Due to the nature of the regional geology and the bitumen extraction process, the post-mined landscape of Canada’s oil sands region will have a much higher concentration of dissolved salts than it did prior to mining. As a result, naturally saline wetlands may constitute appropriate reclamation targets and knowledge of saline wetland hydrology can provide important clues to their form and function. Furthermore, the presence of saline discharge features in the Athabasca oil sands region (AOSR) provides an opportunity to study more closely the nature of groundwater flow in a region of considerable hydrogeologic complexity, including the origin and flow history of brines and the link between springs, subsurface wastewater containment and surface water quality. A low-flow saline-spring fen peatland located adjacent to a proposed in-situ oil extraction facility was examined south of the oil sands hub of Fort McMurray, Alberta. Hydrologically disconnected from underlying Devonian deposits that are a typical source of salinity, a saline groundwater plume originating from a Lower Cretaceous aquifer (the Grand Rapids Formation) was identified as a likely source for the accumulation of Na+ (mean of 6,949 mg L-1) and Cl- (mean of 13,766 mg L-1) in fen groundwater. Considerable spatial variability in ground and surface water salinity was observed, with the concentration of dissolved salts decreasing by an order of magnitude in the direction of flow. A sharp decrease in near-surface salinity was found along the entire perimeter between the fen and adjacent freshwater wetlands. Patterns in deep groundwater flux were difficult to interpret due to possible inaccuracies associated with the piezometer network (e.g., time-lag errors in low hydraulic conductivity substrates), and rates of groundwater input were estimated to be small (< 1 mm over a season) due to the low conductivity of the underlying mineral till (5.5x10-7 cm s-1). Water table dynamics were exaggerated in response to wetting and drying for both study seasons and the fen’s small subsurface storage capacity was readily exceeded under periods of sustained rainfall. The large pond network functioned as an effective transmitter of surface water during periods of high water table but was a sink of groundwater during dry periods due to high rates of evaporation. Despite flooding conditions observed in 2012, groundwater exchange between the fen and adjacent wetlands was low and the rough microtopography worked to detain surface waters and restrict runoff in the fen’s lower reaches. Together these mechanisms worked to isolate the saline fen and restrict the flux of saline waters into the surrounding landscape. Elevated concentrations of dissolved salts in nearby wetland and river systems indicates that influence of saline discharge is not solely restricted to the region’s major river systems. The flux of salt from saline wetlands may play an important role in the overall water quality of groundwater and receiving water bodies (e.g., nearby river systems). The geochemical signature of fen groundwater points to halite as a source of salinity, as indicated by Cl-/Br- ratios in excess of 7,000. This is in contrast to what has been observed for regional formation brines that are typically related to evaporated seawater. Isotopic evidence and relatively low salinities compared to springs in the Wood Buffalo region suggests that fen discharge water may be significantly diluted as a result of mixing with freshwater sources. The contribution of evaporite to discharge water may be coming from somewhere deeper and further south in the basin. This has important implications for the disposal of wastewater by deep well injection, as disposal zones may be hydrologically linked to near-surface aquifers and discharge features well beyond the immediate production and storage area.

