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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.
1

Indicadores de sustentabilidade na larvicultura de camarão-da-amazônia, Macrobrachium amazonicum / Sustainability indicators of the Amazon River Prawn hatchery

Frota Filho, Josué Fernandes 19 April 2018 (has links)
Submitted by JOSUÉ FERNANDES FROTA FILHO (frotafilho.jf@outlook.com) on 2018-04-24T17:00:58Z No. of bitstreams: 1 Josue_Dissertação_24_04_FINAL.pdf: 705810 bytes, checksum: c7f70d2764da25e302dc2b38af6c84bd (MD5) / Rejected by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br), reason: Solicitamos que realize correções na submissão seguindo as orientações abaixo: O arquivo pdf submetido ao repositório deve conter a ficha catalográfica e o certificado de aprovação (documentos obrigatórios). Favor inserir no arquivo pdf a ficha catalográfica e o certificado de aprovação (tudo em um arquivo só). Agradecemos a compreensão. on 2018-04-25T12:56:05Z (GMT) / Submitted by JOSUÉ FERNANDES FROTA FILHO (frotafilho.jf@outlook.com) on 2018-04-26T11:48:21Z No. of bitstreams: 1 Josue_Dissertação_24_04_FINAL corrigido.pdf: 927542 bytes, checksum: a658dd423a96120871bc91bfa99cbc9b (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-26T12:10:28Z (GMT) No. of bitstreams: 1 fotafilho_jf_me_jabo.pdf: 927542 bytes, checksum: a658dd423a96120871bc91bfa99cbc9b (MD5) / Made available in DSpace on 2018-04-26T12:10:28Z (GMT). No. of bitstreams: 1 fotafilho_jf_me_jabo.pdf: 927542 bytes, checksum: a658dd423a96120871bc91bfa99cbc9b (MD5) Previous issue date: 2018-04-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O crescimento acelerado da aquicultura vem sendo acompanhado pela crescente preocupação em se garantir a sustentabilidade das atividades aquícolas. A sustentabilidade neste trabalho é baseada principalmente em duas dimensões: ambiental, e econômica. O presente trabalho teve como objetivo avaliar a sustentabilidade ambiental e a viabilidade econômica em pequena escala de produção de pós-larvas do camarão de água doce da espécie Macrobrachium amazonicum, por meio de um conjunto indicadores de sustentabilidade. Foram considerados os ciclos de produção durante um ano de cultivo de pós-larvas do camarão-da-amazônia. A capacidade produtiva considerada foi de 290 milheiros de pós-larvas/mês. A sustentabilidade ambiental foi medida com base na utilização de recursos naturais, eficiência no uso destes recursos e poluição liberada ao ambiente pelo meio de cultivo. A sustentabilidade econômica foi medida com base nos aspectos sobre a eficiência no uso dos recursos financeiros e a capacidade de gerar recursos para reinvestimentos na atividade. Os resultados sugerem que há viabilidade econômica para o produtor que realiza larvicultura em sistemas de fundo de quintal (backyard hatchery). Além disso, os dados obtidos também mostraram que embora a larvicultura seja uma atividade bastante intensificada, há eficiência na utilização dos recursos naturais, sendo mais sustentável do que outras fases de produção, como o berçário e crescimento final da mesma espécie. Desse modo, o modelo utilizado é uma alternativa viável com sustentabilidade econômica e ambiental para produção de pós-larvas de M. amazonicum em sistemas familiares de produção. / The rapid growth of aquaculture has been accompanied by the increasing concern to ensure sustainability of aquatic activities. In this work, sustainability is based on environmental and economic dimensions. The objective of the study is to evaluate the environmental and economic sustainability of a small scale Macrobrachium amazonicum post-larvae production using a set of indicators for sustainability. Production cycles during one year of the Amazon Prawn hatchery was considered. The considered productive capacity was 290 thousand post larvae/month. Environmental sustainability measurements were based on the use of natural resources, efficiency in the use of resources and pollution released to environment from the production facility. Economic sustainability measurements were based on the aspects of efficiency in the use of financial resources and the capacity to generate resources for reinvestments in the activity. Results show that there is economic feasibility for the ‘backyard’ hatcheries system for freshwater prawn farmers. In addition, data indicate that in spite of hatchery being a highly intensified activity, there is efficiency in using natural resources, and it is more sustainable than other production phases, such as nursery and grow-out phase of the same species. To sum it up, the hatchery model studied is a feasible and sustainable alternative to produce M. amazonicum post-larvae with environmental and economic sustainability to be operated using either family labour production. / 88882.156917/2017-01
2

