The remote sub-Arctic/Arctic environment has due to human activities become a sink for organohalogen contaminants (OHCs). These OHC include traditional contaminants such as polychlorinated biphenyls (PCBs), DDTs and technical mixtures of polybrominated diphenyl ethers (PBDEs), all included in the Stockholm Convention list of persistent organic pollutants (POPs). Other OHCs, currently under evaluation to be included among the POPs i.e. short chain chlorinated paraffins (SCCPs) and hexabromocyclododecane (HBCDD) are also found in these environments as well as a whole range of other OHCs. The main objective of this thesis is to increase the knowledge about the presence of OHCs in a high trophic Arctic shark species, the Greenland shark (Somniosus microcephalus). The Greenland shark is an opportunistic feeder, occasionally feeding at the top of the Arctic marine food chain. Furthermore may this species have a life span in excess of 100 years and is probably among the oldest of any fish species. These traits make the shark prone to accumulate elevated concentrations of OHCs. This has shown to be true for the Greenland sharks studied and most of the targeted OHCs were determined in the species. The highest concentrations were observed for the DDTs, ranging up to 26 μg/g fat. Other OHCs reported that are of special interest are SCCPs and brominated flame retardants used as replacement products to PBDEs; pentabromoethylbenzene (PBEB) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE). Also a range of OHCs whose origin is assumed to be natural, were shown to be present in Greenland sharks. This thesis is stressing the fact that even though the use of certain OHCs has been banned for decades they are still present at high concentrations in the deep waters of the Arctic. Therefore it is of major importance to continue to monitor the fate of traditional and emerging OHCs in the environment, and for this purpose the Greenland shark is an excellent species. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.

This thesis addresses questions of identity and ontological legitimacywithin the commercial shark fishing community of Bass Strait,Australia. I consider the implications of competing discourses for theintegrity of fisher identity, environmental conservation and publicnarratives on environmental ‘crises’. I draw upon ethnographic materialdeveloped with commercial fishers and, to a lesser extent, fisheries‘experts’, to explore ambiguities in understandings of individuality andperceptions of the marine environment. Informing this analysis aretheories of practice, particularly notions of embodied relationships andknowledge, the role of ‘luck’ in enabling a particular expression of‘individuality’, the ‘skipper effect’, a consideration of nation-statesanctioned and popular media representations of the environment, andthe peculiarly Australian experience and representation of individuality,both as performance and as trope. These themes are consideredagainst a backdrop of the physical and social activities involved incommercial fishing, and the 2001 nation-state-initiated introduction ofan Individual Transferable Quota management system.

The conservation status of the widely-distributed whale shark Rhincodon typus is presently listed as 'Indeterminate - Data Deficient'. One of the main hindrances to obtaining biological data on whale sharks that is relevant to determining its 'conservation status' is that this species has rarely been recorded as occurring in sufficient numbers to obtain quantitative data. However, R. typus does form aggregations at Ningaloo Marine Park (NMP), Western Australia, annually between March and June. This has enabled studies to be made of aspects of the biology of R. typus and of the possible impacts of the ecotourism industry on this species. Using a position provided on vessels involved with the whale shark ecotourism industry at NMP, R. typus was observed on 360 separate occasions in 1995, 1996 and 1997, and it was possible to sex 90.3% of these sharks. The majority of the sexed sharks (84.6%) were male and ranged in length from 4 to 12 m, with a mean of 7.4 m, while the females ranged in length from 4.5 to 8.5 m, with a mean of 6.2 m. The size and degree of abrasion of the claspers was used as an indicator of whether or not a male shark had mated. Using such criteria, it was estimated that male whale sharks start to mature at ca 8 m and that ca 50% are mature by the time they reach 8.6m. Observations suggested that R. typus feeds by using both suction and flow-through mechanisms. The prey that were observed being ingested included coral spawn, tropical krill, mysids and small jellyfish. The contents of a faecal