O presente estudo foi realizado com o objetivo de identificar genomas de vírus em fezes de lobos marinhos sul-americanos (Arctocephalus australis) e lobos marinhos subantárticos (Arctocephalus tropicalis), duas espécies de pinípedes encontradas no litoral do Rio Grande do Sul. Embora já existam estudos sobre esse tema em outras espécies de pinípedes, nas espécies aqui trabalhadas o tema permanece inexplorado. Amostras de fezes foram obtidas de vinte e um lobos marinhos sul-americanos e dois lobos marinhos subantárticos encontrados no litoral rio-grandense com indícios de morte recente, durante os meses de Junho e Julho de 2012. Através de técnicas de PCR e sequenciamento buscou-se identificar genomas de circovírus, adenovírus, morbilivírus, calicivírus e coronavírus. A amplificação de um fragmento do gene rep permitiu a identificação de prováveis circovírus em amostras de seis lobos marinhos sul-americanos. Análises filogenéticas revelaram que três dos seis segmentos são sugestivos de prováveis membros do gênero Cyclovirus. Os genes amplificados de outras duas amostras provavelmente correspondem a membros do gênero Circovirus. Uma das amostras deu origem a um segmento gênico que não apresenta similaridade com nenhum gênero já proposto da família Circoviridae. Além disso, foi possível detectar também fragmentos de genomas de adenovírus em duas amostras; estes apresentam alto grau de similaridade de nucleotídeos com amostras de adenovírus humano tipo C. Nenhum fragmento genômico indicativo da presença de morbilivírus, calicivírus ou coronavírus foi encontrado. Os resultados aqui obtidos sugerem a presença de circovírus, ciclovírus e adenovírus em populações de lobos marinhos encontrados na costa do Rio Grande do Sul. Estes achados reforçam a necessidade da ampliação do conhecimento a respeito da ocorrência de infecções virais nestas espécies. / This study was conducted with the objective of identifying genomes of viruses in feces of south american fur seals (Arctocephalus australis) and subantarctic fur seals (Arctocephalus tropicalis), two species of pinnipeds found on the coast of Rio Grande do Sul. Although there are studies about this topic in other species of pinnipeds, it remains unexplored in these two species. Stool samples were obtained from twenty-one south american fur seals and two subantarctic fur seals found in Rio Grande do Sul coastline with evidences of recent death, during the months of June and July 2012. PCR and sequencing techniques were utilized to identify circovirus, adenovirus, morbillivirus, calicivirus and coronavirus genomes. The amplification of a rep gene fragment allowed the identification of supposed circoviruses in samples of six south american fur seals. Phylogenetic analysis revealed that three of the six segments are suggestive of probable members of the genus Cyclovirus. The amplified genes from two other samples probably correspond to members of the genus Circovirus. One of the samples gave rise to a gene segment that has no similarity with any genera already proposed of the Circoviridae family. Furthermore, it was also possible to detect fragments of adenovirus genomes in two samples: these have a high degree of nucleotide similarity with a human adenovirus type C genomic fragment. No indication of the presence of morbillivirus, calicivirus and coronavirus genomes was found. The work reported here provide evidence for the occurrence of circoviruses, cicloviruses and adenoviruses in fur seal populations found in Rio Grande do Sul. These findings reinforce the need to expand the knowledge about the occurrence of viral infections in these species.

