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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.
191

The New Zealand common dolphin (Delphinus sp.) : identity, ecology and conservation : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Zoology, Massey University, Auckland, New Zealand

Stockin, Karen A January 2008 (has links)
Common dolphins (genus Delphinus) are poorly understood within New Zealand waters. Prior to this study, most information relating to the taxonomy, population structure, diet and pollutant loads of this genus relied upon untested assumptions. Furthermore, factors affecting the occurrence, demographics and habitat use of common dolphins in the Hauraki Gulf remained unknown. This lack of empirical data has resulted in the inadequate recognition and management of New Zealand Delphinus. Inappropriately classified by the New Zealand Threat Classification System, the anthropogenic impacts that affect this genus have clearly been overlooked. The present study examines behaviour of common dolphins in the Hauraki Gulf and details analyses undertaken on tissue samples collected from around New Zealand. Results detailed here challenge many of the untested assumptions about this genus within New Zealand waters. The taxonomy of New Zealand common dolphins was assessed using 92 samples analysed for 577 base pairs (bps) of the mtDNA control region (D-loop). New Zealand samples were compared with 177 published sequences from eight other populations from around the world. New Zealand Delphinus exhibited a high genetic variability, sharing haplotypes with both short- (D. delphis) and long-beaked (D. capensis) populations. Indeed, the New Zealand population showed significant genetic differentiation when compared with most other populations world-wide. Furthermore, intrapopulation analyses revealed significant genetic differentiation between Hauraki Gulf individuals and other common dolphins sampled within New Zealand waters. Results suggest habitat choice and site fidelity may play a role in shaping the fragmented population structure of New Zealand Delphinus. Data relating to the occurrence and demographics of common dolphins in the Hauraki Gulf region were collected during boat-based surveys between February 2002 and January 2005. In total, 719 independent encounters, involving one to > 300 common dolphins were recorded. Dolphin presence was significantly affected by month, latitude and depth. Group size varied significantly by month, season, depth, sea surface temperature (SST) and latitude, and was highly skewed towards smaller groups comprising fewer than 50 animals. Calves were observed throughout the year but were most prevalent in the austral summer months of December and January. Group composition was significantly affected by month, season, depth and SST. The yearround occurrence and social organisation of Delphinus in Hauraki Gulf waters suggest this region is an important nursery and potential calving area. The effects of diel, season, depth, sea surface temperature, and group size and composition on dolphin behaviour were investigated using activity budgets. Foraging and social were the most and least frequently observed behaviours, respectively. A correlation between group size and behaviour was evident, although behaviour did not vary with the composition of dolphin groups. Resting, milling and socialising animals were more frequently observed in smaller groups. Foraging behaviour was prevalent in both small and large groups, suggesting foraging plasticity exists within this population. Behaviour differed between single- and multi-species groups, with foraging more frequent in mixed-species aggregations, indicating the primary mechanism for association is likely prey-related. Stomach contents analysed for forty-two stranded and eleven commercially by-caught individuals collected from around North Island, New Zealand between 1997 and 2006, revealed arrow squid (Nototodarus spp.), jack mackerel (Trachurus spp.) and anchovy (Engraulis australis) as the most prevalent prey. Stranded individuals and dolphins bycaught within neritic waters fed on both neritic and oceanic prey. Moreover, a mixed prey composition was evident in the diet of common dolphins by-caught in oceanic waters, suggesting inshore/offshore movements of New Zealand Delphinus on a diel basis. Additionally, prey differences were also evident in the stomach contents of common dolphins sampled from within the Hauraki Gulf. Trace elements, polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticide levels were determined in five stranded and fourteen by-caught Delphinus sampled from around New Zealand between 1999 and 2005. Generally, levels of trace elements were low. However, concentrations of OC pesticides were similar in range to those previously reported for Hector’s (Cephalorhyncus hectori) and common bottlenose dolphins (Tursiops truncatus). Organochlorine pesticides dieldrin, hexachlorobenzene (HCB), o,p’-DDT and p,p’-DDE were present at the highest concentrations. Markov chain models were used to assess the impact of tourism activities on Delphinus within the Hauraki Gulf. Foraging and resting bouts were significantly disrupted by boat interactions. Both the duration of bouts and the time spent in these two behavioural states decreased during boat interactions. Additionally, foraging dolphins took significantly longer to return to their initial behavioural state in the presence of a tour boat. Impacts identified are similar to those previously reported for the common bottlenose dolphin, a coastal species typically considered to be more susceptible to cumulative anthropogenic impacts. Data presented here reveal the nature and apparent susceptibility of New Zealand common dolphins to human-induced impacts, namely fisheries by-catch, pollution and tourism. This in conjunction with taxonomic uncertainty, lack of abundance estimates and the year-round use of inshore waters for feeding, clearly warrants immediate attention from managers. Furthermore, the current threat classification of New Zealand Delphinus should be reconsidered in light of population uncertainties, and in view of the susceptibly to human-induced impacts revealed by the present study.
192

