970 resultados para Fishing effort


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Within the frame of the EU Data Collection Regulation (DCR), Germany is obliged since 2002 to collect basic fisheries data to support the Common Fisheries Policy. Various governmental institutions are involved in the collection of landings and effort data, biological and economic data of the German fisheries. About 200 trips on commercial fishery vessels were sampled from 2002 to 2006. Additional stock data are collected on research surveys. The landings of cod in the recreational fisheries in the North and Baltic Seas were recorded within a pilot study. In order to assess the economic situation of the fishing fleet and processing industry, economic data were collected. The collected data are being stored in a national database and being made available for scientific working groups. At present, the legal regulations within the DCR framework are being reviewed and adapted to the changing requirements of fisheries management.

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We have developed a hierarchy of target levels, designated to address sustainability, efficiency, and recovery scenarios. Targets were derived from: 1) reported catches and effort in the commercial fishery, 2) statistics from fishery-independent surveys, and 3) knowledge of the biology of blue crab. Targets that are recommended include population sizes, catches, and effort levels, as well as reference fishing mortality rates. They are intended to be conservative and risk-averse. (PDF contains 182 pages)

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The cod stock in the Western Baltic Sea is assessed to be overfished regarding the definitions of the UN World Summit on Sustainable Development at Johannesburg in 2002. Thus, the European Fisheries Council enforced a multi-annual management plan in 2007. Our medium term simulations over the future 10 years assume similar stock productivity as compared with the past four decades and indicate that the goals of the management plan can be achieved through TAC and consistent effort regulations. Taking account of the uncertainty in the recruitment patterns, the target average fishing mortality of age groups 3 – 6 years of F = 0.6 per year as defined in the management plan is indicated to exceed sustainable levels consistent with high long term yields and low risk of depletion. The stipulated constraint of the annual TAC variations of ±15% will dominate future fisheries management and implies a high recovery potential of the stock through continued reductions in fishing mortality. The scientific assessment of sustainable levels of exploitation and consideration in the plan is strongly advised, taking account of uncertainties attributed to environmental and biological effects. We recommend our study to be complemented with economic impact assessments including effects on by-catch species, which have been disregarded in this study. It is further demonstrated, that the goals of the management plan can alternatively be achieved by mesh size adaptations. An alternative technical option of mesh size increases to realize the required reductions in fishing mortality provides avoidance of discards of undersized fish after a few years by means of improved selectivity, another important element of the Common Fisheries Policy. However, it is emphasized that technical regulations since 1990 failed to affect the by-catch and discards of juvenile cod. In any way, the meaningful implementation of the multiannual management plan through stringent control and enforcement appears critical.

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Landings of brown shrimp (Crangon crangon) for human consumption are not the only part that is taken from the North Sea shrimp stocks. Small amounts of industrial shrimps taken in the second half of a year in Germany add as well to the total amount that is taken from the stocks as the moribund animals discarded all over the year during the first sieving process on board, as the cooked and discarded ones in the second sieving on board and as those from the third sieving process ashore normally being crushed and used for animal feed stuff. All these fractions of the total catch of brown shrimps give a total of approximately 74 000 tonnes that were taken from the North Sea in 2005. Nevertheless, due to low predator abundance and changing climate conditions Crangon stocks show no signs of overexploitation so far with increasing LPUE values in the north-eastern part of the German Bight and decreasing ones in the south-east and Channel. There is the need of further investigations of these changes in the life history and distribution of shrimp as well as in the fishing behaviour and effort of the shrimp fleets .