sample contained parts of the exoskeleton of copepods and the scales of small fishes. The degree of mouth distension, which is assumed to be related to feeding activity, was low during most observation periods. Photographs of the scars and natural patterning on the skin of individual sharks were used to construct a photographic library for subsequent identification of these sharks. The features used for identifying individual sharks were chosen because they were considered likely to remain for a protracted period. The Whale Shark Photo -identification Library that was produced provides details on the characteristic features of 52 R. typus that were present at NMP. Six individuals were recorded at NMP in both 1995 and 1996, four in both 1996 and 1997, and one in both 1995 and 1997. No identified whale sharks were recorded in all three years. Rhincodon typus was distributed widely throughout NMP, with most boat and aerial sightings lying within 1 - 2 Ism of the reef crest between Tantabiddi and Turquoise Bay. Rhincodon typus was typically sighted in water depths of 10 to 30 m. The sharks were predominantly travelling parallel to Ningaloo Reef, with significantly more moving in a northward than southward direction. Acoustic tracking of R. typus in 1997 suggested that this species remains within NMP for extended periods and is at the surface for ca 17% of daylight hours. The number and species of fauna observed to be associated with R. typus were recorded, and a new species of copepod, Pandarus sp. nov., which lives on the skin of R. typus has been described. Golden trevally (Gnathanodon speciosus), miscellaneous trevally (Carangid sp.), remora (Remora sp.) and slender suckerfish (Echeneis naucrates) were common. The prevalence of Pandarus sp. nov. was inversely proportional to the number of Remora sp. and E. mucrates in 1996, while the opposite was true in 1997, suggesting that Pandarus sp. nov. were preyed on by these diskfish. Rhincodon typus is the basis of the ecotourism industry that operates within NMP each year. While there was considerable variation in the number of tour vessels searching for whale sharks at NMP each year, the greatest mean number of vessels operating per week in successive whale shark seasons were 6.7 during Week 8 (April 19 - 25) of 1995, 6.1 during Week 7 (April 12 - 18) of 1996 and 6.9 during Week 8 (April 19 - 25) of 1997. The greatest mean numbers of whale sharks sighted per week in each year were 5.1 during Week 14 (May 31 - June 6) of 1995,4.2 during Week 6 (April 5 - 11) of 1996 and 4.1 during Week 8 (April 19 - 25) of 1997. Tourists, who were permitted to swim alongside R. tyus, interacted with sharks for a mean period of 19.3 rnin in 1995, 14.2 min in 1996 and 9.5 rnin in 1997. The reduction in the duration of interaction in three successive years suggests that, over time, R. typus may have become slightly less tolerant of the ecotourism industry at NMP. The mean minimum distance between vessel and shark during each interaction was 20.7 m in 1995, 21.3 m in 1996 and 31.0 m in 1997. The mean minimum distance between tourist and shark during each interaction was 1.5 m in 1995, 2.05 m in 1996, and 2.1 m in 1997. The mean minimum distance of vessel and tourist from R. typus during each individual interaction decreased as the duration of the interaction increased. Therefore, both R. typus and this industry must be carefully monitored to ensure that the impacts of humans are kept to a minimum and thereby ensure that whale sharks return to NMP each year. An ethology of whale shark behaviours, which included banking, porpoising, diving and eye-rolling, was produced in an attempt to determine whether there is evidence that the ecotourism industry has a negative impact on R. opus at NMP. The frequency of behavioural change was greatest in the first 0 - 5 min of an observation. Eye-rolling by R. typus was recorded as a reaction to flash-photography, while banking was often recorded when SCUBA was used and/or tourists swam beneath the head of the shark. The swimming speed of R. typus at NMP was rarely too fast for tourists to maintain proximity to the sharks. Several sharks possessed both recent and healed scars, which were probably inflicted by vessel contact. The recent wounds indicate that vessels had caused injuries to R. typus within NMP. These individuals tended to display a higher frequency of avoidance behaviours and reduced interaction times. Recommendations are provided to the Western Australian Department of Conservation and Land Management which are aimed at reducing the potential deleterious effects of the ecotourism industry on the whale sharks at NMP.

Thesis (M. Sc.)--University of Hong Kong, 2007.

