Fishery statistics and length data series for Colossoma macropomum Cuvier obtained during 1992 and 1993 in the Lower Amazon, Brazil were used to describe the fishery and to estimate growth and mortality rates. Mean population parameters were L∞ = 119.85 cm (total length), W∞ = 33.4 kg, K = 0.228 year–1, C = 0.505, Winter Point = July, M = 0.445 year–1, F = 0.94 year–1 and Lc = 28.29 cm. Yield‐per‐recruit analysis showed that an excessive fishing effort and principally a very low length at first capture lead to an increase in overfishing in the region. Corrective measures are recommended.

In this study, the complete mitochondrial control region of 48 tambaqui Colossoma macropomum specimens from five localities along a 2200 km transect of the Amazon basin was analysed. High genetic variability was observed in all localities sampled. Analyses of molecular variance indicated that nearly all of the molecular variance was contained within localities, and estimates of gene flow among localities were high. These results suggest that the tambaqui forms a panmictic population along the Solimo˜es-Amazon River channel and are in agreement with species-typical behaviour of semi-migratory movements driven by dispersal for feeding and reproduction during its life cycle. Inspite of the observed high levels of genetic variability and mutation-drift equilibrium of the mtDNA control region, the tambaqui has experienced a 90% demographic decrease and reduction of size at maturity in the past two decades. Population estimates based on molecular markers therefore do not reflect its current demographic status but rather its status in ecological time.

ResumoEste estudo caracteriza quali e quantitativamente a atividade pesqueira comercial na bacia do rio Madeira, afluente do rio amazonas, no trecho entre Guajará-Mirim e Porto Velho, estado de Rondônia. no período de janeiro a dezembro/2004, foram registrados 460 t, correspondendo 935 viagens. a análise dos dados oriundos do monitoramento dos desembarques demonstrou que a pesca na região tem caráter artesanal de pequena escala, destacando a maior participação das canoas motorizadas (131 unidades) do que barcos pesqueiros (45 unidades; capacidade média: 3.000kg) na frota pesqueira. os peixes migradores jaraqui (Semaprochilodus spp.), dourada (Brachyplatystoma rousseauxii), sardinha (Triportheus spp.), jatuarana/ matrinxã (Brycon amazonicus e B. cephalus), curimatã (Prochilodus nigricans) e filhote (Brachyplatystoma filamentosum) se destacaram na composição das espécies desembarcadas. as informações técnicas geradas são importantes para subsidiar ações de ordenamento pesqueiro, bem como para avaliar futuras variações que possam ocorrer na atividade frente aos impactos dos empreendimentos hidrelétricos em construção na região. PalavRas-chave: produção pesqueira, pescadores, esforço de pesca, pescarias. The Commercial fisheries of the Madeira river basin in the Rondônia state, brazilian Amazon abstRactThis study presents qualitative and quantitative information about commercial fishery in the basin of the Madeira River, tributary of the amazon River, describing the fishing activity in the segment between Guajará-Mirim and Porto Velho, in Rondônia State. from january to December/2004, 219 fishermen and 935 trips were registered, corresponding to the capture of 460 t of fish. Data from fish landings demonstrate that fisheries in the region are small-scaled and point to a higher participation of small motorized canoes (130 units) than of fishing boats (45 units; average capacity: 3000 kg) in the fishing fleet. Migratory species like jaraqui (Semaprochilodus spp.), dourada (Brachyplatystoma rousseauxii), sardinha (Triportheus spp.), jatuarana/ matrinxã (Brycon amazonicus e B. cephalus), curimatã (Prochilodus nigricans) and filhote (Brachyplatystoma filamentosum) were the most important in terms of landings. The technical information produced are very important in order to subsidize fishery management, as well as to assess future variations that might happen due to the hydro-electric enterprises under construction in the region.

RESUMO -O presente artigo apresenta resultados sobre o consumo de pescado e outros alimentos pela população ribeirinha do Lago Grande de Monte Alegre, no Estado do Pará, Brasil. Os dados foram coletados mensalmente, por um período de dois anos juntos a 35 famílias de 17 comunidades, que praticam a pesca com fins comerciais e de subsistência, bem como as famílias que nào pescam. O consumo médio de pescado foi de 369 g/capita/dia, complementado com 6,lg/capita/dia de farinha de peixe (piracuí). As espécies mais consumidas foram: curimatá (Prochilodus nigricans) e acarí-bodó (Liposarcus partialis). Em média, as famílias tiveram alguma refeição constituída de pescado em 6 dias de cada semana. Extrapolando para toda a população do Lago, o consumo diário de pescado é pouco mais de 3 t, chegando a 1.114 t/ano. Palavras-chave:Baixo Amazonas, consumo de pescado, lago de várzea, pesca de subsistência, piracuí. Fish consumption and others food itens by the riverine population of the Lago Grande deMonte Alegre, PA -Brazil.ABSTRACT -The present study shows the results on the fish consumption and other food itens by the riparian population from Monte Alegre Lake, Lower Amazon, in Pará State, Brazil. The data were colected monthly during two years jointly with 35 families from 17 fishery communities that practice the fishery with a subsistence or commercial goal, as well as families that not fish. The mean fish consumption was of 369 g/capita/day complemented with 6.1 g/capita/ day of fish flouer, called locally "piracuí". The species preferred were curimatá (Prochilodus nigricans) and acarí-bodó (Liposarcus pardalis). Manioc flouer consumption was higher than in other regions. Families consume fish each 6 days a week. Extrapoling for all population of Lago Grande de Monte Alegre, the fish consumption is more than 3 t/day and about 1,114 t/year.

