Environmental science

Three long-term mark and recapture/resight data sets of individually marked

Semipalmated Plovers (Charadrius semipalmatus) were analyzed using Cormack-Jolly-

Seber models. Data came from two breeding populations (Churchill, Manitoba, Canada,

n=982, and Egg Island, Alaska, USA, n=84) and one overwintering population

(Cumberland Island, Georgia, USA, n=62). For Alaska and Georgia, time-invariant

models were best-supported, giving annual survival estimates of 0.67 (95%C.I.: 0.58-

0.76) and 0.59 (95%C.I.: 0.49-0.67) respectively. Data from Manitoba supported a timedependent

model: survival estimates varied from 1.00 to 0.36, with lowest estimates from

recent years, supporting observations of local population decline. Seasonal survival

analysis of the Georgia population indicated lower mortality during winter (monthly

Φoverwinter: 0.959, 95%CI: 0.871-0.988; for 6 month period Φoverwinter: 0.780 (0.440-0.929))

than during combined breeding and migratory periods (monthly ΦBreeding+Migration: 0.879

(0.825-0.918); for 8 month ΦBreeding+Migration: 0356 (0.215-0.504)). I recommend, based on

high resight rates, continued monitoring of survival of wintering populations, to

determine potential range-wide population declines.

Keywords: survival, longevity, mortality, shorebird, overwinter, breeding, migration, life

cycle

Author Keywords: life cycle, longevity, mortality, non-breeding, shorebird, survival

A series of experiments was designed to assess the relative efficacy of various dust suppressants to suppress PM10 emissions from nepheline syenite tailings. The experiments were conducted in the Trent University Environmental Wind Tunnel, Peterborough, Ontario, and on the tailings ponds at the Unimin Ltd Nephton mine near Havelock, Ontario. Treated surfaces were subjected to particle-free airflow, abrasion with blown sand particles, particle-free airflow after physical disturbance, and were measured independently using a pin penetrometer. In the particle-free wind tunnel tests, three of the surfaces performed well, and PM10 emissions scaled inversely with crust strength. Light bombardment of each surface by saltating sand grains resulted in PM10 emission rates two orders of magnitude higher. All treated surfaces emitted significantly more PM10 after physical disturbance in both the laboratory and field research. The results suggest that the site conditions, inclusive of the potential for dust advection and resuspension, must be taken into account when considering the use of a commercial dust suppressant.

Author Keywords: dust suppression, field testing, mine tailings, wind tunnel experiment

The network composition hypothesis (NCH) suggests that i) large confluence symmetry ratios (drainage area of the tributary relative to the mainstem) and ii) landscape differences (differences in landscape characteristics between the mainstem and tributary drainages) lead to greater ecological changes below confluences. As a test of the NCH, 34 confluences were sampled in southern Ontario to examine the effects of these two factors on benthic invertebrate communities to infer the degree of ecological change at confluences. Given the typology of streams surveyed, there was subtle evidence that benthic invertebrate communities below confluences changed as a function of confluence symmetry ratio and landscape differences. This indicates that abrupt changes in stream networks are not as common as theory may suggest. Further support for the network composition hypothesis may be found by examining a wider range of stream types and examining single-species responses.

Author Keywords: benthic invertebrates, community similarity, landscape characteristics, stream networks, tributary

In this thesis, water mass distribution of dissolved organic matter (DOM) characteristics (i.e. molecular weight, fluorescent components, thiols and humic substances concentration) was observed in the Arctic Ocean. For the first time, DOM molecular weight (MW) in Beaufort Sea was assessed using asymmetrical flow field-flow fractionation, as well as the first monitoring of thiols and humic substances (HS) using cathodic stripping voltammetry (CSV) in the Arctic Ocean. Based on fluorescence property, DOM characterization was carried out using parallel factor analysis – excitation-emission matrices. Pacific winter waters in the Canada Basin showed higher MW DOM associated with higher fluorescence intensity. High HS was associated with the Arctic outflow waters in top 300 m of the Canadian Arctic Archipelago. Interestingly, maximum thiol concentration was associated with the subsurface chlorophyll-a maximum at most sites, but not universal along the study area. Comparable distributions of CSV-based HS and humic-like fluorescent components suggest similar sources/ processes in the Arctic Ocean. The findings in this thesis suggested DOM characteristics could be used as fingerprints in tracing water masses in the Arctic Ocean.

