72 resultados para productivity index
em Aquatic Commons
Resumo:
The Improved Fish Smoker (IFS) was designed and constructed by NIFFR in collaboration with GTZ in 1997. After the on-station trials, five fishing villages with pronounced fishing activities were selected for the demonstration. The IFS and the traditional Smoking Kiln were compared in one of the fishing villages using Gross Margin analysis (GM) and productivity index to determine the profitability and productivity of the two kilns. It was found that the average income of IFS users at fully capacity was N5, 555.50 per day in a year N1.3 million would be realized. Conversely, the average income of the users of Traditional Smoking Kiln (TSK) was N649.00 per day and about N152, 150.50 would be realized in a year. From this estimate, it is evident that the IFS are more profitable than the TSK. Productivity index of the two kilns also revealed that the productivity of IFS is higher than the TSK. Thus, using the IFS would enhance the income of artisanal women Fish Processors (AWOFPS) and ensure food security for the household
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This study is concerned with the measurement of total factor prodnctivity in the marine fishing industries in general and in the Pacific coast trawl fishery in particular. The study is divided into two parts. Part I contains suitable empirical and introductory theoretical material for the examination of productivity in the Pacific coast trawl Deet. It is self-contained, and contains the basic formulae, empirical results, and discussion. Because the economic theory of index numbers and productivity is constantly evolving and is widely scattered throughout the economics literature, Part D draws together the theoretical literature into one place to allow ready access for readers interested in more details. The major methodological focus of the study is upon the type of economic index number that is most appropriate for use by economists with the National Marine Fisheries Service. This study recommends that the following types of economic index numbers be used: chain rather than fIxed base; bilateral rather than multilateral; one of the class of superlative indices, such as the Tornqvist or Fisher Ideal. (PDF file contains 40 pages.)
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One of the paradigms in the management of fish resources is that annual yield is a function of water quality. Consequently, the use of shorthand methods for predicting yields from morphological and /or edaphic factors of the water body are most appropriate for tropical multi-species fisheries. In this study, the morpho-edaphic index (MEI) was used to estimate the productivity of Ologe lagoon (Nigeria). The predicted yield was 73.8 kg ha super(-1) yr super(-1) and a comparison with yields in other African waters showed that Ologe lagoon is highly productive. However, its potential is not fully harnessed due to the traditional nature of the fishing
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The environmental conditions of Kainji Lake from 1971/72 to date appear to have stabilized to a large extent, judging from the similarity of physico-chemical parameters investigated in this study over the period. Solar radiation (as reflected in variation in temperature) and pH have remained largely constant over the years, while conductivity (index of nutrient enrichment), though significantly higher in 1995/96, could be described as sporadic and needs further monitoring to ascertain its trend in the lake. While water transparency and dissolved oxygen were higher in 1971/72 compared to the other years, these increases cannot be said to be overwhelming. The lower transparency in 1995/96 was due to the exceptional flood of that year and may have also accounted for the poorer dissolved oxygen concentration compared to the other years due to its impact on photosynthesis. There is no evidence from this study to indicate that primary productivity has increased over the years. Consequently, the observed increase in fish yield by the KLFPP from CAS, which is corroborated by estimates from the MEI, cannot be supported on the basis of improved photosynthetic production. The phenomenal high levels of conductivity recorded during certain periods in 1995 (600 mu mhos cm super(-1)) are hitherto unknown in the lake and may indicate a trend towards nutrient enrichment. However, it is premature at this stage to conclude on its long-term impact on primary production and consequently, on fish yield. Secondly, the notion of overfishing in the 80s (Ita, 1993), may need to be further examined as low or dwindling catches could be due to a number of factors among which are the level of fishing effort, the type and efficiency of gears and the intensity of sampling. It would appear that with the intervention of KLFPP, the better management of the lake's fisheries would increase the current level of catch. It also needs to be examined how much of the clupeid fisheries, which is now known to account for a substantial proportion of the total fish yield in Kainji Lake, was included in the sampling of the 80s. (PDF contains 43 pages)
Resumo:
Assessing the vulnerability of stocks to fishing practices in U.S. federal waters was recently highlighted by the National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration, as an important factor to consider when 1) identifying stocks that should be managed and protected under a fishery management plan; 2) grouping data-poor stocks into relevant management complexes; and 3) developing precautionary harvest control rules. To assist the regional fishery management councils in determining vulnerability, NMFS elected to use a modified version of a productivity and susceptibility analysis (PSA) because it can be based on qualitative data, has a history of use in other fisheries, and is recommended by several organizations as a reasonable approach for evaluating risk. A number of productivity and susceptibility attributes for a stock are used in a PSA and from these attributes, index scores and measures of uncertainty are computed and graphically displayed. To demonstrate the utility of the resulting vulnerability evaluation, we evaluated six U.S. fisheries targeting 162 stocks that exhibited varying degrees of productivity and susceptibility, and for which data quality varied. Overall, the PSA was capable of differentiating the vulnerability of stocks along the gradient of susceptibility and productivity indices, although fixed thresholds separating low-, moderate-, and highly vulnerable species were not observed. The PSA can be used as a flexible tool that can incorporate regional-specific information on fishery and management activity.
