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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

A pesca de arrasto de camarÃes na Zona Costeira do MunicÃpio de Fortaleza, Estado do Cearà / Trawling for shrimp in the Coastal Zone Municipality of Fortaleza, State of Ceara

Miguel SÃvio de Carvalho Braga 11 June 2000 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Os camarÃes de importÃncia comercial na zona costeira do municÃpio de Fortaleza-CE, pertencem à famÃlia Penaeidae e aos gÃneros Penaeus: camarÃo-rosa, P. brasiliensis, camarÃo-vermelho, P. subtilis e camarÃo-branco, P. schmitti; Xiphopenaeus : camarÃo-sete-barbas, X. kroyeri; e Trachypenaeus: camarÃo-ferrinho, T. constrictus. A Ãrea de pesca tem uma superfÃcie de 30 km2, e profundidades entre 5 e 13 m, sendo apropriada para operaÃÃes por embarcaÃÃes arrasteiras com casco de madeira entre 7-12 m de comprimento total. O aparelho-de-pesca à a rede-de-arrasto de p ortas, com panagem de 8 m na sua parte superior e 7 m na inferior, comprimento total de 14 m e malhas de 18mm entre nÃs. A hipÃtese central da dissertaÃÃo f oi avaliar se o ciclo vital do estoque na Ãrea de estudo seguia o padrÃo estabelecido para os peneÃdeos: desenvolvimento larval e juvenil em estuÃrios, recrutamento na zona costeira e reproduÃÃo em Ãreas afastadas da costa. A coleta de dados foi feita atravÃs do embarque em 44 viagens de pesca realizadas no perÃodo julho/97-junho/98, quando foi realizada a amostragem de exemplares dos quais foi registrado o comprimento do cefalotÃrax, determinaÃÃo do sexo, i dentificaÃÃo de fÃmeas em estÃgio de desova. AlÃm disso, foi feito o controle estatÃstico da produÃÃo/esforÃo de pesca, e avaliaÃÃo da fauna acompanhante quanto a frequÃncia de ocorrÃncia e Ãndices de diversidade especÃfica. Os principais resultados foram: (a) o estoque capturado à constituÃdo, principalmente, por indivÃduos jovens; (b) as fÃmeas sÃo maiores do que os machos em comprimento e peso, devido a um maior tamanho da cauda; (c) a proporÃÃo sexual indica predominÃncia de fÃmeas, mas ocorreu reversÃo dessa taxa em alguns meses do ano; (d) a reproduÃÃo das espÃcies de peneÃdeos ocorre no perÃodo fevereiro-julho; (e) o processo de recrutamento para a pesca das espÃcies de peneÃdeos à mais intenso no perÃodo setembro-fevereiro; (f) a composiÃÃo relativa numÃrica das espÃcies foi a seguinte: P. brasiliensis (28,1%), P. subtilis (26,5%), T. constrictus (22,2%), X. kroyeri (12,5%) e P. schmitti (10,7%); (g) a produÃÃo total anual foi de 26.881 kg, gerada por esforÃo de 19.221 horas de pesca, com CP UE de 1,40 kg/hora; (h) a produÃÃo potencial atingiu 5.638 kg; (i) a Ãpoca de safra corresponde ao meses de abril-agosto; (j) a hipÃtese da dissertaÃÃo nÃo foi confirmada, ou seja, jovens xv em recrutamento e fÃmeas em reproduÃÃo habitam a zo na costeira; (k) a cada kg de camarÃo correspondem 3,28 kg de fauna acompanhante, sendo 0,93 kg (28,6%) de espÃcies aproveitÃveis (peixe e camarÃo pequeno) e 2,34 kg (71,4%) de espÃcies nÃo-aproveitÃveis (peixes); (l) a fauna acompanhante da captura de camarÃes esteve formada por 98 espÃcies de peixes, 14 das quais contribuÃram com 90,4% do total de ocorrÃncias; (m) a diversidade da ictiofauna acompanhante variou de acordo com os seguintes Ãndices: diversidade especÃfica, Hâ = 2,610; equitabilidade, E = 