1000 resultados para Esforço de pesca


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As pescarias no reservatório da UHE-Tucuruí no rio Tocantins, Pará, envolvem cerca de 6.000 pescadores e movimentam cerca de R$ 4,2 milhões/ano. A atividade se concentra em três espécies principais: tucunaré Cichla monoculus (capturado com anzol), pescada Plagioscion squamosissimus (capturado com rede e/ou anzol) e mapará Hypophthalmus marginatus (capturado com rede). Com o objetivo de caracterizar os pescadores e as pescarias do reservatório, criar cenários de aumento do esforço pesqueiro e prever os momentos de conflito pela escassez de recursos, foram levantadas informações da literatura e realizadas duas campanhas de coleta de dados nos anos de 1999 e 2000, envolvendo entrevistas com líderes comunitários e pescadores. As seguintes variáveis foram consideradas: desembarque por espécie-alvo (de acordo com os registros fornecidos pelas colônias de pescadores), artes de pesca, estratégias dos pescadores, conflitos e formas de apropriação do espaço e rendimentos da atividade. Estas variáveis foram inseridas em um modelo dinâmico, simulado no software Vensim PLE para um período de 10 anos a partir de 1999. Os resultados indicam que a pesca de anzol é a estratégia mais rentável, e que possíveis momentos de conflito devido à escassez de recursos podem acontecer em curto prazo (2005). A metodologia utilizada para as simulações e análises de risco também se revelou adequada à realidade local e ao conjunto de dados disponíveis.

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Estimating total landings of artisanal fisheries in managed areas is essential for the development of programs aimed at the establishment of sustainable production systems. However, few experiences addressed the constraints of assessments targeted at multispecific and small scale fisheries with pulverized landings. Total annual production (fish, lobsters and octopus) at the Marine Extractive Reserve of Corumbau, Bahia, Brazil, in 2006, was estimated through yields recorded by fisherfolks, in the scope of a participatory fisheries monitoring program. Three designs were employed: 1) simple random sampling, 2) stratified random sampling by month and fishing frequency, 3) stratified random sampling by community, fishing frequency and months, resulting in estimates of 349t (95% confidence interval = 305-393), 330t (289-372) and 315t (279-351), respectively. This kind of information can help design strategies for aggregation of value to small scale fisheries production, and also for the dimensioning of the corresponding infrastructure. However, these estimates shall not be used to support fishing effort increase, as there is high uncertainty regarding the state of the stocks, as well as limitations related to the asymmetry in monthly landings per fisherfolk and to the sampling coverage in the different strata.

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PURPOSE--To provide a critical analysis of the fluid filled manometric system and M-mode echocardiography and, by their association, to standardize the determination of left ventricular (LV) pressure-diameter and stress-diameter relationships in humans. MATERIAL AND METHODS--The pressure curve and the LV M-mode image was obtained in 24 patients with cardiopathy. The dynamic characteristics of the fluid-filled system have been studied to define the amplitude, the resonance and the time gap of the pressure curve register. The delay of the pressure curve recording was determined in all cases by comparing pressure curve and echocardiographic aortic valve registers. The values of pressure, diameter, posterior wall thickness and LV meridional stress was calculated at every 0.02s. RESULTS--Preliminary analyses of the fluid-filled manometric system indicated that this system has variable dynamic characteristics. The pressure-diameter and stress-diameter loops obtained were similar to those of the literature. The values of end-systolic stress, percentage of fractional shortening, ejection fraction and circumferential fiber shortening rate of patients with dilated cardiomyopathy (n = 5) were significantly reduced when compared to the values of patients without left ventricular overload (n = 8) and patients with ventricular volume overload. It has been verified, also, that the retard of the pressure curve record introduced by the fluid-filled manometric system does not modify the values of these variables. CONCLUSION--The LV pressure-diameter and stress-diameter relationships obtained by the association of echocardiography and LV manometry showed functional characteristics of the ventricle that could not appear by the use of the echocardiography or by the LV manometry themselves.