The Role of Epibenthic and Planktonic Fauna in Subtropical Prawn Grow Out Ponds

Coman, Francis Edmund, n/a January 2003 (has links)
The assemblage composition, biomass and dynamics of zooplankton and epibenthos were examined in a commercial prawn pond in southeast Queensland over two seasons. Physico-chemical characteristics of the pond water were measured concurrently. Numbers and biomass of zooplankton in the surface tows (140 micrometre mesh) varied from 8 ind. L-1 (44 micrograms L-1) to 112 ind. L-1 (324 micrograms L-1) in the first season, with peaks in biomass corresponding to peaks in numbers. In the second season the zooplankton numbers varied from 12 to 590 ind. L-1, but peaks in numbers did not correspond with peaks in biomass, which varied from 28 to 465 micrograms L-1. This was due to differences in the size of the dominant taxa across the season. Although this occurred in both seasons, the effect on biomass was more pronounced in the second season. In both seasons, immediately after the ponds were stocked with prawn postlarvae there was a rapid decline in zooplankton numbers, particularly of the dominant larger copepods. This was probably due to predation by the postlarvae. Subsequent peaks in zooplankton numbers were principally due to barnacle nauplii. The largest peaks in zooplankton numbers occurred before stocking in the first season, but the largest peaks were in the middle of the second season. While changes in abundance and biomass of the zooplankton assemblage were not correlated with physico-chemical characteristics in the first season, there were correlations between zooplankton numbers and temperature, dissolved oxygen, pH and secchi disk readings in the second season. No correlations were found with zooplankton biomass and physico-chemical characteristics in the second season. The correlations in the second season were mainly due to the high prevalence of barnacle nauplii through the middle part of the season, and may reflect suitable conditions for barnacle reproduction. Epibenthic faunal abundance in the beam trawls (1 mm mesh) peaked at 14 ind. m-2 and 7 ind. m-2 in the first and second seasons respectively and the biomasses at 0.8 g m-2 and 0.7 g m-2. Peaks in abundance of epibenthos did not correspond to peaks in biomass. This was due to large differences in the size of the taxa across the seasons. Sergestids (Acetes sibogae) and amphipods were the most abundant taxa in beam trawl samples. Amphipods were only abundant in the first season, with their numbers increasing towards the end of the grow out period. Acetes were abundant in both seasons, but were dominant in the second season. Correlations between physico-chemical parameters and epibenthos numbers were found to be strongly influenced by the dominant taxa in each season. In the first season, negative correlations were found between epibenthos abundance and pH and temperature. These relationships may reflect an effect on the growth of macroalgae in the pond, with which the amphipods were strongly associated, rather than a direct effect on the epibenthos. In the second season, a positive correlation existed between temperature and epibenthos abundance, however this was strongly influenced by the very high abundance of Acetes in the last sampling period. No correlations were found between epibenthic fauna biomass and physico-chemical parameters. Abundances of epibenthic fauna were not related to zooplankton densities indicating this source of food was not likely to be a limiting factor. Neither the pond water exchange regime nor moon phase could explain changes observed in abundances of zooplankton or epibenthos assemblages in the first season, however the sampling regime was not designed to specifically investigate these effects. In the second season water exchanges were sampled more rigorously. The density of zooplankton in the outlet water was from 2 to 59% of the density of zooplankton in the pond, and the zooplankton density of the inlet water was from 9 to 50% of the outlet water. The number of zooplankton recruited into the pond from the inlet water, after the prawns were stocked, was negligible and contributed little to changes observed in zooplankton assemblages. Reproduction of barnacles within the pond appeared to play the most important role in changes in the assemblage. Water exchange did, however, appear to play a greater role in the changes observed in epibenthic fauna assemblages. In the last season of sampling the feeding of the dominant epibenthic species, Acetes sibogae, was examined using a combination of gut content and stable isotope analysis. Acetes gained little nutrition directly from the pelleted feed, probably relying primarily on zooplankton as their direct food source. Other dietary items such as macroalgae also played a role in the nutrition of the Acetes. If Acetes numbers were high at the beginning of a season they may compete with the newly stocked prawns for the zooplankton resource. However, they will not compete with the prawns later in the season when the prawns are gaining most of their nutrition from the pelleted feed. Overall it appears that zooplankton are important to the nutrition of the prawns at the beginning of the season when the assemblage is usually dominated by copepods. Later in the season the assemblage is dominated by barnacle nauplii which are recruited from within the pond. The establishment of an abundant assemblage of suitable zooplankton species before stocking prawn postlarvae would appear to be beneficial, if not essential. The assemblage of epibenthic fauna changes throughout the season as new recruits are brought in from outside the pond. Epibenthic faunal assemblages in ponds from southeast Queensland are dominated by Acetes which are not likely to adversely affect the production of prawns unless they are particularly abundant early in the grow out season when the prawns would be utilising the same food resources as Acetes.

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