0,569; e riqueza d e espÃcies, D = 8,353; (n) existe uma tendÃncia decrescente, com dependÃncia geomÃtrica, entre o nÃmero de espÃcies da ictiofauna acompanhante e sua abundÃncia numÃrica; (o) a regulamentaÃÃo da pesca dos camarÃes, na zona costeira, deve se apoiar na seguinte medida: defeso no perÃodo marÃo-abril. / The shrimp species of economic value that inhabit t he coastal zone of Fortaleza county, Cearà State, Brazil belong to family Penaei dae and genera Penaeus, namely the redspotted shrimp, P. brasiliensis, the brown shrimp, P. subtilis and the white shrimp, P. schmitti; iphopenaeus , namely the Atlantic seabob shrimp, X. kroyeri; and Trachypenaeus, namely the roughneck shrimp, T. constrictus. The fishing operations are performed on a sandy substra te, suitable for trawling, 5-13m deep, 30-km2 area, by wooden, 7-12 m in overall length fishing b oats. The fishing gear is a single-hauling, 14 m long otter t rawl, 18mm meshes. The working hypothesis of this dissertation was to evaluate whe ther the life cycle of the species in the studied area conformed to the known pattern for penaeid shrimp, namely larval and juvenile development in estuaries, recru itmnt occurs in the coastal zone and reproduction in offshore areas. The data collection was performed through direct sampling of the catch in 44 fishing trips in period July, 1997 to June, 1998, for measurement of the caught individualsâ ca rapace length, sex determination and identification of females in spa wning condition. Besides, control of yield/fishing effort and evaluation of t he by-catch as shown by frequency of occurrence and diversity indices was carried out . The main conclusions drawn from data analysis are: (a) the catchable stock is mostly made up of juvenile individuals; (b) females are larger than males in l ength and weight at the expense of a bigger tail size; (c) the sex-ratio is, in general, ignificantly favorable to females, but the reverse is true in some months; (d) spawning of penaeid species takes place in the period February-July; (e) the re cruitment of penaeid species is concentrated in the period September-February; (f) the interspecific relationship, in numbers, was as follows: P. brasiliensis (28.1%), P. subtilis (26.5%), T. constrictus (22.2%), X. kroyeri (12.5%) and P. schmitti (10.7%); (g) the total annual yield was 28,881 kg, obtained by a fishing effort of 19,221 hours, and a CPUE of 1.40 kg/hour; (h) the annual potential production reache d a value of 5,638 kg; (i) the peak harvest period occurs in April-August; (j) the working hypothesis was not confirmed, that is, both recruiting juveniles and re productive females are found in the coastal zone; (k) the by-catch/shrimp ratio was estimated at 3.28:1, broken down to 0.93:1 (28.6%) for the usable species and 2 .34:1 (71.4%) for the xvii discarded ones; (l) the by-catch was comprised of 9 8 fish species, out of which fourteen accounted for 90.4% of total numbers; (m) the by-catch ecological diversity was determined: specific diversity, Hâ = 2.610; equitability, E = 0.568; species richness, D = 8.353; (n) there was found to exist a decreasing trend, with a geometrical dependence, between species numbers a nd their numerical abundance; (o) fishing management should be enforce d through the following measures: a closed season in March-April.
2

