892 resultados para Fisheries -- Queensland
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There is an imminent need for conservation and best-practice management efforts in marine ecosystems where global-scale declines in the biodiversity and biomass of large vertebrate predators are increasing and marine communities are being altered. We examine two marine-based industries that incidentally take migratory birds in Canada: (1) commercial fisheries, through bycatch, and (2) offshore oil and gas exploration, development, and production. We summarize information from the scientific literature and technical reports and also present new information from recently analyzed data to assess the magnitude and scope of mortality. Fisheries bycatch was responsible for the highest levels of incidental take of migratory bird species; estimated combined take in the longline, gillnet, and bottom otter trawl fisheries within the Atlantic, including the Gulf of St. Lawrence, and Pacific regions was 2679 to 45,586 birds per year. For the offshore oil and gas sector, mortality estimates ranged from 188 to 4494 deaths per year due to the discharge of produced waters resulting in oil sheens and collisions with platforms and vessels; however these estimates for the oil and gas sector are based on many untested assumptions. In spite of the uncertainties, we feel levels of mortality from these two industries are unlikely to affect the marine bird community in Canada, but some effects on local populations from bycatch are likely. Further research and monitoring will be required to: (1) better estimate fisheries-related mortality for vulnerable species and populations that may be impacted by local fisheries, (2) determine the effects of oil sheens from produced waters, and attraction to platforms and associated mortality from collisions, sheens, and flaring, so that better estimates of mortality from the offshore oil and gas sector can be obtained, and (3) determine impacts associated with accidental spills, which are not included in our current assessment. With a better understanding of the direct mortality of marine birds from industry, appropriate mitigation and management actions can be implemented. Cooperation from industry for data collection, research to fill knowledge gaps, and implementation of mitigation approaches will all be needed to conserve marine birds in Canada.
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There is a need for better links between hydrology and ecology, specifically between landscapes and riverscapes to understand how processes and factors controlling the transport and storage of environmental pollution have affected or will affect the freshwater biota. Here we show how the INCA modelling framework, specifically INCA-Sed (the Integrated Catchments model for Sediments) can be used to link sediment delivery from the landscape to sediment changes in-stream. INCA-Sed is a dynamic, process-based, daily time step model. The first complete description of the equations used in the INCA-Sed software (version 1.9.11) is presented. This is followed by an application of INCA-Sed made to the River Lugg (1077 km2) in Wales. Excess suspended sediment can negatively affect salmonid health. The Lugg has a large and potentially threatened population of both Atlantic salmon (Salmo salar) and Brown Trout (Salmo trutta). With the exception of the extreme sediment transport processes, the model satisfactorily simulated both the hydrology and the sediment dynamics in the catchment. Model results indicate that diffuse soil loss is the most important sediment generation process in the catchment. In the River Lugg, the mean annual Guideline Standard for suspended sediment concentration, proposed by UKTAG, of 25 mg l− 1 is only slightly exceeded during the simulation period (1995–2000), indicating only minimal effect on the Atlantic salmon population. However, the daily time step simulation of INCA-Sed also allows the investigation of the critical spawning period. It shows that the sediment may have a significant negative effect on the fish population in years with high sediment runoff. It is proposed that the fine settled particles probably do not affect the salmonid egg incubation process, though suspended particles may damage the gills of fish and make the area unfavourable for spawning if the conditions do not improve.
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This document provides guidelines for fish stock assessment and fishery management using the software tools and other outputs developed by the United Kingdom's Department for International Development's Fisheries Management Science Programme (FMSP) from 1992 to 2004. It explains some key elements of the precautionary approach to fisheries management and outlines a range of alternative stock assessment approaches that can provide the information needed for such precautionary management. Four FMSP software tools, LFDA (Length Frequency Data Analysis), CEDA (Catch Effort Data Analysis), YIELD and ParFish (Participatory Fisheries Stock Assessment), are described with which intermediary parameters, performance indicators and reference points may be estimated. The document also contains examples of the assessment and management of multispecies fisheries, the use of Bayesian methodologies, the use of empirical modelling approaches for estimating yields and in analysing fishery systems, and the assessment and management of inland fisheries. It also provides a comparison of length- and age-based stock assessment methods. A CD-ROM with the FMSP software packages CEDA, LFDA, YIELD and ParFish is included.