Developing critical loads for nitrogen (N) in the Athabasca Oil Sands Region (AOSR) requires an understanding of the hydrological connectivity and potential for N transport among uplands, fens and bogs typical in the wetland-rich Boreal region of northern Alberta. The Cumulative Environmental Management Association’s (CEMA) overarching mandate is to determine a nitrogen critical load specific to the Boreal region of northern Alberta. To this end, nitrogen amendment experiments were initiated at two Boreal wetland sites: an upland – rich fen gradient at Jack Pine High (JPH) and an upland – fen – bog mosaic at Mariana Lakes (ML), 45 km north and 100 km south of Fort McMurray respectively. The objectives of this study are to use geochemical and isotopic tracers to describe baseline hydrogeochemical variability and connectivity between bog, fens and upland areas in the AOSR. Sites were instrumented with piezometer nests and water table wells along transects that cover the targeted landscape units (n = 108 sampling locations). Fieldwork related to this thesis was conducted during the open-water season: in June and August 2011, and in May, July, and September 2012. Field campaigns also included a snow survey (March 2012), and spring melt/freshet sampling (April 2012). The analysis of spatiotemporal variability of water isotopes and geochemistry in the years 2011-2012 yielded: i) a characterization of baseline conditions from which perturbations can be assessed, and ii) evidence of connectivity among landscape units. No evidence for elevated concentrations of nitrogen related to the amendment experiments was found in 2011 or 2012. The baseline characterization and annual monitoring did show increasing concentrations of inorganic ammonium with increasing depth associated with increasing solute concentrations: average concentrations of inorganic ammonium were 23 mg/L at deepest sampling locations (7 m) at ML bog and ML fen landscape units. These ammonium concentrations in porewaters, given a porosity of 0.90 for peatlands, constitute a store of ammonium that may be a significant source of nitrogen if the hydrology is altered due to co-occurring changes in vegetation (due to, for example, elevated nitrogen inputs), climate and/or landuse. Hydrologic connectivity at JPH is likely driven by topography. Hydraulic head in 2011 and 2012 field seasons showed that flow persisted from the upland to the fen. The consistent and distinct geochemical signatures and isotopic labelling of mid-depth and deep groundwater samples of fen and upland landscape units is consistent with such a stable groundwater continuum. Near-surface water samples at JPH fen however varied hydrogeochemically in response to seasonal changes in precipitation inputs, water levels, and biogeochemical productivity. At ML, hydrological connectivity is a function of antecedent moisture conditions (which determines run-off) and low and variable (10-6 to 10-9 m/s) hydrological conductivity of the peatland substrate (which may result in lateral flow where hydraulic head shows potential for vertical re- or discharge). Near-surface samples showed greater temporal than spatial variability as snowmelt inputs, variations in antecedent moisture conditions and seasonal changes in biogeochemical process rates affected nutrient and solute concentrations. In contrast, shallow, mid-depth and deep samples showed greater spatial than temporal variability. The spatial distributions of parameters could be associated to some degree with vegetation, distance along a surficial flowpath, or depth to mineral substrate or distance from the upland/edge transition. / Graduate / 0996 / 0388 / 0425 / cbkusel@yahoo.ca

Waterbird habitat in the Saskatchewan River Delta (SRD) has been altered by numerous upstream and downstream anthropogenic developments. Wetland water-level management has been used in an attempt to mitigate these changes, but the effects on the local waterbird community are unknown. Using an experimental approach, I examined the effects of wetland water-level management on waterfowl and marsh birds in the SRD. In 2007, three wetland basins in the Summerberry Marsh Complex, Manitoba were partially drawn down and paired with three additional wetlands managed with high water levels. In 2008-09, I surveyed waterfowl within the study wetlands during different life stages using point counts and aerial surveys. Abundances of breeding marsh birds, including American Bitterns, Least Bitterns, Soras, Virginia Rails, Yellow Rails, American Coots, and Pied-billed Grebes were estimated using call-response surveys. Generalized linear and generalized linear mixed models were used to determine relationships between relative bird abundances and the physical characteristics, vegetation characteristics, and forage fish and invertebrate abundances within the wetlands. Dabbler species of waterfowl preferred the partial drawdown wetlands during nearly all life stages, except brooding. Diver species preferred the non-drawdown wetlands, but only during the spring-breeding and fall-staging periods. Invertebrate abundance affected wetland use by dabbler and diver species, particularly during the spring-breeding and brooding periods. Subsequently, wetlands with high forage fish abundances were avoided. In the fall, dabbler densities on the partial drawdown wetlands increased from an average of 0.4 birds per hectare to 1.5 birds per hectare. This influx was likely due to the accessibility and availability of submerged aquatic vegetation. The partial water-level drawdowns did not benefit any species of marsh birds examined. American Bitterns, American Coots, and Pied-billed Grebes chose the deeper, non-drawdown wetlands, due to high abundances of forage fish. Vegetation interspersion, particularly that offered by Schoenoplectus, was preferred by these species. Soras and Virginia Rails were not affected by water depth or vegetation characteristics, but were positively correlated to invertebrate abundances. Subsequently, the Sora avoided wetlands with high forage fish abundance. The conditions created by the partial water-level drawdowns did not meet the requirements of all species present in the SRD. Therefore, future wetland management should focus on providing a wide range of water depths within wetland complexes to accommodate the requirements of different avian species.