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ENGLISH: Catch and effort statistics from the Japanese longline fishery operating in the eastern Pacific Ocean east of 130°W, from 1964 through 1966, were examined to study the geographic distribution, trends in apparent abundance, sexual maturity, and size composition of the tunas and billfishes. Yellowfin and bigeye tuna are generally most abundant in the equatorial regions of the high seas between about 10°N and 20°S, but west of 95°W. The marlins are more coastal in distribution, usually occurring to the east, and to the north and south of the heavy concentration of tropical tunas. Sailfish tend to be associated with coastal areas also, whereas shortbill spearfish are more frequently captured on the high seas. Swordfish are found most abundantly in the coastal regions off northern Mexico, and off northern Peru and southern Ecuador. The albacore, a temperate-water species of tuna, is most abundant in the high-seas area of the southeastern Pacific, Trends in apparent abundance were measured by the hook-rate (i.e. catch per 100 hooks). Hook-rates for bigeye tuna have decreased from about 3.5 fish per 100 hooks in 1958 to about 1.1 fish per 100 hooks in 1966. During the same period, effort was increased substantially and total catch has decreased since 1963. It does not appear that increased effort will result in sustained increased catches of bigeye. Hook-rates for yellowfin tuna in recent years have decreased to about one third of their initial levels. The surface fishery for yellowfin in the eastern Pacific apparently affects recruitment to the longline fishery. Assuming that present conditions in the surface fishery do not change appreciably, increased effort in the longline fishery probably would not produce sustained increased catches, but might in fact result in reduced catch rates. Unlike the situation for the other tunas of the eastern Pacific, it appears that the albacore fishery east of 130°W is not having a marked effect on their abundance. Although a high degree of variability was observed in the hookrates for striped marlin, no obvious trends are evident. Catches have decreased slightly from 13,500 tons in 1964 to about 11,000 tons in 1966. Heavy fishing for sailfish began in 1964 with a hook-rate of 10.6 fish per 100 hooks; by 1966 it had dropped to 5.8. Catches of this species in the area of major concentration dropped from 329,900 fish in 1965 to 173,600 fish in 1966. This fishery has operated for too short a period of time to enable one to determine its effect on the sustainable yield. Length-frequency measurements and gonad samples from yellowfin and bigeye tunas collected in the eastern Pacific were analyzed to determine sexual maturity and growth characteristics. The results corroborate the findings of earlier investigators. SPANISH: Las estadísticas de captura y del esfuerzo de la pesca japonesa con palangre que maniobra en el Océano Pacífico oriental al este de los 130°W, desde 1964 hasta 1966, fueron examinadas para estudiar la distribución geográfica, las tendencias de la abundancia aparente, la madurez sexual y la composición de talla de los atunes y de los peces espada. Los atunes aleta amarilla y ojo grande son generalmente más abundantes en las regiones ecuatoriales de alta entre unos 10°N y 20°S, pero al oeste de los 95°W. Los marlines son costaneros en distribución, apareciendo habitualmente hacia el y hacia el norte y sur de la densa concentración de atunes tropicales. pez vela tiende a asociarse también con las áreas costaneras, mientras el pez aguja corta es capturado con más frecuencia en alta mar. Los peces espada se encuentran más abundantemente en las regiones costaneras de México septentrional y frente al norte del Perú y del Ecuador meridional. La albacora, una especie de atún de aguas templadas, es más abundante en el área de alta mar del Pacífico sudoriental. Las tendencias en la abundancia aparente fueron evaluadas por la tasa de captura por anzuelo (i.e., captura por 100 anzuelos). Las tasas de captura por anzuelo del atún ojo grande, disminuyeron en 1958, de unos 3.5 peces por 100 anzuelos a cerca de 1.1 pez por 100 anzuelos en 1966. Durante el mismo período, el esfuerzo fue aumentado substancialmente y, desde 1963, la captura total disminuyó. No parece que el aumento del esfuerzo resultara en un aumento sostenido de las capturas del atún ojo grande. Las tasas de captura por anzuelo de atún aleta amarilla han disminuido en un tercio de los niveles iniciales, en años recientes. La pesca de superficie de esta especie en el Pacífico oriental afectó aparentemente el reclutamiento en la pesca con palangre. Suponiendo que las condiciones actuales de la pesquería no cambien apreciablemente, un aumento del esfuerzo en la pesquería palangrera probablemente no produciría un aumento sostenido de las capturas, pero en realidad podría resultar en tasas de captura reducidas. A diferencia de la situación de otros túnidos del Pacífico oriental, parece que la pesca de la albacora al este de los 130°W no ha tenido un efecto marcado en su abundancia. Aunque se observó un alto grado de variabilidad en las tasas de captura por anzuelo correspondientes al marlin rayado, no fueron evidentes tendencias obvias. Las capturas han mermado ligeramente de 13,500 toneladas en 1964 a unas 11,000 toneladas en 1966. La fuerte pesca por peces vela empezó en 1964 con una tasa por anzuelo de 10.6 peces por 100 anzuelos; en 1966 había mermado a 5.8. Las capturas de esta especie en el área de mayor concentración disminuyeron de 329,000 peces en 1965, a 173,600 peces en 1966. Esta pesquería ha maniobrado por un período demasiado corto de tiempo para que pueda determinarse su efecto en el rendimiento sostenible. Las mediciones frecuencia-longitud, y las muestras de las gónadas de los atunes aleta amarilla y ojo grande, obtenidas en el Pacífico oriental, fueron analizadas para determinar la madurez sexual y las características del crecimiento. Los resultados corroboraron los hallazgos anteriores de investigadores. (PDF contains 144 pages.)

