale and then individually applied to 266 fields on the watershed for a 30-year simulation period. Field-specific information for the period of 1997-1999, was used as basic inputs to the model. Climatic information was obtained from local sources. The additional information required to run the model was derived from the literature. Model outputs were analysed at three different levels: (i) the overall watershed impacts, (ii) by cropping system, and (iii) for field management practices presenting a high risk of P losses. Specific outputs examined were: soil test Mehlich-III P, soil P saturation with aluminium, RUSLE soil loss potential and TP export. / The model was used to examine the impacts of crop rotations, fertilizer application and tillage management on TP export. For the Castor watershed, the soil test P increased at a mean rate of 3.71 kg Mehlich-III P ha -1 yr-1, equivalent to a mean input of about 32 kg P2O5 ha-1 yr-1 in excess of plant requirements, assuming current field management practices remain constant. / If TP export is considered the most important parameter in terms of P contamination, crop rotations are a good alternative to continuous corn monocropping under which losses could reach as high as 3.36 kg TP ha-1 yr -1. Crop rotations were shown to be an important management practice that should be more carefully examined when establishing field management practices. Just one year of grassland within a rotation can greatly improve the overall environmental health of a watershed. The management of P inputs is also an important target for improvement, as fertiliser inputs often surpassed plant requirements by two- or three-fold.

Pacific lamprey (Entosphenus tridentatus) are experiencing population declines throughout their range. Xenobiotics could be an important risk factor for lamprey populations. Our goal was to establish if common herbicides, as used in forest management, could affect reproductive fitness. We determined that atrazine was a likely compound of greatest concern to lamprey populations. Using an odorant response behavioral assay we were able to demonstrate that environmentally relevant concentrations of atrazine caused a depressed response to adult lamprey holding tank effluent, likely pheromones. Atrazine also depressed their activity level; the number of times they crossed into the effluent arm after being treated with atrazine was significantly lower than controls. In addition, activity level post exposure to atrazine differed between adult life history stages, something which was not significantly different during control trials. Using an odorant detection assay, based on evaluating ventilation rate, we were able to show that environmentally relevant concentrations of atrazine caused a significant increase in ventilatory response to a repulsive odorant, a conspecific necromone. Through the detection study we also showed that lamprey,exposed to atrazine, had a slight increase in ventilatory response to odor from adult lamprey. If we are concerned about the decline in Pacific lamprey populations, then we should logically be concerned with their exposure to atrazine in the environment. / Graduation date: 2012

No description available.

No description available.

No description available.

