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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Culture, Conflict and Crises in the Icelandic Fisheries : An Anthropological Study of People, Policy and Marine Resources in the North Atlantic Arctic

Einarsson, Níels January 2011 (has links)
This thesis is offered as a contribution to studies of social and cultural change in the Icelandic fisheries and fishing communities. Such changes may be seen as a result of the interplay of internal dynamics with both national and global forces and processes, not least with regard to the impacts of fisheries governance. These changes occur also in an international context of new environmental ideologies and perceptions of marine mammals, with consequences for social dynamics of local resource-use. Here it is argued that the conflicts over the harvesting or conservation of cetaceans can productively be understood from a cultural perspective. The thesis discusses the elevation of whales as symbols of particular value, and the metaphorical and cognitive aspects of, in particular, anthropomorphism, the projection of human motives and values onto animal behaviour, as a significant and effective part of conservation rhetoric and ideology. Specifically, the thesis deals with issues concerning whaling and whale watching along with issues and debates concerning these alternative forms of exploiting marine mammals. It also discusses central questions regarding fisheries governance and rights to fishing with reference to social and economic viability in Icelandic fishing communities. The unifying themes of this thesis are: how marine-mammal issues and controversies and social impacts of fisheries governance form part of globalization processes; how environmental and economic paradigms influence change, particularly in terms of marine-mammal conservation campaigns and market liberalist resource policy; and how these external ideological forces call for responses at local and national levels. The adaptive actions of the human agents and communities involved are described as creative, cumulative and complex. The thesis also highlights the central transformative role of the new regime of private property rights introduced into Icelandic fisheries governance in the 1980s.
32

Secrets of the deep : the molecular genetics of cryptic beaked whales

Thompson, Kirsten Freja January 2017 (has links)
Beaked whales are comparatively unknown social mammals due to their deep-ocean distribution and elusive habits. The deep-ocean is the largest biome on Earth and the final frontier for human expansion. Since their first discovery, beaked whales have remained largely hidden from science. In this era of rapid technological advancement, genetic and genomic methods are key tools for population biologists and are particularly useful in describing rarely seen species. Using DNA-barcoding and nuclear markers, the publications in this thesis provide data on the distribution and external appearance of two species of beaked whale: the spade-toothed (Mesoplodon traversii) and Derinayagala’s whale (Mesoplodon hotaula). These whales were previously known from only a handful of tissue and bone specimens. Long-term efforts have facilitated the collection of samples of Gray’s beaked whale (Mesoplodon grayi) and we have used shot-gun sequencing to characterise the mitochondrial genome and isolate species-specific nuclear microsatellite loci. Using genetic species and sex identification, together with museum specimens and multivariate analyses, we provide clear evidence of sexual dimorphism in cranial dimensions and geographic variation in external morphology. No genetic differentiation was evident in Gray’s beaked whales across a large study area (~ 6,000 km). With a large female effective population size (Ne) and genetic homogeneity, we hypothesise that gene flow is facilitated by large-scale oceanographic features, such as the sub-tropical convergence. Genetic kinship analyses within Gray’s beaked whale groups suggest that the whales that strand together are not related. Both sexes disperse from their parents and these groups are not formed through the retention of kin. These results are consistent with a ‘fission-fusion’ social system that has been observed in some oceanic dolphin species. Taken together, these data provide the first insights into the population dynamics, dispersal and social organisation in Gray’s beaked whales. These publications highlight the value of using genetics alongside other techniques to describe inter- and intraspecific diversity. For beaked whales, the dead can tell us much about the living.
33

Diferenças estratégicas de movimentação associadas à estrutura social em baleias jubarte, Megaptera novaeangliae (Borowski, 1781), através de dados de telemetria satelital

Ferreira, Anne Elise Landine 20 March 2017 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-07-04T15:42:12Z No. of bitstreams: 1 anneeliselandineferreira.pdf: 1810442 bytes, checksum: 8c99cf95376ca26c12a8487c26e8750e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-08T13:36:13Z (GMT) No. of bitstreams: 1 anneeliselandineferreira.pdf: 1810442 bytes, checksum: 8c99cf95376ca26c12a8487c26e8750e (MD5) / Made available in DSpace on 2017-08-08T13:36:13Z (GMT). No. of bitstreams: 1 anneeliselandineferreira.pdf: 1810442 bytes, checksum: 8c99cf95376ca26c12a8487c26e8750e (MD5) Previous issue date: 2017-03-20 / A movimentação dos organismos pode ser considerada uma resposta comportamental mensurável, resultante da combinação de fatores ambientais, estados internos e restrições fisiológicas. O objetivo deste trabalho foi avaliar e caracterizar os diferentes padrões de movimentação realizados pelas baleias jubarte (Megaptera novaeangliae), em relação ao gênero e o papel social. Dados de localização por telemetria satelital foram filtrados e modelados pelo Modelo de Estado e Espaço (State-Space Model). A rota obtida foi divida em área de alimentação e rota migratória, considerando como limite a isóbata de 500m. A partir disso, foram calculados os ângulos de virada e as frequências com que ocorrem para o lado direito e esquerdo, utilizando o programa ArcGIS 9.3 e o programa livre R. As médias das angulações variaram significativamente, tanto para o lado esquerdo, quanto para o lado direito na análise comparativa das duas áreas, considerando conjunto total dos grupos. Fêmeas com filhote apresentaram valores de significância maior para ambos os lados, enquanto machos exibiram angulações mais proeminentes para o lado direito. A frequência média relativa de virada para a direita e para a esquerda, mostraram-se significativamente diferentes quando comparadas entre machos, fêmeas e fêmeas com filhote, na área de reprodução, bem como o papel social. Animais categorizados como mães, realizaram mais viradas para ambas as direções, em relação à acompanhantes e animais adultos sem presença de filhote. Concluímos que os animais, quando na área de alimentação, realizam movimentos mais irregulares e que fêmeas apresentam mais variação na movimentação quando associadas a filhotes. Novas ferramentas devem ser associadas à técnica de telemetria para obtenção de dados de fina escala, a fim de avaliar de forma mais apurada a movimentação dos animais. / Organisms movements may be considered a measurable behavioral response which outcomes from a combination of environmental factors, internal states and physiological restrictions. In this work, our goal was to evaluate and characterize the different patterns of movements of humpback whales (Megaptera novaeangliae Borowski, 1781), regarding gender and social role. Location data obtained with satellite telemetry were filtered and patterned by State - Space Model. The obtained route was divided in feeding area and migration route going from the isobath of 500 m. In this context, the turning angles and their frequencies to the right and to the left were calculated using ArcGIS 9.3 and the open source software R. The average angulations varied significantly, both to the left and right sides, in the comparative analysis of the areas regarding the whole group. Females with calf showed more significant differences to both directions, while males presented more prominent angles to the right side. The average frequencies for the moves facing right and left turned out to be significantly different when correlated between males, females and females with calf, in the reproduction areas, as well as the social role. Animals categorized as mothers presented more turns to both directions, when compared to companions and adult animals without calves. We have concluded that when the animals are in feeding area, they present more irregular movements and that females with calf are the ones with the highest movement variation. New tools should be associated with the satellite telemetry in order to obtain fine scale data providing a more accurate form to evaluate the animal movement.
34

