The major aim of this thesis project was to determine the variables that most explain the elevated mercury concentrations in lake trout (<i>Salvelinus namaycush</i>), a predatory aquatic fish species in some lakes in northwestern Canada. High mercury concentrations in lake trout in other regions have been associated with the biological features of the fish and various chemical and physical aspects of their aquatic ecosystems. Data including lake trout age, length, weight, and stable isotope values, water chemistry, latitude, and lake and watershed area were collected, compiled and then included in statistical analyses of the factors affecting mercury concentration in the muscle of lake trout from a series of lakes from the Mackenzie River Basin (MRB) in the Northwest Territories (NT), Canada. These results are reported in Chapter 2. Fish age and lake surface area were the most important variables affecting mercury concentrations. However mercury concentration in muscle also was significantly (p < 0.05) related to: fish length, weight, and δ13C; watershed area to lake area ratio; and to total mercury concentration in zooplankton and water. These variables were run through best subsets analyses and multiple regressions in order to determine the regression equation most efficiently capable of predicting mercury concentration in lake trout in unstudied lakes in the MRB region. The resulting equation was: log Hg = 0.698 (0.0156 × latitude) + (0.0031 × age) + (0.000535 × length) (0.245 × log lake area) + (0.00675 × watershed area/lake area ratio), r2 = 0.73<p>Small lakes located in the southern NT and dominated by large and/or old lake trout are most likely to have lake trout whose mean mercury concentrations exceed 0.5 μg/g; the guideline for the commercial sale of fish. Latitude may be linked to mean annual temperature (and variables such as duration of ice cover, summer water temperature) while fish age and length may be related in part to fishing pressures and growth rates on these lake populations. In chapter 3, a more in-depth study was undertaken to investigate of role of feeding and relative tropic level in the bioaccumulation of mercury in lake trout. This was accomplished by comparing MRB lake trout population characteristics with those from a series of lakes in northern Alberta and Saskatchewan (NAS). The two population groups were compared with respect to size, age, growth rates, and mercury concentrations. In addition, trophic and mercury biomagnification relationships, as inferred from stable carbon and nitrogen isotope analyses, for the two lake trout populations were compared. Lake trout from the NT exhibited significantly higher mercury concentrations than those from the NAS lakes (p < 0.001). Mercury concentrations in biota (including lake trout, forage fish, benthic invertebrates and zooplankton) were positively and significantly correlated to δ15N values in all lakes in both of the study areas (p < 0.001). Mercury biomagnification in the NT lakes, as estimated from the slope of δ15N versus mercury concentration, was lower than in the NAS lakes. Thus, mercury biomagnifies more slowly in NT lake trout, but because of their greater mean age, reaches higher values than in NAS lakes. Northwest Territory lake trout generally exhibited more negative δ13C values, indicating more pelagic feeding habits than in NAS lakes: higher mercury concentrations previously have been associated with more pelagic feeding. <p>Finally, the relationship between mercury levels and growth rates in lake trout was investigated by comparing NAS and NT lake trout populations. These results are reported in chapter 4. Lake trout from the NT lakes grew at a slower rate (10.4 mm per year) than those from the NAS lakes (35.1 mm per year). Log mercury concentration was inversely correlated (p < 0.001) with growth rate for both lake trout populations; however, growth rate explained more of the variation in mercury level in the NT lakes than in the NAS lakes (NT, r2 = 0.11, p < 0.001; NAS, r2 = 0.03, p = 0.024). However, the correlation between mercury concentration and growth rate in the NAS study area improved when Reindeer Lake, possibly affected by anthropogenic inputs, was removed from the analyses (r = 0.13, p = 0.001). Therefore, lower mercury levels in lake trout are associated with higher growth rates through growth dilution. The higher mercury concentrations in NT lake trout are due not only to the old age of the fish, but to slower growth rates as well.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 221-231). Also available in electronic version. Access restricted to campus users.

Thesis (M. Phil.)--University of Hong Kong, 1975. / Parallel title in Chinese.

- / -

Latent and sensible heat fluxes at the surface of Baffin Bay are calculated throughout the year using, in addition to the essential meteorological data and surface temperatures, values of the ice cover corresponding to three different periods of years, ranging from 1919 to 1965. [...]

This thesis explores the process of remediation and renewal in the context of decommissioned gold mining operations in Yellowknife, Northwest Territories, Canada. The work aims to demonstrate that architecture can facilitate understanding and bring awareness to the processes involved in reclaiming industrial sites by creating places for observation, interaction and refl ection. Existing mine infrastructure will be adapted and augmented to support phytoremediation processes, clean energy generation and municipal waste treatment for adjacent Yellowknife residents. These interventions are based on a series of studies involving mineral extraction processes, historic mine development and geological formations. The architectural interventions are phased and are intended to be prototypical strategies for decommissioned mine sites in general, but are specifi cally relevant to those located in sub-arctic climates.

Chronic non-communicable diseases related to excessive or unbalanced dietary intakes are on the rise among some Indigenous populations in Canada. Nutritional problems of Indigenous peoples arise in the transition from a traditional diet to a market diet characterised by highly processed foods with reduced nutrient density. This study used food frequency and 24-hour recall questionnaires to quantify traditional food intake in 18 communities in Denendeh (Western Northwest Territories) and the Yukon. These data allowed comparisons between the two regions (Yukon and Denendeh) and the two seasons of data collection (summer and winter, perceived to be the seasons of highest and lowest traditional food intake, respectively). Food choice in general is affected by a multitude of factors determined by individual, societal and environmental influences. In this study, individual, household, and community correlates of traditional food intake were assessed in order to construct a multivariate statistical model to describe the correlates of the quantity and diversity of traditional food intake in the Western Canadian Arctic. The variables used in this study reflected household demography, market food affordability, access to traditional food, individual characteristics such as age and gender, and perceptions about traditional food. The analysis of the associations between the traditional food correlates and traditional food intake in terms of quantity and diversity allowed for the description of the profile of men and women who are high consumers of traditional food in both regions. This study described and used a tool to measure traditional food diversity, which may be an appropriate indicator of the process of dietary change experienced by Indigenous Peoples in Denendeh and the Yukon.

