The purpose of this thesis is to document and analyse the development of the 1985 Clyde River - Broughton Island Memorandum of Understanding on Polar Bears. Based on a population estimate of 400 to 600 polar bears on Northeast Baffin Island, the quotas for Clyde River were reduced from 45 to 15, and the quotas for Broughton Island were reduced from 22 to 10. The case study approach to the analysis is organised according to various scales of analysis (from the individual to the global level) for the political, ecological, and cultural variables in the analysis. Three chapters are dedicated to a presentation of the three variables of analysis identified in the case study. The ecological variable is concerned with evaluating the biological data that were used to calculate a reduction in quotas. The political variable evaluates the structure and proceedings of the negotiation meetings, and the cultural variable evaluates the role that cultural meaning may have played in the creation of the agreement. The major finding is that a comanagement approach to wildlife management does not guarantee that decision-making power is equally distributed amongst user groups and territorial agencies.

Les interactions entre les océans, l'atmosphère et les calottes glaciaires constituent la clé de voûte de la compréhension du système climatique global. Deux méthodes croisées sont possibles afin de dénouer les fils de cette trame complexe : la modélisation des processus et l'étude des fluctuations passées. Dans cette thèse, nous nous sommes intéressés à la seconde alternative et, plus précisément, aux interactions entre les marges glaciaires et les changements climatiques et océanographiques du dernier cycle glaciaire. La reconstitution et la compréhension de la dynamique des marges glaciaires exigent une connaissance précise de leur instabilité dans le temps afin d'appréhender les processus intrinsèques. Cependant, l'érosion des traces géologiques directes des fluctuations des marges glaciaires contraint à l'étude d'empreintes indirectes, les sédiments marins, comme unique source d'information. La localisation de la séquence sédimentaire étudiée ici (HU2008-029-016PC) est idéale puisque le régime sédimentaire du site a été influencé par la dynamique des calottes glaciaires régionales (i.e., laurentidienne, innuitienne et groenlandaise) durant les dernières glaciations. Cependant, l'analyse de cette archive sédimentaire présente des difficultés de datation. En effet, les méthodes traditionnelles chronostratigraphiques, telles que la stratigraphie isotopique (δ18O sur les tests de foraminifères) ou la datation par le radiocarbone (14C), ne permettent pas l'établissement de modèles d'âges concluants dans cette région. L'approche paléomagnétique utilisée dans cette thèse a dès lors été guidée par cette problématique chronostratigraphique, avant de permettre une lecture environnementale de la variabilité des lithofaciès sédimentaires et de leurs origines. Dans le premier chapitre de cette thèse, nous proposons une chronostratigraphie originale sur base de mesures paléomagnétiques, plus précisément à partir de l'enregistrement de la paléointensité relative du champ magnétique terrestre par les sédiments. Toutefois, l'identification d'une modulation lithologique (e.g., taille des grains, concentration) des propriétés magnétiques nous a obligé à filtrer les données pour éliminer la composante "environnementale" du signal magnétique. Pour ce faire, nous avons conduit des analyses détaillées afin de caractériser les minéraux magnétiques présents. Les résultats nous ont permis de définir que l'aimantation rémanente naturelle était portée majoritairement par des grains de magnétite dans une gamme de taille adéquate pour un enregistrement optimal du champ magnétique terrestre existant au moment de leurs dépôts. Aussi, ces analyses ont permis l'identification de certaines couches non représentatives, ayant surtout enregistré une lithologie particulière; elles ont dès lors été écartées de l'enregistrement paléomagnétique proprement dit. Nous avons reconstruit le signal de paléointensité relative en normalisant l'aimantation rémanente naturelle par l'aimantation rémanente anhystérétique induite, afin de réduire significativement l'empreinte magnétique environnementale secondaire. Le signal obtenu se compare avec succès aux enregistrements et compilations existants ce qui a permis de dériver un modèle d'âge fiable couvrant le dernier cycle glaciaire (depuis 115 ka BP). La reconstruction des directions du champ magnétique terrestre a permis notamment l'identification de 2 excursions géomagnétiques (i.e., de Laschamp et de la mer de Norvège-Groenland) déjà bien connues et datées, renforçant ainsi la confiance dans le modèle d'âge proposé. Dans le second chapitre, nous avons mis à profit le nouveau cadre chronostratigraphique afin d'interpréter l'origine des dépôts carbonatés. Sur base d'analyses minéralogiques des carbonates associées à des données granulométriques, de microfluorescence X et aux propriétés magnétiques des grains, nous avons identifié 14 couches carbonatées grossières. La composition minéralogique a permis de lier l'origine de ces dépôts aux glaciers du nord de la baie de Baffin (i.e., Laurentidien et Innuitien), tandis que les couches de sédiments fins riches en titane ont été associées à d'autres sources (Groenland et/ou est de l'île de Baffin). Le chronométrage des couches carbonatées a permis d'associer ces dépôts à la dynamique des glaciers nordiques, sensibles aux oscillations climatiques (ou océanographiques) de haute fréquence de type Dansgaard-Oeschger (dépôt bref, <1.5 ka), ou avec des avancées majeures (suivis pas des retraits progressifs) des glaciers nordiques à différentes périodes glaciaires (dépôt long, 3-6 ka). Nous concluons que ces dépôts sont distincts des événements de Heinrich enregistrés dans l'Atlantique Nord. Dans le troisième chapitre, nous avons étudié les lithofaciès sédimentaires et les assemblages minéralogiques afin de retracer précisément les apports sédimentaires en provenance des marges groenlandaises et de l'île de Baffin. Pour ce faire, nous avons utilisé le programme SedUnMix afin d'estimer statistiquement les sources ayant contribué aux assemblages minéralogiques observés. Les sédiments en provenance de l'île de Baffin sont caractérisés par des dépôts rapides de sédiments grossiers transportés par la glace de mer et/ou des icebergs. Ils présentent également un synchronisme avec les dépôts carbonatés, ce qui suggère des réponses similaires des glaciers nordiques et de l'ouest de la baie de Baffin aux fluctuations et réorganisations océaniques de haute fréquence. Les sédiments en provenance du grand complexe glaciaire d'Uummannaq ont été mis en place durant de longs intervalles correspondant à des niveaux marins plus bas. Notamment, la signature sédimentaire singulière du dernier maximum glaciaire suggère une étendue de la marge glaciaire groenlandaise jusqu'à la marge du plateau continental. Des avancées plus réduites sur le plateau continental groenlandais ont également été identifiées durant les stades isotopiques 5b, 5d et 4. Globalement, les résultats de cette thèse permettent de confirmer l'installation rapide de larges glaciers couvrant la région innuitienne immédiatement après le dernier interglaciaire, comme le suggèrent de récents efforts de modélisation. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Baie de Baffin, Dernier cycle glaciaire, Sédiments glaciomarins, Couches carbonatées, Paléocéanographie, Glaciers, Multi-proxy

