nÃo hà / A pesca indiscriminada de lagostas vem causando a diminuiÃÃo dos estoques, minimizando a efetividade da pesca artesanal e reduzindo a renda de comunidades pesqueiras, estimulando a ainda mais a sobrepesca e a captura de indivÃduos juvenis. Como alternativa, vem sendo implantadas as marambaias, que sÃo estruturas para fixaÃÃo de microorganismos aquÃticos para a formaÃÃo de cadeia trÃfica, servindo como atrator para espÃcies de interesse comercial. Na praia de Ponta Grossa, IcapuÃ- CE, o uso de marambaias voltadas prioritariamente para a pesca de lagosta partiu de
pescadores locais em 2002. Com o sucesso das primeiras pescarias, houve âbloomâ de marambaias instaladas e dificuldade de controle sobre o uso das mesmas. Sobre o
litoral cearense ainda sÃo poucas as informaÃÃes sobre o efeito de marambaias para a atraÃÃo de lagostas. Visando dar subsÃdios ao ordenamento de uso dessas estruturas,
urge a necessidade de se determinar a efetividade para o aumento da produtividade e avaliar os impactos socioeconÃmicos e ambientais. Marambaias para lagosta sÃo
estruturas de madeira com 30 cm de altura da base e 6 m2 de Ãrea. O lanÃamento foi realizado pelos pescadores em profundidades entre 3 e 13 m. Participaram deste
estudo 36 pescadores. Foram analisados dados de 484 pescarias nos anos de 2003 (Ano I) a 2005 (Ano III), sendo 280 em profundidades <5 m e 204 em profundidades >5
m. A escolha dos intervalos de profundidade foi arbitrÃria. Estes dados serviram para a determinaÃÃo da captura por unidade de esforÃo (CPUE), do tamanho mÃdio das lagostas e do percentual de lagostas com tamanho comercial. A avaliaÃÃo
socioeconÃmica foi realizada pelo cÃlculo do rendimento das pescarias. A avaliaÃÃo do impacto ambiental foi realizada pelo mÃtodo G.U.T.. O comprimento mÃdio das lagostas (Panulirus argus) ficou abaixo do tamanho mÃnimo determinado por lei (13 cm). As CPUEÂs ficaram acima da mÃdia histÃrica do CearÃ, indicando a eficiÃncia destas estruturas para o aumento da produtividade, embora os valores de receita mÃdia por pescador tenham sofrido significativa queda na renda no segundo e terceiro anos, indicando que houve apenas concentraÃÃo do estoque nas pescarias no primeiro ano. No Ano I, os impactos negativos mais significantes foram a sobreexploraÃÃo do estoque e a incidÃncia de lagostas juvenis nas capturas. Os impactos positivos mais
significantes foram o incremento da pesca local, a criaÃÃo de novos habitats, o desenvolvimento de tecnologias e o fomento a pesquisa cientÃfica. No Ano III, os impactos negativos mais significantes foram a incidÃncia de lagostas juvenis nas capturas, a reduÃÃo da biomassa de pescado, a sobreexploraÃÃo de estoques pesqueiros e a reduÃÃo da pesca local. Quanto aos impactos positivos, destacam-se a
reduÃÃo das pescarias com rede de emalhar e o fomento a pesquisa cientÃfica. Concluise que as marambaias nÃo atuaram de forma sustentÃvel, pois funcionaram apenas como concentradoras de estoque. Recomenda-se que o uso de marambaias deve obedecer a um plano de manejo e respeitar as normativas de proibiÃÃo da captura de juvenis de lagosta. / The indiscriminate lobster fisheries has been causing stock reduction, minimizing the effectiveness of artesian fisheries and reducing the income of fishing communities,
stimulating even more the overfisheries and the capture of undersized lobsters. As an alternative, the community has been implanting artificial reefs, which are structures
where microorganisms settle forming a feeding chain, therefore serving as an attractor for commercial species. At Ponta Grossa community, Icapuà â CE, the use of artificial reefs exclusively for lobster fishing was an initiative taken by some of the local fishermen
in 2002. With the successful result of the first fisheries at the artificial reefs, a fast increase on the number of artificial occurred, what made the control of their use very
difficult. So far, there a very few information about the effects of artificial reefs on the lobster fishery at Cearà State. In order to provide information to organize the use of these structures there is an urgent need to determine the real effectiveness of the initiative in terms of increasing fisheries and to evaluate social, economic and
environmental impacts. The artificial reefs for lobster are build of wood measuring 30 cm in height and 6 m2 of Ãrea. The launching of the structures was carried through by the
fishing in depths between 3 and 13 m. A total of 36 fishermen took part in this study. Data from 484 fishing activities were analyzed during the years of 2003 (year I) to 2005 (year III), being 280 of them in shallow waters (less than 5 m of depth) and 204 in waters deeper than 5m. These depths intervals were chosen arbitrarily. The data were used to determine the amount of lobster captured in relation to the fishery effort (CPUE), the average lobsterâs size and the percentage of lobsters above the legal commercial size. The socio-economic analysis was performed using the profit earned by each fishing
activity. The environmental impact was performed by G.U.T. method. The results showed that the average size of captured lobsters (Panulirus argus) was below legal
minimum size (13 cm). The amount of lobster captured in relation to the fishery effort was above the historical average of Cearà State, showing the efficiency of these
structures to increase productivity, however the values for the average profit per fisherman decreased significantly during the second and third years of the study,
suggesting that in the first year occurred just a concentration of lobster stock in the same area. In the first year the most significant negative impacts were the over exploitation of the stocks and the occurrence of juvenile lobster on the catches. The most significant
positive impacts were the increase of local fishery, the formation of new habitats, the development of new technologies and the possibility to develop scientific research. In Year III the most significant negative impacts were the presence of juvenile lobsters in
the catches, the reduction of fisheries biomass, the over exploitation and the reduction on the amount of local fishery. In relation to positive impacts, the reduction of the fisheries using gill nets and the possibility for scientific research were the most evident. In conclusion, the artificial reefs have not played a sustainable role because the main result was just the concentration of stocks in the same area. The use of artificial reefs
should follow a management plan and respect the law restriction on capturing juvenile lobsters.
| Identifer | oai:union.ndltd.org:IBICT/oai:www.teses.ufc.br:1511 |
| Date | 10 May 2006 |
| Creators | Robson Cabral do Nascimento |
| Contributors | Masayoshi Ogawa, George Satander SÃ Freire, Maria Lucia da Silva Nunes |
| Publisher | Universidade Federal do CearÃ, Programa de PÃs-GraduaÃÃo em Desenvolvimento e Meio Ambiente, UFC, BR |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFC, instname:Universidade Federal do Ceará, instacron:UFC |
| Rights | info:eu-repo/semantics/openAccess |
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