Dene women are leading and directing efforts toward "healing" themselves, their families, and their communities. Employing a modality of montage and storytelling, this thesis explores this enigmatic concept of "healing" among Dene, and its gendered dimensions, in the community of Fort Good Hope, Northwest Territories. This account challenges the limitations of a resistance-hegemony paradigm often used to describe Aboriginal actions as embedded within colonial relations, and endeavours toward a more nuanced analysis which explores Dene "healing" beyond the colonial space. "Healing" is emerging as a vehicle for the assertion and celebration of Dene identity, Dene tradition and "Dene ways". This thesis further explores how many Dene women in Fort Good Hope are mobilizing the power of tradition, such as -aet'sechi/ (practices associated with "becoming woman"), as a means of "healing" social/health concerns, and influencing gender and power relations in the community.

During the Paleoproterozoic Era (ca. 2.5 Ga to 1.6 Ga), Earth underwent dramatic changes to its tectonic and atmospheric parameters. These changes included: the formation and breakup of the supercontinent Nuna (Columbia) and the gradual rise in atmospheric oxygen levels. The gradual rise in atmospheric oxygen, referred to as the Great Oxidation Event (GOE), altered the behaviour of silicate mineral weathering, and permitted the formation of new types of economic uranium deposits. Beaverlodge Lake, Northwest Territories (NT), allows for the study of a weathering profile and uranium mineralization post GOE. At Beaverlodge Lake, NT, a regolith is preserved in a rhyodacitic porphyry of the ca. 1.93 Ga Hottah plutonic complex, which is unconformably overlain by the ca. 1.9 Ga quartz arenite of the Conjuror Bay Formation. Coincident with the unconformity is a past-producing uranium deposit (called the Tatie U deposit), which was mined out in the 1930s. Other uranium showings have been discovered at Beaverlodge Lake including the Bee showing. The initial purpose of this project was to examine the regolith through field, petrography, electron microprobe analysis (EMPA), whole-rock geochemistry, and mass balance calculations. The weathering profile shows an increase in Al2O3, Fe2O3T, K2O, P2O5, Ba, and Rb, a loss in SiO2, Na2O, MgO, and Sr, and constant and low abundance of CaO. Titanium remains constant in the weathering profile. Rare earth element (REE) analysis reveals remobilization of light REE (LREE) on a micrometer scale, but no cerium anomaly is preserved in the weathering profile. The weathering profile displays characteristics similar to other post GOE paleoweathering profiles developed on felsic parental material. The timing of uranium mineralization at Tatie and Bee was constrained by in-situ U-Pb uraninite dating by Secondary Ion Mass Spectrometer (SIMS), which yielded two variably discordant ages of 1370.2 ± 7.9 Ma and 407 ± 21 Ma. In addition, REE contents of uraninite were determined by in-situ Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Results revealed two types of uraninite mineralization are preserved at Beaverlodge Lake and they consist of synmetamorphic at Bee and basement-hosted unconformity-type at Tatie similar to those in the Athabasca Basin. The ca. 1370 Ma uraninite (Tatie) is characterized by an asymmetric bell-shaped REE pattern centered on Tb to Er where LREEs are depleted compared to heavy REEs (HREE). The ca. 407 Ma uraninite at Bee has low La concentrations and a flat to slightly negative REE pattern. The Mesoproterozoic age is similar to a Pb loss age of ca. 1400 Ma found in the Athabasca Basin. The younger Devonian age may be related to meteoric fluids cycling and uranium remobilization during the Phanerozoic.

Despite the repeated collapse of mining towns and sites in the Great Slave Lake region, most residents embrace new resource projects as possibilities for creating viable futures. Situated at the intersection of socio-cultural and linguistic anthropology, this ethnographic investigation of the Canadian diamond boom of the 2000s illustrates how imagining stable livelihoods despite a record of impermanence and crises depends on integrating and reframing past failures with present aspirations for “the good life”. At the height of the diamond boom in 2007, future imaginaries were largely associated with high wage job creation in the rapidly expanding industrial sector. Based on 18 months of fieldwork among those said to benefit most from new industrial development: the Aboriginal under/unemployed, this dissertation’s ethnographic attention is on job training programs and employment interventions that promised local residents new futures. The fieldwork coincided with the global financial crisis and almost none of the 90 students followed through the research secured work in the industry at the conclusion of their training. Nevertheless, people continue to maintain faith in a future linked to resource development. Capturing people’s everyday re-makings of tomorrow in uncertain times, this dissertation reveals that while employment in global extractive industries is unable to provide economic security to those who seek it, its promises are productive for four reasons. First, they (re)define the natural world as ‘opportunities for work’. Second, the specific techniques of industry and statecraft that surround mining (impact and benefit agreements, and socio-economic monitoring) transform everyday events of difference and inequality into catastrophes which render industrial development sensible even urgent. Third, they orient public sentiment towards a “future anterior,” a form of temporal longing that I argue impedes a deep reading of the historical present and participates in a politics of deferral. Fourth, they rely on and reproduce a chronotopically constrained public debate on natural resource development.