O presente estudo foi realizado com o objetivo de identificar genomas de vírus em fezes de lobos marinhos sul-americanos (Arctocephalus australis) e lobos marinhos subantárticos (Arctocephalus tropicalis), duas espécies de pinípedes encontradas no litoral do Rio Grande do Sul. Embora já existam estudos sobre esse tema em outras espécies de pinípedes, nas espécies aqui trabalhadas o tema permanece inexplorado. Amostras de fezes foram obtidas de vinte e um lobos marinhos sul-americanos e dois lobos marinhos subantárticos encontrados no litoral rio-grandense com indícios de morte recente, durante os meses de Junho e Julho de 2012. Através de técnicas de PCR e sequenciamento buscou-se identificar genomas de circovírus, adenovírus, morbilivírus, calicivírus e coronavírus. A amplificação de um fragmento do gene rep permitiu a identificação de prováveis circovírus em amostras de seis lobos marinhos sul-americanos. Análises filogenéticas revelaram que três dos seis segmentos são sugestivos de prováveis membros do gênero Cyclovirus. Os genes amplificados de outras duas amostras provavelmente correspondem a membros do gênero Circovirus. Uma das amostras deu origem a um segmento gênico que não apresenta similaridade com nenhum gênero já proposto da família Circoviridae. Além disso, foi possível detectar também fragmentos de genomas de adenovírus em duas amostras; estes apresentam alto grau de similaridade de nucleotídeos com amostras de adenovírus humano tipo C. Nenhum fragmento genômico indicativo da presença de morbilivírus, calicivírus ou coronavírus foi encontrado. Os resultados aqui obtidos sugerem a presença de circovírus, ciclovírus e adenovírus em populações de lobos marinhos encontrados na costa do Rio Grande do Sul. Estes achados reforçam a necessidade da ampliação do conhecimento a respeito da ocorrência de infecções virais nestas espécies. / This study was conducted with the objective of identifying genomes of viruses in feces of south american fur seals (Arctocephalus australis) and subantarctic fur seals (Arctocephalus tropicalis), two species of pinnipeds found on the coast of Rio Grande do Sul. Although there are studies about this topic in other species of pinnipeds, it remains unexplored in these two species. Stool samples were obtained from twenty-one south american fur seals and two subantarctic fur seals found in Rio Grande do Sul coastline with evidences of recent death, during the months of June and July 2012. PCR and sequencing techniques were utilized to identify circovirus, adenovirus, morbillivirus, calicivirus and coronavirus genomes. The amplification of a rep gene fragment allowed the identification of supposed circoviruses in samples of six south american fur seals. Phylogenetic analysis revealed that three of the six segments are suggestive of probable members of the genus Cyclovirus. The amplified genes from two other samples probably correspond to members of the genus Circovirus. One of the samples gave rise to a gene segment that has no similarity with any genera already proposed of the Circoviridae family. Furthermore, it was also possible to detect fragments of adenovirus genomes in two samples: these have a high degree of nucleotide similarity with a human adenovirus type C genomic fragment. No indication of the presence of morbillivirus, calicivirus and coronavirus genomes was found. The work reported here provide evidence for the occurrence of circoviruses, cicloviruses and adenoviruses in fur seal populations found in Rio Grande do Sul. These findings reinforce the need to expand the knowledge about the occurrence of viral infections in these species.

O presente estudo foi realizado com o objetivo de identificar genomas de vírus em fezes de lobos marinhos sul-americanos (Arctocephalus australis) e lobos marinhos subantárticos (Arctocephalus tropicalis), duas espécies de pinípedes encontradas no litoral do Rio Grande do Sul. Embora já existam estudos sobre esse tema em outras espécies de pinípedes, nas espécies aqui trabalhadas o tema permanece inexplorado. Amostras de fezes foram obtidas de vinte e um lobos marinhos sul-americanos e dois lobos marinhos subantárticos encontrados no litoral rio-grandense com indícios de morte recente, durante os meses de Junho e Julho de 2012. Através de técnicas de PCR e sequenciamento buscou-se identificar genomas de circovírus, adenovírus, morbilivírus, calicivírus e coronavírus. A amplificação de um fragmento do gene rep permitiu a identificação de prováveis circovírus em amostras de seis lobos marinhos sul-americanos. Análises filogenéticas revelaram que três dos seis segmentos são sugestivos de prováveis membros do gênero Cyclovirus. Os genes amplificados de outras duas amostras provavelmente correspondem a membros do gênero Circovirus. Uma das amostras deu origem a um segmento gênico que não apresenta similaridade com nenhum gênero já proposto da família Circoviridae. Além disso, foi possível detectar também fragmentos de genomas de adenovírus em duas amostras; estes apresentam alto grau de similaridade de nucleotídeos com amostras de adenovírus humano tipo C. Nenhum fragmento genômico indicativo da presença de morbilivírus, calicivírus ou coronavírus foi encontrado. Os resultados aqui obtidos sugerem a presença de circovírus, ciclovírus e adenovírus em populações de lobos marinhos encontrados na costa do Rio Grande do Sul. Estes achados reforçam a necessidade da ampliação do conhecimento a respeito da ocorrência de infecções virais nestas espécies. / This study was conducted with the objective of identifying genomes of viruses in feces of south american fur seals (Arctocephalus australis) and subantarctic fur seals (Arctocephalus tropicalis), two species of pinnipeds found on the coast of Rio Grande do Sul. Although there are studies about this topic in other species of pinnipeds, it remains unexplored in these two species. Stool samples were obtained from twenty-one south american fur seals and two subantarctic fur seals found in Rio Grande do Sul coastline with evidences of recent death, during the months of June and July 2012. PCR and sequencing techniques were utilized to identify circovirus, adenovirus, morbillivirus, calicivirus and coronavirus genomes. The amplification of a rep gene fragment allowed the identification of supposed circoviruses in samples of six south american fur seals. Phylogenetic analysis revealed that three of the six segments are suggestive of probable members of the genus Cyclovirus. The amplified genes from two other samples probably correspond to members of the genus Circovirus. One of the samples gave rise to a gene segment that has no similarity with any genera already proposed of the Circoviridae family. Furthermore, it was also possible to detect fragments of adenovirus genomes in two samples: these have a high degree of nucleotide similarity with a human adenovirus type C genomic fragment. No indication of the presence of morbillivirus, calicivirus and coronavirus genomes was found. The work reported here provide evidence for the occurrence of circoviruses, cicloviruses and adenoviruses in fur seal populations found in Rio Grande do Sul. These findings reinforce the need to expand the knowledge about the occurrence of viral infections in these species.

This study found evidence of intermittent, multi-year residency periods in northern fur seals (Callorhinus ursinus) using stable isotope ratios in vibrissae and canine teeth. Northern fur seals migrate from the Bering Sea during summer months to lower latitudes and slightly warmer waters of the northeastern Pacific Ocean and California Current in the winter. To determine the length of time spent away from the Bering Sea, growth rate was estimated using the covarying oscillations δ13C and δ15N, estimated to be 0.09 mm/day. The δ13C and δ15N in vibrissae from 30 male fur seals showed a minimum of 13 separate periods of stable covariance covering 3.25+ cm, indicating at least 1 year in warmer, less productive waters of the northeastern Pacific Ocean. The vibrissae isotope ratios were used in conjunction with δ18O from tooth dentin growth layer groups of 20 male northern fur seals; they showed significant enrichment in δ18O in 50% of the animals at age 1-2 years, which indicates extended periods of time spent in lower latitudes in the North Pacific Ocean as δ18O is typically enriched in warmer, less productive waters. Significant changes in δ18O were found to be ~ 0.2‰ enrichment per 10º south latitude, while longitude was found to have 0.2‰ enrichment per 50˚ East longitude. These data show that latitudinal changes, those related to the southerly migration from the Bering Sea to the northeastern Pacific Ocean, are a stronger factor in the shifts in dentinal δ18O than longitudinal shifts. These intermittent periods of occupation are important when estimating population abundance of northern fur seals, especially pups and juveniles.

Bibliography: pages 168-180. / This thesis adopts an holistic approach to evaluation of the "seal problem", which encompasses the operational and biological interactions between the South African fur seal and fisheries in the Benguela Ecosystem. The operational interactions are examined using a qualitative assessment, and speculative, single-species simulation models are developed to improve understanding of seal population dynamics, present options for seal management and explore seal-fishery interactions. The models show that the probability of a seal living longer than 20 years is 14%; that the population has increased at a rate of 5.1 % p.a. since the last major census in 1983; that in 1988 there were an estimated 1.5 million seals that consumed over 2 million tons of fish; that although seal population size is usually estimated by multiplying the number of pups by a factor of 4, this factor is very variable and under different culling regimes is usually greater than 4; that historically, the mean population : pup ratio is 4.55. The most effective means of reducing the population is to cull both pups and bulls (the population decrease resulting mainly from reduced pup production caused by disturbance during bull culling). Culling pups is the least effective means of population control. Culling cows alters the population sex ratio drastically and is considered undesirable. To achieve a small or negative population growth rate, more bulls and pups need to be culled than have been taken historically. Each of the fisheries is found to be subject to operational interactions with seals, this being most severe for the purse-seine fishery. The per capita consumption of fish by seals is similar under any management regime so it is not justified to adopt a particular culling strategy to reduce overall consumption. When either seal predation or fishing mortality is reduced, the model simulates an increase in fishery yield of Cape hakes. But there is inadequate understanding of hake population dynamics at present, and depending on the interactions between species, decreased predation may result in increased or decreased fishery yields. This study shows that operational interactions are a real problem and this biases the opinion of fishermen towards seals as competitors for fish resources.