Developing critical loads for nitrogen (N) in the Athabasca Oil Sands Region (AOSR) requires an understanding of the hydrological connectivity and potential for N transport among uplands, fens and bogs typical in the wetland-rich Boreal region of northern Alberta. The Cumulative Environmental Management Association’s (CEMA) overarching mandate is to determine a nitrogen critical load specific to the Boreal region of northern Alberta. To this end, nitrogen amendment experiments were initiated at two Boreal wetland sites: an upland – rich fen gradient at Jack Pine High (JPH) and an upland – fen – bog mosaic at Mariana Lakes (ML), 45 km north and 100 km south of Fort McMurray respectively. The objectives of this study are to use geochemical and isotopic tracers to describe baseline hydrogeochemical variability and connectivity between bog, fens and upland areas in the AOSR. Sites were instrumented with piezometer nests and water table wells along transects that cover the targeted landscape units (n = 108 sampling locations). Fieldwork related to this thesis was conducted during the open-water season: in June and August 2011, and in May, July, and September 2012. Field campaigns also included a snow survey (March 2012), and spring melt/freshet sampling (April 2012). The analysis of spatiotemporal variability of water isotopes and geochemistry in the years 2011-2012 yielded: i) a characterization of baseline conditions from which perturbations can be assessed, and ii) evidence of connectivity among landscape units. No evidence for elevated concentrations of nitrogen related to the amendment experiments was found in 2011 or 2012. The baseline characterization and annual monitoring did show increasing concentrations of inorganic ammonium with increasing depth associated with increasing solute concentrations: average concentrations of inorganic ammonium were 23 mg/L at deepest sampling locations (7 m) at ML bog and ML fen landscape units. These ammonium concentrations in porewaters, given a porosity of 0.90 for peatlands, constitute a store of ammonium that may be a significant source of nitrogen if the hydrology is altered due to co-occurring changes in vegetation (due to, for example, elevated nitrogen inputs), climate and/or landuse. Hydrologic connectivity at JPH is likely driven by topography. Hydraulic head in 2011 and 2012 field seasons showed that flow persisted from the upland to the fen. The consistent and distinct geochemical signatures and isotopic labelling of mid-depth and deep groundwater samples of fen and upland landscape units is consistent with such a stable groundwater continuum. Near-surface water samples at JPH fen however varied hydrogeochemically in response to seasonal changes in precipitation inputs, water levels, and biogeochemical productivity. At ML, hydrological connectivity is a function of antecedent moisture conditions (which determines run-off) and low and variable (10-6 to 10-9 m/s) hydrological conductivity of the peatland substrate (which may result in lateral flow where hydraulic head shows potential for vertical re- or discharge). Near-surface samples showed greater temporal than spatial variability as snowmelt inputs, variations in antecedent moisture conditions and seasonal changes in biogeochemical process rates affected nutrient and solute concentrations. In contrast, shallow, mid-depth and deep samples showed greater spatial than temporal variability. The spatial distributions of parameters could be associated to some degree with vegetation, distance along a surficial flowpath, or depth to mineral substrate or distance from the upland/edge transition. / Graduate / 0996 / 0388 / 0425 / cbkusel@yahoo.ca

Passive treatment systems for mine water pollution remediation require no chemical or energy inputs, and should only incur limited maintenance costs if properly constructed. This thesis investigates two such passive treatment systems that have been installed at sites in County Durham, UK. The overall objectives of the investigation were to improve understanding of the operation of passive systems in order to produce more accurate design guidelines, and to develop a new passive treatment option to complement existing technologies. To put the research into context the causes, impacts and extent of mine water pollution in the UK and overseas are outlined. In addition a detailed and up-to-date review of passive treatment research and development is provided, which highlights areas in which further research is required. At Quaking Houses, County Durham, a full-scale compost wetland has been constructed to treat an acidic and metal-rich discharge from the spoil heap of an abandoned coal mine. Over the 27 month study period the discharge had pH >_ 4, and mean iron, manganese and aluminium concentrations of 5.4 mg/L, 3.6 mg/L and 6.2 mg/L respectively. The unique design and construction of the 440 m2 wetland is described. An examination of the performance of the wetland illustrates that it has yielded significant improvements in water quality since its construction. Mean reductions in acidity, iron and