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Among other tasks the “Working Group on Crangon Fisheries and Life Cycle” of the “International Council for the Exploration of the Sea” collects data on landings and effort in the North Sea brown shrimp fisheries by country. Landings per unit effort data are calculated and all are compared on basis of long-term series as well as on seasonal basis. The development for each country is described and compared for the year 2001 to the ten-year average from 1992 to 2001 were possible, as some data are missing especially for the Netherlands. While the Dutch and British fleets increased their landings substantially in 2001 compared to the previous years, Danish,German and Belgian fishermen had reduced landings. There are regional differences in fishing pattern between the countries, especially Denmark versus the rest of Europe. Effort measures remain incomparable between the countries, and fluctuations in landings per unit effort data seem to be in a normal biological range, giving no reason for concern at present for the situation of brown shrimp stocks in the North Sea. An improvement of the data basis is required and possibly achievable by the EU logbook system being in force for brown shrimp fisheries as well.

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ENGLISH: The fishing power of the tuna purse-seine fleet of the eastern Pacific Ocean has increased since the early 1960's. Because the entire fleet seems to have adopted equipment and techniques to increase its efficiency in capturing tunas, traditional methods of adjusting catch rates to a reference vessel type of fixed efficiency to index tuna abundance from fishing success are inapplicable. Instead, a methodology for such adjustment based on a mathematical representation of purse seining activities is developed. Observed changes in efficiency in subprocesses of purse seining are then used to adjust catch rates when computing abundance histories for yellowfin and skipjack in large regions of the eastern Pacific Ocean. SPANISH: La eficacia de pesca de la flota de cerco atunera en el Océano Pacífico oriental ha aumentado desde el comienzo del decenio de 1960. Como toda la flota parece haber adoptado equipo y métodos para incrementar su eficaciaen capturar atunes, no se pueden aplicar los métodos tradicionales de ajustar los índices de captura a un tipo normalizado de barco (es decir de eficacia fija) para indicar la abundancia del atún según los resultados de pesca. En su lugar se ha desarrollado un método para realizar tal ajuste basado en una representación matemática de las actividades de las embarcaciones de cerco. Cuando se calcula la abundancia histórica del atún aleta amarilla y barrilete en grandes regiones del Océano Pacífico oriental, se usan entonces los cambios observados en la eficacia de los subprocesos cerqueros para ajustar los índices de captura. (PDF contains 120 pages.)

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This paper deals with the relation between trawling gear and towing power of the Nigerian inshore fishing trawlers. Information on the size as well as weight variations of the existing otter boards as they relate to the horse power of the engine and length of warps in relation to fishing depth are given

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An examination is made of the organization and administration of fisheries training institutes in Nigeria, highlighting their inadequacies in achieving required goals. A systems approach to fisheries manpower training is described which is based on 4 principles: 1) wholeness; 2) systematization; 3) compatibility; and 4) optimization

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For 10 years the Institute for Fishing Technology, Hamburg (IFH) has been carrying out experiments in the brown shrimp fishery with beam trawls aiming at a reduction of unwanted bycatches. When the tests were transferred to commercial fishery conditions the personnel effort and costs increased markedly. It became e.g. necessary to install a deep-freeze chain to make it possible to evaluate more samples in the laboratory. This again required to increase the number of technicians for measuring the fish and shrimp samples, but also made it necessary to perform this work in the most rational and time-saving way by applying modern electronic aids. Though all samples still have to be sorted by species and have to be weighed and measured the introduction of electronic aids, however, like electronic measuring board and computer-aided image processing system, all weight and length data are immediately and digitally recorded after processing. They are transferred via a network to a server PC which stores them into a purpose-designed database. This article describes the applicationof two electronic systems: the measuring board (FM 100, Fa. SCANTROL), iniated by a project in the Norwegian Institute for Fishing Technology, and a computer-aided image processing system, focussing on measuring shrimps in their naturally flexed shape, also developed in the Institute for Fishing Technology in close collaboration with the University of Duisburg. These electronic recording systems allow the consistent and reproducible record of data independent of the changing day-to-day personal form of the staff operating them. With the help of these systems the number of measurements the laboratory could be maximized to 250 000 per year. This made it possible to evaluate, in 1999, 525 catch samples from 75 commercial hauls taken during 15 days at sea. The time gain in measuring the samples is about one third of the time previously needed (i.e. one hour per sample). An additional advantage is the immediate availability of the digitally stored data which enables rapid analyses of all finished subexperiments. Both systems are applied today in several institutes of the Federal Research Centre. The image processing system is now the standard measuring method in an international research project.