The New Zealand common dolphin (Delphinus sp.) : identity, ecology and conservation : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Zoology, Massey University, Auckland, New Zealand

Stockin, Karen A January 2008 (has links)
Common dolphins (genus Delphinus) are poorly understood within New Zealand waters. Prior to this study, most information relating to the taxonomy, population structure, diet and pollutant loads of this genus relied upon untested assumptions. Furthermore, factors affecting the occurrence, demographics and habitat use of common dolphins in the Hauraki Gulf remained unknown. This lack of empirical data has resulted in the inadequate recognition and management of New Zealand Delphinus. Inappropriately classified by the New Zealand Threat Classification System, the anthropogenic impacts that affect this genus have clearly been overlooked. The present study examines behaviour of common dolphins in the Hauraki Gulf and details analyses undertaken on tissue samples collected from around New Zealand. Results detailed here challenge many of the untested assumptions about this genus within New Zealand waters. The taxonomy of New Zealand common dolphins was assessed using 92 samples analysed for 577 base pairs (bps) of the mtDNA control region (D-loop). New Zealand samples were compared with 177 published sequences from eight other populations from around the world. New Zealand Delphinus exhibited a high genetic variability, sharing haplotypes with both short- (D. delphis) and long-beaked (D. capensis) populations. Indeed, the New Zealand population showed significant genetic differentiation when compared with most other populations world-wide. Furthermore, intrapopulation analyses revealed significant genetic differentiation between Hauraki Gulf individuals and other common dolphins sampled within New Zealand waters. Results suggest habitat choice and site fidelity may play a role in shaping the fragmented population structure of New Zealand Delphinus. Data relating to the occurrence and demographics of common dolphins in the Hauraki Gulf region were collected during boat-based surveys between February 2002 and January 2005. In total, 719 independent encounters, involving one to > 300 common dolphins were recorded. Dolphin presence was significantly affected by month, latitude and depth. Group size varied significantly by month, season, depth, sea surface temperature (SST) and latitude, and was highly skewed towards smaller groups comprising fewer than 50 animals. Calves were observed throughout the year but were most prevalent in the austral summer months of December and January. Group composition was significantly affected by month, season, depth and SST. The yearround occurrence and social organisation of Delphinus in Hauraki Gulf waters suggest this region is an important nursery and potential calving area. The effects of diel, season, depth, sea surface temperature, and group size and composition on dolphin behaviour were investigated using activity budgets. Foraging and social were the most and least frequently observed behaviours, respectively. A correlation between group size and behaviour was evident, although behaviour did not vary with the composition of dolphin groups. Resting, milling and socialising animals were more frequently observed in smaller groups. Foraging behaviour was prevalent in both small and large groups, suggesting foraging plasticity exists within this population. Behaviour differed between single- and multi-species groups, with foraging more frequent in mixed-species aggregations, indicating the primary mechanism for association is likely prey-related. Stomach contents analysed for forty-two stranded and eleven commercially by-caught individuals collected from around North Island, New Zealand between 1997 and 2006, revealed arrow squid (Nototodarus spp.), jack mackerel (Trachurus spp.) and anchovy (Engraulis australis) as the most prevalent prey. Stranded individuals and dolphins bycaught within neritic waters fed on both neritic and oceanic prey. Moreover, a mixed prey composition was evident in the diet of common dolphins by-caught in oceanic waters, suggesting inshore/offshore movements of New Zealand Delphinus on a diel basis. Additionally, prey differences were also evident in the stomach contents of common dolphins sampled from within the Hauraki Gulf. Trace elements, polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticide levels were determined in five stranded and fourteen by-caught Delphinus sampled from around New Zealand between 1999 and 2005. Generally, levels of trace elements were low. However, concentrations of OC pesticides were similar in range to those previously reported for Hector’s (Cephalorhyncus hectori) and common bottlenose dolphins (Tursiops truncatus). Organochlorine pesticides dieldrin, hexachlorobenzene (HCB), o,p’-DDT and p,p’-DDE were present at the highest concentrations. Markov chain models were used to assess the impact of tourism activities on Delphinus within the Hauraki Gulf. Foraging and resting bouts were significantly disrupted by boat interactions. Both the duration of bouts and the time spent in these two behavioural states decreased during boat interactions. Additionally, foraging dolphins took significantly longer to return to their initial behavioural state in the presence of a tour boat. Impacts identified are similar to those previously reported for the common bottlenose dolphin, a coastal species typically considered to be more susceptible to cumulative anthropogenic impacts. Data presented here reveal the nature and apparent susceptibility of New Zealand common dolphins to human-induced impacts, namely fisheries by-catch, pollution and tourism. This in conjunction with taxonomic uncertainty, lack of abundance estimates and the year-round use of inshore waters for feeding, clearly warrants immediate attention from managers. Furthermore, the current threat classification of New Zealand Delphinus should be reconsidered in light of population uncertainties, and in view of the susceptibly to human-induced impacts revealed by the present study.
193