Obtenção, caracterização da carne mecanicamente separada de bagre africano (Clarias gariepinus) e avaliação de sua estabilidade durante estocagem sob congelamento / Obtaining, characterization of african catfish (Clarias gariepinus) minced fish and stability evaluation under frozen storage

Durães, Juliana Pola 30 July 2009 (has links)
A carne mecanicamente separada (CMS) de pescado é um produto obtido a partir de uma única espécie, ou mistura de espécies de peixes através do processo de separação mecanizada da parte comestível. O bagre africano (Clarias gariepinus) é produzido principalmente nos países africanos e europeus e recentemente foi introduzido na Índia, China e Brasil, destinados exclusivamente ao consumo. O objetivo deste trabalho foi obter e caracterizar a CMS de bagre africano e avaliar sua estabilidade durante o armazenamento a -18°C. Foi determinado o rendimento do processo de obtenção da CMS e a estabilidade foi acompanhada por seis meses com relação a aspectos microbiológicos e físico-químicos (TBARS, BVT, pH e drip), de três tratamentos (A - CMS sem lavar, B - CMS com uma lavagem e C - CMS com duas lavagens). No início e após 90 e 180 dias de armazenamento sob congelamento, as CMS foram utilizadas para elaboração de fishburgers, os quais foram avaliados microbiológica e sensorialmente. A lavagem promoveu mudanças na composição centesimal da CMS, principalmente o aumento do teor de umidade e diminuição dos teores de proteína bruta. Durante o período de estocagem, as CMS mantiveram-se estáveis independentemente da lavagem. Foi observado rendimento da CMS, de aproximadamente 50% em relação ao peixe inteiro. A CMS com duas lavagens apresentou maior umidade (84,26%) que as CMS com uma lavagem (78,52%) e sem lavar (78,42%), ocorrendo também perda de proteína, lipídeos e cinzas, pela lixiviação desses compostos. Os teores de BVT mantiveram-se estáveis durante o período de armazenamento diferindo apenas entre os tratamentos, sendo que a CMS sem lavar apresentou maior valor médio (15,79 mg BVT/100g) que as CMS com uma (5,46 mg BVT/100g) e duas lavagens (2,61mg/100g). No dia zero, o maior valor de TBARS foi encontrado na CMS sem lavar (0,216 mg malonaldeído/kg), ao passo que nas CMS com 1 e 2 lavagens os valores foram respectivamente de 0,083 e 0,099 mg malonaldeído/kg, indicando que a lavagem causou lixiviação da maior parte dos compostos responsáveis pela oxidação lipídica. A legislação brasileira não indica um limite de oxidação lipídica avaliado pelo método de TBARS para CMS de pescado, porém os valores encontrados no final do período de estocagem (0,405; 0,511 e 0,420 mg malonaldeído/kg) para as CMS sem lavar, com 1 e 2 lavagens respectivamente são baixos e indicam pouca oxidação. Os parâmetros microbiológicos da CMS e do fishburger se mantiveram de acordo com a legislação brasileira. Os fishburgers foram muito bem aceitos pelos provadores e o fishburger elaborado com CMS com uma lavagem foi melhor avaliado quanto à aceitação global. As pequenas alterações ocorridas durante o período de armazenamento não afetaram a qualidade da CMS, indicando viabilidade para formulação de produtos com CMS estocada congelada por 180 dias. O processamento de bagre africano na forma de CMS pode ser uma alternativa para aproveitamento de uma espécie sub-utilizada, gerando produtos da piscicultura com valor agregado. / Minced fish (CMS) is a product obtained from only or sereral fish species through the mechanical separation of edible section. African catfish is produced mainly in African and european countries and recently was introduced in India, China and Brazil, destined exclusively to comsumption. The aim of the present study was obtain and characterize the african catfish minced and evaluate the stability during the period of storage under -18°C. Minced fish process yield was determinated and the stability was measured for six months concerning microbiological and physico-chemical analysis (TBARS, BVT, pH and drip), from three treatments (A CMS unwashed, B CMS washed once and C CMS washed twice). The beginning and after 90 and 180 days of frozen storage, the CMS was utilized for preparation of fishburger, that was evaluated for microbiological and sensorial analysis. The CMS washing process promoted changes in centesimal composition, mainly the increase of the moisture and decrease of total protein. During the storage period, the CMS kept the stability apart of washing process. The minced fish process yield was approximately 50% respecting whole fish. The CMS washed twice showed higher moisture (84,26%) than the CMS washed once (78,52%) and CMS unwashed (78,42%), occuring waste of protein, lipid and ash, by washing. During the storage, the BVT kept stable, disagree between the treatments, and the CMS unwashed exhibit higher mean value (15,79 mg BVT/100g) than CMS washed once (5,46 mg BVT/100g) and CMS washed twice (2,61mg/100g). At the zero day, the bigger value of TBARS was determinated in CMS unwashed (0,216 mg malonaldeído/kg), but in CMS washed once and twice, the values was 0,083 e 0,099 mg malonaldeído/kg respectively, signify that the washing process induced removal the majority part of compounds responsible by the lipidic oxidation. The Brazilian legislation do not indicate a limit of CMS lipid oxidation evaluated by TBARS method, however the values at the end of the storage (0,405; 0,511 e 0,420 mg malonaldeído/kg) for CMS without, with one and with two washing are low and indicate low oxidation. The CMS and the fishburger microbiological parameters kept agreed with Brazilian legislation. The fishburgers was accepted by the samplers and the fishburger elaborated with CMS washed once was better evaluated to general acceptability. The changes occured during the period of storage have not affect on CMS quality, indicating availability to products formulated by CMS with 180 days of frozen storage. The CMS process of african catfish can be a alternative to employment of a specie under-utilized, creating aquaculture products with aggregated value.
3