Determining the dynamic nature of animal movement has been an important component in a wider understanding of animal population ecology. Generally, this is because temporal change in the density of a population at a specific geographic location is not only a function of births and deaths but also of movements, including migration. The increased availability of remote telemetry and biologging systems in recent years has enabled many studies tracking marine predators, such as turtles, seabirds and marine mammals, but a general understanding of spatial dynamics in large sharks remains less well developed. This is in part due to few studies having achieved sufficiently long-term, multi-year tracks to detect changes in movement behaviour over time. Determining the timing, repeatability and potential motivations for movements of large sharks is necessary to understand the ecological and evolutionary role of such behaviour more generally in marine predators. Furthermore, given global concerns of declining shark populations, a detailed appreciation of shark movements can reveal the extent 6 of overlap with area-focused human activities (e.g. fishing), as well as inform assessments of population trends and spatial management options. In order to demonstrate how shark migratory behaviour and spatial dynamics can vary dramatically depending on the species and location, with subsequent contrasting conservation implications, the present work used longterm, remote telemetry to reveal detailed patterns in shark movement behaviour at two very different geographical scales: broad-scale movements of larger species that encompass ocean basins, versus fine-scale movements of reef-associated species at a remote atoll. First, using satellite telemetry, it was revealed for the tiger shark Galeocerdo cuvier, that adult males undertake annually repeated, roundtrip migrations of over 7,500 km in the northwest Atlantic. Second, acoustic telemetry was used to determine the fine-scale spatial dynamics of a multispecies shark assemblage at a small, remote atoll in the Seychelles, Indian Ocean, where a number of species displayed perennial residency. While the fine-scale movements of reef sharks in the Seychelles suggest an MPA of moderate size may be an effective management option, the long-distance migrations of the tiger sharks in the Atlantic reveal that conservation efforts targeting them must account for dynamic fisheries interactions over large geographical scales, potentially requiring time-area closures to be effective. Examining the long-term movement behaviour of different shark species over contrasting geographical scales has emphasised the importance of understanding spatial dynamics when informing management decisions, and has contributed to a wider understanding of the population ecology of these species.

The nurse shark, Ginglymostoma cirratum, is a sedentary shark species that inhabits coral reefs in the tropical and subtropical Atlantic Ocean and along the western coast of the Americas in the Pacific Ocean. Nurse shark tissue samples were collected from the Bahamas, Belize, Brazil, and Dry Tortugas National Park in Florida. 186 individuals were genotyped at 11 microsatellite loci, the control region of the mitochondrial genome was sequenced in 190 individuals, and 89 individuals from the Bahamas, Belize, and Dry Tortugas were genotyped at the major histocompatibility complex (MHC) class IIα locus. An analysis of molecular variance (AMOVA) for the microsatellite loci indicated significant subdivision only between the Bahamas and Dry Tortugas populations. An AMOVA for the mitochondrial control region sequences indicated significant subdivision between all population pairs. The AMOVA for MHC class IIα locus indicated significant subdivision between two population pairs: the Bahamas population and the Dry Tortugas population and the Belize population and the Dry Tortugas population. The nurse shark has the lowest mitochondrial DNA nucleotide diversity (π=0.0125%) and haplotype diversity (h=0.2402) of any shark species to date. There were 14 MHC alleles from 39 polymorphic sites; ten were the same as published alleles (Kasahara et al. 1993; Ohta et al. 2000). This study was the first study to use MHC class IIα genes as a marker for population genetics in sharks. Our results showed that MHC class IIα locus behaves as a diploid locus and is a powerful tool for determining population genetic structure between populations.