The New Zealand common dolphin (Delphinus sp.) : identity, ecology and conservation : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Zoology, Massey University, Auckland, New Zealand

Stockin, Karen A January 2008 (has links)
Common dolphins (genus Delphinus) are poorly understood within New Zealand waters. Prior to this study, most information relating to the taxonomy, population structure, diet and pollutant loads of this genus relied upon untested assumptions. Furthermore, factors affecting the occurrence, demographics and habitat use of common dolphins in the Hauraki Gulf remained unknown. This lack of empirical data has resulted in the inadequate recognition and management of New Zealand Delphinus. Inappropriately classified by the New Zealand Threat Classification System, the anthropogenic impacts that affect this genus have clearly been overlooked. The present study examines behaviour of common dolphins in the Hauraki Gulf and details analyses undertaken on tissue samples collected from around New Zealand. Results detailed here challenge many of the untested assumptions about this genus within New Zealand waters. The taxonomy of New Zealand common dolphins was assessed using 92 samples analysed for 577 base pairs (bps) of the mtDNA control region (D-loop). New Zealand samples were compared with 177 published sequences from eight other populations from around the world. New Zealand Delphinus exhibited a high genetic variability, sharing haplotypes with both short- (D. delphis) and long-beaked (D. capensis) populations. Indeed, the New Zealand population showed significant genetic differentiation when compared with most other populations world-wide. Furthermore, intrapopulation analyses revealed significant genetic differentiation between Hauraki Gulf individuals and other common dolphins sampled within New Zealand waters. Results suggest habitat choice and site fidelity may play a role in shaping the fragmented population structure of New Zealand Delphinus. Data relating to the occurrence and demographics of common dolphins in the Hauraki Gulf region were collected during boat-based surveys between February 2002 and January 2005. In total, 719 independent encounters, involving one to > 300 common dolphins were recorded. Dolphin presence was significantly affected by month, latitude and depth. Group size varied significantly by month, season, depth, sea surface temperature (SST) and latitude, and was highly skewed towards smaller groups comprising fewer than 50 animals. Calves were observed throughout the year but were most prevalent in the austral summer months of December and January. Group composition was significantly affected by month, season, depth and SST. The yearround occurrence and social organisation of Delphinus in Hauraki Gulf waters suggest this region is an important nursery and potential calving area. The effects of diel, season, depth, sea surface temperature, and group size and composition on dolphin behaviour were investigated using activity budgets. Foraging and social were the most and least frequently observed behaviours, respectively. A correlation between group size and behaviour was evident, although behaviour did not vary with the composition of dolphin groups. Resting, milling and socialising animals were more frequently observed in smaller groups. Foraging behaviour was prevalent in both small and large groups, suggesting foraging plasticity exists within this population. Behaviour differed between single- and multi-species groups, with foraging more frequent in mixed-species aggregations, indicating the primary mechanism for association is likely prey-related. Stomach contents analysed for forty-two stranded and eleven commercially by-caught individuals collected from around North Island, New Zealand between 1997 and 2006, revealed arrow squid (Nototodarus spp.), jack mackerel (Trachurus spp.) and anchovy (Engraulis australis) as the most prevalent prey. Stranded individuals and dolphins bycaught within neritic waters fed on both neritic and oceanic prey. Moreover, a mixed prey composition was evident in the diet of common dolphins by-caught in oceanic waters, suggesting inshore/offshore movements of New Zealand Delphinus on a diel basis. Additionally, prey differences were also evident in the stomach contents of common dolphins sampled from within the Hauraki Gulf. Trace elements, polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticide levels were determined in five stranded and fourteen by-caught Delphinus sampled from around New Zealand between 1999 and 2005. Generally, levels of trace elements were low. However, concentrations of OC pesticides were similar in range to those previously reported for Hector’s (Cephalorhyncus hectori) and common bottlenose dolphins (Tursiops truncatus). Organochlorine pesticides dieldrin, hexachlorobenzene (HCB), o,p’-DDT and p,p’-DDE were present at the highest concentrations. Markov chain models were used to assess the impact of tourism activities on Delphinus within the Hauraki Gulf. Foraging and resting bouts were significantly disrupted by boat interactions. Both the duration of bouts and the time spent in these two behavioural states decreased during boat interactions. Additionally, foraging dolphins took significantly longer to return to their initial behavioural state in the presence of a tour boat. Impacts identified are similar to those previously reported for the common bottlenose dolphin, a coastal species typically considered to be more susceptible to cumulative anthropogenic impacts. Data presented here reveal the nature and apparent susceptibility of New Zealand common dolphins to human-induced impacts, namely fisheries by-catch, pollution and tourism. This in conjunction with taxonomic uncertainty, lack of abundance estimates and the year-round use of inshore waters for feeding, clearly warrants immediate attention from managers. Furthermore, the current threat classification of New Zealand Delphinus should be reconsidered in light of population uncertainties, and in view of the susceptibly to human-induced impacts revealed by the present study.
194