Recent paleolimnological research in the eastern Canadian high Arctic on the ecological impact of the Thule c.1000-1500 AD has documented the influence of prehistoric anthropogenic activities. Six lake and pond sites (three pairs) on the south-western coast of Baffin Island, Nunavut, were used to compare impacted and non-impacted sites in the southern-most region of Thule occupation, as well as to compare Thule occupation sites with sites occupied by another early Arctic population group, the Dorset. Tanfield 1 and Tanfield 2 (impacted and control, respectively) are adjacent to several multiple-occupation Dorset sites on Cape Tanfield; Juet 1 and 2 (impacted and control, respectively) are adjacent to a short-term occupation Dorset site on Juet Island; McKellar 1 is adjacent to a multiple-occupation Thule site near McKellar Bay. A nearby site (McKellar 2) was also studied, but it was clearly an anomalous, eutrophic site, rather than a control for McKellar 1. Diatom assemblages and sedimentary 15N profiles were analyzed in sediment cores from all study sites. Selected paired sediment intervals were AMS radiocarbon dated using both humic acids and terrestrial macrofossils in an attempt to establish basal dates for each core. Significant differences between several of the paired AMS radiocarbon dates serve as a cautionary note for dating Arctic sediments using either humic acids or terrestrial macrofossils. Paleolimnological analyses revealed that at both multiple-occupation sites (Tanfield 1 and McKellar 1), the activities of the Dorset and the Thule influenced lake ecology, while at the short-term occupation site (Juet 1), the Dorset occupation was not sufficiently large to have a discernible impact. McKellar 1 showed a greater impact compared to Tanfield 1, consistent with the intense marine mammal hunting by Thule at the former, compared to the moderate marine mammal hunting by Dorset at Tanfield 1. The origin of marine-derived nutrients at McKellar 2 could not be ascertained with certainty. The influence of early Arctic population groups remains obvious in present-day nutrient- and production-related water chemistry variables. This research points to the value of collaborations between paleolimnologists and archaeologists and may provide insight into the future implications of current anthropogenic activities in the Arctic. / Thesis (Master, Biology) -- Queen's University, 2011-10-04 15:52:18.29