Resumo:
This project was done during a one-year period (2006-2007) with the aim of assessing and evaluating the susceptible and vulnerable habitat of Tajan River estuarine region as well as identifying its ecological features. This region consists of Tajan estuarine region as one of the sub-basins of the Caspian Sea basin which covers a surface of 2km2. In this assessment, 6 riverine estuarine and marine stations were chosen in which non-biotic parameters such as temperature, salinity, dissolved oxygen, pH and nutrients, and biotic parameters such as variation, density, plankton, primary production by chlorophyll-a. Benthos variation density, silt and the organic materials of the sediments were sampled and measured monthly. The amount of chlorophyll-a concentration and primary production showed a lot of seasonal changes at these stations which ranged from0.3 to 96 mg/m3. The results from the primary productions indicated that the eastern station of the estuary had high concentrations of chlorophyll-a during all seasons (96mg/m3). The most important and dominant planktonic groups in this region included Bacillariophyta from plankton and copepoda from zooplankton. The most important Benthos communities consisted of Driessena polymorpha.Cerastoderma lamarki in estuarine region,Chironomus plumosus in riverine region and Hypaniola sp. In marine region. Assessing the annual variation in these three riverine, estuarine and marine regions, phytoplankton with 3.1, Zooplankton with 2.7 and Benthos with 1.9 Showed the most density in the estuarine region. Assessing the annual density, phytoplanktonic (6118967 no . in m3) and zooplanktonic (7272 no . in m3) communities showed the most density in the marine region. Assessing the statistical tests showed that the estuarine and riverine regions had a significant difference in planktonic density (p<0.005) compared with the marine region. Moreover, The zeoplanktonic density in the marine region had a significant difference (p<0.005) with estuarine and riverine regions. Tooki test and one-way variance Analysis showed that in assessing the planktonic groups (p<0.005) and Benthos (p<0.005), there was a significant difference in variation index between river with estuary, and estuary with the sea. The amount of the total annual live biomass of the Benthos resource in Tajan river estuarine region was estimated 757.66 g/m2.
Resumo:
ENGLISH: In the eastern Pacific Ocean nearly all of the commercial catches of yellowfin tuna (Thunnus albacares) and skipjack (Katsuwonus pelamis) are taken by two types of vessels, baitboats, which use pole and line in conjunction with live-bait, and purse-seiners. From its inception until very recently (1959), this fishery was dominated by baitboats. This method of fishing has been described by Godsil (1938) and Shimada and Schaefer (1956). From 1951 through 1958 baitboats caught between 66.4 and 90.8 per cent of the yellowfin and between 87.2 and 95.3 per cent of the skipjack landed by the California-based fleet. These vessels fished for tuna throughout the year and covered virtually all of the area from southern California to northern Chile. The purse-seine fishery for tunas developed out of the round-haul net fisheries for California sardines and other species. Scofield (1951) gives a detailed description of the development of gear and fishing methods. Prior to 1959 many of the seiners engaged in other fisheries during the fall and early winter months and consequently most of the fishing effort for tuna occurred in the period February-August. The vessels were quite small, averaging approximately 120 tons carrying capacity (Broadhead and Marshall, 1960), in comparison to the baitboats, of which the most numerous size-class was 201-300 tons. The seiners were naturally more restricted in range than the baitboats and most of their effort was restricted to the northern grounds. During the period 1959-61 most of the large baitboats were converted for purse-seining and the existing seiner fleet was modernized. These developments increased the range of the seiner fleet and resulted in a wider and more nearly even spatial and temporal distribution of effort. By the early part of 1961, the purse-seine fleet approximated the level of the preconversion baitboat fleet in amount of effort applied and area covered. The changes in the purse-seine fishery and the fishing methods employed in the modernized fleet are described by Orange and Broadhead (1959), Broadhead and Marshall (1960), McNeely (1961) and Broadhead (1962). The change in the relative importance of the two gears is illustrated by the decline in the proportion of the total logged tonnage landed by California-based baitboats, in comparison to the proportion landed by seiners. In 1959 baitboats landed 49.5 per cent of the yellowfin and 87.8 per cent of the skipjack. In 1960 these percentages were 22.9 and 74.7 respectively and in 1961 the decline continued to 12.6 per cent of the yellowfin and 30.0 per cent of the skipjack (Schaefer, 1962). In previous Bulletins of this Commission (Griffiths, 1960; Calkins, 1961) the baitboat catch and effort statistics were used to compute two indices of population density and an index of concentration of fishing