Neolithic Fisheries : Osteoarchaeology of Fish Remains in the Baltic Sea Region

Olson, Carina January 2008 (has links)
<p>The variety of fish species found at the archaeological sites indicates the exploitation of local and regional ecosystems. The focus of the fisheries varies from site to site. </p><p> The study is based on the analyses of faunal materials from 10 archaeological sites from Eastern Middle Sweden, Gotland, and Åland dating to approximately 3800 – 1850 B.C. The mainland assemblages are mainly burnt and highly fragmented. When comparing burnt and unburnt bone materials, results showed a marked predominance of fish specimens within the unburnt assemblages. The burnt bone materials showed a striking preponderance of marine mammals. The burning process impairs identification and quantification of fishbone. Species presence per context complemented summary data and showed that low and medium frequency species were handled more often than summary data indicate. Intra-site studies of burnt bones demonstrated the importance of detailed studies of the taphonomic history of the faunal assemblages.</p><p> At Ajvide on the island of Gotland, large amounts of well preserved unburnt faunal remains, and ca. 600 bone fishhooks have been unearthed. Replicas of fishhooks from this assemblage were subjected to strength test, osteometric, morphological, and breakage studies. Results point to an elaborated fishing technology for capturing medium sized cod. Incremental studies of cod otoliths (ear stones) from Ajvide showed that most cod were captured in fall and winter. A comparison with the contemporaneous Jettböle site on the Åland islands, showed that in general smaller cod and herring were captured there. </p><p> The ecological conditions were somewhat different during the Neolithic. The growth pattern for cod indicate a more rapid growth for young cod but with a lower asymptotic length compared to modern cod.</p>
4

Neolithic Fisheries : Osteoarchaeology of Fish Remains in the Baltic Sea Region

Olson, Carina January 2008 (has links)
The variety of fish species found at the archaeological sites indicates the exploitation of local and regional ecosystems. The focus of the fisheries varies from site to site. The study is based on the analyses of faunal materials from 10 archaeological sites from Eastern Middle Sweden, Gotland, and Åland dating to approximately 3800 – 1850 B.C. The mainland assemblages are mainly burnt and highly fragmented. When comparing burnt and unburnt bone materials, results showed a marked predominance of fish specimens within the unburnt assemblages. The burnt bone materials showed a striking preponderance of marine mammals. The burning process impairs identification and quantification of fishbone. Species presence per context complemented summary data and showed that low and medium frequency species were handled more often than summary data indicate. Intra-site studies of burnt bones demonstrated the importance of detailed studies of the taphonomic history of the faunal assemblages. At Ajvide on the island of Gotland, large amounts of well preserved unburnt faunal remains, and ca. 600 bone fishhooks have been unearthed. Replicas of fishhooks from this assemblage were subjected to strength test, osteometric, morphological, and breakage studies. Results point to an elaborated fishing technology for capturing medium sized cod. Incremental studies of cod otoliths (ear stones) from Ajvide showed that most cod were captured in fall and winter. A comparison with the contemporaneous Jettböle site on the Åland islands, showed that in general smaller cod and herring were captured there. The ecological conditions were somewhat different during the Neolithic. The growth pattern for cod indicate a more rapid growth for young cod but with a lower asymptotic length compared to modern cod.
5

