Thesis (Ph.D.)--University of Tasmania, 2004. / For consultation only. No copying permitted until 13-3-2006. Includes bibliographical references.

Commercial longline fishing results in large amounts of incidental bycatch of elasmobranch fishes (sharks, skates, and rays). Teleost species lack electrosensory systems and development of technologies which target the ampullary organs of sharks provides an avenue to selectively deter elasmobranchs without affecting the catch rate of target teleosts. Electric field measurements and a controlled scientific longline study were conducted testing whether the lanthanide metal neodymium or zinc/graphite might reduce elasmobranch catch per unit effort (CPUE). Baited longline hooks were treated with neodymium and zinc/graphite and catch rates were compared to that of controls. Shark CPUE decreased by 60% on neodymium treated hooks and 80% on zinc/graphite treated hooks. The effectiveness of both treatments varied among species with significant reductions shown for Atlantic sharpnose sharks (Rhizoprionodon terranovae) but less dramatic differences for others. Zinc/graphite is potentially a viable tool for reduction of shark bycatch in a commercial longline fishery. / by Kieran Thomas Smith. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

This study formed part of a larger provincial marine systematic conservation plan for KwaZulu-Natal (KZN), South Africa, called SeaPLAN. Owing to budget and time constraints, not all ± 1640 fish species that occur in the region were considered. A method to prioritise species was therefore developed to identify those species which were most at most risk of being excluded by a conservation plan based primarily on habitat representation (i.e. SeaPLAN). The method was based on three underlying principles: (i) species with limited conservation options; (ii) threatened species; and (iii) inherently vulnerable species. From these three principles, seven criteria were defined (e.g. endemic or rare species). Sixtyseven species met the qualifying conditions for these criteria and were consequently included in this study (FishPLAN). In order to map the distributions of these 67 fish species, the spatial and temporal accuracy of existing marine fish data for KZN was investigated. Only 17 percent of the data evaluated met the spatial resolution requirements of 1 km2, while temporal resolution was high: >99 percent of the data were collected at daily resolution. A resulting recommendation is that future data collection employ handheld data recording devices (with GPS capability), in order to increase the spatial accuracy of data, minimise human error and improve the efficiency of data flow. Species life cycle envelopes (SLICES) were developed to capture spatial differences in areas occupied during three life-cycle phases (reproductive, juvenile and feeding). Two distribution modelling techniques were used: Maxent, which uses quantitative data, and CHARMS (cartographic habitat association range models), which uses qualitative range data. A combination of statistical and biological criteria was used to determine the most informative and appropriate model for each species. Species distribution models (SDMs) were constructed for three temporal partitions of the data: annual, summer and winter. Patterns of species richness developed from the seasonal models showed seasonal differences in patterns that conformed to known seasonal distributions of fish assemblages: richness was higher in southern KZN during winter, while it was higher in northern KZN during summer. The resulting SDMs were used to develop a conservation plan for fish: conservation targets were set using the minimum recommended baseline of 20 percent of a species’ range, to which biological retention targets (additional proportion of the range) were added, in an attempt to ensure species persistence. The conservation targets were then adjusted using catch per unit effort (CPUE) data to match seasonal abundance of a given species. Within the existing network of marine protected areas (MPAs), none of the species’ targets are met by MPA sanctuary zones (zone As) alone, and all species require greater areas of protection. Three areas, namely offshore of the Tugela River mouth, the reefs offshore of Durban, and Aliwal Shoal, were consistently identified as being important in addition to existing MPAs for conservation of the fish species investigated. The greater efficiency of a seasonal MPA network to protect seasonally varying distributions of biodiversity, suggests that this may be a useful tool to consider in conservation management. The outcome of a conservation plan from this study (FishPLAN) was finally compared with the broader, more inclusive conservation plan, SeaPLAN. This comparison demonstrated how conservation plans based on a single group of species run the risk of identifying areas that are appropriate only for the relevant species, and might fail to conserve biodiversity as a whole.

