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Made available in DSpace on 2015-01-26T13:21:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-27Bitstream added on 2015-01-26T13:30:32Z : No. of bitstreams: 1 000792978_20150127.pdf: 384795 bytes, checksum: e2d28327453e133ac0c4f145810767c2 (MD5) Bitstreams deleted on 2015-01-30T18:23:36Z: 000792978_20150127.pdf,Bitstream added on 2015-01-30T18:24:05Z : No. of bitstreams: 1 000792978.pdf: 3958190 bytes, checksum: 616d234386031ca87d88755d7374b280 (MD5) / Frente aos impactos causados pela ação antrópica no ambiente marinho, a proposta desse trabalho foi fornecer subsídios para a conservação das espécies, na área adjacente à Baía da Babitonga, estado de Santa Catarina, Brasil. O objetivo foi inventariar as espécies existentes da comunidade de camarões marinhos, detectar e descrever padrões gerais na sua distribuição espaço-temporal e relação às variáveis ambientais que caracterizam seu habitat. Portanto, foram mensurados os índices ecológicos e testados os parâmetros ambientais aos biológicos com análise multivariada. Os camarões foram coletados em julho de 2010 a junho de 2011, junto às variáveis ambientais, como temperatura e salinidade da água e textura e conteúdo de matéria orgânica do sedimento. Utilizou-se um barco camaroneiro equipado com redes double-rig, o qual percorreu cinco pontos paralelos a costeira com profundidades de 5, 8, 11, 14 e 17 m. A riqueza total chegou a doze espécies, pertencendo a três superfamílias, seis famílias e onze gêneros. Dessas, seis espécies de camarões peneídeos são comercializados: Xiphopenaeus kroyeri, Artemesia longinaris, Pleoticus muelleri, Farfantepenaeus brasiliensis, Farfantepenaeus paulensis e Litopenaeus schmitti. As demais espécies de peneídeos, Rimapenaeus constrictus e Sicyonia dorsalis, e carídeos, Exhippolysmata oplophoroides, Alpheus intrinsecus, Nematopalaemon schmitti e Periclimenes paivai, pertencem à fauna acompanhante dos recursos pescados. X. kroyeri foi a espécie dominante (D) espacialmente e temporalmente, apresentando valores discrepantes de abundância relativa 97,7% quando comparada à segunda espécie de maior abundância P. muelleri (1,1%), circunstância que influenciou diretamente nos resultados das análises de agrupamento e nos valores de diversidade (H’) e equitabilidade (J’), que foram altos quando a abundância da espécie foi menor. Esse resultado corroborou aos padrões das ... / Due to the impact caused by anthropic action on marine environment, the purpose of this work was to provide subsidies for species conservation at Babitonga Bay adjecent area in the state of Santa Catarina, Brazil. The aim was to catalogue existing species of marine shrimps communities, to detect and to describe general patterns in its temporal-spatial distribution and the relation to environmental variables that characterize its habitat. Therefore, ecological indexes were measured and environmental to biological parameters were tested with multivariate analysis. A shrimp boat equipped with double-rig nets was used and it travelled five parallel to the coast with a depth of stations 5, 8, 11, 14 e 17 m. The total richness reached twelve species, belonging to three superfamilies, six families and eleven genera. Of these, six species of peneid shrimps are marketed: Xiphopenaeus kroyeri, Artemesia longinaris, Pleoticus muelleri, Farfantepenaeus brasiliensis, Farfantepenaeus paulensis and Litopenaeus schmitti. The other species of peneids Rimapenaeus constrictus and Sicyonia dorsalis, and caridean shrimps Exhippolysmata oplophoroides, Alpheus intrinsecus, Nematopalaemon schmitti and Periclimenes paivai belong to bycatch of fisheries resources. X. kroyeri was a dominant (D) species in space and time, presenting discrepant values of relative abundance 97.7% when compared with the second most abundant species P. muelleri 1.1%, a circumstance that directly influenced the results of cluster analysis, the diversity (H’) and eveness (J’) values, which were high when the abundance of the species was lower. The patterns of the marine shrimp communities investigated in other regions were corroborated by the result of this study. Changes in shrimp communities could be related to variations in measured environmental variables and biological requirements specific to each species. The bottom temperature and sediment grain size were the preponderant ...