Made available in DSpace on 2014-06-11T19:26:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-09-27Bitstream added on 2014-06-13T19:12:56Z : No. of bitstreams: 1 000749214.pdf: 1021607 bytes, checksum: d716daae1fd7be486189d76347e657ad (MD5) / Até poucas décadas atrás, a pesca de tubarões era incidental e sem efeitos significativos para as suas populações. No entanto, devido ao grande aumento no valor de suas nadadeiras na Ásia e ao declínio das populações de peixes mais tradicionais para o consumo humano, os tubarões passaram a ser alvo de pescarias em quase todo o mundo, promovendo a inclusão de diversas espécies na lista de espécies ameaçadas de extinção. Entre os tubarões mais explorados, as espécies pelágicas apresentam uma maior complexidade na avaliação e monitoramento de suas populações devido à sua distribuição em vastas áreas geográficas. Destas, o tubarão mako, Isurus oxyrinchus, com ocorrência circunglobal, está entre as principais espécies que apresentam sinais de vulnerabilidade, com tendência ao esgotamento populacional e, no entanto, avaliações que viabilizem o manejo adequado da pesca ainda são inconsistentes. Estudos relacionados à estruturação genética populacional de peixes têm contribuído substancialmente para a elucidação de questões como a variabilidade genética, distribuição geográfica, padrões de migração, estoques reprodutivos, taxonomia, sistemática e eventos históricos. Tais aspectos são especialmente relevantes para o setor pesqueiro, fornecendo subsídios para o manejo e conservação dos estoques. Considerando a urgente necessidade de controle sustentável da pesca, dificultada principalmente pela falta de informações, este estudo buscou caracterizar a estrutura genética populacional da espécie I. oxyrinchus no Oceano Atlântico, utilizando sequências da região controladora do DNA mitocondrial (D-loop). Foram analisados 144 indivíduos e a análise de 729 pares de bases nucleotídicas desta região genômica permitiu a caracterização de 27 haplótipos, sendo que 18 destes haplótipos (67%) estão compartilhados por todas as regiões amostradas. Os resultados indicam a... / Until a few decades ago, shark fishing was only incidental and had no significant effects on their populations. However, due to the large increase in the value of shark’s fins in Asia and the decline of more traditional fish populations for human consumption, sharks became target fishing around the world, promoting the inclusion of several species in the list of endangered species. Among the most exploited sharks, the pelagic species exhibit greater complexity in the assessment and monitoring of their populations due to their distribution in broad geographical areas. From these species, the mako shark, Isurus oxyrinchus, of global occurrence, is among the main species that show vulnerability signs, with a trend to deplete population, and however, evaluations that facilitate appropriate management of fisheries are still inconsistent. Studies related to genetic structure of fish populations have contributed substantially to the elucidation of issues such as genetic variability, geographical distribution, migration patterns, reproductive stocks, taxonomy, systematics, and historical events. These aspects are especially relevant to fisheries sector, providing subsidies for the management and conservation of fish stocks. Considering the urgent need for a sustainable control of fisheries, hampered mainly by the lack of information, this study aimed to characterize the population genetic structure of the shark I. oxyrinchus in the Atlantic Ocean, using sequences of mitochondrial DNA control region (D-loop). We analyzed 144 individuals and analysis of 729 nucleotide base pairs of this genomic region allowed the characterization of 27 haplotypes, with 18 of these haplotypes (67%) being shared by all regions sampled. The results indicate the occurrence of a moderate genetic variability (π = 0.004 and h = 0.791 ± 0.029), with high population structure between the northern and southern hemispheres (FST values: ...