The ecology of two New Zealand opisthobranch molluscs

Willan, R. C. (Richard Cardew) January 1979 (has links)
An intertidal population of the anaspidean Aplysia dactylomela Rang was followed for three consecutive years at the Leigh Marine Reserve, North Auckland, New Zealand. Field assessments were made of recruitment, growth (by recapture of tagged individuals), density, crawling rate, gonad index and mortality. These data allowed monthly estimates of the entire population within the entire study area (2.76 ha) to be made. Complementary laboratory studies investigated acceptable foods and an energy budget including data on energy of the food, growth rates, egestion, respiration and assimilation efficiency were also obtained in the laboratory. In conjunction with these studies, field work on the algal food of A. dactylomela (species of Laurencia) elucidated the entities present, their separate yearly changes in biomass and the causes. From this information, data on food requirements for A. dactylomela.ha-1 month-1 are contrasted with standing crop estimates for Laurencia spp. in the same units to permit consideration of the theoretical grazing effects of A. dactylomela. Several lines of evidence show this environment to be suboptimal for A. dactylomela. storms account for the greatest mortality, but some losses are due to predation by the asteroid Coscinasterias calamaria (Gray). Few individuals reach reproductive maturity and the population is not self-recruiting. An intertidal population of a second opisthobranch, the Cephalaspidean Haminoea zelandiae (Gray in Dieffenbach) was followed for three consecutive years at Motukaraka Island, Hauraki Gulf, New Zealand. Field determinations of growth, annual abundance and reproductive cycles were made. The cryptogamic flora at Motukaraka Island has been characterised and annual patterns of cover and distribution presented for five major seasonal components. The relationship between Haminoea zelandiae and these algae is considered. Additional studies on two less-common anaspideans were carried out. Field data on breeding, growth and density are given for Aplysia parvula Mörch which exists in separate, spatially-isolated intertidal and subtidal populations at Goat Island Bay. For these two populations differences exist in diet, colouration, size distribution, growth and survivorship. The intertidal habitat is marginal whereas the subtidal is close to being optimal. Bursatella leachii Blainville shows variable annual recruitment to the cyanophyte Lyngbya majuscula intertidally at Motukaraka Island. Growth rates have been determined for field and laboratory populations. In the field a deliberate offshore migration takes place whilst L. majuscula is still abundant. Speculations on the possibilities and causes for migrations amongst opisthobranchs are discussed. A taxonomic revision of the New Zealand Anaspidea follows as an appendix. There are eight sea hares authentically recorded for New Zealand: Aplysia (Pruvotaplysia) parvula Mörch 1863; A. (Varria) dactylomela Rang 1828; A. (V.) keraudreni Rang 1828; (V.) extraordinaria (Allan 1932); A. (Aplysia) juliana (Quoy & Gaimard 1832); Bursatella leachii Blainville 1817; Stylocheilus longicauda (Quoy & Gaimard 1825); Dolabrifera dolabrifera (Cuvier 1817). For each species a complete synonymy is given as well as full description, locality records and discussion.
195

Gradiente ambiental e peixes de riachos de cabeceira da Mata Atlântica (SP) / Environmental gradient and fishies of headwater of Atlantic Forest (SP)

Mello, Bruno José Gomes 22 May 2014 (has links)
Submitted by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T12:18:43Z No. of bitstreams: 1 MELLO_Bruno Gomes_2014.pdf: 2169418 bytes, checksum: 157bccc008d9bb3bac70c082f1d983c3 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T12:18:51Z (GMT) No. of bitstreams: 1 MELLO_Bruno Gomes_2014.pdf: 2169418 bytes, checksum: 157bccc008d9bb3bac70c082f1d983c3 (MD5) / Approved for entry into archive by Maria de Lourdes Mariano (lmariano@ufscar.br) on 2017-01-12T12:19:00Z (GMT) No. of bitstreams: 1 MELLO_Bruno Gomes_2014.pdf: 2169418 bytes, checksum: 157bccc008d9bb3bac70c082f1d983c3 (MD5) / Made available in DSpace on 2017-01-12T12:19:08Z (GMT). No. of bitstreams: 1 MELLO_Bruno Gomes_2014.pdf: 2169418 bytes, checksum: 157bccc008d9bb3bac70c082f1d983c3 (MD5) Previous issue date: 2014-05-22 / Não recebi financiamento / The growing interest in studies of functional diversity allows to address the relationship between the functional characteristics of species with variations in the environment attempt to understand the organization of biological communities. We examined the relationship between physical and structural characteristics of 19 stretches of headwater streams in the Atlantic Forest and morphological characteristics related to swimming ability of fish species. The environment was described by altitude, distance from species pool, substrate composition and depth of the channel. The functional characteristics were described by 11 morphological measurements. The RLQ analysis was used and the first two axes explained 97.8% of the total variation. The first axis was interpreted as the action of the altitudinal/longitudinal gradient in the structuring of assemblies of fish which varied with morphological measurements of length of caudal fin and caudal peduncle. We can say that there are two distinct assemblies positioned at the extremes of the environmental gradient separated by capacity of swimming of the species. Within these groups we can say that on a local scale the physical structure of the channel generates subgroups related to the use of the niche, suggesting the action of environmental filters. Thus, we present evidence that environmental attributes of headwaters of the Atlantic Forest are related to the structure of the assemblies of fishes that inhabit these environments. / O crescente interesse por estudos de diversidade funcional permite abordar a relação entre as características funcionais das espécies com variações no ambiente buscando entender a organização das comunidades biológicas. Nós examinamos a relação entre as características físicas e estruturais de 19 trechos de riachos de cabeceira na Mata Atlântica e as características morfológicas relacionadas com a capacidade de natação das espécies de peixes. O ambiente foi descrito quanto à altitude, distância da fonte de espécies, composição do substrato e profundidade do canal; enquanto que as características funcionais foram descritas por 11 medidas morfológicas. Utilizamos uma análise RLQ e os dois primeiros eixos explicaram 97,8% do total da variação. O primeiro eixo foi interpretado como a ação do gradiente altitudinal/longitudinal na estruturação das assembleias de peixes que variou com as medidas morfológicas de comprimento da nadadeira e pedúnculo caudal. Podemos afirmar que existem duas assembleias distintas posicionadas nos extremos do gradiente ambiental separadas pela capacidade de deslocamento das espécies. Dentro destes grupos podemos dizer que em escala local a estrutura física do canal gera subgrupos relacionados ao uso do nicho, sugerindo a ação de filtros ambientais. Desta forma, apresentamos evidências de que a estrutura das assembleias de peixes está relacionada com atributos ambientais de riachos de cabeceira da Mata Atlântica.
196