Author Keywords: Asymmetrical flow field-flow fractionation, Cathodic stripping voltammetry, DOM, Metal-binding ligands, Molecular weight, PARAFAC-EEMs

A set of experiments was designed to investigate the factors—atmospheric and surficial—controlling fugitive dust emissions from the tailings ponds of UNIMIN Canada, a mining company that extracts and produces nepheline syenite (feldspar) at two adjacent sites (Nephton and Blue Mountain) located north of Havelock, Ontario. Using wind tunnel measurements, the combined influence of relative humidity and temperature (represented by the absolute matric potential,

Timber harvest can influence the rate of transfer of organic matter from the terrestrial catchment to streams, which may have both direct and indirect effects on in-stream nutrient pools and dynamics. In the interest of developing sustainable forestry practices, the continued study of the effects of forestry on nutrient dynamics in aquatic systems is paramount, particularly in sensitive nutrient-poor oligotrophic systems. The goal of this study was to investigate the impacts of harvest-related woody debris on stream nutrient status in streams located in the Canadian Shield region of south-central Ontario. Surveys showed greater large (> 10 cm) and small (< 10 cm) woody debris dry masses and associated nutrient pools in streams located in recently (2013) selectively harvested catchments, when compared with catchments not harvested for at least 20 years. Experimental releases of flagging tape underlined the importance of woody debris as a mechanism of coarse particulate organic matter (CPOM) retention. Sediment surveys showed a significant exponential decline in both OM content and nutrients associated with coarse sediment with distance upstream from debris dams. Laboratory leaching experiments suggest that fresh woody debris may be an important short-term source of water-soluble nutrients, particularly phosphorus and potassium. This study suggests that woody debris from timber harvest is both a direct and indirect source of nutrients, as trapped wood and leaves that accumulate behind debris dams can augment stream nutrient export over long time periods.

Author Keywords: nutrient leaching, nutrient pools, organic matter retention, selection harvest, southern Ontario, woody debris

Decreasing lake calcium (Ca) concentration, in lakes located in base poor

catchments of the Muskoka River Watershed (MRW) in south-central Ontario, is a well- established acid-rain driven legacy effect threatening the health and integrity of aquatic ecosystems that can be compounded by additional Ca removals through forest harvesting. The objectives of this thesis were to assess patterns and temporal trends in key water chemistry parameters for a set of lakes in forested catchments in the MRW in south- central Ontario, to predict the pre-industrial steady state lake Ca concentration and the potential impact of harvesting on lake Ca levels in lakes located in managed MRW Crown forests, and to assess potential effects of various mitigation strategies in Ca depleted managed forests. Mean lake Ca (mg L-1) in 104 lakes across the MRW have decreased by 30% since the 1980's with the rate of decrease slowing over time. Mean Lake SO4 (mg L-1), and Mg (mg L-1) concentration also decreased significantly with time (37% and 29%, respectively) again with a declining rate of decrease, while mean lake pH and DOC increased significantly between the 1980's and the 1990's (16% and 12%, respectively) but exhibited no significant pattern after that. Principal components and GIS spatial analyses of 75 lakes with data from 2011 or 2012 water seasons suggested that smaller lakes, at higher elevation in smaller catchments with higher runoff and minimally impacted by the influence of roads and agriculture are associated with lower Ca concentrations and thus are the lakes at risk of amplified Ca depletion from forest harvesting. Spatial analyses of harvested catchments indicated that, under the proposed 10 year land forest management cut volumes, 38% of 364 lakes in the MRW will fall below the critical 1 mg L-1 Ca threshold compared with 8% in the absence of future harvesting. With respect to potential mitigation measures, soil pH and foliar Ca were indicated by meta-analysis to be more responsive to lime addition studies while soil base saturation and tree growth appeared more responsive to wood-ash addition. Future research should address the spatial extent of lakes at risk and identify when critical levels will be reached under harvesting regimes. Further investigation into the use of Ca-addition as a tool for managing the cumulative effects of past, present and future stressors is recommended.