The Fishery Conservation and Management Act of 1976 took effect on March 1, 1977. By this Act the United States extended its management over fisheries to 200 nautical miles from shore. Extended fishery jurisdiction was expected to promote industry development and expand the contribution of the fishing industry to the economies of the coastal regions. Benefits to the Pacific Coast groundfish industry have, however, been less than were expected when the Act was passed. A spatial equilibrium model was formulated for the broader United States interregional/international groundfish market. Two steps were involved: First, a system of simultaneous econometric equations was estimated for each of the three product forms—fresh and frozen cod, ocean perch, and flounder fillets. Second, regionalized forms of these equations were collapsed into simple equations and combined with transportation and storage costs in a larger mathematical programming model. The resulting quadratic programming (QP) problem was then solved (for each product) for the competitive equilibrium quantities demanded and supplied, prices, and product movements. Two objectives were achieved: A model was formulated that accounts for most of the relevant factors influencing the United States groundfish market; and the multiregional nature of this market was established. The estimated price and income elasticities were similar to those suggested by earlier studies, and the estimated product movements were consistent with survey data in the Pacific Northwest. The various policies evaluated in this study (using the spatial equilibrium model) suggest mixed blessings to the Pacific Coast groundfish industry. There is no evidence to suggest that harvesting some average quantities uniformly throughout the year would improve industry revenues. In general, increasing Pacific Coast landings by 30 percent (or more) would depress wholesale revenues but substantially increase fleet revenues. On the other hand, both wholesale and fleet revenues would increase if at least 80 percent of the increase in landings could be sold in markets outside the region. This suggests that an industry policy aimed at expanding landings on the Pacific Coast will improve revenues for all industry participants only if access to outside markets also takes place. / Graduation date: 1987

O presente estudo teve por objetivo avaliar o desempenho do Teste do Cometa em confronto com métodos convencionais de avaliação de frescor e qualidade higiênica e sanitária de filés de Tilápia (Oreochromis niloticus - LINNAEUS, 1758) refrigerados, durante a vida útil comercial, correlacionando os seus resultados com aqueles obtidos nas análises físico-químicas, microbiológicas e sensorial. As análises foram realizadas nos dias zero - cinco - nove - 12 - 14 pós-processamento dos filés. Em cada dia de estudo foram processados três filés diferentes, pertencentes ao mesmo lote de produto. O protocolo foi repetido em três momentos diferentes, completando 45 amostras. Nos resultados encontrou-se no dia zero e no quinto dia útil do produto, condições impróprias para consumo com relação aos microrganismos psicrotróficos e mesófilos, respectivamente, e o tipo de cometa predominante foi o tipo 3. Aos nove dias de vida útil dos filés, a média dos parâmetros Trimetilamina, Odor e Intenção de Compra indicavam produto impróprio e no teste do cometa predomina o tipo 5. Aos 12 dias de vida útil dos filés de Tilápia, refrigerados, bases voláteis nitrogenadas totais e textura obtiveram resultados impróprios, enquanto que a aparência se revelou imprópria a partir do 14º dia. Concluiu-se que o teste do cometa se presta para o estudo de vida útil de filés de Tilápia refrigerados e apresentou correlação com os métodos convencionais de avaliação de frescor e qualidade higiênica e sanitária do pescado. A partir do 9º dia de estudo predominavam cometas do tipo 5, indicativos do grau máximo de dano celular e fragmentação de DNA das células, pelo teste do cometa, o que coincidiu com a rejeição da Intenção de Compra na análise sensorial. / The present study aimed to evaluate the performance of the Comet assay in comparison with conventional methods of assessing freshness and hygienic and sanitary quality of chilled Tilapia (Oreochromis niloticus - Linnaeus, 1758) fillets, over the shelf-life, correlating their results with those obtained in the physical-chemical, microbiological and sensory. The analyzes were performed on days zero - 5 - 9 - 12 - 14 post-processing of the fillets. In each study day were processed three different fillets, belonging to the same batch of product. The protocol was repeated at three different times, completing 45 samples. The results showed that at the zero and fifth day of the product, improper conditions for consumption, with respect to psychrotrophic and mesophilic microorganisms, respectively, and the predominant type of comet was the type 3. At nine days of the fillets shelf-life, the average of the parameters trimethylamine, odor and purchase intent indicate improper product, and at the comet assay predominate type 5. At 12 days of the shelf-life of chilled tilapia fillets, total volatile basic nitrogen and texture results obtained improper conditions, while appearance showed improper at the 14th day. It was concluded that the comet assay lends itself to the study of shelf-life of chilled tilapia fillets and correlated with conventional methods of assessing freshness and hygienic and sanitary qualities of fishery. From the 9th day of study, predominated comets type 5, indicative of maximum degree of cell damage and DNA fragmentation of the cells by the comet assay, which coincided with the rejection of Purchase Intent at sensory analysis.