Historic and future extreme precipitation and wind events over southern Baffin Island, more specifically Iqaluit, Kimmirut, Pangnirtung and Cape Dorset are examined. Two sets of modeled re-analysis data, the Canadian Regional Climate Model (CRCM) forced with European Centre for Medium-Range Weather Forecasts Regional Analysis 40 (ERA40) and the other the North American Regional Re-analysis (NARR) dataset were used to characterize the atmosphere during historic events. Two sets of CRCM data forced with Canadian Global Climate Model (CGCM) data, one from 1961-1990 and the other from 2041-2070, are compared to assess the changes in extreme events in the future. Extreme events were defined by daily precipitation and sustained wind thresholds. Based on the CRCM future projection, events were inferred to increase in intensity for all communities and increase in frequency for 3 of the 4 communities. A shift in the Arctic storm season was also inferred in the future projection.

Historic and future extreme precipitation and wind events over southern Baffin Island, more specifically Iqaluit, Kimmirut, Pangnirtung and Cape Dorset are examined. Two sets of modeled re-analysis data, the Canadian Regional Climate Model (CRCM) forced with European Centre for Medium-Range Weather Forecasts Regional Analysis 40 (ERA40) and the other the North American Regional Re-analysis (NARR) dataset were used to characterize the atmosphere during historic events. Two sets of CRCM data forced with Canadian Global Climate Model (CGCM) data, one from 1961-1990 and the other from 2041-2070, are compared to assess the changes in extreme events in the future. Extreme events were defined by daily precipitation and sustained wind thresholds. Based on the CRCM future projection, events were inferred to increase in intensity for all communities and increase in frequency for 3 of the 4 communities. A shift in the Arctic storm season was also inferred in the future projection.

Thesis (Ed. D.)--University of Toronto, 2004. / Adviser: Marlene Scardamalia.

Thesis (M.Sc.) -- Memorial University of Newfoundland. / Restricted until October 1991. Typescript. Bibliography: leaves 92-97. Also available online.