Impact of Nutritional Status on the Somatotropic Axis and Ghrelin in Phocid Seals

Dailey, Rachael 01 January 2013 (has links)
Metabolic hormones and their axes, including the target tissues and receptors, regulate the tissue specific utilization of nutrients with in the body. The purpose of this research was to understand the hormonal control of complex nutrient partitioning mechanisms involved in young, growing animals. Specifically, this involved the investigation of metabolic hormones and the regulation of growth in two common species of phocids (true seals): harbor seal (Phoca vitulina) and Northern elephant seal (Mirounga angustirostris) pups. This longitudinal study examines young phocids from nutritional nadir through realimentation (realimentation) to investigate how metabolic hormones involved in both food intake and nutrient partitioning change with respect to nutritional state. To investigate the role of metabolic hormones during realimentation in a small phocid seal, chapter 2 focuses on the changes in the somatotropic axis and ghrelin during a 10-week period of realimentation following nutritional nadir. Chapter 3 focuses on the application of the results of previous research and the second chapter of this thesis to a specific experimental feeding project. Chapter 4 focuses on the response to changes in nutritional status in the fasting adapted NES. Given the changes in metabolism and priority of nutrient utilization associated with transitioning from a nursing neonate to a fasting adapted juvenile, NES provide a unique opportunity to assess the effect of age on the response to realimentation. Overall, this research will further expand the understanding of tissue specific demands and the effect on endocrine response to realimentation. By incorporating assessments of metabolic changes based on nutrition as well as age, this study will expound on how metabolic hormones are involved in regulating the trade-off between adipose and lean tissue development in this unique taxon.
35

Metabolic Activity in a Non-Model System: Leptin and Lipolysis in Bowhead (Balaena Mysticetus) and Beluga (Delphinapterus Leucas) Whale

Ball, Hope C. 19 August 2013 (has links)
No description available.
36

Population demographics of New Zealand fur seals (Arctocephalus forsteri)

McKenzie, Jane, janemckenzie@malpage.com January 2006 (has links)
Assessment of trophic interactions between increasing populations of New Zealand fur seals (Arctocephalus forsteri) and fisheries in southern Australia is limited due to a lack of species specific demographic data and an understanding of the factors influencing population growth. To establish species specific demographic parameters a cross-sectional sample of New Zealand fur seal females (330) and males (100) were caught and individually-marked on Kangaroo Island, South Australia between 2000 and 2003. The seals were aged through examination of a postcanine tooth, which was removed from each animal to investigate age-specific life-history parameters. Annual formation of cementum layers was confirmed and accuracy in age estimation was determined by examination of teeth removed from individuals of known-age. Indirect methods of assessing reproductive maturity based on mammary teat characteristics indicated that females first gave birth between 4-8 years of age, with an average age at reproductive maturity of 5 years. Among reproductively mature females, age-specific reproductive rates increased rapidly between 4-7 years of age, reaching maximum rates of 70-81% between 8-13 years, and gradually decreased in older females. No females older than 22 years were recorded to pup. Age of first territory tenure in males ranged from 8-10 years. The oldest female and male were 25 and 19 years old, respectively. Post-weaning growth in females was monophasic, characterised by high growth rates in length and mass during the juvenile growth stage, followed by a gradual decline in growth rates after reproductive maturity. In contrast, growth in males was biphasic and displayed a secondary growth spurt in both length and mass, which coincided with sexual and social maturation, followed by a rapid decline in growth rates. Age-specific survival rates were high (0.823-0.953) among prime-age females (8-13 yrs of age) and declined in older females. Relative change in annual pup production was strongly correlated with reproductive rates of prime-age females and adult female survival between breeding seasons.
37

Sea Change

Vice President Research, Office of the January 2009 (has links)
As political debate over the overexploitation of fish stocks rages on, UBC’s Fisheries Centre is targeting the responsible management of aquatic ecosystems from multiple perspectives.

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