The middle stretch of the Madeira River has supported an intensive commercial fishery for several decades. Developed in an area of rapids and waterfalls, this fishery focuses primarily on catfish stocks, mainly pimelodids. Data from fish landings collected in the years immediately prior to the start in operations of two large hydroelectric dams were used to estimate growth and mortality rates for Pirinampus pirinampu (Spix & Agassiz) and Brachyplatystoma platynemum Boulenger. In addition, stock assessment was carried out for both species, and the results used to evaluate the status of the fishery. Mean population parameters were L∞ = 80.85 cm (total length), k = 0.52 year−1, ϕ = 3.53, A0.95 = 6 year, M = 0.87, F = 1.41–1.64 and Z = 2.28–2.51 for P. pirinampu; and L∞ = 95.55 cm (total length), k = 0.28 year−1, ϕ = 3.40, winter point = 0.41, A0.95 = 11 year, M = 0.55, F = 0.16–0.35 and Z = 0.71–0.90 for B. platynemum. Yield‐per‐recruit analysis indicated P. pirinampu was overfished and that the stock of B. platynemum was under‐exploited. Moreover, overfishing of the P. pirinampu stock and the effects of fragmentation caused by the construction of the dam should be monitored.
Armoured catfish Pterygoplichthys pardalis is an endemic fish from the Amazon basin (Brazil) and currently is the top ten target species in the regional fisheries. A total of 1200 samples were collected monthly from March 2011 to February 2012 with an average length of 28 ± 2.57 cm and average weight of 441.57 ± 103.37 g. The growth stock parameters for this species (Wt = 0.431227 * Lt2.08637; M = 0.93 year-1; F-Estimated = 0.91 year-1; F-10 = 3.02 year-1; A0.95 = 7.31 years; K = 0.41 year-1; Tr = Tc = 1.92 years; Lc = 21.14 cm; L∞= 38.85 cm; W∞ = 869.76 g) and exploitation rate (E-Estimated = 0.50; E-10= 0.80) reveal that its stocks are not being overfished in the study area. The baseline information obtained in this study can help support fisheries management strategies of P. pardalis, especially regarding the potential implementation of a policy to increase landings of individuals larger than 22.3 cm length. However, before making a final decision, it is necessary to carefully examine the available information and evidence aimed at sustainable fishing management and conservation of their stocks, which is of great cultural, social and economic importance for Amazonian peoples.
A pesca de pequena escala tem importância histórica nas comunidades do rio Madeira, garantindo segurança alimentar e renda às populações tradicionais ribeirinhas. A Cachoeira do Teotônio, antes da construção das barragens (UHE SAE e Jirau), destacava-se pela pescaria altamente adaptada a captura dos bagres migradores e pela alta produtividade. O objetivo desse trabalho é descrever as mudanças ocorridas na pesca, na Cachoeira do Teotônio, após a construção da UHE SAE. Os resultados mostraram que a pesca praticada na região envolvia conhecimentos tradicionais de engenharia, do ambiente e das espécies, bem como práticas de rodízio, com a submersão e a formação do reservatório teve que ser substituída ou adaptada ao novo ambiente. A alteração da condição da pesca pela modificação antropogênica do ambiente ou deslocar comunidades, altera locais de pesca historicamente mapeados ao longo de gerações de pescadores.
The present study analyzed landing events of commercial fishing of two species of large catfish in 11 fish landing sites along the Madeira River, and temporally and spatially characterized the exploitation of these species before and after the closure of the Jirau and Santo Antônio hydroelectric dams. Our results show that the Madeira River dams have negatively affected the fishing production of Pinirampus pirinampu and Brachyplatystoma platynemum catfish, drastically reducing these species' harvest as well as the incomes of regional fishers. If the irreversible loss of these species of Amazonian catfish is to be avoided, public policies and measures for the management and sustainable handling of this fishery resource must be implemented urgently.
Avaliamos as mudanças na dinâmica da pesca e nos aspectos sociais, econômicos, político-institucionais e ecológicos, em duas localidades do reservatório da Usina Hidroelétrica Santo Antônio: Distrito Jaci Paraná e Vila Nova do Teotônio, Rondônia, Brasil. A dinâmica pesqueira e o Índice do Desenvolvimento dos Pescadores do Médio Madeira (IDPM) foram obtidos e comparados entre os períodos: 2007/2009 e 2017/2019. Observamos: redução na captura e na contribuição das comunidades no mercado de Porto Velho; variações na composição das capturas, diminuição de algumas espécies; e diminuição na renda média mensal dos pescadores. O IDPM das localidades diminuiu no POSR e abaixo do ideal de desenvolvimento, influenciado pelo baixo desempenho dos indicadores ecológico e pesca. Ambas as localidades sofreram com as mudanças, os poucos pescadores que persistiram na atividade, demostram estratégias de adaptação ao novo cenário, com variações entre as localidades.
Na região amazônica o Tucunaré (Cichla spp) é bastante apreciado na pesca comercial e esportiva, com isso compreender suas características biológicas é essencial para o manejo e conservação da espécie. Este trabalho teve como objetivo analisar a situação do estoque e dinâmica pesqueira do tucunaré, comercializado no mercado pesqueiro de Porto Velho (Rondônia), no período de 2011 a 2020. Foram utilizadas as taxas de crescimento (comprimento e peso), identificadas os indicadores de estoque e parâmetros. Os indicadores de estoques mostram que os anos de 2011 e 2017 apresentaram valores maiores na idade de primeira maduração, com média de 20%, 2013 apresenta uma melhor captura, sendo de 7,6% na idade de primeira maturação, apenas os anos de 2012, 2013 e 2017 ficaram com as porcentagens de captura ideal (Popt), sendo 60, 79 e 69% respectivamente, onde os valores de referência são de 60 a 80%, porém o indicador de estoque (Pobj) mostrou sobrepesca em todos os anos apresentam, destacando-se 2011 e 2018 com a maior taxa de sobrepesca. Os resultados indicam que os tucunarés, na região de estudo, estão sobrepescados sendo necessário monitoramento e gestão pesqueira, visando a proteção do estoque.
The Surinam anchovy (Anchovia surinamensis) is a small fish of commercial and ecological interest in the Amazon basin. To understand the reproductive and population dynamics of this species, in 2019 and 2020, experimental fisheries were carried out during periods of flood and low water in the Cujubim Lake in Porto Velho (Rondônia, Brazil). This study aimed to analyze the seasonal pattern (flood and low water) for the reproductive period and the population dynamics of the Surinam anchovy in this region, which resulted in the collection of 870 individuals. The specimens showed mean lengths (Ls) of 6.85 ± 0.51 cm to 9.01 ± 2.56 cm and mean weight (Wt) of 5.8 ± 3.37 g to 6.6 ± 2.72 g between low and flood water periods, respectively. The growth parameters for this species (Wt = 0.0226*Ls2,6635; Natural mortality, M = 1.66 year-1; Growth rate, k = 0.70 year-1; Asymptotic length, L∞ = 16.53 cm; Theoretical maximum weight, W∞ = 42.83 g) and the quantity of individuals in mature stages during periods of flood and low water were also evaluated. The mean values of Gonadosomatic index - GSI (5.41 and 4.96 between females and males) and animal welfare index, Kn (1.009 and 1.010 between low and flood water periods) did not show significant differences. All the population growth information presented, added to the values of physicochemical parameters of the water (which were suitable for tropical fish) indicates that the Surinam anchovy population is governed by hydrological seasonality and is well adapted to the floodplain lake where it colonizes and reproduces.
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