Orientador: Antonio Leão Castilho / Banca: Maria Lúcia Negreiros Fransozo / Banca: Sérgio Rosso / Resumo: Frente aos impactos causados pela ação antrópica no ambiente marinho, a proposta desse trabalho foi fornecer subsídios para a conservação das espécies, na área adjacente à Baía da Babitonga, estado de Santa Catarina, Brasil. O objetivo foi inventariar as espécies existentes da comunidade de camarões marinhos, detectar e descrever padrões gerais na sua distribuição espaço-temporal e relação às variáveis ambientais que caracterizam seu habitat. Portanto, foram mensurados os índices ecológicos e testados os parâmetros ambientais aos biológicos com análise multivariada. Os camarões foram coletados em julho de 2010 a junho de 2011, junto às variáveis ambientais, como temperatura e salinidade da água e textura e conteúdo de matéria orgânica do sedimento. Utilizou-se um barco camaroneiro equipado com redes double-rig, o qual percorreu cinco pontos paralelos a costeira com profundidades de 5, 8, 11, 14 e 17 m. A riqueza total chegou a doze espécies, pertencendo a três superfamílias, seis famílias e onze gêneros. Dessas, seis espécies de camarões peneídeos são comercializados: Xiphopenaeus kroyeri, Artemesia longinaris, Pleoticus muelleri, Farfantepenaeus brasiliensis, Farfantepenaeus paulensis e Litopenaeus schmitti. As demais espécies de peneídeos, Rimapenaeus constrictus e Sicyonia dorsalis, e carídeos, Exhippolysmata oplophoroides, Alpheus intrinsecus, Nematopalaemon schmitti e Periclimenes paivai, pertencem à fauna acompanhante dos recursos pescados. X. kroyeri foi a espécie dominante (D) espacialmente e temporalmente, apresentando valores discrepantes de abundância relativa 97,7% quando comparada à segunda espécie de maior abundância P. muelleri (1,1%), circunstância que influenciou diretamente nos resultados das análises de agrupamento e nos valores de diversidade (H') e equitabilidade (J'), que foram altos quando a abundância da espécie foi menor. Esse resultado corroborou aos padrões das ... / Abstract: Due to the impact caused by anthropic action on marine environment, the purpose of this work was to provide subsidies for species conservation at Babitonga Bay adjecent area in the state of Santa Catarina, Brazil. The aim was to catalogue existing species of marine shrimps communities, to detect and to describe general patterns in its temporal-spatial distribution and the relation to environmental variables that characterize its habitat. Therefore, ecological indexes were measured and environmental to biological parameters were tested with multivariate analysis. A shrimp boat equipped with double-rig nets was used and it travelled five parallel to the coast with a depth of stations 5, 8, 11, 14 e 17 m. The total richness reached twelve species, belonging to three superfamilies, six families and eleven genera. Of these, six species of peneid shrimps are marketed: Xiphopenaeus kroyeri, Artemesia longinaris, Pleoticus muelleri, Farfantepenaeus brasiliensis, Farfantepenaeus paulensis and Litopenaeus schmitti. The other species of peneids Rimapenaeus constrictus and Sicyonia dorsalis, and caridean shrimps Exhippolysmata oplophoroides, Alpheus intrinsecus, Nematopalaemon schmitti and Periclimenes paivai belong to bycatch of fisheries resources. X. kroyeri was a dominant (D) species in space and time, presenting discrepant values of relative abundance 97.7% when compared with the second most abundant species P. muelleri 1.1%, a circumstance that directly influenced the results of cluster analysis, the diversity (H') and eveness (J') values, which were high when the abundance of the species was lower. The patterns of the marine shrimp communities investigated in other regions were corroborated by the result of this study. Changes in shrimp communities could be related to variations in measured environmental variables and biological requirements specific to each species. The bottom temperature and sediment grain size were the preponderant ... / Mestre