Modern pig farming production may over burden the environment with organic substances, exposure of bacterial pathogens and introduction of resistance gene. This may be caused by the pig’s droppings, lack of seepage management or accidental spillage of seepage which may impact on the environment and its physicochemical parameters. The objective of this study is to determine and assess the level of bacteriological pollution emanating from the pig farm and their impact on the physicochemical parameters of soil and water as well as to identify the presence of antibiotic resistance gene of these prevailing bacteria. Soil and water samples were collected monthly for a period of six months (March- August 2013). Samples were collected at pig enclosures, soil 20 m and 100 m away from pig enclosures, constructed wetland used for treating pig farm wastewater, soil 20m and 100 m away from constructed wetland. Procedure followed for analysing soil and water samples includes physicochemical analyses, viable cell counts of 10-1 to 10-8 dilutions, identification of bacteria using API 20E test kit, antibiotic susceptibility analyses, and identification of resistance gene using molecular procedures. The media that were used for viable cell counts were, Nutrient agar, MacConkey Agar, Xylose Lysine Deoxycholate agar (XLD agar), and Eosin Methylene Blue (EMB). Physicochemical parameters of water showed unacceptable high levels of analysed parameters for BOD (163 mg/L to 3350 mg/L), TDS (0.77 g/L to 6.48 mg/L), COD (210 mg/L to 9400 mg/L), NO3 (55 mg/L to 1680 mg/L), NO2 (37.5 mg/L to 2730 mg/L), and PO43− (50 mg/L to 1427 mg/L) were higher than the maximum permissible limits set by Department of Water Affairs and Forestry (DWAF). For soil samples TDS (0.01g/L to 0.88 g/L), COD (40 mg/L to 304 mg/L), NO3 (32.5 mg/L to 475 mg/L), and NO2 (7.35 mg/L to 255 mg/L) and PO43- (32.5 mg/L to 475 mg/L ) were observed to be higher than recommended limits set by Federal Ministry for the Environmental (FME). The viable cells in soil samples 30cm depth ranged from 0 cfu/mL to 2.44 x 1010cfu/mL, in soil 5cm depth ranged from 1.00 x 101 cfu/mL to 1.91 x 1010 cfu/mL, and in water samples viable cells ranged from 5.00 x 101 to 5.05 x 109. Pseudomonas luteola (Ps. luteola), Escherichia vulneris (E. vulneris), Salmonella choleraesuis spp arizonae, Escherichia coli 1(E. coli 1), Enterobacter cloacae, Pseudomonas flourescens/putida (Ps. flourescens/putida), Enterobacter aerogenes, Serratia ordoriferal, Pasteurella pneumotropica, Ochrobactrum antropi, Proteus vulgaris group, Proteus vulgaris, Salmonella spp, Aeromonas Hydrophila/caviae/sobria1, Proteus Mirabillis, Vibrio fluvials, Rahnella aquatillis, Pseudomonas aeruginosa (Ps. aeruginosa), Burkholderia Cepacia, Stenotrophomonas maltophilia (St. maltophilia), Shwenella putrefaciens, Klebsiela pneumonia, Cedecea davisa, Serratia liquefaciens, Serratia plymuthica, Enterobacter sakaziki, Citrobacter braakii, Enterobacter amnigenus 2, Yersinia pestis, Serratia ficaria, Enterobacter gergoriae, Enterobacter amnigenus 1, Serratia marcescens, Raoutella terrigena, Hafnia alvei 1, Providencia rettgeri, and Pantoa were isolated from soil and water samples from the pig farm. Isolates were highly resistant to Penicillin G, Sulphamethaxazole, Vancomycin, Tilmocozin, Oxytetracycline, Spectinomycin, Lincomycin, and Trimethoprim. The most resistance genes detected in most isolates were aa (6’)-le-aph (2”)-la, aph (2”)-lb, aph (3”)-llla, Van A, Van B, Otr A and Otr B. Pig farm seepage is causing bacterial pollution which is impacting negatively on the natural environment in the vicinity of pig farm by introducing bacterial pathogens that have an antibiotic resistance gene and is increasing the physicochemical parameters for soil and water in the natural environment at the pig farm. It is therefore recommended that pig farms should consider the need to implement appropriate regulatory agencies that may include the regular monitoring of the qualities of final effluents from waste water treatment facilities. In addition there is a need to limit soil pollution in order to safe guard the natural environment in the vicinity of pig farm from bacteriological pollution and introduction of antibiotic resistance gene. It is also recommended that more advanced technologies should be introduced that will assist pig farms to manages the seepage properly. / Environmental Sciences / M. Sc. (Environmental Sciences)

The environmental impact of agricultural activities on water quality was studied on two sub-watersheds of the L'Assomption river in Quebec, over a 3 year period. The sub-watersheds studied were the Saint Esprit (26.1 km 2) and Desrochers (17.9 km2). Development of a methodology and associated tools for targeting conservation activities and assessing the potential impacts of conservation practices was one of the study's components. A goal of this research was the development of a tool using NPS modelling capability and GIS tools. The ANSWERS 2000 model and SPANS GIS software were selected for integration. / Using the advanced SPANS operation and EASI script language, the ANSWERS 2000 model was integrated into the latest version of SPANS GIS (Explorer ver. 7). Integration of these two software packages provided assistance in creating and handling the extensive input and output data for models, evaluating of model output, and delineating of critical areas. A sensitivity analysis of the ANSWERS model was performed on thirteen parameters to determine their effects on runoff ANSWERS 2000 was found to be most sensitive to depth of soil horizon, silt and clay contents of soil texture, and solar radiation. Four years of runoff predictions by the model were analysed using observed data. Overall, the model was in good agreement with observed runoff in the Saint Esprit watershed, particularly in the years with above the average precipitation. The coefficient of (CP'A) between predicted and observed runoff values was 0.5 and 1.5 for 1994 and 1995, respectively. The model predictions of total cumulative runoff were 66.6% in 1994, 54.9% in 1995, 71.7% in 1996, and 42.4% in 1997, of measured cumulative runoff values.