Estudo limnológico da bacia do rio Sorocaba (SP) e utilização do índice de integridade biótica da comunidade de peixes para avaliação ambiental / not available

Fernanda Teixeira e Marciano 09 February 2001 (has links)
Dentre os sistemas naturais de regiões tropicais e sub-tropicais destacam-se os ambientes aquáticos que são representados por diferentes tipos de \"habitats\" como rios, riachos e lagoas marginais. A bacia do rio Sorocaba é um exemplo destes sistemas, sendo constituída por ambientes variados e, portanto, por condições ecológicas distintas. Tendo em vista a necessidade de caracterizar tais \"habitats\" por meio de índice de integridade biótica (IBI) e de prover informações ecológicas nesta bacia, foi realizado um estudo limnológico e ictiológico em doze tributários do rio Sorocaba de quatro ordens diferentes. Foram realizadas coletas para a avaliação das variáveis físicas, químicas e biológicas nas épocas de cheia e seca, nos anos de 1999 e 2000. Onze variáveis relacionadas à organização e saúde da comunidade de peixes foram avaliadas para análise do índice de integridade biótica dos \"habitats\" aquáticos em estudo, sendo essas variáveis selecionadas de maneira a detectar impactos sobre a estrutura da comunidade. Para tanto, verificou-se a riqueza e a abundância total das espécies, além da intolerância e categoria trófica dos indivíduos. Os resultados indicaram que a organização e a saúde da comunidade de peixes foram as variáveis mais importantes para composição do índice de integridade biótica nas três diferentes ordens de rio estudadas (2ª, 3ª e 4ª). De maneira geral, a bacia do rio Sorocaba apresentou-se alterada em relação aos padrões estabelecidos para comunidade íctica nesta última década, o que é indicativo de certo grau de degradação no sistema. / Tropical and sub-tropical rivers distinguish themselves among the aquatic systems in producing different types of habitats such as rivers, stream, creeks and floodplain lakes. The Sorocaba river in the State of São Paulo, Brazil, is an example of this type of system constituted by a variety environments and, hence producing distinct ecological conditions. A limnological and ictiological study of 12 tributaries of Sorocaba river four different stream orders was conducted to characterize these habitats in relation to the index of biological integrity and also to provide ecological information about the environmental conditions on the hydrographic basin. Data on physical, chemical and biological variables were obtained in dry and wet seasons during years 1999 and 2000. Eleven variables related to the organization and integrity of the fishes communityes were evaluated for the analysis of biotic integrity index of the aquatic habitats under study. These variables were selected to detected any environmental impacts on the structure of communities. The species richness and total abundance of the species as well as the intolerance and trophic category of individual were focused for this purpose. The results indicate that the organization and well-being of the communities were the most important variables, in determining the biotic integrity index in three higher stream orders, namely 2nd, 3rd and the 4th. In general, the Sorocaba river showed alterations in relation to the established patterns for ictic communities have been indicating of a certain degree of degradation in the system.
197