Author Keywords: calcium, harvesting, lakes, lime, Muskoka River Watershed, wood-ash

This study focused on detecting 22 target anti-estrogenic and anti-androgenic compounds in surface waters influenced by both discharges of municipal wastewater and agricultural runoff in Canada and Argentina. Polar organic chemical integrative samplers (POCIS) were used to monitor the target compounds in surface waters. The removals of the target compounds in a municipal wastewater treatment plant (WWTP) in Canada were also evaluated. In both Canada and Argentina pesticides with potential anti-estrogenic and anti-androgenic activities were detected in the surface waters. The highest concentrations were found in Argentina (up to 1010 ng L-1) in areas impacted by heavy agricultural practices. Cyproterone acetate and bicalutamide were the only two anti-cancer drugs detected only at the Canadian study site, the Speed River, ON. In the Guelph WWTP, that discharges into the Speed River, these target compounds were not all efficiently removed (>70%) during treatment. Overall, this study provides insight to possible anti-estrogenic and anti-androgenic compounds that may be contributing to endocrine disrupting activities in surface waters.

Author Keywords: Anti-androgens, Anti-estrogens, Cancer Therapy Drugs, Current use pesticides, Pharmaceuticals and Personal Care Products, Polar Organic Chemical Integrative Samplers

The increasing production and use of silver nanoparticles (AgNPs) raise concerns on environmental exposure and impact. A large scale in situ enclosure study was conducted at the Experimental Lakes Area to determine the effect of AgNPs on natural phytoplankton and zooplankton communities. This study investigated AgNPs of varying concentrations (4, 16 and 64 μg/L), dosing regimens (chronic vs. pulse), and capping agents (poly-vinyl pyrrolidone vs. citrate). Phytoplankton communities were influenced only by the natural limnological properties of the system signifying tolerance to AgNPs. Zooplankton community structure significantly changed with AgNP concentration and dosing regimen indicating AgNP sensitivity. A microcosm study investigating the effect of AgNPs and phosphorus-dosed periphyton before and after grazing by two benthic invertebrate species (snails and caddisfly larvae) showed reduced periphyton stoichiometry with AgNP exposure. Grazers foraged less on silver dosed periphyton indicating a preferential choice in food quality. Phosphorus reduced the detrimental effects of AgNPs across all conditions. These studies verify the need for in situ experimental designs to fully investigate the effects of AgNPs and their interaction with environmental factors, multiple species assemblages, and across trophic levels.

Author Keywords: benthic invertebrate, Experimental Lakes Area, periphyton, phytoplankton, silver nanoparticles, zooplankton

There are three cattail (Typha) taxa in Canada: T. latifolia (native), T. angustifolia (introduced), and their hybrid T. x glauca. The latter is invasive in regions around the Laurentian Great Lakes, and I investigated the potential role that commercial suppliers may be playing in the introduction of non-native Typha by comparing genotypes of North American, European, and commercially available plants. I found that Ontario garden centres are importing both hybrids and non-native lineages of T. angustifolia into Canada, but was unable to identify the provenance of T. latifolia. I also investigated the possibility that the hybrid cattail leaf litter shade and leachate influences germination and early growth of the parental species of the hybrids. Using three common garden experiments, I found that T. x glauca leaf litter suppresses germination rates of the three taxa. In the early seedling growth experiment, plant performance varied by taxa, and for the competition experiment there were no intra- or interspecific competition or treatment effects on the performance of plants. Overall, my research identified a potential mechanism allowing T. x glauca to dominate wetlands, and also shows that non-native lineages are being introduced into Canada through commercial trade

Author Keywords: Competition, Germination, Non-native lineages, Plant nurseries, Seedling Growth, Typha spp.