effort and the fluctuations of these indices were analyzed in some detail. Due to the change in the relative importance of the two gears it is appropriate to extend this investigation to include the purse-seine data. The objectives of this paper are to compute two indices of population density and an index of concentration of fishing effort and to examine the fluctuations in these indices before and after the changes in the fishery. A further objective is to compare the purse-seine indices with those of the baitboats for the same time periods. SPANISH: En el Océano Pacífico Oriental casi todas las capturas comerciales del atún aleta amarilla (Thunnus albacares) y del barrilete (Katsuwonus pelamis) son efectuadas por dos tipos de barcos, los barcos de carnada que emplean la caña y el anzuelo en conjunto con la carnada viva, y los barcos rederos. Desde su comienzo hasta hace poco tiempo (1959), esta pesquería estaba dominada por los barcos de carnada. El método de pesca usado por estos barcos ha sido descrito por Godsil (1938) y por Shimada y Schaefer (1956). De 1951 a 1958, los barcos de carnada pescaron entre el 66.4 y el 90.8 por ciento del atún aleta amarilla y entre el 87.2 y el 95.3 por ciento del barrilete descargados por la flota que tiene su base en California. Estos barcos pescaron atún durante todo el año y cubrieron virtualmente toda el área de California meridional hasta la parte norte de Chile. La pesquería del atún con redes de cerco se originó en las pesquerías de las sardinas de California y otras especies, con redes que se remolcaban circularmente. Scofield (1951) dá una descripción detallada del desarrollo de los métodos y del equipo de pesca. Antes de 1959 muchos de los rederos se dedicaban a otras pesquerías durante los meses del otoño y a principios del invierno y consecuentemente, la mayor parte del esfuerzo depesca para la producción del atún ocurría en el período febrero-agosto. Las embarcaciones eran bastante pequeñas, con un promedio de aproximadamente 120 toneladas de capacidad para el transporte (Broadhead y Marshall, 1960) en comparación con los barcos de carnada, de los cuales la clase de tamaño más numerosa era de 201 a 300 toneladas. Los rederos estaban naturalmente más restringidos en su radio de acción que los barcos de carnada y la mayor parte de su esfuerzo se limitaba a las localidades del norte. Durante el período 1959-61, la mayoría de los grandes barcos de carnada fueron convertidos al sistema de pesca con redes de cerco, y se modernizó la flota existente de los rederos. Estos cambios aumentaron el alcance de la flota de los barcos rederos dando como resultado una distribución más amplia y casi más uniforme del esfuerzo espaciado y temporal. En la primera parte del año 1961, la flota de rederos se aproximó al nivel de la preconversión de la flota de clipers, en la cantidad de esfuerzo aplicado y al área comprendida. Los cambios en la pesquería con red y los métodos de pesca empleados en la flota modernizada, han sido descritos por Orange y Broadhead (1959), Broadl1ead y Marshall (1960), McNeely (1961) y Broadhead (1962). El cambio en la importancia relativa de los dos sistemas de pesca está ilustrado por la declinación en la proporción del tonelaje total registrado, como descargado por los barcos de carnada que tienen su base en California, comparado con la proporción desembarcada por los barcos rederos. En 1959 los clipers descargaron el 49.5 por ciento del atún aleta amarilla y el 87.8 por ciento del barrilete. En 1960 estos porcentajes fueron del 22.9 y 74.7 respectivamente, y en 1961 continuó la reducción hasta el 12.6 por ciento del atún aleta amarilla y el 30.0 por ciento del barrilete (Schaefer, 1962). En Boletines anteriores de la Comisión (Griffiths, 1960; Calkins, 1961) las estadísticas de la pesca y el esfuerzo de los clipers se utilizaron para computar dos índices de la densidad de población y un índice de la concentración del esfuerzo de pesca, y se analizaron algo detalladamente las fluctuaciones de estos índices. Debido al cambio en la importancia relativa de los dos sistemas de pesca, es conveniente extender esta investigación para incluir los datos correspondientes a los barcos rederos. Los objetivos del presente estudio son de computar dos índices de la densidad de población y un índice de la concentración del esfuerzo de pesca, y examinar las fluctuaciones en estos índices, antes y después de los cambios en la pesquería. Otro objetivo es de comparar los índices de los barcos rederos, con aquellos de los clipers en los mismos períodos de tiempo.
Resumo:
The following series of fishery publications produced in calendar years 1980-85 by the Scientific Publications OffIce of the National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), are listed numerically and indexed by author and subject: Circular, Fishery BuUetin, Marine Fisheries Review, Special Scientific Report-Fisheries, and Technical Report NMFS. Also included is an alphanumeric listing of the NOAA Technical Memorandum NMFS series published in calendar years 1972-85 by NMFS regional offices and fisheries centers. Authors and subjects for the Memoradum series are indexed with the other publication series. (PDF file contains 156 pages.)