O lobo-marinho-sul-americano (Arctocephalus australis) membro da Ordem Carnivora, é comumente visto nos períodos de outono e inverno na costa brasileira do Rio Grande do Sul até o Rio de Janeiro, porém, sem colônias reprodutivas estabelecidas. A espécie pertence ao grupo dos pinípedes, carnívoros com membros em forma de nadadeiras que vivem em ambiente aquático e terrestre. Estudos sobre a morfologia da pele em pinípedes são raros e antigos, destes procederam muitos relatos divergentes, em virtude da colheita da pele sem referências anatômicas. O objetivo desta pesquisa foi descrever o sistema tegumentar da espécie Arctocephalus australis, utilizando animais que vieram a óbito por causas naturais de uma colônia reprodutiva do Uruguai. As áreas corporais colhidas dorso-ventralmente foram identificadas anatomicamente. Essas regiões foram examinadas por microscopia óptica, segundo critérios histológicos, histomorfométricos, histoquímicos e imuno-histoquímicos nas diferentes estruturas que constituem o sistema tegumentar. A pele do Arctocephalus australis apresentou diferenças entre as regiões de epiderme delgada e espessa. A epiderme delgada apresentou maior quantidade de pêlos do que a epiderme espessa, a qual em algumas regiões era destituída destes. Como os demais mamíferos, a pele do lobo-marinho-sul-americano apresentou glândulas sebáceas, glândulas sudoríparas apócrinas e merócrinas. As nadadeiras apresentaram o maior número de especializações entre as regiões do corpo estudadas, especialmente vinculadas à termorregulação, como o maior volume de glândulas sudoríparas e secções vasculares. Esta pesquisa apontou os aspectos morfofuncionais relacionados à biologia da espécie em ambientes distintos, e esclareceu alguns dados controversos na literatura sobre o sistema tegumentar em pinípedes. / The South American fur seal (Arctocephalus australis) members of the Order Carnivora is usually seen during the autumn and winter season in the Brazilian coast from Rio Grande do Sul to Rio de Janeiro, however, there are no reports of reproductive colonies established. The species belongs to the group of pinnipeds, carnivorous with limbs fin-shaped that inhabits both terrestrial and aquatic environments. Studies of the skin morphology are rare and ancient; these studies have arisen many divergent reports, due to sampling of the skin without anatomical references. The purpose of this research was to describe the integumentary system of the species Arctocephalus australis, using animals that came to death by natural cases from reproductive colonies from Uruguay. The body dorsal and ventral regions were identified anatomically. These regions were examined by light microscopy, according to the histological, histomophometric, histochemical and immunohistochemical criteria in the different structures constituting the integumentary system. The skin of the Arctocephalus australis showed differences between the thin and thick epidermis. The thin epidermis showed larger amount of hair follicles than the thicker epidermis, which in some regions was devoid of hair. As well as the other mammals, the South-american-fur-seal skin showed sebaceous glands, apocrine and eccrine sweat glands. The limbs showed the largest number of the specialization among the regions of the body examined, particularly related to thermoregulation, as well as the largest volume fraction of sweat glands and vascular sections. This research pointed the morphofunctional aspects related to biology of the species in different environments, and elucidated some controversial data in the investigation about the integumentary system in pinnipeds.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pinnipeds are marine mammals of the Carnivora order. Some species were close to the complete extinction due to predatory hunt for their skin and blubber. Conservation measures have been taken to avoid extinction and population monitoring is essential to evaluate how populations are responding along the years. Remote sensing, from satellite images and aerial photographs, allows the monitoring through individual counting without interfering directly in the animals. The main objective of this work is to analyze aspects of the demography and the distribution of pinnipeds in the Elephant Island, located northeast of the Antarctic Peninsula, in the South Shetlands Islands, during the Austral summer (November to March) in the years of 2005 to 2010, using aerial censuses performed around the Elephant Island. The aerial censuses photographs were taken from Squirrel helicopters of the Brazilian Navy flying at a constant speed, 30 to 50 meters height along the island s perimeter. The data were obtained by counting the individuals registered in the