The groundfish trawl fishery operating off the coasts of Oregon and Washington 1985-1987 caught six major assemblages of species which could be treated as units in developing mixed-species management plans. Eighty-one percent of the tows observed on commercial vessels were consistently placed in one of the assemblage designations using three multivariate techniques. Two of the assemblages were dominated by a single species, pink shrimp (Pandalus jordani) or widow rockfish (Sebastes entomelas). The other assemblages identified were: a deepwater rockfish assemblage, a deepwater Dover sole assemblage, a nearshore mixed-species assemblage, and a bottom rockfish assemblage. The assemblage designations of the consistently placed tows were predicted with an estimated 85% average accuracy using discriminant functions based on the gear used and bottom depth fished. Fishermen had different targets (intended catch) for each assemblage caught. The mixed-species assemblages had several targets, representing at least some of the dominant species in the assemblage. Targeting and discarding information indicated that fishermen did not always intend to catch the species together; there were unintentional or unavoidable catches of all the major species except for shrimp in the shrimp assemblage. Discarding occurred in all the assemblages, primarily due to unmarketable species or fish that were too small to market. Monitoring the assemblages over time could be accomplished by using the defined strategies with logbook data, particularly if the large and small rockfish categories were used to consistently separate shelf and deepwater rockfish. The defined strategies could not effectively predict the research cruise assemblages or catches; research data do not accurately describe commercial catches. / Graduation date: 1994

The Wing Trawling System (WTS) was tested as an alternative to traditional shrimp capture methods in the Gulf. Compared to an otter trawl, this trawl was conceived to reduce bycatch, retain shrimp catch, and minimize seafloor disturbance. Through seventy-one paired tows, the WTS was assessed against a standard otter trawl. The WTS was found to reduce bycatch by 63-65% and reduce shrimp catch by 30-35%. Additionally, I measured the depth of the scars produced by both trawls and quantified the turbidity of the plumes behind them. The scars left by the WTS and the otter trawl were between 9.9 cm-13.6 cm. The turbidity behind the WTS was 18.6 NTU, while the turbidity behind the otter trawl was 206.8 NTU. In conclusion, the WTS offers an alternative to an otter trawl that reduces bycatch and the impact trawling has on the seafloor but results in a significant amount of shrimp loss.

Management of prawn trawling fisheries is a difficult task due to the competing interests of strongly motivated stakeholders and interest groups. This occurs because prawn trawling operations are technically complex, require large capital investments and exhibit high running costs while owners have limited property rights over the resources that they harvest. Prawn stocks are public resources and are managed with a view to provide maximum benefit to the broad community. Additionally their exploitation also involves the incidental capture of significant numbers of other animals of no commercial value (bycatch) and causes impacts on seabed morphologies, which are involved in many diverse ecosystem processes. At the policy level an intention to manage trawl fisheries in a comprehensive way is backed by a mandated approach that is designed to capture all of the above issues and interests. That approach is termed Ecological Sustainable Development (ESD). The work in this thesis is designed to produce a prediction tool for prawn trawling performance that is based on modelling the physical nature of prawn trawling activities. It is proposed that the resulting tool is essential for working to manage the multi-dimensional aspects of prawn trawling fisheries. Three discrete objectives for the thesis are; to expand and improve an existing Prawn Trawling Performance Model (PTPM) so that it is more accurate and relevant to a broader range of questions, to evaluate the capacity of the PTPM to predict the performance characteristics of real prawn trawling operations in terms of both engineering and catching performance and to investigate the problem space surrounding prawn trawl fisheries to identify and develop applications for the model. A rudimentary PTPM (Sterling 2000b) is expanded through the analysis of further empirical data collected for model and full-scale trawl gear. / ght area of improvement to the PTPM were considered and in all cases significant changes were made. The accuracy of the new form of the model is here tested by comparing performance predictions with measurements of trawling performance for a variety of industrial trawl systems operated in the Queensland East Coast Trawl Fishery and also through comparing predicted trawling performance with prawn catches returned for trawlers operating in the Northern Prawn Fishery over the years 1970 to 2000. In the first case, errors in predicting swept area rate, considered an important performance parameter, were less than 5%. Fine scale issues were explored using the available sea mal data and a number of areas of concern within the model are highlighted. These relate to accurately quantifying the forces involved in the interaction of the trawl gear with the seabed and accurately accounting for the interaction between components within trawl systems. In the second case, the results suggest that between 50% and 60% of the variation in the seasonal catching performance of trawlers in the NPF is explained by predictions of swept area rate derived by the PTPM from the available data for that fishery. A comprehensive survey of applications for the PTPM is conducted in context with approaching the management of prawn trawling fisheries using the principles of ESD as defined by the National Strategy for ESD (1992). The Northern Prawn Fishery is used as a case study to explore in finer detail applications for the PTPM. Issues arising from the implementation of some of the applications are discussed.