Resumo:
This document is part of a series of 5 technical manuals produced by the Challenge Program Project CP34 “Improved fisheries productivity and management in tropical reservoirs”. Inland capture fisheries in India have declined in recent years, leaving thousands of fishers to sink deeper into poverty. Freshwater aquaculture in small water bodies like ponds now contributes 80% of the country¡¯s inland fish production. This manual outlines the use of small reservoir for freshwater aquacultureas a means of providing rural areas with food and livelihoods and protecting aquatic ecosystems, in particular by facilitating the conservation of indigenous fish species. (PDF contains 22 pages)
Resumo:
Fish research institutes in Europe have made considerable effort in developing rapid, objective sensory methods for evaluation of fish freshness. The Quality Index Method(QIM) has been recommended for a European initiative regarding standardisation and harmonisation of sensory evaluation of fish. QIM-schemes have been developed for various common European fish species. Research has now provided the industry with a convenient, objective and powerful tool for measuring freshness of fish kept in ice Further research is needed to evaluate the applicability of QIM for fish handled, stored and processed under different conditions. However, for progress and development of QIM it is now very important that the fish sector implements QIM in fish auctions and the quality management system of the fish processing plants.
Resumo:
Three fertilizer types (NPK, Super-phosphate and cow dung) were applied at two levels (Low, 0.3 kg/25m super(2)/2weeks and High, 0.7kg/25 m super(2)/2weeks) to 12 ponds with two ponds serving as control. Each pond had an area of 25 m super(2). Application of fertilizers and monitoring of plankton productivity and water quality parameters continued fortnightly for 52 days. Results obtained were subjected to Statistical Variance Analysis. The abundance of phytoplankton was in the order: Chlorophyceae > Bacillariophyceae > Cyanophyceae > Desmideaceae. While that of zooplankton followed the order: Crustacean > Rotifer > Protozoan. Primary productivity showed a variation between treatments with lowest value of 5592 mg/O sub(2)/m super(3)/day obtained in the control and cow dung low application rates (1.5 kg/25 m super(2)/2weeks). The highest value for primary productivity was obtained at M sub(2) (0.7 kg/25 m super(2)/2weeks, N.P.K) with primary productivity value of 7200 mg/O sub(2)/m super(3)/day, closely followed by M sub(4) (0.7 kg/25 m super(2)/2weeks, super phosphate) with 6792 mg/O sub(2)/m super(3)/day.
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A Human Security Index (HIS) enumerating 200 countries was introduced in 2008. A community-level HSI is under development in the USA. Coastal communities face large disparities in components of human security. How can a HSI support improved policies/services (such as environmental or public health forecasts or warnings) for improving lives? Several issues are discussed. (PDF contains 4 pages)
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The rate of sea level change has varied considerably over geological time, with rapid increases (0.25 cm yr-1) at the end of the last ice age to more modest increases over the last 4,000 years (0.04 cm yr-1; Hendry 1993). Due to anthropogenic contributions to climate change, however, the rate of sea level rise is expected to increase between 0.10 and 0.25 cm year-1 for many coastal areas (Warrick et al. 1996). Notwithstanding, it has been predicted that over the next 100 years, sea levels along the northeastern coast of North Carolina may increase by an astonishing 0.8 m (0.8 cm yr-1); through a combination of sea-level rise and coastal subsidence (Titus and Richman 2001; Parham et al. 2006). As North Carolina ranks third in the United States with land at or just above sea level, any additional sea rise may promote further deterioration of vital coastal wetland systems. (PDF contains 4 pages)
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Changes in sustainability of aquatic ecosystems are likely to be brought about by the global warming that has been widely predicted. In this article, the effects of water temperature on water-bodies (lakes, oceans and rivers) are reviewed followed by the effects of temperature on aquatic organisms. Almost all aquatic organisms require exogenous heat before they can metabolise efficiently. An organism that is adapted to warm temperatures will have a higher rate of metabolism of food organisms and this increases feeding rate. In addition, an increase in temperature raises the metabolism of food organisms, so food quality can be altered. Where populations have a different tolerance to temperature the result is habitat partitioning. One effect of prolonged high temperature is that it causes water to evaporate readily. In the marine littoral this is not an important problem as tides will replenish water in pools. Small rain pools are found in many tropical countries during the rainy season and these become incompletely dried at intervals. The biota of such pools must have resistant stages within the life cycle that enable them to cope with periods of drying. The most important potential effects of global warming include (i) the alteration of existing coastlines, (ii) the development of more deserts on some land masses, (iii) higher productivity producing higher crop production but a greater threat of algal blooms and (iv) the processing of organic matter at surface microlayers.