No description available.

O presente estudo teve por objetivo avaliar o desempenho do Teste do Cometa em confronto com métodos convencionais de avaliação de frescor e qualidade higiênica e sanitária de filés de Tilápia (Oreochromis niloticus - LINNAEUS, 1758) refrigerados, durante a vida útil comercial, correlacionando os seus resultados com aqueles obtidos nas análises físico-químicas, microbiológicas e sensorial. As análises foram realizadas nos dias zero - cinco - nove - 12 - 14 pós-processamento dos filés. Em cada dia de estudo foram processados três filés diferentes, pertencentes ao mesmo lote de produto. O protocolo foi repetido em três momentos diferentes, completando 45 amostras. Nos resultados encontrou-se no dia zero e no quinto dia útil do produto, condições impróprias para consumo com relação aos microrganismos psicrotróficos e mesófilos, respectivamente, e o tipo de cometa predominante foi o tipo 3. Aos nove dias de vida útil dos filés, a média dos parâmetros Trimetilamina, Odor e Intenção de Compra indicavam produto impróprio e no teste do cometa predomina o tipo 5. Aos 12 dias de vida útil dos filés de Tilápia, refrigerados, bases voláteis nitrogenadas totais e textura obtiveram resultados impróprios, enquanto que a aparência se revelou imprópria a partir do 14º dia. Concluiu-se que o teste do cometa se presta para o estudo de vida útil de filés de Tilápia refrigerados e apresentou correlação com os métodos convencionais de avaliação de frescor e qualidade higiênica e sanitária do pescado. A partir do 9º dia de estudo predominavam cometas do tipo 5, indicativos do grau máximo de dano celular e fragmentação de DNA das células, pelo teste do cometa, o que coincidiu com a rejeição da Intenção de Compra na análise sensorial. / The present study aimed to evaluate the performance of the Comet assay in comparison with conventional methods of assessing freshness and hygienic and sanitary quality of chilled Tilapia (Oreochromis niloticus - Linnaeus, 1758) fillets, over the shelf-life, correlating their results with those obtained in the physical-chemical, microbiological and sensory. The analyzes were performed on days zero - 5 - 9 - 12 - 14 post-processing of the fillets. In each study day were processed three different fillets, belonging to the same batch of product. The protocol was repeated at three different times, completing 45 samples. The results showed that at the zero and fifth day of the product, improper conditions for consumption, with respect to psychrotrophic and mesophilic microorganisms, respectively, and the predominant type of comet was the type 3. At nine days of the fillets shelf-life, the average of the parameters trimethylamine, odor and purchase intent indicate improper product, and at the comet assay predominate type 5. At 12 days of the shelf-life of chilled tilapia fillets, total volatile basic nitrogen and texture results obtained improper conditions, while appearance showed improper at the 14th day. It was concluded that the comet assay lends itself to the study of shelf-life of chilled tilapia fillets and correlated with conventional methods of assessing freshness and hygienic and sanitary qualities of fishery. From the 9th day of study, predominated comets type 5, indicative of maximum degree of cell damage and DNA fragmentation of the cells by the comet assay, which coincided with the rejection of Purchase Intent at sensory analysis.

Although the marine environment has generally been considered to be less in need of attention from conservationists, politicians and managers than the terrestrial environment, there has been an increasing appreciation that there is little left in the marine environment that can be considered unaltered by humans. Conservation action is therefore urgently needed to protect marine populations, species and environments from anthropogenic pressures. Since overharvesting seems to be the main cause of the collapse in coastal ecosystems, areas need to be protected so that stocks can recover. However, the proclamation of such marine protected areas (MPAs) need to be well planned to ensure that species are well represented and that their biological requirements are met in the long term. While terrestrial conservation planners have started to incorporate biological, social and economic information into so-called systematic conservation plans, marine planners have been more hesitant to use these approaches due to the greater openness of the ocean (with the associated greater dispersal of marine organisms and propogules, lower levels of endemism, and lack of ownership) and the paucity of available information. The current study aimed to investigate the applicability of systematic approaches to the process of selecting sites for a network of potential replenishment zones for seabream species that could supplement protection already afforded by existing no-fishing reserves. Since many of these seabream species are popular targets in both the recreational and commercial linefishery sectors, they have been overexploited and are in need of additional protection. Information on these species and the diversity of their associated reefs were obtained through consultations with scientists, managers and resource-users (namely SCUBA divers, spearfishers as well as recreational and commercial fishers). These data were obtained during workshops where Participatory Rural Appraisal (PRA) scoring and mapping methods were applied. Although ordinal-scale, rather than interval-or ratio-scale data were obtained, these data could be used in an interactive selection process. Because these methods require relatively cheap materials and few personnel, they could be used to collect information where limited budgets are available. Quantitative targets for the protection of individual species were set on the basis of their status in the Marine Living Resource Act, since this reflected their different requirements for protection. A preliminary investigation indicated that the current no-fishing reserves effectively achieved most of these goals for seabream species. The selection of sites for the replenishment network was based on irreplaceability analyses, while decisions between sites with lower irreplaceability values were based on explicit design rules. A total of 26 sites were required to achieve targets for all species. These replenishment zones could potentially be established, managed and monitored by voluntary community groups. This study therefore indicated that systematic conservation planning can successfully be applied to the marine environment, while the involvement of stakeholders is crucial to ensure that conservation action is supported.