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Queensland experiences considerable inter-annual and decadal rainfall variability, which impacts water-resource management, agriculture and infrastructure. To understand the mechanisms by which large-scale atmospheric and coupled air–sea processes drive these variations, empirical orthogonal teleconnection (EOT) analysis is applied to 1900–2010 seasonal Queensland rainfall. Fields from observations and the 20th Century Reanalysis are regressed onto the EOT timeseries to associate the EOTs with large-scale drivers. In winter, spring and summer the leading, state-wide EOTs are highly correlated with the El Nino–Southern Oscillation (ENSO); the Inter-decadal Pacific Oscillation modulates the summer ENSO teleconnection. In autumn, the leading EOT is associated with locally driven, late-season monsoon variations, while ENSO affects only tropical northern Queensland. Examining EOTs beyond the first, southeastern Queensland and the Cape York peninsula emerge as regions of coherent rainfall variability. In the southeast, rainfall anomalies respond to the strength and moisture content of onshore easterlies, controlled by Tasman Sea blocking. The summer EOT associated with onshore flow and blocking has been negative since 1970, consistent with the observed decline in rainfall along the heavily populated coast. The southeastern Queensland EOTs show considerable multi-decadal variability, which is independent of large-scale drivers. Summer rainfall in Cape York is associated with tropical-cyclone activity.
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In many lower-income countries, the establishment of marine protected areas (MPAs) involves significant opportunity costs for artisanal fishers, reflected in changes in how they allocate their labor in response to the MPA. The resource economics literature rarely addresses such labor allocation decisions of artisanal fishers and how, in turn, these contribute to the impact of MPAs on fish stocks, yield, and income. This paper develops a spatial bio-economic model of a fishery adjacent to a village of people who allocate their labor between fishing and on-shore wage opportunities to establish a spatial Nash equilibrium at a steady state fish stock in response to various locations for no-take zone MPAs and managed access MPAs. Villagers’ fishing location decisions are based on distance costs, fishing returns, and wages. Here, the MPA location determines its impact on fish stocks, fish yield, and villager income due to distance costs, congestion, and fish dispersal. Incorporating wage labor opportunities into the framework allows examination of the MPA’s impact on rural incomes, with results determining that win-wins between yield and stocks occur in very different MPA locations than do win-wins between income and stocks. Similarly, villagers in a high-wage setting face a lower burden from MPAs than do those in low-wage settings. Motivated by issues of central importance in Tanzania and Costa Rica, we impose various policies on this fishery – location specific no-take zones, increasing on-shore wages, and restricting MPA access to a subset of villagers – to analyze the impact of an MPA on fish stocks and rural incomes in such settings.
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A realidade de mudanças no agronegócios requer novas ferramentas gerenciais dos proprietários rurais e o conhecimento ganha importância como fator gerador de diferencial competitivo. O objetivo desta tese é desenvolver um método dinâmico de análise da criação de conhecimento para o elo da produção no agronegócios no Brasil e na Austrália com base no modelo de Nonaka e Takeuchi (1997). A presente pesquisa caracteriza-se por um estudo descritivo de caráter qualitativo, complementada por dados quantitativos. É realizado um estudo de dois casos, utilizando-se de documentação e observação in loco, questionário, entrevista e focus group. As realidades estudadas localizam-se no Rio Grande do Sul, Brasil, e em Queensland, na Austrália. Os dados da pesquisa possibilitaram o desenvolvimento de uma figura representativa do modo como ocorre a criação de conhecimento nas duas realidades. Da figura foi feito um desdobramento e desenvolveu-se um método dinâmico de análise da criação de conhecimento para o elo da produção no agronegócios. Os resultados demonstraram haver significativas similaridades e diferenças entre as realidades, sendo, no Brasil, os produtores rurais inseridos num contexto cooperativo (Cooperativa Tritícola Mista Alto Jacuí – Cotrijal) e, na Austrália, os negócios conduzidos individualmente. Para a ocorrência da criação de conhecimento é necessária a existência de grupos de relacionamento e de certa liderança em nível de propriedade, de comunidades de prática (CoPs) ou da cooperativa. O aspecto cultural e o estilo das relações pareceram exercer forte influência para que as trocas ocorram e para a maior ampliação da atuação das CoPs, as quais podem ser suporte para a criação de conhecimentos.As CoPs não se constituem num processo tecnológico e, sim, num processo social e cognitivo; assim, sua formação nas CoPs não parece depender somente de tecnologia, mas do estabelecimento de relações informais, nas quais as pessoas podem utilizar esses ambientes para definir suas verdades quanto às suas posturas frente aos processos de mudança. A forma de conduzir os negócios pode afetar o modo como se dá a criação de conhecimento, pois, numa propriedade onde as pessoas buscam socializar, questionar e inovar constantemente, evidencia-se haver maior espaço para transformar conhecimento tácito em explícito; assim, pessoas mais abertas ao novo e ao questionamento de suas práticas demonstram apresentar maiores possibilidades para criar um campo de interação para que o conhecimento seja criado. O estudo mostrou que há um grande percurso entre o produtor rural ter conhecimento e a capacidade de torná-lo uma atitude que possibilite trazer bons resultados nos negócios.