Thesis (Ph. D.)--Murdoch University, 2007. / Title from PDF title page (viewed on Apr. 23, 2007). Includes bibliographical references (p. 342-357).

No description available.

The purpose of this study was to develop a methodology to analyse ROV video and scanning-sonar data to document the abundance and distribution of epi-benthic megafauna on the continental slope off Vancouver Island and to quantify the impact of trawling on these megafaunal assemblages. Impacts of bottom trawling on deep-sea ecosystems vary depending on habitat types and species present. Environmental factors such as depth, dissolved oxygen concentration, substratum type, and bottom roughness also affect the diversity and composition of benthic communities. We studied two transects (30km and 12km long) on the upper continental slope off Vancouver Island, BC, Canada, that included areas of seafloor with visible trawl marks. Our study area was also located in an oxygen minimum zone with very low bottom water dissolved oxygen concentrations in its core (600m-1000m). The main target for bottom trawling fisheries in this area is the longspine thornyhead (Sebastolobus altivelis). Field data were collected using the ROV ROPOS equipped with a 3CCD video camera and high-resolution scanning sonar. Megafaunal composition/abundance and bottom characteristic information were extracted from video imagery and assembled using a custom-designed MS Access database. The same database was used to compile information on trawl-door marks detected in recorded sonar imagery. The sonar surveyed a 50m radius around the submersible during transects, providing a broader view of evidence of trawling in the area than video. This thesis reports on relationships between environmental variables and faunal abundance, diversity and species distribution. Following the video and sonar analysis, diversity patterns and general species distribution for both transects were determined. Relationships of community structure to depth and trawling intensity were investigated using the hierarchical clusters technique to identify similarities in the megafauna assemblages between stations . Finally, spatial structures in the megafaunal community and their associated environmental variables were examined using the Principal Coordinates Neighbour Matrices (PCNM) and redundancy analysis tests. Differences in total abundance, species composition and distribution, and species diversity were detected between the high and low trawling intensity areas. One of the main highlights of our results was the dominance of ophiuroids and holothurians along most of the transect, except for the highly trawled area. Spatial structures were identified in the megafaunal community, showing a strong influence of bottom trawling intensity and, to a lesser extent, depth. Nearby water column measurements of dissolved oxygen concentrations suggest that depth might be associated with dissolved oxygen levels, but in situ oxygen data were not available during the ROV surveys. A deeper understanding of in situ oxygen levels would help clarify the role of this factor in shaping megafauna assemblages and its interaction with trawling. / Graduate

Thesis (M.M.S.)--Memorial University of Newfoundland, 2001. / Includes bibliographical references (leaves 75-82).