It has been estimated that approximately half of all anthropogenic fossil fuel carbon dioxide (CO2) emissions have been absorbed by the oceans. Air-sea gas exchange of CO2 and the buffering capacity of seawater allows the oceans to store significant amounts of dissolved inorganic carbon (DIC; ~38,000 GtC). The Arctic Ocean is currently warming at double the rate of the rest of the planet, yet the effect of climate change on the Arctic marine carbon cycle remains unconstrained. Recent work suggests that Arctic marine environments are a carbon sink for the majority of the year, and plays a key role in storing anthropogenic carbon below the mixed layer. Baffin Bay is a semi-enclosed, Arctic basin that supplies cold surface water to the Labrador Sea; a critical region for North Atlantic deep-water formation. While the physical oceanography of surface Baffin Bay is well characterized, less is known about deep water formation mechanisms and its ventilation age. The few residence times for Baffin Bay Deep Water (BBDW) range widely from 20-1450 years. Improved residence time estimates are essential for understanding the role Baffin Bay plays in the Arctic carbon cycle and how this region will respond to climate change. Radiocarbon (D14C) and stable carbon (δ13C) measurements of DIC are powerful tools for parameterizing water mass sources, aging and residence times. However, very few DIC Δ14C and d13C data have been reported in the Arctic Ocean, comprising only a handful of stations in the Eurasian Basin, Canadian Basin, and Beaufort Sea. With this goal in mind, we conducted a study in which DIC samples were collected aboard the CCGS Amundsen in 2019 for δ13C and Δ14C analysis. DIC δ13C and D14C values ranged from 0.68‰ to +1.90‰ and -90.0‰ to +29.8‰, respectively. Surface DIC δ13C values were +0.69‰ to +1.90‰, while deep (>100m) d13C values ranged -0.01 to -0.68‰. Significant linear correlations were found for δ13C and potential density, suggesting DIC δ13C is an effective water mass and carbon source tracer in Baffin Bay. Surface DIC Δ14C values ranged -5.4‰ to +22.9‰, while deep DIC (>1400m) DIC Δ14C averaged -82.2 8.5‰ (n = 9). Much larger surface to deep gradients in DIC Δ14C are observed in Baffin Bay vs. that of the North Atlantic Ocean, suggesting significant aging of BBDW. Next, we used the potential alkalinity method (Palk) and the ΔC* method to quantify the amount of “bomb” 14C and anthropogenic C (DICanth) to model “natural” DIC Δ14C profiles. Both Palk and ΔC* proxies had high errors in cold, low salinity surface water. In particular, surface (<400m) Δ14Cbomb was overestimated at all stations. However, both proxies did not indicate Δ14Cbomb or DICanth contributions below 1000m. Two 14C residence times were estimated based on two proposed mechanisms of BBDW formation. A residence time of 690 +/- 35 years was estimated assuming surface brine rejection in Nares Strait is the main source of BBDW. Another plausible source of BBDW is the entrainment of dense north Atlantic Water over Davis Strait mixed with brine enriched surface water. A comparison of DICanth and Δ14Cbomb corrected deep DIC Δ14C values from the North Atlantic (GO SHIP A16N) to BBDW, resulted in a residence time of 360 +/- 35 years. These residence times (360-690 years) provide new constraints on the ventilation age of deep Baffin Bay and suggest this basin has the potential to store carbon for centuries.

<p> The interaction of biological and physical processes has resulted in distinct morphological and biological zonation across the Subarctic macrotidal tidal flats at the head of Frobisher Bay. The tidal flats have been divided into six morphological zones which are closely related to the three biological communities found there. </p> <p> Faunal species of the Upper Flat inhabit the beach and fines flat morphological zones where ice action during breakup and freezeup has the greatest influence. Species inhabiting these zones are hardy, and freshwater tolerant. Many are highly motile and recolonize the area after ice breakup. </p> <p> The Middle Flat extends from 5.0 m ALLT to 2.2 m ALLT. It is inhabited by motile polychaetes at its upper end (bouldery flat >4.5 m ALLT). with more sedentary species appearing towards its lower end (very bouldery flat). Below 2.2 m ALLT, on the Lower graded flat, sedentary infauna such as Cyrtodaria kurriana, Mya truncata and sabellid polychaetes, dominate the substrate. </p> <p> The three major processes acting on the tidal flats are, in order of importance, tidal, ice and wave action. Exposure indices, generated from tidal data, reveal 2 critical tidal heights at around 4 m and 7.5 m ALLT, in Frobisher Bay. The boundary between motile and less motile fauna, and bouldery and very bouldery morphological zones, occurs around 4.0 m ALLT. Of the flora and fauna only Fucus evanescens is found beyond the 7.5 m ALLT limit. </p> / Thesis / Master of Science (MSc)

No description available.