Orientador: Fausto Foresti / Coorientador: Otto Bismarck Gadig / Banca: Paulo Guilherme Vasconcelos de Oliveira / Banca: Claudio Oliveira / Resumo: O tubarão azul, Prionace glauca, é considerado a espécie de elasmobrânquio encontrada em maior abundância, com ampla distribuição geográfica, alta taxa de natalidade e de rápido crescimento. Entretanto, também é a espécie mais explorada na pesca oceânica em nível mundial, o que tem levado a desequilíbrios estruturais das populações e aumentado as possibilidades de risco para a espécie. Em avaliações sobre o estado de conservação da espécie, realizadas no Brasil e também de maneira global, P. glauca foi classificada como "quase ameaçada". Para o setor pesqueiro, a identificação de estoques diferenciados constitui informação fundamental pela sua relação direta com a produtividade total e uso sustentável dos recursos. A diferença nas freqüências de haplótipos de DNA entre amostras geográficas pode ser usada para estimar indiretamente padrões de diferenciação e de fluxo gênico e, portanto, a estrutura genética das amostras. Este trabalho utilizou amostras de tecidos musculares e epiteliais de tubarões azuis capturados pela frota pesqueira brasileira no Rio Grande do Sul (n = 38), São Paulo (n = 28) e Rio Grande do Norte (n = 31). Os níveis de variabilidade e estruturação genética nas regiões amostradas foram determinados a partir do sequenciamento da região controle do DNA mitocondrial (D-loop). Para P. glauca, este marcador apresentou 16 sítios polimórficos e 32 haplótipos. Os valores encontrados para diversidade haplotípica e nucleotídica foram, respectivamente, Hd =0,89±0,020 e π=0,00258±0,00013. O teste AMOVA detectou uma moderada estruturação populacional entre as regiões amostradas, com o maior valor de Fst = 0,103. Assim, considera-se para os efeitos de manejo pesqueiro, um único estoque da espécie na costa brasileira. Os níveis de estruturação genética demonstrados... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The blue shark, Prionace glauca, is the most abundant elasmobranch, with widest distribution, high birth rates and faster growth. However, it is also the most exploited species in the ocean fisheries worldwide, which has led to structural imbalances of their population and increased potential risk to the specie. In assessments of the state of conservation of the species, carried out in Brazil and globally, P. glauca was classified as "near threatened" according to IUCN categories. In fisheries, the stock identification are considered very important information due the direct relation with the total productivity and sustainable use of resources. The difference in the frequencies of haplotypes of DNA among geographic samples can be used to indirectly estimate patterns of differentiation and gene flow and thus the genetic structure of stocks. In the present study samples of muscle and epithelial tissues of blue sharks caught by the fishing fleet in Rio Grande do Sul (n = 38), São Paulo (n = 28) and Rio Grande do Norte (n = 31) estates were used. The levels of variability and genetic structure of the sampled regions were determined from the sequencing of mitochondrial DNA control region (D-loop). The use of this marker in P. glauca resulted in 16 polymorphic sites and 32 haplotypes. The nucleotide and haplotype diversity was, respectively, Hd = 0.89 ± 0.020 and π = 0.00258 ± 0.00013. The AMOVA test detected a moderate population subdivision among the sampled regions, with highest value of Fst = 0,103. Similarly, it is considered for the effects of fisheries management, a single stock in the Brazilian coast. The levels of genetic structure demonstrated in the present study, combined with data from fisheries exploitation of the blue shark, indicate the need for greater attention to the preservation of the species in Brazil... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:30:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-22Bitstream added on 2014-06-13T20:00:07Z : No. of bitstreams: 1 teixeira_af_me_botib.pdf: 246482 bytes, checksum: f600cfeeac47a49d85d69a991ad9d920 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O tubarão azul, Prionace glauca, é considerado a espécie de elasmobrânquio encontrada em maior abundância, com ampla distribuição geográfica, alta taxa de natalidade e de rápido crescimento. Entretanto, também é a espécie mais explorada na pesca oceânica em nível mundial, o que tem levado a desequilíbrios estruturais das populações e aumentado as possibilidades de risco para a espécie. Em avaliações sobre o estado de conservação da espécie, realizadas no Brasil e também de maneira global, P. glauca foi classificada como “quase ameaçada”. Para o setor pesqueiro, a identificação de estoques diferenciados constitui informação fundamental pela sua relação direta com a produtividade total e uso sustentável dos recursos. A diferença nas freqüências de haplótipos de DNA entre amostras geográficas pode ser usada para estimar indiretamente padrões de diferenciação e de fluxo gênico e, portanto, a estrutura genética das amostras. Este trabalho utilizou amostras de tecidos musculares e epiteliais de tubarões azuis capturados pela frota pesqueira brasileira no Rio Grande do Sul (n = 38), São Paulo (n = 28) e Rio Grande do Norte (n = 31). Os níveis de variabilidade e estruturação