photographs. The counting of all censuses summed 27.592 individuals along the years. Due to the fact that it was not possible to cover the totality of the island s perimeter in all censuses, the distribution and occurrence were studied dividing the island into seven sectors along its total perimeter. In general, the species observed more frequently in all sectors were the Southern elephant seals (Mirounga leonina) and Antarctic fur seals (Artocephalus gazella). Even though other seals species such as the Weddell seal (Leptonychotes weddelli), the leopard seal (Hydrurga leptonyx) and the crabeater seal (Lobodon carcinophaga) registered to the Elephant Island exhibited low representativeness in their occupancy, their presence is constant in all censuses. Using the statistical technique Principal Coordinates Analysis, we notice that the occupancy pattern of the Elephant Island by the pinnipeds is related to the substrate present in the different sectors of the island and to the period of the Austral summer sampled. Southern elephant seals settle in sectors of sandy substrate and exhibit the largest occupation during the earlier months of summer (November and December), while Antarctic fur seals preferably settle in rocky substrates and its occupancy is larger during the latest months of summer (January to February). New breeding sites were described in particular for the Antarctic fur seals in so called sectors of Valentin and Piloto Pardo. Preliminary data taken from satellite images of Valentin sector corroborated the aerial photograph data and indicated that the Antarctic fur seals are the predominant species in this region. To our knowledge, this is the first study taken with aerial censuses data in the Elephant Island, and the results presented here have great use for the correct management and conservation politics for the pinnipeds. / Pinípedes são mamíferos marinhos pertencentes à Ordem Carnívora. Algumas espécies foram levadas quase à extinção devido à caça por sua pele e gordura. Medidas de conservação foram tomadas para evitar a extinção e o monitoramento das populações é essencial para avaliar como estas estão reagindo ao longo dos anos. O sensoriamento remoto através de imagens de satélite e fotografias aéreas permite este monitoramento através da contagem dos indivíduos sem interferir diretamente com os animais. Este trabalho tem por objetivo geral analisar aspectos da distribuição e ocorrência de pinípedes na Ilha Elefante, situada a nordeste da Península Antártica no Arquipélago das Shetlands do Sul, durante o verão austral (novembro a março) entre os anos de 2005 a 2010 através de censos aéreos realizados no entorno da Ilha Elefante. As fotografias de censo aéreo foram tomadas a partir de helicópteros Esquilo da Marinha do Brasil voando em velocidade constante, entre 30 e 50 m de altura ao longo do perímetro da ilha. Os dados foram obtidos através da contagem de indivíduos registrados nas fotografias. Os animais contados a partir dos censos somados atingiram 27.592 indivíduos ao longo dos anos. Devido ao fato de que não foi possível cobrir todo o perímetro da ilha em todos os censos aéreos, a distribuição e abundância foram estudadas dividindo-se a ilha em sete setores ao longo de seu perímetro total. Em geral, as espécies observadas com maior frequência em todos os setores foram os elefantes-marinhos do sul (Mirounga leonina - EMS) e os lobos-marinhos antárticos (Artocephallus gazella - LMA). Ainda que os demais focídeos como a foca-de-Weddell (Leptonychotes weddelli), foca-leopardo (Hydrurga leptonyx) e a foca-caranguejeira (Lobodon carcinophaga) registrados para a Ilha Elefante apresentem baixa representatividade na sua ocupação, sua presença é constante em todos os censos. Utilizando técnica estatística de Análise de Coordenadas Principais, nota-se que o padrão de ocupação da Ilha Elefante pelos pinípedes está relacionado com o substrato presente nos diferentes setores da ilha. Os EMS permanecem em locais de substrato arenoso e apresentam maior ocupação nos primeiros meses do verão (novembro e dezembro), enquanto os LMA permanecem preferencialmente em locais rochosos e sua ocupação é maior nos últimos meses de verão (janeiro e fevereiro). Novos locais de reprodução foram descritos em especial para LMA nos setores denominados de Valentin e Piloto Pardo. Dados preliminares tomados a partir de uma imagem de satélite para o setor de Valentin corroboraram os dados de fotografias aéreas e indica que LMA é a espécie predominante dessa região. Ao nosso conhecimento, esse é o primeiro estudo realizado com dados de censo aéreo na Ilha Elefante e os resultados apresentados aqui tem grande utilidade para o correto manejo e para as políticas de conservação de pinípides.

