RSS 1.0Revista de Investigação Pesqueira
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A preliminary assessment of the scad and mackerel stocks at Sofala Bank, MozambiqueRevista de Investigação PesqueiraScads (Decapterus russellii, D. macrosoma, Selar crumenophthalmus), Indian mackerel (Rastrelliger kanagurta) and horse mackerel (Trachurus trachurus) are the main pelagic species caught in a bottom trawl fishery at Sofala Bank and at Boa Paz. Information on catch and effort is presented together with available data on distribution, spawning, size at first maturity, growth, mortality and biomass of the species. As the present catch and fishing mortality are low compared to the estimates of biomass and total mortality it is concluded that the fishery may be expanded further in the future.
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Hydrology and fish distribution at the Sofala Bank (Mozambique)Revista de Investigação PesqueiraA brief review is made of the hydrologic conditions at the Sofala Bank, mainly based on the research data obtained from 1978 to 1982. A description is attempted of the circulation pattern and the distribution of water masses in the area, four hydrologic regimes being identified. These are compared with the distributions of different pelagic and demersal fish species. A tendency is found for different groups of species to prefer different hydrologic regimes.
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A study on growth of Metapenaeus monoceros (Fabricius) of Maputo BayRevista de Investigação PesqueiraBiological data on Metapenaeus monoceros has been regularly collected in Maputo Bay since 1968. The main objective of this report is to study growth as a function of the size, since this is one of the basic parameters for population dynamics. As the possibility of studying shrimp growth by modal progression analysis depends very much on the space-time configuration of sampling, the years 1968 and 1969 were chosen to study growth of the population available to the bottom trawl used by the fishing industry. In those years sampling was very frequent (twice a week) and the samples were collected from a rather small fishing area. Complementary data on the spawning, juvenile phase and recruitment to the fishery was used to establish the relationship between the different stages of the life cycle and to obtain an age/length key. Data on juveniles in estuaries was only available for 1969 and 1973.
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Mortality rates estimates for Metapenaeus monoceros (Fabricius) of Maputo BayRevista de Investigação PesqueiraThe species Metapenaeus monoceros in Maputo Bay recruits to the fishery almost all over the year, but the main recruitment occurs over a short period of time, each year, during April-May. Growth curves were constructed by following the progression of modes over a period of time. The von Bertalanffy growth parameters were estimated as L∞=31.9 mm and K(monthly)=0.25, for males, and L∞=48.3 mm and K(monthly)=0.14, for females (Brinca and Sousa, 1984). Using data on growth and length composition of the catches, the following methods were applied to estimate mortality rates of M. monoceros: estimation of natural mortality by using approximative methods; use of c.p.u.e. data; catch curves; cohort analysis; average age and length methods.
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Circulation system and areas of potentially successful tuna fishing with surface methods off MozambiqueRevista de Investigação PesqueiraCharts with 3-months running means of thermal data collected during 1977-1982 are used to describe the seasonal variability of the circulation pattern off Mozambique, and to identify the areas of tuna vulnerability to surface gears. The main conclusions reached by Sætre and Jorge da Silva (1984) have received further support. Areas of potentially successful exploitation of tunas by surface methods have been identified during the whole year, with emphasis for November-April.
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Relatório do cruzeiro realizado no Banco de Sofala pelo navio SRTM "Sebastopolsky ribak" de Setembro a Outubro de 1982: camarāo de águas pouco profundasRevista de Investigação PesqueiraIn September-October 1982, the Soviet ship "Sebastopolsky Rybak" conducted a cruise on the Sofala Bank in the area between 16°20'S and parallel 19°40'S. Two surveys were made, one from South to North (depth 10-110 meters) and vice versa. The type of coverage used was systematic. The Sofala Bank was divided into seven sub-areas. During this cruise sub-areas 3 and 4 were covered. Sub-area 5 has not been fully covered.
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Camparaçāo entre os cruzeiros de investigaçāo realizados no Banco de Sofala pelo navio SRTM "Sebastopolsky rybak" em Setembro-Outubro e Novembro-Dezembro de 1982: camarao de [águas pouco profundas]Revista de Investigação PesqueiraDuring the last 4 months of 1982, two research cruises had been carried out at the Sofala Bank by the SRTM"Sevastopolsky Rybak". The authors analyze and compare data on biological characteristics, sexual maturity and localization of Penaeus indicus and Metapenaeus monoceros.
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Relatório do cruzeiro realizado no Banco de Sofala pelo navio SRTM "Sebastopolsky rybak" de Novembro a Dezembro de 1982: camarāo de águas pouco profundasRevista de Investigação PesqueiraFrom November 18th to December 17th 1982, the SRTM "Sebastopolsky Rybak" carried out research cruises on the Sofala Bank in the area between 16°20'S and parallel 19°40'S. The authors analyze data collected on biological characteristics, sexual maturity and localization of Penaeus indicus, Metapenaeus monoceros, Penaeus japonicus, Penaeus monodon and Penaeus latisulcatus.