The history of marine fish systematics in South Africa

Gon, O (Ofer), 1949- January 2003 (has links)
South African marine fish collections and systematic research are relatively young, essentially a product of the 20th century. Their history in South Africa comprises three distinct periods: the emergence of fish collections (before 1895), the beginning of research (1895-1945) and modern research (1945-1999). From the outset of their arrival in South Africa in the mid-17th century, the European settlers of the Cape Colony supplemented their diet with fishes. Therefore it is not surprising that when natural history museums appeared in the 19th century fishes were among the first specimens they procured or received from the public. In these early days, fishes were acquired for display purposes and were curated together with other natural history specimens. There were no fish collections as such and, in many ways, the early history of South African fish collections closely followed the history of the institutions in which they were housed. Major political events in South Africa between 1850-1910 had little effect on the slow growth offish collections as the low influx of specimens from the public did not change. None of the museums did any active fish collecting and no fish research as such took place during these years. The second period in the growth of fish collections in South Africa was characterised by a general shift to collecting for research rather than display. It was also a period during which the need for aquatic research was recognized by and began to attract funding from the South African government, starting with the establishment of the Marine Biological Survey in Cape Town. However, with the exception of the Albany Museum's self-trained J.L.B. Smith, no trained marine fish systematists were working in museums either as curators or as researchers. In the first half of the 20"' century South Africa experienced the fast growth of the fishing industry, the development of academic and applied research in marine biology, and the thriving of sport fishing. These developments created a demand for well-trained professional ichthyologists. J.L.B. Smith was the first to fill this professional gap. The growth rate offish collections increased significantly through the interaction between museum scientists, such as Smith in Grahamstown and K.H. Barnard in Cape Town, with the fishing industry, government biologists and fisheries officers, and anglers. Barnard's review of the South African marine fish fauna was published in mid-I920s. The discovery of the first living coelacanth placed South African ichthyology and Smith on the international stage. The identification of this fish, made by a relatively inexperienced Smith, changed the way ichthyology has been viewed in South Africa. At the beginning of the third period, largely due to the establishment of the Council for Scientific and Industrial Research in 1945, science in South Africa underwent a process of reorganisation. As funding became more available museums were able to enlarge their research staff. Natural history museums hired qualified experts to conduct research and manage collections of specific groups of organisms. For the first time, trained ichthyologists started working in museums and initiated research projects that were the main contributors to the growth of fish collections around the country. Furthermore it was a period of consolidation offish collections resulting in two large marine fish collections, one at the South African Museum, Cape Town, and another at the J .L.B. Smith Institute of Ichthyology, Grahamstown. This period also witnessed the establishment of the latter as a research institute dedicated to the study of fishes and its rise to international prominence. The last 55 years at J.L.B. Smith Institute of Ichthyology can be divided into two distinct periods, 1945-1967 and 1968-1999, each consisting of similar elements of research work and objectives. These included the research and production of major reviews of the fish faunas of South Africa, the western Indian Ocean and the Southern Ocean, as well as research on the coelacanth. While in the former period the work was done by one scientist, J.L.B. Smith, the latter period has been characterised by collaborative projects including scientists from South Africa and abroad. As this history shows, the establishment of a viable, long-lasting collection is a lengthy process. For about 60 years the durability of fish collections depended on the enthusiasm and persistence of individual curators and scientists who were not ichthyologists. More often than not, enthusiasm disappeared when such individuals left their museums. This dependence existed until Rhodes University College established the Department of Ichthyology (1947) and the South African Museum created a post specifically for the curation of the fish collection (1957) and thus ensured continuity. The continuity of biosystematic research in South Africa has been a minor concern for the nation's systematists for decades. The threats to marine fish systematics have been of a financial, political and professional nature. The latter has been the most serious one because of the dearth of South Africans trained in marine fish systematics. After J.L.B. Smith's death in 1968 M.M. Smith had to work hard to convince the Council for Scientific and Industrial Research and Rhodes University that she could step into her late husband's shoes. Realizing that there was nobody to take over from her she initiated the first and only postgraduate programme in ichthyology in South Africa. The teaching started in the academic year of 1970171 at the J.L.B. Smith Institute of Ichthyology, but to date only one student has completed a thesis in marine fish systematics. Due to the government's transformation policy all the practising marine fish systematists in South Africa will be retiring in the course of the present decade. Consequently, if no aspiring, motivated students appear on the scene in the next couple of years marine fish systematics in this country will be in a deep crisis by the year 2010, possibly even earlier.
198

<strong>MOVEMENTS, HOME RANGES, AND HABITAT USE OF  JUVENILE GREEN TURTLES IN SANTA ELENA BAY, MATAPALITO BAY, AND LEONCILLOS BAY IN COSTA RICA</strong>

