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Caracterização da pesca com arte de xávega na zona costeira adjacente ao estuário do Tejo

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Detalhes bibliográficos
Resumo:The beach seine fishery is carried out along the Portuguese coast by small fishing communities. The fishery is characterised by a non-selective gear, significant bycatch and large amounts of discards. The catches and discards were monitored monthly on the Costa de Caparica, from October and November 2006 and April until September 2007. A total of 72 hauls were analysed, 36 in spring tides and 36 in neap tides. The specimens were identified, weighted and measured and the amounts of retained and discarded fish were determined for each haul. The amounts retained by fishermen, direct sale and sold on the fish resale market were also determined. A total of 49 fish species, 4 mollusc species and 1 crustacean species were identified. Sardina pilchardus (Walbaum, 1792), Scomber japonicus Houttuyn, 1782 and Trachurus trachurus (Linnaeus, 1758), represented 95% of the catches. The discards and juveniles ratio represented 13% and 53% of the total catches, respectively. The discards were mainly species with no or low commercial value and juveniles. Discard levels varied according to species. Catches were influenced by seasons but not by tide cycles. Discards do not varied between seasons. The catches of some species presented variations according to environmental factors. The overall estimate for the annual catches and discards values were 840 tonnes and 106 tonnes, respectively. It was concluded that catches amount are extremely variable and the percentage of discarded fish very high. The amount of discards is sometimes higher than the amount of retained fish, which shows the need for new mitigation measures
Autores principais:Antunes, Mariana, 1981-
Assunto:Pesca Artes de pesca Portugal Teses de Mestrado
Ano:2007
País:Portugal
Tipo de documento:dissertação de mestrado
Tipo de acesso:acesso aberto
Instituição associada:Universidade de Lisboa
Idioma:português
Origem:Repositório da Universidade de Lisboa
Descrição
Resumo:The beach seine fishery is carried out along the Portuguese coast by small fishing communities. The fishery is characterised by a non-selective gear, significant bycatch and large amounts of discards. The catches and discards were monitored monthly on the Costa de Caparica, from October and November 2006 and April until September 2007. A total of 72 hauls were analysed, 36 in spring tides and 36 in neap tides. The specimens were identified, weighted and measured and the amounts of retained and discarded fish were determined for each haul. The amounts retained by fishermen, direct sale and sold on the fish resale market were also determined. A total of 49 fish species, 4 mollusc species and 1 crustacean species were identified. Sardina pilchardus (Walbaum, 1792), Scomber japonicus Houttuyn, 1782 and Trachurus trachurus (Linnaeus, 1758), represented 95% of the catches. The discards and juveniles ratio represented 13% and 53% of the total catches, respectively. The discards were mainly species with no or low commercial value and juveniles. Discard levels varied according to species. Catches were influenced by seasons but not by tide cycles. Discards do not varied between seasons. The catches of some species presented variations according to environmental factors. The overall estimate for the annual catches and discards values were 840 tonnes and 106 tonnes, respectively. It was concluded that catches amount are extremely variable and the percentage of discarded fish very high. The amount of discards is sometimes higher than the amount of retained fish, which shows the need for new mitigation measures