This study characterizes the fishermen and the commercial fishing fleet of the lower Amazon, based on data collected from 5446 boats operating out of the city of Santarém in 1997. An economic analysis of the activities of these boats was based on 50 interviews with boat operators. Larger and smaller boats use essentially the same technology, but there are significant differences in fishing strategies. Smaller boats supply local markets and their catch consists of a large variety of fish species. Larger boats tend to specialize in a small number of catfish species, and supply fish processing plants. Smaller boats are less efficient in terms of catch per unit effort (CPUE) (kg fisherman–1 day–1), but are more efficient economically, earning more for each unit of capital invested than larger boats. Most boats operating from Santarém have a storage capacity of <4 t. Boats in this size (0<4 t) account for 87% of the total fleet direct employment, and 73% of total income. Thus despite the lack of attention from regional policy makers, these smaller boats are an important source of food, income and employment in the lower Amazon region.

RESUMO -Dados sobre esforço e captura por espécie correspondentes à produção pesqueira desembarcada no porto de Santarém, no ano de 1993, foram submetidos a duas técnicas de análise multivariada: uma análise de fatores segundo o método de componentes principais e outra de covariância conforme o modelo linear geral (GLM). Os resultados indicam que a atividade pesqueira na região está influenciada pelas características dos ciclos de vida das espécies-alvo, pelo ciclo hidrológico e condição climáticas de sistema, e ainda pelas preferências culturais e interesses econômicos do mercado consumidor. Os resultados indicam o direcionamento da atividade pesqueira para determinados grupos de espécies, e as diferentes variáveis incluídas no modelo permitiram uma explicação aproximada dos padrões desse direcionamento. Esses padrões são: (a) pesca de grandes bagres, alvo de pesca para a exportação (FATOR 1); (b) pesca de entre-safra do mapará (Hypophthalmus spp.) e da pescada (Plagioscion spp.), realizada nos lagos com um componente para exportação e outro para o consumo local (FATOR4); (c) pesca de peixes de escamas de hábitos sedentários e/ou migratórios, alvo da pesca comercial de pequena escala e de importância no mercado local (FATOR2, FATOR3 e FATOR5), que inclui pescarias importantes como a do tambaqui (Colossoma macropomum) e do pirarucu(Arapaima gigas) nos lagos, ou a do jaraqui (Semaprochilodus spp.) e pacu (Mylossoma spp. e Metynnis spp.) nos rios.Palavras-chave: pesca artesanal, Baixo Amazonas, dinâmica da pesca. Artisanal Fishery in the Lower Amazon: Multivariate Analysis of the Catch by Species.ABSTRACT -Effort and catch data per species making up for fisheries yield landed in 1993 in the city of Santarém were submitted to two techniques of multivaliate analysis: a factor analysis by the principal components method and a covariance one using the general lineal model (GLM). Results suggest fishing activities in the region is influenced by the life cycle peculiarities of target species, by the water cycle and the weather conditions in the system, as well as by the cultural biases and economic interests of the consumer market. The results revealed the directioning of fishery activities toward certain groups of species, and those patterns were identified: (a) the fishing of large catfishes for export (FACTOR1); (b) the between-seasons fishing of mapará (Hypophthalmus spp.) and pescada (Plagioscion spp.) in lakes, with local and for export components (FACTOR4); (c) the fishing of sedentary and/or migratory scaled fishes, targeted by small-scale commercial fisheries with local importance (FACTOR2; FACTOR3 and FACTORS), which includes important catches such as tambaqui (Colossoma macropomum) and pirarucu (Arapaima gigas) in the lakes, or jaraqui (Semaprochilodus spp.) and pacu (Mylossoma spp. and Metynnis spp.) in rivers. Key-words: local fisheries, Lower Amazon, fisheries pattern INTRODUÇÃOA pesca artesanal na Amazônia brasileira é de vital importância para o fornecimento de alimento à população local e como fonte de ...

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We analyze the invisibility of fisheries and inadequacy of fishers' participation in the process of hydropower development in the Amazon, focusing on gaps between legally mandated and actual outcomes. Using Ostrom's institutional design principles for assessing common-pool resource management, we selected five case studies from Brazilian Amazonian watersheds to conduct an exploratory comparative case-study analysis. We identify similar problems across basins, including deficiencies in the dam licensing process; critical data gaps; inadequate stakeholder participation; violation of human rights; neglect of fishers' knowledge; lack of organization and representation by fishers' groups; and lack of governmental structure and capacity to manage dam construction activities or support fishers after dam construction. Fishers have generally been marginalized or excluded from decision-making regarding planning, construction, mitigation, compensation, and monitoring of the social-ecological impacts of hydroelectric dams. Addressing these deficiencies will require concerted investments and efforts by dam developers, government agencies and civil society, and the promotion of inter-sectorial dialogue and cross-scale participatory planning and decision-making that includes fishers and their associations.