A study was conducted to assess the efficiency of a constructed wetland for sediment and nutrient removal from a riverine source containing non-point source pollution (NPS) in a Nordic climate. The constructed wetland, built near the town of Mystic, Southern Quebec, consists of a sedimentation basin, a sinuous subsurface horizontal flow section and an open water body or pond that continuously receives up to 5% of Walbridge Creek. Flow into and through the system is controlled by gravity. There is a gate on the intake structure, which allows inflow into the wetland to be adjusted, along with three composite weirs; located at the outlet of each section of the wetland. Water samples were analyzed for orthophosphates (PO4), dissolved phosphorus (DP), total phosphorus (TP), ammonium (NH4+) and nitrates (NO3-) The study occurred from May to December 2003 and from May to December 2004. In 2003, there was a 33.6% reduction in TP load from intake to outlet with a retention rate of 2.23 g m-2 year-1. The greatest reduction in TP load during 2003 took place during the summer months (32.2%). In 2004, there was a further reduction of 42.8% in TP load from intake to outlet with a retention rate of 1.56 g m-2 year-1 compared to 2003. The largest reduction in TP load during the operational year of 2004 took place during the summer months (43.7%). Within the wetland, both the submerged flow section and open water basin showed similar and significant reductions of TP load in 2003 and 2004 annually and seasonally. Both annually and seasonally in 2003, NO3- showed no significant decrease in load from intake to outlet or within portions of the wetland. In 2004, there was a 22% annual load reduction from intake to outlet with a retention rate of 43.9 g m-2 year-1. The largest reduction in NO3- load during 2004 took place during the summer months (25.6%). Within the wetland, the submerged flow section showed the greatest reduction in NO3- concentrations annually and during the summer months of 2004. These results confirm the range of treatment efficiencies that can be achieved using a constructed wetland for NPS pollution in a Nordic climate.

Endocrine disrupting compounds and pesticides have been detected in rivers and irrigation canals of Southern Alberta, a semiarid region with irrigation-dependent crop production, intensive livestock operations, and a growing human population. However, little is known about the effects of agricultural runoff or wastewater treatment plant (WWTP) effluent in Southern Alberta on fish. Reproductive effects of WWTP effluents from the cities of Lethbridge and Medicine Hat, as well as agricultural runoff in the Lethbridge Northern Irrigation District canals, were investigated in a field study with wild fathead minnows (FHMN) in the Oldman and the South Saskatchewan rivers, in Alberta, Canada, and in a laboratory study with laboratory reared FHMN exposed in vivo to the city of Lethbridge WWTP effluent for 21 days. Biochemical and morphological endpoints were measured to characterize reproductive status. Liver vitellogenin, a biomarker of exposure to estrogen mimics, was analyzed using quantitative RT-PCR, and gonadal histology was used to determine sex, gonadal maturity, and intersex. Adverse reproductive effects were detected in FHMN exposed for 21 days to 10 and 25% of Lethbridge WWTP effluent. In the field, effluents from both Lethbridge and Medicine Hat had an effect on the reproductive systems of FHMN. In canals, reproductive effects were detected in wild fathead minnows in years when water quality in irrigation drain canals decreased. Exposure to pesticides was estimated using acetylcholinesterase (AChE) inhibition. Exposure to Lethbridge WWTP effluent did not inhibit AChE, whereas results from the field study were inconclusive. In conclusion, reproductive systems of fathead minnows in Southern Alberta were impacted by anthropogenic chemicals. / xi, 104 leaves : ill. (some col.), maps ; 29 cm

Two tile-drained agricultural fields in the Pike River watershed of Southern Quebec were instrumented in October 2000 to monitor phosphorus and nitrate concentrations in surface runoff and tile drainage. Data collected from these sites were used as the primary input to test a GIS-based hydrological and water quality simulation model (ArcView SWAT2000) at the field scale. Surface runoff, subsurface flow, sediment yield, nitrate loads and phosphorus loads were the principal parameters evaluated by the model. The SWAT model was calibrated using data collected in the year 2002 while 2003 data was used for validating the model. Particulate phosphorus and total dissolved phosphorus loads in streamflow were also simulated using SWAT and compared with field measurements. / A sensitivity analysis showed that curve number, available soil water content and soil evaporation factors significantly influenced water yield simulations while model performance for water quality parameters was governed mainly by the accuracy of simulating field operations such as fertilization and tillage. The monthly coefficients of performance after calibration ranged from being very good for some parameters (0.27 to 0.66 for total water yield; 0.38 to 0.67 for total phosphorus; and 0.23 to 0.89 for sediments) to being inconsistent for others (0.44 to 2.28 for subsurface flow; 0.63 to 4.36 for surface runoff; and 0.66 to 1.35 for total nitrate loads). Overall, it was found that SWAT results on a seasonal scale were generally more reliable whereas daily or monthly simulations could be improved by using a longer calibration period or incorporating model changes. Short-term impacts of implementing different best management practices for tillage, crop rotation and fertilization were also evaluated using the validated SWAT model. It was found that conservation tillage of corn coupled with pasture or soybean rotations can reduce total phosphorus loads in the range of 25-50% over conventional tillage with corn.