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Billings Reservoir is an urban reservoir located in the São Paulo Metropolitan Region. Tt supports 101 active artisanal fishermen. To describe this fishery, landings were recorded daily between February 1996 and January 1997 at Colonia (23 degrees 50' 57 S; 46 degrees 40' 02 W). In every landing, a data collector recorded catch, effort, fishing gears and fishing grounds. A total of 147 593 kg of fish were recorded in 3515 fishing trips. The exotic Nile tilapia, Oreochromis niloticus (L.), was the main species exploited (81.4% of the annual catches). Five other species were also targeted: the characid Astyanax eigenmaniorum (Cope) (13.0% of the annual catches); the erythrinid Hoplias aff malabaricus (Block) (2.1%); the exotic cyprinid Cyprinus carpio L. (Campos & Fernandez-Yepez) (2.4%); the curimatid Cyphocharax modestus L. (1.1%); and the pimelodid Rhamdia sp. (0.1%). Two main groups of fishermen were discriminated using Principal Components Analysis; these were associated with the type of fishing gear and fishing strategies, i.e. those who exploited Nile tilapia with cast nets and beating gill nets, and those who exploited other species with set gill nets. Management and maintenance of this fishery should consider the positive top-down effects that Nile tilapia could have in controlling eutrophication and also the social benefits.
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Several runs of the BEAM4 model were carried out, combining several sets of input parameters from von Bertalanffy's growth curve (Lt = L-x[1 - e(-k(-to))]) and the natural mortality (M), with sets or parameters from the length-weight relationship (W=aL(b)). Further simulations were made with variations of +/- 20%, in the input parameters: recruitment (R), catchability coefficient (q), and the lengths at which 50 and 75% of the fishes are retained by the net (L-50%, and L-75%). The data used were those of the pair trawl fisheries for corvina Micropogonias furnieri, off southeastern Brazil. Results showed variations in the output (landed weight) ranging from - 62 to 147% associated with the diverse sets of VBGF and LWR parameters, and lower variations associated with the other input parameters tested. (C) 2001 Elsevier B.V. B.V. All rights reserved.
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In this paper we describe the present status of the large migratory catfish fisheries in the Upper Amazon. We present biological information about the main species and we give strong evidence that the stock of piraiba (Brachyplatystoma filamentosum), the largest catfish in the Amazon Basin is probably over-exploited. In conclusion, we raise some hypotheses about the causes and prospects for the future.
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The presence or absence of motorized boats, partnerships and multispecies catches characterize the fisheries of Sao Francisco River, Minas Gerais, Brazil. Fishing activity based on 109 interviews, carried out in the wet (high water: February and March) and dry (low water: July and August) seasons, with professional fishermen are described. Aiming to identify the fishery income components, a covariance model was proposed, with the income as the response variable, related to the factors: fishing ground, use of motorized or paddle boat; seasonality; presence of fishing assistant, and the following covariates: capture in weight in the week Frier to the interview, fisherman experience in yrs; and distance (km) travelled for fishing. The results indicated that the main contributions to income were the absence of an engine (because of high price of the fuel), the absence of a partner (because of low capture) and the amount of fish caught by the fishermen.
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The description of the small-scale fisheries in the middle River Tocantins and their dynamics, in a full year cycle, was made out using questionnaires when interviewing fishermen at Imperatriz market. The landed fish exhibited a seasonal pattern related to the hydrological cycle, fishing effort and species diversity. Curimata, Prochilodus nigricans Agassiz, is the most important commercial fish. The fishing gears used in the area are castnets, gillnets, longlines and beach seines. Thirty-six percent of fish landed were caught exclusively by beach seine which mainly targets curimata. Alterations in the physical and biological characteristics of the middle River Tocantins due to the building of the Tucurui dam (2850 km(2) total area) allowed the mapara, Hipophthalmus marginatus Valenciennes, to colonise this area. During the closed season for nets, Siluriformes are the target of the fisheries, caught exclusively by longlining.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)