Fanqi Wu (16317180) 13 June 2023 (has links)
<p>This study monitored daily and seasonal locations of juvenile green turtles in three coastal bays of northwest Costa Rica, determining their home ranges and assessing their habitat use. My objective was to produce insights which might help future Pacific Ocean green turtle conservation efforts.</p> <p>I tracked 14 juvenile green turtles for 51-629 days using acoustic transmitters (VECOM v16) and 12 acoustic receivers (VECOM VR2Tx and VR2W) in 5 study area habitats: sandy areas, reef patches, macroalgae, rocky reefs, and mangroves. I divided these 14 turtles into large (equal to or larger than 65 cm CCL) and small (smaller than 65 cm CCL) size classes so I could highlight any changes as they grew toward adulthood. </p> <p>Both the large and small size turtles used habitats differently during the dry and rainy seasons. During the dry season, the large juveniles had a High Detection Rate (HDR) of 40% in the macroalgae area. During the rainy season, their HDR was 33% in the reef patch area. The small juveniles had their HDR in the reef patch area during both seasons: 33% in the dry season and 43% in the rainy season. The mean home range for the 14 turtles was 1.96 km²; their core use area was 0.19 km2. I saw no connection between body size and home range. The HDR findings suggest that juvenile green turtles preferred reef patches, rocky reefs, and macroalgae habitat types. The large juveniles prefer vegetation areas more as they grew; similar to that of adult green turtles. Some turtles moved between Matapalito Bay and Santa Elena Bay and along the coast to small bays east of Matapalito Bay. Travel speed varied between 0.23 km/h and 12.90 km/h with a mean of 1.57 km/h.  </p> <p>My findings highlight certain habitat areas preferred by Pacific juvenile green turtles. This can guide conservationists in identifying and protecting similar habitats in other inshore Pacific bays in Central America. By protecting habitat areas that are important for juvenile green turtles, this can help rebuild the green turtle population in the Pacific Ocean. </p>
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L’exploitation des faunes marines à Qal’at al-Bahreïn (île de Bahreïn, Golfe persique), du Bronze Ancien à l’époque islamique : Etude diachronique et comparaison avec les sites du Golfe / Fish exploitation at Qal'at al-Bahrain, (archipelago of Bahrain, Arabo-Persian Gulf), from the Early Dilmun to the Middle Islamic period

Vorenger, Justine 05 May 2017 (has links)
Localisé sur l'île de Bahreïn, le tell de Qal'at al-Bahreïn fut un grand port occupant une position géographique stratégique, au milieu du Golfe persique, entre le Proche-Orient et le reste du continent asiatique. Grâce à cette position littorale, le site joua pendant plusieurs millénaires (du 3e millénaire avant J.-C., jusqu'au 17e siècle de notre ère), un important rôle commercial et maritime, entre la Mésopotamie, les côtes iraniennes et arabes, l'Oman, le sous-continent indien ou encore l'Extrême-Orient.Fouillé depuis près de soixante années, ce site d'habitat offre aux archéologues une stratigraphie exceptionnelle, unique dans la Péninsule arabique, qui s’étend du Dilmoun Ancien (c. 2200 av. J.-C.) jusqu’à la période islamique (c. 13e-16e siècle ap. J.-C.) et permet l’étude comparative des occupations successives du site. Au-delà de ce statut de référence régionale, Qal'at al-Bahreïn présente par ses monuments (résidentiels, administratifs, commerciaux, religieux et militaires) un véritable témoignage du développement historique de Dilmoun, culture la plus importante du Golfe antique.Les nombreux vestiges architecturaux sont associés à un matériel archéologique diversifié (céramique, métal, représentations figurées, inscriptions, sceaux, macrorestes végétaux et fauniques, incluant un grand nombre de restes de poissons). La présente étude porte sur les restes osseux de poissons exhumés lors des différentes campagnes de fouilles conduites par la mission archéologique française, de 1989 à 1996, puis de 2000 à 2004, complétés par les résultats obtenus lors des fouilles danoises, menées entre les années 50 à 70.Ce matériel osseux, abondant, et généralement bien conservé, est très bien stratifié, ce qui a permis une étude diachronique de cet échantillon.La détermination des os de poissons a permis de mettre en évidence un spectre constant de quatre familles tout au long de l’occupation du site : les Serranidae (mérous), les Carangidae (carangues), les Sparidae (sars) et les Lethrinidae (empereurs). Leur importance varie au sein de chaque occupation et il est alors intéressant de noter la corrélation entre les espèces consommées et les habitants du site.Si la période du Dilmoun Ancien montre un spectre assez varié, l’arrivée sur l’île des Kassites (c. 1450 av. J.-C.) met en avant une pêche très orientée, avec la capture des empereurs. Il semble qu’il y ait une préférence pour cette famille. Les périodes suivantes montrent un spectre à nouveau plus diversifié, qui s’étoffe d’avantage lors de la diffusion de l’Islam sur l’île. Les espèces consommées se rapprochent alors de celles commercialisées de nos jours. Cette grande variété s’accompagne d’une diminution des tailles des poissons, qui peut s’expliquer par un nouveau territoire de pêche et la capture de nouvelles espèces afin de diversifier la consommation de poisson.Malgré ces différences notables au cours des occupations qui peuvent être liées aux habitants et à leur préférence alimentaire, il apparait que les populations successives de Qal’at al-Bahreïn ont intensément exploité les ressources côtières et avaient une parfaite connaissance du milieu marin et des comportements des espèces capturées. / Located on the island of Bahrain, the tell of Qal’at al-Bahrain was a main port occupying a strategic geographical position, in the middle of the Persian Gulf, between the Middle East and the rest of the Asian continent. Thanks to its coastal position, the site played during several millenia (from the 3rd millenium BC, until the 17th century AD), an important commercial and maritime role, between Mesopotamia, the Iranian and Arab coasts, Oman, the Indian sub-continent or the Far East.Excavated since nearly sixty years, this coastal settlement offers to the archaeologists an exceptional, unique stratigraphy in the Arabian Peninsula, which extends from the Early Dilmun (c. 2200 BC) to the Middle Islamic period (c. 13-16th centuries AD), and provides the opportunity to study and compare the successive occupations at the site. Beyond this regional reference status, Qal’at al-Bahrain presents by its monuments (residential, administrative, commercial, religious and military) a true testimony of the historical development of Dilmun, the most important culture of the ancient Gulf.The numerous architectural vestiges are associated with a diversified archaeological equipment (ceramic, metal, figurative art, inscriptions, seals, vegetal and faunal macro-remains, including a large number of fish remains). The present study is devoted to the fish remains unearthed during the various excavation seasons led by the French archaeological mission, from 1989 to 1996, then from 2000 to 2004, and completed by the results gathered at the time of the Danish excavations, carried out since the 1950s. The bone material, which is abundant and quite well preserved, allows a diachronic study of this sample.The determination of the fish bones reveals a constant spectrum of four families throughout the occupation of the site: Serranidae (groupers), Carangidae (carangues), Sparidae (seabream) and Lethrinidae (emperors). Their importance varies within each occupation and it is then interesting to note the correlation between the consumed species and the inhabitants of the site.If the Early Dilmun period shows a rather diversified spectrum, the arrival of the Kassites on the island (c. 1450 BC) suggests a much more directed fishing activity, with the capture of the emperors. It seems that there is a preference for this family. The following periods show again a more diversified spectrum, which increased at the time of the spread of Islam on the island. The consumed species approach those marketed then nowadays. This large variety is linked with a reduction in the sizes of the fishes, which can be explained by a new fishing territory and the capture of new species to diversify the fish consumption.In spite of these notable differences during occupations which can rely on the inhabitants and their food preference, it appears that the successive populations of Qal’at al-Bahrain exploited intensely the coastal resources and had a perfect knowledge of the marine environment and behaviours of the captured species.
200