aluminium concentrations are all around 50%. Bacterial sulphate reduction may be an important contaminant removal mechanism, but its proportional significance is unclear. Comparison of the system at Quaking Houses with other wetlands reveals that the mean reduction in acidity in terms of mass removal per unit area (5.01 g/m2/d) is comparatively low. However, it is shown that comparing wetland performance on this basis may be misleading where influent contaminant concentrations are relatively low, because contaminant removal is demonstrably influent concentrationdependent. A first-order removal assessment method of performance may be more appropriate, and on this basis the Quaking Houses wetland performs well when compared to systems in the USA. An algorithm for predicting wetland effluent iron concentrations is derived using a linear multiple regression technique. Time series analysis strongly suggests that some effluent water quality variables (and therefore wetland performance measures) are significantly affected by seasonal climate changes. In particular aluminium and acidity removal rates rise with increasing air temperature. This implies that to meet the same effluent water quality targets passive treatment systems in cold climate locations may need to be larger than equivalent systems in warmer climates. At Kimblesworth, also in County Durham, a pilot-scale passive treatment system has been operated for 4 months. The Kimblesworth discharge is a net-alkaline pumped mine water containing up to 2 mg/L iron and up to 1 mg/L manganese. The novel system at this site was designed to rapidly remove iron by oxidation and accretion of iron to high surface area media. The monitoring programme has revealed the system to be very efficient. Iron concentrations are consistently reduced to < 0.5 mg/L, and removal rates are an order of magnitude greater than in wetland systems. Furthermore, lithium tracer tests reveal that the residence time of water in the reactors is just 5- 10 minutes. The results of this research suggest that the technology could be applied at full-scale. The compost wetland at Quaking Houses and the new reactor at Kimblesworth may well complement each other. The Quaking Houses system generates alkalinity and removes metal contaminants, but effluent water still contains marginally elevated concentrations of iron (mean 2.4 mg/L). The Kimblesworth system is shown to be very effective at rapidly removing low concentrations of iron, and thus could conceivably be used as a polishing unit following a compost wetland such as that at Quaking Houses. Alternatively high surface area media reactors such as those at Kimblesworth could be used to treat discharges in topographically difficult locations, where the installation of a wetland is not feasible.

Vacuum harvested peatlands do not easily regain their hydrological function after peat production therefore restoration is required to create hydrological conditions appropriate for the growth of peat producing fen plant species. Peat extraction at Bic-Saint-Fabien peatland by the block-cut method began in 1946, converted to vacuum harvesting in the early 1970’s and ceased in 2000. After exploitation, about 0.04-1 m of residual minerotrophic sedge peat remained; therefore Bic-Saint-Fabien was restored as a fen. Research occurred in 2008-2011 and restoration began fall 2009 so we have two pre-restoration and two post-restoration study years. Rewetting consisted of blocking active drainage ditches, contouring the peat surface into level terraces to even out elevation differences, and building peat ridges (bunds) to retain runoff. Vegetation was introduced to some recontoured parts of the site by the surface layer transfer method. A straw mulch treatment was applied to minimize evapotranspiration. A water budget was created for the harvested cutover area and an adjacent undisturbed section of Bic-Saint- Fabien for all study years. Data collection for the water budget occurred June 2-August 7 (day of year 153-219). Water table, volumetric soil moisture content and soil-water pressure were also examined to better understand the impact of reconfiguration on the hydrology of the system. A 1-1.5 m thick layer of gyttja (a low permeability, high porosity lake-bed sediment) underlies the residual peat; it was parameterized and assessed to see if it could potentially compress and supply water to the overlying peat when the system is stressed. In 2011, the volumetric moisture content and thickness of gyttja were monitored in the field to estimate the strain placed on the gyttja by seasonal water table variability. Gyttja samples were collected and brought back to the laboratory for parameterization and compressibility tests. A water budget was completed annually for the cutover and undisturbed areas of the peatland. There were no distinguishable differences between study years except that 2008 and 2009 were climatologically wetter. During the water budget period surface and groundwater run-on into the cutover area were negligible making precipitation the principle water input. The dominant water