O lobo-marinho-sul-americano (Arctocephalus australis) membro da Ordem Carnivora, é comumente visto nos períodos de outono e inverno na costa brasileira do Rio Grande do Sul até o Rio de Janeiro, porém, sem colônias reprodutivas estabelecidas. A espécie pertence ao grupo dos pinípedes, carnívoros com membros em forma de nadadeiras que vivem em ambiente aquático e terrestre. Estudos sobre a morfologia da pele em pinípedes são raros e antigos, destes procederam muitos relatos divergentes, em virtude da colheita da pele sem referências anatômicas. O objetivo desta pesquisa foi descrever o sistema tegumentar da espécie Arctocephalus australis, utilizando animais que vieram a óbito por causas naturais de uma colônia reprodutiva do Uruguai. As áreas corporais colhidas dorso-ventralmente foram identificadas anatomicamente. Essas regiões foram examinadas por microscopia óptica, segundo critérios histológicos, histomorfométricos, histoquímicos e imuno-histoquímicos nas diferentes estruturas que constituem o sistema tegumentar. A pele do Arctocephalus australis apresentou diferenças entre as regiões de epiderme delgada e espessa. A epiderme delgada apresentou maior quantidade de pêlos do que a epiderme espessa, a qual em algumas regiões era destituída destes. Como os demais mamíferos, a pele do lobo-marinho-sul-americano apresentou glândulas sebáceas, glândulas sudoríparas apócrinas e merócrinas. As nadadeiras apresentaram o maior número de especializações entre as regiões do corpo estudadas, especialmente vinculadas à termorregulação, como o maior volume de glândulas sudoríparas e secções vasculares. Esta pesquisa apontou os aspectos morfofuncionais relacionados à biologia da espécie em ambientes distintos, e esclareceu alguns dados controversos na literatura sobre o sistema tegumentar em pinípedes. / The South American fur seal (Arctocephalus australis) members of the Order Carnivora is usually seen during the autumn and winter season in the Brazilian coast from Rio Grande do Sul to Rio de Janeiro, however, there are no reports of reproductive colonies established. The species belongs to the group of pinnipeds, carnivorous with limbs fin-shaped that inhabits both terrestrial and aquatic environments. Studies of the skin morphology are rare and ancient; these studies have arisen many divergent reports, due to sampling of the skin without anatomical references. The purpose of this research was to describe the integumentary system of the species Arctocephalus australis, using animals that came to death by natural cases from reproductive colonies from Uruguay. The body dorsal and ventral regions were identified anatomically. These regions were examined by light microscopy, according to the histological, histomophometric, histochemical and immunohistochemical criteria in the different structures constituting the integumentary system. The skin of the Arctocephalus australis showed differences between the thin and thick epidermis. The thin epidermis showed larger amount of hair follicles than the thicker epidermis, which in some regions was devoid of hair. As well as the other mammals, the South-american-fur-seal skin showed sebaceous glands, apocrine and eccrine sweat glands. The limbs showed the largest number of the specialization among the regions of the body examined, particularly related to thermoregulation, as well as the largest volume fraction of sweat glands and vascular sections. This research pointed the morphofunctional aspects related to biology of the species in different environments, and elucidated some controversial data in the investigation about the integumentary system in pinnipeds.