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The perceived exertion has been a target of several investigations, many times with association with objective physiological indicators in exercise. Recently, the identification of the perceived exertion threshold (PET) was proposed in the water running, which presented no difference in relation to the critical velocity. Theoretically, both parameters would be indicators of the maximum steady state of variables such as V̇O2 and blood lactate. The objective of this work was to verify the coincidence between PET, critical power (PCrit) and an indicator of maximum V̇O2 steady state (PCrit') in cycle ergometer. Eight male participants were submitted to progressive effort test in order to determine V̇O2peak (46.7 ± 8.5 ml/kg/min) and to four rectangular tests until exhaustion for the estimation of the critical power model parameters, PET and PCrit'. The hyperbolic relation between mechanical power and time spent for the V̇O2peak to be reached in each test was used for the PCrit' estimation, considered as the asymptote in the power axis, and the portion of the anaerobic work capacity (CTAnaer) depleted up to the establishment of the V̇O2peak (CTAnaer'). In order to identify PET, the straight lines angular coefficients of the perceived exertion in time (ordinate) and the powers used (abscissa) were adjusted to a linear function that provided a point in the power axis in which the perceived exertion would be kept indefinitely stable. The parameters PCrit and CTAnaer were estimated by means of the power-time non-linear equation. In order to compare the estimations of PET, PCrit and PCrit', the analysis of variance ANOVA for repeated measurements was employed, and the associations were established through the Pearson correlation. CTAnaer and CTAnaer' were compared through the t test. PET (180 W ± 61 W), PCrit (174 W ± 43 W) and PCrit' (176 W ± 48 W) were not significantly different and the correlations were of 0.92-0.98. CTAnaer' (14,080 ± 5,219 J) was lower than CTAnaer (22,093 ± 9,042 J). One concludes that the PET predicts the intensity of PCrit and PCrit' with accuracy.

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This work evaluates the impact of the pink shrimp Farfantepenaeus paulensis (Perez-Farfante, 1967) fishery on fish and crab assemblages of Lagoa do Peixe National Park, Brazil. We observed that composition of catches is similar to shrimp fisheries using fyke-net at others estuaries of Rio Grande do Sul State: pink shrimp (53%), accessory catches (24%) and bycatch (23%). However, fishery composition showed distinct differences along the saline gradient of the main park's lagoon. Regarding only fish species, the most impacted species in this fishery were Brevoortia pectinata (Jenyns, 1842), Micropogonias furnieri (Desmarest, 1823), and Jenynsia multidentata (Jenyns, 1842). In others estuaries from Rio Grande do Sul, in contrast, the most impacted species were M. furnieri, Genidens barbus (Lacepède, 1803) and Genidens genidens (Cuvier, 1829). The potential impact of the pink shrimp fishery at Lagoa do Peixe National Park seemed to be weaker when compared to shrimp fisheries elsewhere. We believe that the decision to prohibit this fishery at the Lagoa do Peixe National Park should not be based on its potential damage to the fish and crab assemblages but based on the simple fact that Brazilian laws do not allow fisheries inside National Parks.

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Incluye Bibliografía

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Nest digging spends a lot of energy existing a question about how much energy is required to dig the tunnel and initial chamber. It was hypothesized that the lipid content is used during nest digging. This hypothesis was tested by comparing the consequences of increasing digging effort in queens that were experimentally stimulated to excavate a complete founding nest either once, twice or three times consecutively, compared to control queens that didn't dig. Weight and lipid content of queens were quantified. Results showed that, in contrast with the initial expectations, weight and lipid content were not affected by the increased digging effort in the experimentally-induced successive excavations. It was conclude that the excavation by the queens did not affect the percentages of lipids and consequently the energy content, in their bodies. Probably, energy resources for the excavation wasn't originated from lipid reserves, but from other energy sources, perhaps carbohydrates.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)