Feeding ecology of the New Zealand sea lion (Phocarctos hookeri) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor Philosophy in Zoology at Massey University, Palmerston North, New Zealand

Meynier, Laureline January 2009 (has links)
The New Zealand (NZ) sea lion Phocarctos hookeri is the only pinniped endemic to NZ with a population of approximately 12,000 individuals. Its breeding range is currently restricted to NZ sub-Antarctic islands, and it has failed to recolonise its pristine distribution around the NZ main islands despite its protection since 1881. The current hypothesis is that the population growth of this pinniped is limited by the distribution of suitable prey on the Auckland Islands (50°30'S, 166°E) shelf, and by the direct and indirect pressure exerted by the arrow squid Nototodarus sloani fishery. However, this hypothesis has not been fully tested to date as there has been limited information on the diet of the NZ sea lion and their potential prey. The objective of this thesis is to analyse the diet of NZ sea lions over several years with particular emphasis on the most reproductively important segment of the population: lactating females. This thesis provides the first quantification by percentage mass of the diet of NZ sea lion using a combination of stomach content analysis, qualitative fatty acid (FA) analysis, and quantitative FA signature analysis (QFASA). Stomach contents and blubber FAs were analysed from 121 individuals incidentally caught (by-caught) in the southern arrow squid fishery from the years 1997 to 2006. The blubber FAs of 78 freeranging lactating females captured at Enderby Island, Auckland Islands, were also examined during January and February of 2000 to 2005. Data obtained from both stomach analysis and QFASA indicate that arrow squid, rattails Macrouridae, hoki Macruronus novaezelandiae and red cod Pseudophycis bachus are key prey species for NZ sea lions in the Auckland Islands region. Because these prey species live mostly at depths greater than 200 m, lactating females must undertake long foraging trips and dive regularly to greater depths than other sea lion species. Data from QFASA indicates that this foraging pattern is conducted over an extended period through the summer and autumn. The daily food requirement of a lactating female was estimated by a simple energetic model to be greater than 20% of its body mass. During years of low arrow squid recruitment such as 1999 and 2001, the amounts of squid required by the NZ sea lion population may have been similar to the amount harvested by the fishery, suggesting that resource competition is likely to occur between the arrow squid fishery and NZ sea lions in years of low squid abundance. Half of the fishing activity of the southern squid fishery occurs in the north of the Auckland Islands shelf where NZ sea lions forage, leading to incidental captures every year. This research emphasises that management of the NZ sea lion must not only consider the direct interactions with the arrow squid fishery, but also the likelihood of food resource competition between the fishery and NZ sea lions.

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