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Recently, the German redfish fishery displayed a pronounced seasonal pattern in geographic effort distribution and depth. The second and third quarters were the main season when 80 % of the effort was exerted. During the second quarter, the fleet activities were concentrated in international waters close to the Icelandic Exclusive Economic Zone (EEZ), fishing at depths exceeding 600 m. In contrast, the catches in the third quarter were taken mainly inside the Greenland EEZ at depths around 300 m. From 1995 to 1998, the annual effort ranged from 14 000 to 18 000 trawling hours, without a trend. This effort yielded about 18 000 to 21 000 t (international catch > 100 000 t) annually. Since 1996, the catch rate (CPUE) decreased during the main season. The decrease in CPUE should be interpreted as the first reaction of the stock to increased exploitation. The fish size also varied seasonally and peaked during the second quarter at depths exceeding 600 m. Here, males were bigger than females and both sexes were equally frequent. The increase of fish size with increasing depth did not contribute to the hypothesis of two separate pelagic redfish stocks above and below 500 m. In contrast, the close relation between fish size and depth point to the so-called “deeper-bigger phenomenon” which was found in numerous fish stocks. Very few redfish in the catches were immature.

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Nigeria's three federal fisheries schools are administered by three autonomous research institutes located in Lagos, New Bussa, and Maiduguri. The schools were established at different periods to train the required manpower for Nigeria's fishing industry which has remained predominantly artisanal since its inception in 1942 as a Second World War exigency. Despite the establishment of the schools, the industry's manpower is still being dominated by non-nationals especially in the capture fisheries sub-sector. The common features of the schools include the apparent insensitivity of their programmes to the industry's dynamic manpower needs; the absence of coordination of their programmes by a national body which would have ensured that the schools are able to communicate with one another and are willing to act and share a purpose. The need and the methodology for a change of emphasis from the on-going training of extension agents and officers to that of fishing operatives and technicians to enable Nigeria effectively harness her local fish resources towards self-sufficiency is highlighted.

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ENGLISH: Catch and effort data from logbooks of tuna seiners were used to make estimates of catch per hour of searching for 1970-1980. The estimates were standardized using a regression model to make annual estimates of abundance adjusted for fishing mode, speed, capacity, use of aerial assistance, net dimensions, and sea-surface temperature. Inside the CYRA the standardized estimates for tuna schools associated with dolphins and those for schools not associated with dolphins showed a similar overall pattern of decline. The 1980 catch rates were about 300/0 of the 1970 rates, the decline being greater for the schools not associated with dolphins. Dolphin-associated schools outside the CYRA declined to about 60% of the 1970 levels. SPANISH: Se emplearon los datos de la captura y el esfuerzo de los cuadernos de bitácora de las embarcaciones cerqueras para hacer las estimaciones de la captura por hora de búsqueda correspondientes a 1970-1980. Se normalizaron estas estimaciones usando un modelo de regresión con el fin' de hacer las estimaciones anuales de la abundancia, ajustadas según la moda de pesca, velocidad, capacidad, uso de ayuda aérea, dimensiones de la red y temperatura de la superficie del mar. En el ARCAA las estimaciones normalizadas de los cardúmenes de atún asociados con delfines y aquellas de los cardúmenes no asociados con delfines, indicaron una pauta general similar de reducción. Las proporciones de captura de 1980, fueron cerca del 300/0 de las de 1970, encontrándose la mayor reducción en los cardúmenes no asociados con delfines. Los cardúmenes asociados con delfines, fuera del ARCAA, se redujeron en un 60% con respecto a los niveles de 1970. (PDF contains 79 pages.)

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This publication is a record of the proceedings of the Siem Reap Workshop and Symposium. It provides a bottom-up perspective on how rights are understood, and what rights are seen as important by small-scale fishing communities, if they are to fulfil their responsibilities for managing resources in a sustainable and equitable manner. It is hoped that these proceedings, and the Statement from the Workshop-the Siem Reap Statement-are found useful by those engaged in policy making and advocacy in support of small-scale fisheries, as well as researchers, non-governmental organizations (NGOs), fishworker organizations, and multilateral and regional organizations

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The Zanzibar Workshop Proceedings consists of the report and the Statement of the Workshop and provides a rich understanding of the dynamics of traditional, indigenous, small-scale and artisanal fisheries and fishing communities in the Eastern and Southern African (ESA) context. The issues covered include: the saga of rights denied to coastal lands, fishing, and threats to livelihood arising from lack of recognition of traditional rights and the livelihood needs of people in the region; the aspirations of coastal and inland communities to maintain or improve their livelihoods; and a bottom-up perspective on access rights to fishing, post-harvest rights and economic and social rights. This report will be a valuable source of information for community organizers, trade union leaders, government officials and the donor community, including multilateral organizations, researchers and for all those who are interested in the well-being of ESA fishing communities.