loss from the cutover area was evapotranspiration since runoff was only 2 and 9 mm in 2010 and 2011, respectively. Rewetting did not result in a uniform wetness across the cutover site chiefly due to local differences in peat surface elevation. An interior section of Bic- Saint-Fabien remained saturated for nearly all of 2011; it had mean seasonal water table of +2.8 cm, and volumetric soil moisture content and soil-water pressure, 5 cm below the peat surface were 86% and +4 mbar. At a peripheral section (~100 m away) the values were -14.4 cm, 67% and -13 mbar, respectively. While the interior was generally wetter than the peripheral regions, there were some exceptions, notably near where dams were installed on peripheral drainage ditches. The markedly different spatial patterns of wetness suggests that a uniform prescription regarding vegetation re-establishment in the rewetted section may not be warranted. The bulk density, particle density and porosity of gyttja averaged 0.12 g cm-3 1.57g cm-3 and 92%, in the top 40 cm of the layer. The organic matter content of gyttja decreased with depth from about 70% at a 5 cm depth to 45% at a 45 cm depth. Laboratory compression tests showed 9 and 72% strain at effective stresses of 3.5 and 200 kPa, respectively, demonstrating the potential for releasing water upon compression, which in the field is caused by water table lowering. From day of year 192 to 202 in 2011, when a ~8 cm water level change occurred (effective stress range ~0.8 kPa), the volumetric moisture content and thickness of the top 30 cm of gyttja decreased by 0.4%, and 0.5 cm, respectively, representing 0.1 and 1.7% strain, respectively, as determined from these two different approaches. The compression of gyttja after Bic-Saint-Fabien was rewetted (2011) was small but might have been significant under drier conditions with greater water table variability, such as during the early stages of site drainage when it was being prepared for peat extraction or after peat production ceased. The release of water to the peat layer from the compression of gyttja after peat production finished and before rewetting occurred, might have been an important self-preservation mechanism, eventually making it easier to rewet. Water table drawdown in 2011 produced very small strain rates suggesting gyttja compression in this year had no important role; hence rewetting success was more reliant on other rewetting techniques implemented at this site.

I reviewed 32 urban amphibian studies from North America and found most amphibians respond negatively to urbanization (69 negative responses, 6 positive and 35 no effect). Additionally, I conducted amphibian surveys (adult, egg, larvae, and metamorphs) at 75 wetlands located throughout the City of Edmonton, Alberta, Canada, with a focus on the wood frog (Lithobates sylvaticus). Wetlands consisted of natural river valley and upland sites, and constructed stormwater wetlands. Breeding male wood frogs occured at 50% of stormwater wetlands versus 93% of natural wetlands. The presence of breeding males was best predicted by the proportion of native vegetation within 100 m of a wetland. Wood frogs successfullly reproduced on stormwater wetlands but relative abundances of eggs, tadpoles and metamorphs were lower than at natural sites. However, stormwater metamorphs were significantly larger which may contribute to higher survivorship and subsequent reproductive success. Stormwater wetlands are required to control flooding and run-off, therefore, future amphibian conservation efforts should focus on preserving native terrestrial habitat surrounding urban wetlands. / Ecology

Reverse auctions for ecological goods and services are an alternative to current agri-environmental government programs to provide incentives for farmers. This thesis reports on a testbed of laboratory auction experiments to assess efficiency and cost effectiveness of different design treatments. These were developed using estimated costs of wetland restoration in southern Manitoba. The testbed included a comparison of payment type (discriminatory versus uniform payments), and ranking rule for both budget based and target based auctions over repeated auction rounds and reserve prices for the target based auctions. It was found that 1) uniform payments outperformed discriminatory payments under a budget constraint, 2) discriminatory payments were superior to uniform payments under a target constraint, 3) where there is no budget constraint a reserve price can greatly increase efficiency and cost effectiveness. These findings highlight the complexity of auction design and may be used as an aid to guide policy decisions and agri-environmental program design. / Agricultural and Resource Economics