Mechanism Design For The Optimal Allocation Of Quotas And The Determination Of The Total Allowable Catch For Eu Fisheries Under An Age-structured Model

Kanik, Zafer 01 September 2012 (has links) (PDF)
In this study, we consider the mechanism design problem for the optimal allocation of fishing quotas at different total allowable catch (TAC) levels. An age-structured fish population model is employed. Fishing technologies are embedded in the economic model as a key determinant. As a result, we showed that the quota allocation mechanism is important to minimize the impact of fishing on total fish biomass or achieve maximum sustainable yield (MSY). Moreover, we indicated technology-based optimality conditions for allocation of quotas at different TAC levels, which minimize the impact of fishing on total fish biomass or enable us to achieve MSY. Under the consideration that the fishermen fulfill their remaining quotas through capturing untargeted (less revenue-generating) fish after the targeted fish population is fully caught, the fix ratio of the catch of targeted fish to untargeted fish is not valid anymore. Concordantly, we indicated technology-based optimal quota levels, including the interior solutions. In the EU, TACs are distributed among states according to the principle of &lsquo / relative stability&rsquo / which prescribes that the fishing quotas should be allocated based on historical catches of the EU states. In this context, rather than allocating the quotas based on historical catches, our main suggestion is that the structure of the fishing industry should be considered for allocation of quotas to provide the sustainability of EU fisheries and achieve responsible and effective management of the fishing industry in the EU.
6

Obtenção, caracterização da carne mecanicamente separada de bagre africano (Clarias gariepinus) e avaliação de sua estabilidade durante estocagem sob congelamento / Obtaining, characterization of african catfish (Clarias gariepinus) minced fish and stability evaluation under frozen storage