Environmental fluctuations in the eastern Pacific Ocean are reflected in the tissues of some of its most vulnerable apex predators, the Peruvian fur seal (PFS) Arctocephalus australis ssp.and the South American sea lion (SASL) Otaria byronia.These large pinnipeds live in sympatry along the Pacific coastline of South America and forage within the neritic waters over the continental shelf. The coastal waters off Peru are a region of great environmental fluctuations due to periodic, oscillating El Niño- La Niña- Southern Oscillation (ENSO) events, which result in ecosystem-wide food web changes. Pinniped vibrissae (whiskers) are continuously growing keratinous tissues and reflect the incorporation of prey from the region. Fine resolution sampling along their length provided trophic information on a weekly to monthly time scale over several years. Vibrissae were obtained from 2010-2016 from female (n=47), male (n=17) and newborn pup (n=6) fur seals and male (n=6) sea lions collected during pinniped rookery health assessments. Stable isotope ratios (δ13C and δ15N) in vibrissae infer temporal primary production and dietary variations in individuals. ENSO conditions were dictated by the sea surface temperature anomaly (SSTA) recordings from the Niño 1+2 Index region over 12 years. Fluctuations in vibrissae δ15N were correlated to varying SSTA readings (p15N (p15N signatures (p13C revealed minor fluctuations ranging from -18.13 to -13.17‰over the 12-year period, δ13C did reveal a significant depletion and enrichment oscillation during specific points in time, such as the 2014-2016 El Niño event, which ranged from -15.09 to -13.83‰(p=0.040). Stable isotope signatures varied between genders, but not by species. Female fur seal stable isotope signatures were significantly more depleted in both δ13C and δ15N than males (p13C and δ15N were inversely correlated to each other from 2014 to 2016; this was during the strongest El Nino-Southern Oscillation event on record (p=0.002). As δ13Csignatures became more enriched, δ15N signatures depleted from 2014 until 2016. This suggests that when ENSO warm phase conditions occur, the environments resources change in historic foraging grounds, possibly forcing pinnipeds to travel farther distances offshoreto forage or altering what they feed on throughout these stressful conditions.This study serves to help understand of the impact of oceanographic influences on these pinnipeds.ENSO conditions influence the trophic dynamics and resultant survival adaptations in both of these vulnerable Peruvian marine mammals.

Craniometrics is a very reliable and effective tool for studying the difference in animal morphology. Previously, traditional craniometrics were conducted with the aid of calipers in two dimensional format (2D). Such discounting of actual three-dimensional 3D form may result in loss of some relevant and critical information leading to compromised and unreliable results for studies such as population variation analysis of morphology. The employment of 3D photogrammetry allows a close to complete representation of the physical dimensions of a specimen. The use of photogrammetry in mammalogy concentrated on measuring of body size/mass, but little has been done on animal skull delineation through photogrammetry. This dissertation describes advances in morphometrics and 3D photogrammetry application in craniometrics, investigates the craniometric variation between closely related species (Arctocephalus gazella and A. tropicalis), and A. tropicalis interpopulation craniometrics between two geographically distinct populations, at Marion Island and Gough Island, using Photomodeler Scanner® (PMSc®) three-dimensional (3D) modelling software to produce accurate, high resolution 3D skull models. A total of 117 3D models were created from adult male fur seal crania, and 16 traditional measurements recorded, using specimens archived at the Port Elizabeth Museum, Bayworld, South Africa. Sixteen linear measurements, (8 caliper recordings and 8 3D recordings) were used for PMSc® methodology testing, 16 (A. gazella n= 8 and A. tropicalis n= 8) used for species cranial comparison and 85 (Marion Island n= 54 and Gough Island n= 31) used for interpopulation variation. The craniometric variations were analysed using the Statistica® v11 software package, StatSoft, Inc. The comparison between linear traditional caliper cranial measurements and 3D measurements produced significantly similar results, attesting to the accuracy of the PMSc® 3D model production. Photomodeler Scanner® therefore produces accurate and high resolution 3D models of skulls which allow 3D measurements. I predicted that PMSc® would detect the existing significant differences between the skulls of adult male A. gazella and A. tropicalis and modelled and compared their 3D models, and I further predicted that PMSc® would detect any existing differences between the skulls of A. tropicalis from Gough and Marion islands by comparison of their 3D models. The Gough Island and Marion Island A. tropicalis populations could not be discriminated based on linear 3D cranial I conclude that PMSc® is a reliable and effective tool for accurate and high resolution 3D modelling. The present study confirms previous findings and contributes additional evidence that suggests that adult A. tropicalis males from Gough Island and Marion Island cannot be discriminated based on linear measurements of craniometrics, and deviates from the Bergmanian rule as applied to large mammals. The present study, however, makes several noteworthy contributions to the use of PMSc® and 3D modelling in morphometrics. Taken together, these findings suggest a role for PMSc® 3D modelling in promoting accurate digitization of museum specimens and creation of online museum libraries. This research will serve as a baseline for future studies and usefulness of PMSc® in 3D morpho-volumetric measurements. / Dissertation (MSc (Zoology))--University of Pretoria, 2014. / Zoology and Entomology / MSc (Zoology) / Unrestricted