Most of the lower River Murray and its floodplain wetlands are impacted upon by degradation caused by river regulation. Increasingly the restoration of these ecosystems and the river water quality has become a high priority for federal and state governments and associated departments and agencies. Public concern is adding to the pressures on these departments and agencies to restore these ecosystems and to sustainably maintain the river water quality. The long term monitoring of floodplain wetlands has been limited, compounding the difficulties faced by managers and decision makers on assessing the potential outcome of restoration options. The role of this project in the broad scheme of restoration/rehabilitation is to contribute to the construction of a model capable of increasing managers and decision makers understanding, and build consensus of potential outcomes of management option. This model was to use available data. The developed model, based on WETMOD developed by Cetin (2001), simulates wetland internal nutrient processes, phytoplankton, zooplankton and macrophyte biomass as well as the interaction (nutrient and phytoplankton exchange) between wetlands and the river. The model further simulates the potential impact management options have on the wetlands, and their nutrient retention capacity, and therefore their impact on the river nutrient load. Due to the limitation of data, wetlands were considered in categories for which data was available. Of these two had sufficient data to develop, calibrate and validate the model. Management scenarios for these two wetlands were developed. These scenarios included, the impact of returning a degraded wetland in a turbid state to a rehabilitated clear state, and the impact the removal of nutrient from irrigation drainage inflows has on wetland nutrient retention, and consequent input to the river. Scenarios of the cumulative impact of the management of multiple wetlands were developed based on using these two wetlands, for which adequate data was available, as “exemplar” wetlands, i.e. data from these wetlands were substituted for other similar wetlands (those identified as belonging to the same category). The model scenarios of these multiple wetlands provide some insight into the potential response management may have on individual wetlands, the cumulative impact on river nutrient load and how wetland morphology may relate to management considerations. The model is restricted by data availability and consequently the outputs. Further, some limitations identified during the development of the model need to be addressed before it can be applied for management purposes. However, the model and methods provide a guide by which monitoring efforts can assist in developing future modelling assessments and gain a greater insight not only at the monitoring site but also on a landscape scale. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1320131 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

Secondary salinisation has affected large areas of inland southwestern Australia, and in particular, low lying aquatic areas; causing the loss of freshwater submerged macrophyte communities and their replacement by salt-tolerant species. At high salinities, the salt-tolerant macrophyte-dominated ecological regime may be replaced by a regime dominated by benthic microbial communities, further reducing the structural and functional diversity of salinised wetland ecosystems. There is little prospect of restoring salinised systems to a freshwater state, meaning that saline macrophyte dominated wetlands have a heightened structural and functional importance in this landscape. Prior to this study, little was known about the drivers for change from one ecological regime to another in salinising wetlands or about rates of ecosystem response to these drivers. This study used experimental and observational data from seven saline wetlands in order to identify some of the potential mechanisms for the transition between the salt tolerant submerged macrophyte-dominated regime and the benthic microbial community-dominated regime. The applicability of existing conceptual models for ecological regime shifts was then tested against these data. Some of the mechanisms responsible for the formation and maintenance of the macrophyte-dominated regime were explored by examining the effects of salinity on germination and flowering in a series of salt-tolerant submerged macrophytes. The initiation and dominance of benthic microbial communities over a range of salinity and wetting regimes was also examined. The results suggested that macrophyte communities are unlikely to develop in seasonally-drying wetlands at high salinities (>45 ppt), but will usually germinate and establish well at lower salinities. It was also predicted that although benthic microbial communities can survive and grow across a wide range of salinities, they are likely to be outcompeted at low salinities by macrophytes or by phytoplankton blooms if water column nutrient levels are high. However, water permanence may facilitate benthic microbial community dominance. Existing conceptual models of ecological regime transitions, such as the alternative regimes model, did not account for the effect of water regime on the dynamics of seasonally-drying systems. Therefore, a new conceptual model incorporating the interaction between hydrology and salinity in seasonally-drying wetlands was proposed.