Juliana Pola Durães 30 July 2009 (has links)
A carne mecanicamente separada (CMS) de pescado é um produto obtido a partir de uma única espécie, ou mistura de espécies de peixes através do processo de separação mecanizada da parte comestível. O bagre africano (Clarias gariepinus) é produzido principalmente nos países africanos e europeus e recentemente foi introduzido na Índia, China e Brasil, destinados exclusivamente ao consumo. O objetivo deste trabalho foi obter e caracterizar a CMS de bagre africano e avaliar sua estabilidade durante o armazenamento a -18°C. Foi determinado o rendimento do processo de obtenção da CMS e a estabilidade foi acompanhada por seis meses com relação a aspectos microbiológicos e físico-químicos (TBARS, BVT, pH e drip), de três tratamentos (A - CMS sem lavar, B - CMS com uma lavagem e C - CMS com duas lavagens). No início e após 90 e 180 dias de armazenamento sob congelamento, as CMS foram utilizadas para elaboração de fishburgers, os quais foram avaliados microbiológica e sensorialmente. A lavagem promoveu mudanças na composição centesimal da CMS, principalmente o aumento do teor de umidade e diminuição dos teores de proteína bruta. Durante o período de estocagem, as CMS mantiveram-se estáveis independentemente da lavagem. Foi observado rendimento da CMS, de aproximadamente 50% em relação ao peixe inteiro. A CMS com duas lavagens apresentou maior umidade (84,26%) que as CMS com uma lavagem (78,52%) e sem lavar (78,42%), ocorrendo também perda de proteína, lipídeos e cinzas, pela lixiviação desses compostos. Os teores de BVT mantiveram-se estáveis durante o período de armazenamento diferindo apenas entre os tratamentos, sendo que a CMS sem lavar apresentou maior valor médio (15,79 mg BVT/100g) que as CMS com uma (5,46 mg BVT/100g) e duas lavagens (2,61mg/100g). No dia zero, o maior valor de TBARS foi encontrado na CMS sem lavar (0,216 mg malonaldeído/kg), ao passo que nas CMS com 1 e 2 lavagens os valores foram respectivamente de 0,083 e 0,099 mg malonaldeído/kg, indicando que a lavagem causou lixiviação da maior parte dos compostos responsáveis pela oxidação lipídica. A legislação brasileira não indica um limite de oxidação lipídica avaliado pelo método de TBARS para CMS de pescado, porém os valores encontrados no final do período de estocagem (0,405; 0,511 e 0,420 mg malonaldeído/kg) para as CMS sem lavar, com 1 e 2 lavagens respectivamente são baixos e indicam pouca oxidação. Os parâmetros microbiológicos da CMS e do fishburger se mantiveram de acordo com a legislação brasileira. Os fishburgers foram muito bem aceitos pelos provadores e o fishburger elaborado com CMS com uma lavagem foi melhor avaliado quanto à aceitação global. As pequenas alterações ocorridas durante o período de armazenamento não afetaram a qualidade da CMS, indicando viabilidade para formulação de produtos com CMS estocada congelada por 180 dias. O processamento de bagre africano na forma de CMS pode ser uma alternativa para aproveitamento de uma espécie sub-utilizada, gerando produtos da piscicultura com valor agregado. / Minced fish (CMS) is a product obtained from only or sereral fish species through the mechanical separation of edible section. African catfish is produced mainly in African and european countries and recently was introduced in India, China and Brazil, destined exclusively to comsumption. The aim of the present study was obtain and characterize the african catfish minced and evaluate the stability during the period of storage under -18°C. Minced fish process yield was determinated and the stability was measured for six months concerning microbiological and physico-chemical analysis (TBARS, BVT, pH and drip), from three treatments (A CMS unwashed, B CMS washed once and C CMS washed twice). The beginning and after 90 and 180 days of frozen storage, the CMS was utilized for preparation of fishburger, that was evaluated for microbiological and sensorial analysis. The CMS washing process promoted changes in centesimal composition, mainly the increase of the moisture and decrease of total protein. During the storage period, the CMS kept the stability apart of washing process. The minced fish process yield was approximately 50% respecting whole fish. The CMS washed twice showed higher moisture (84,26%) than the CMS washed once (78,52%) and CMS unwashed (78,42%), occuring waste of protein, lipid and ash, by washing. During the storage, the BVT kept stable, disagree between the treatments, and the CMS unwashed exhibit higher mean value (15,79 mg BVT/100g) than CMS washed once (5,46 mg BVT/100g) and CMS washed twice (2,61mg/100g). At the zero day, the bigger value of TBARS was determinated in CMS unwashed (0,216 mg malonaldeído/kg), but in CMS washed once and twice, the values was 0,083 e 0,099 mg malonaldeído/kg respectively, signify that the washing process induced removal the majority part of compounds responsible by the lipidic oxidation. The Brazilian legislation do not indicate a limit of CMS lipid oxidation evaluated by TBARS method, however the values at the end of the storage (0,405; 0,511 e 0,420 mg malonaldeído/kg) for CMS without, with one and with two washing are low and indicate low oxidation. The CMS and the fishburger microbiological parameters kept agreed with Brazilian legislation. The fishburgers was accepted by the samplers and the fishburger elaborated with CMS washed once was better evaluated to general acceptability. The changes occured during the period of storage have not affect on CMS quality, indicating availability to products formulated by CMS with 180 days of frozen storage. The CMS process of african catfish can be a alternative to employment of a specie under-utilized, creating aquaculture products with aggregated value.

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