Orientador: Otto Bismarck Fazzano Gadig / Abstract: The establishment of no-take marine reserves (NTRs), i.e. areas with total fishing restrictions, has been an alternative worldwide aiming to preserve both biodiversity and ecosystem functions. Brazil has important NTRs with few studies describing their relevance and efficiency for marine life. With this, the central objective of this thesis was to evaluate the effects of NTRs on fish assemblage, testing the hypothesis that the differences in richness, abundance, biomass and fish body size is more explained by protection status than environmental characteristics. Thus, innovative techniques in Brazil, Baited Remote Underwater stereo-Videos (stereo-BRUVs) and Diver Operated stereo-Videos (stereo-DOVs) were tested in the Southwestern Atlantic, comparing with traditional visual census (stationary point count and belt transects), and used to analyze the effects of the Tupinambás Ecological Station and Abrolhos Marine National Park on fish assemblages. For this, fish assemblage characteristics, such as richness, abundance, biomass and body size, were compared to areas where fishing is allowed, and the habitat complexity was estimated through the footages. Concerning methods comparison, stereo-DOV showed to be more effective, sampling more richness and abundance within less effort, and Stereo-BRUVs showed to sample a very specific assemblage, comprised mostly by mobile and large bodied fish species, usually targeted by fisheries. Within both NTRs evaluated, target species characteri... (Complete abstract click electronic access below) / Resumo: O estabelecimento de reservas marinhas de restrição total (No-take reserves - NTRs), ou seja, áreas com proibição total de pesca, tem sido uma alternativa mundial para preservar a biodiversidade e as funções dos ecossistemas. O Brasil tem importantes NTRs com poucos estudos descrevendo sua relevância e eficiência para a vida marinha. Com isso, o objetivo central desta tese foi avaliar os efeitos de NTRs em assembleias de peixes, testando a hipótese de que as diferenças em riqueza, abundância, biomassa e tamanho corporal dos peixes são mais explicadas pelo status de proteção do que por características ambientais. Para tanto, técnicas inovadoras no Brasil, estéreo-vídeos subaquáticos com isca (Baited Remote Underwater stereo-Videos - stereo-BRUVs) e estéreo-vídeos operados por mergulhador (Diver Operated stereo-Videos - stereo-DOVs) foram testados no Atlântico Sudoeste, comparando com os censos visuais tradicionalmente aplicados (estacionário e transecto), e utilizados para analisar os efeitos da Estação Ecológica Tupinambás e do Parque Nacional Marinho dos Abrolhos nas assembleias de peixes. Para isso, as características das assembleias de peixes em termos de riqueza, biomassa, abundância e tamanho corpóreo, foram comparadas com as áreas onde a pesca é permitida, e a complexidade do habitat foi estimada através das imagens. Em relação à comparação dos métodos, o estéreo-DOV apresentou maior eficiência, amostrando mais riqueza e abundância com menor esforço, e o estéreo-BRUV am... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Murray cod Maccullochella peelii peelii is an iconic freshwater angling species that has suffered declines in abundance and is now listed as a nationally vulnerable species. Despite recognition of the need for biological knowledge to provide future management directions, little is known of its ecology. This thesis examines that ecology to provide new knowledge and recommendations for improved conservation management. (For complete abstract open document)