genética nas regiões amostradas foram determinados a partir do sequenciamento da região controle do DNA mitocondrial (D-loop). Para P. glauca, este marcador apresentou 16 sítios polimórficos e 32 haplótipos. Os valores encontrados para diversidade haplotípica e nucleotídica foram, respectivamente, Hd =0,89±0,020 e π=0,00258±0,00013. O teste AMOVA detectou uma moderada estruturação populacional entre as regiões amostradas, com o maior valor de Fst = 0,103. Assim, considera-se para os efeitos de manejo pesqueiro, um único estoque da espécie na costa brasileira. Os níveis de estruturação genética demonstrados... / The blue shark, Prionace glauca, is the most abundant elasmobranch, with widest distribution, high birth rates and faster growth. However, it is also the most exploited species in the ocean fisheries worldwide, which has led to structural imbalances of their population and increased potential risk to the specie. In assessments of the state of conservation of the species, carried out in Brazil and globally, P. glauca was classified as near threatened according to IUCN categories. In fisheries, the stock identification are considered very important information due the direct relation with the total productivity and sustainable use of resources. The difference in the frequencies of haplotypes of DNA among geographic samples can be used to indirectly estimate patterns of differentiation and gene flow and thus the genetic structure of stocks. In the present study samples of muscle and epithelial tissues of blue sharks caught by the fishing fleet in Rio Grande do Sul (n = 38), São Paulo (n = 28) and Rio Grande do Norte (n = 31) estates were used. The levels of variability and genetic structure of the sampled regions were determined from the sequencing of mitochondrial DNA control region (D-loop). The use of this marker in P. glauca resulted in 16 polymorphic sites and 32 haplotypes. The nucleotide and haplotype diversity was, respectively, Hd = 0.89 ± 0.020 and π = 0.00258 ± 0.00013. The AMOVA test detected a moderate population subdivision among the sampled regions, with highest value of Fst = 0,103. Similarly, it is considered for the effects of fisheries management, a single stock in the Brazilian coast. The levels of genetic structure demonstrated in the present study, combined with data from fisheries exploitation of the blue shark, indicate the need for greater attention to the preservation of the species in Brazil... (Complete abstract click electronic access below)

Small-scale fisheries (SSF) are poorly documented, yet 90% of the 120 million employed in capture fisheries work in the SSF sector and >1 billion people globally rely on fish as an important source of protein. There is a lack of data on the status of the majority of fisheries in Madagascar owing to the difficulty in surveying the vast coastline and large number of small-scale fishers. In Madagascar, marine turtles and elasmobranchs are important culturally and as sources of income and food for many small-scale fishers. However, very little data exist on the status of these two animal groups. The five chapters of this thesis intend to increase our understanding of the status of marine turtles and elasmobranchs in Madagascar. This is achieved through the assessment of the fisheries, legislation and in the case of turtles, the nesting population. I also document community-based methods for monitoring fisheries and marine turtle nesting, that are easily replicable for gathering data across remote regions. Results show that the turtle fishery in Madagascar appears to have remained at the same level since the 1970s, despite being illegal since the 1990s, with landings estimated to be approximately 10,000 to 16,000 turtles.year-1. To further contextualise the take of turtles in Madagascar, by carrying out a global review, I estimate that the worldwide legal take in turtle fisheries to be over 42,000 turtles.year-1. Contrary to reports from fishers, actual numbers of elasmobranchs (the majority of which are sharks) taken by the traditional (non-motorised) fishery has not declined. Results support previous reports that fishing effort has increased, as well changes in fishing gears, to account for declining catch per unit effort (CPUE) to maintain shark landing numbers. Furthermore, the size of some shark species has significantly declined, even across this study. Community-based turtle nesting monitoring and protection in western Madagascar revealed a small, yet potentially significant, nesting population. Across the 17 current nesting sites recorded, the majority of nesting populations in Madagascar have <50 nests.year-1. A further >40 historic nesting sites were recorded. Community-led monitoring methods not only helped to fill a data gap, but were also found to reduce loss of nests through human disturbance. Misinterpretations, poor enforcement and gaps in current legislation mean that both marine turtles and elasmobranchs are effectively unprotected from overexploitation. This thesis provides recommendations for improved legislation and management of both groups of species and demonstrates that participatory monitoring methods can not only reduce data deficiency, but enhance locally-led management and protection, and increase Madagascar's capacity for improved management and conservation.