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Ensaio sobre a forma de comunicaçāo dos resultados da investigaçāo de recursos pesqueiros à administraçāo pesqueira. Tema 1: Síntese dos resultados e métodos de análise utilizado na avaliaçāo do recurso de camarao de águas pouco profundas do Banco de Sofala.Revista de Investigação PesqueiraThe main goal of this paper is to provide samples of fishing methods analyses applied to studies on shrimps stock assessment in the Sofala Bank. Especially the authors provide the administrators with the main limits of application of described methods.
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Os problemas encontrados no desenvolvimento e planeamento das pescas em MoçambiqueRevista de Investigação PesqueiraThe author outlines the role of fisheries in the national economy of Mozambique and describes the way in which the objectives of fishery development reflect the aims of development in the economy. The history of the country is described and the steps to increase the fishery sector are detailed with a presentation of problems encountered.
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Relatório do cruzeiro realizado no Banco de Sofala pelo navio Pantikapey em Julho-Agosto de [1981]: peixes demersaisRevista de Investigação PesqueiraThanks to an agreement between the Institute of Fisheries Research of Mozambique and the Soviet part Azcherniro and Ingribpomrazvedka, surveys in the waters of Mozambique were conducted from June to August 1981 on the ship Pantikapei. The survey made along the Sofala Bank and Boa Paz (16°00-21°00'S) was at a depths of 11 and 90 meters. Demersal and pelagic fisheries experiments were conducted using acoustic devices. This paper described the results obtained on demersal fishery resources.
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Report on the oceanographic investigations carried out at the Sofala Bank by the Soviet trawler "Sevastopolsky rybak" in September-December 1982Revista de Investigação PesqueiraIn September-December 1982 a fisheries research cruise was carried out at the Sofala Bank by the SRTM "Sevastopolsky Rybak". Oceanographic investigations have been conducted in association with the fisheries research. Three coverages were made of the Sofala Bank each lasting for slightly less than three weeks. This will allow for three descriptions of the oceanographic conditions in the area, with some reference being made to variability. This paper is just a preliminary report of those investigations.
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Investigaçāo, gestāo e planifiçāo pesqueirasRevista de Investigação PesqueiraThe paper deals with the main objectives and functions of research, management and fisheries planning, as well as their correlation and organization. Several aspects of general application and more specific issues of fisheries research are stressed. The author provides a perspective of the fishing sector in Mozambique, using for this purpose regional and global comparisons. Some brief comments on current tasks for fisheries research in Mozambique are given.
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Avaliaçāo do estado dum recurso e da pescaRevista de Investigação PesqueiraOne of the key sectors of fisheries research is assessment and exploration which should have as main goal the support to the fishing industry: analyzing the effects of fishing on stocks, determining the potential stock to be exploited and the formulation of rules for an appropriate exploitation and preservation of resources. In this paper the author intends to analyze some aspects of the investigation in support to fishery management.
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Aquacultura de mexilhão marinho Perna-perna (L.)Revista de Investigação PesqueiraThe Mozambican experimental project on mussel culture began in 1977 to promote cheap food production with high protein value for domestic market. The species Perna perna (L.) has been selected due to its abundance, sustainable culture processes and better yields.
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Outros recursos marinhosRevista de Investigação PesqueiraThe paper describes marine fish resources living in Mozambican waters. Resource data on distribution areas, reproduction, age, growth and stock size are described. Actual price of the commercially exploited stocks are also given. The problems involving the assessment of catch areas are discussed.
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Peixes demersais: águas marinhasRevista de Investigação PesqueiraThis paper deals with demersal fish. The authors described the characteristics of species composition, biology, distribution of catches by area and depth. They also provided the biomass of two main fishing areas: Boa Paz and Sofala Banks.
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Revisão dos conhecimentos sobre os recursos pesqueiros marinhos de MoçambiqueRevista de Investigação PesqueiraA marine fish resources first assessment of Mozambique was made in 1979 (Sætre and Paula e Silva, 1979). Up to now, information on resources has increased significantly as result of the work done by the IIP’s technicians. A brief review of data is given.
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Pequenos peixes pelágicosRevista de Investigação PesqueiraThe paper describes small pelagic fishes including several marine resources ranked among the most important in abundance(anchovy, horse mackerel and sardines) off the coast of Mozambique.
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Informaçāo geral sobre o manancial de camarāo de profundidade e a sua exploraçāo nas águas da República Popular de MoçambiqueRevista de Investigação PesqueiraThe deep-water shrimp were already studied many years ago, but their commercial fishing on large scale, only developed from the seventies. Two Luso-U.S. fishing companies (1966), and a Luso-South African company (1963- 1968), dedicated to the fishing of deep-water crustaceans, including Haliporoides triarthrus species (Araújo, 1973). Also Champion (1973) described commercial catches of Plesiopenaeus edwardsianus, Aristaeomorpha foliacea and Haliporoides triarthrus in the waters of Mozambique. The first Spanish vessels began fishing activity in 1968 (Freitas and Araújo, 1973) but all of these companies captured mainly penaideos on the continental shelf.
