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| Registros recuperados: 173 | |
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| Hansen, J.E.; Madirolas, A.. |
| Two pelagic surveys to study were carried out during 1993. Those surveys covered the regions inhabited by either the bonaerensis stock in october (34-41°S)and the patagonian stock in November - December (41-45°30'S). Pre-stratified random sampling designs, including two random steps to allocate the transects, were adopted to perform the acoustic sampling by echo integration. A midwater trawl net (9-16 m vertical opening, 10 mm mesh-sized codend)was used to collect fish samples. The biomass of the northern stock was acoustically estimated to be about 1,45 million tons, whereas that of the southern stock was almost 740,000 t. Young anchovies, up to two-year old, allow for most of theose abundance values within each stock. The arrays of individuals at the sea... |
| Tipo: Journal Contribution |
Palavras-chave: Pelagic fisheries; Geographical distribution; Biomass; Mortality; Echo surveys; Stock assessment; Geographical distribution; Biomass; Stock assessment; Pelagic fisheries; Mortality; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_5659; Http://aims.fao.org/aos/agrovoc/c_4945. |
| Ano: 1996 |
URL: http://hdl.handle.net/1834/1955 |
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| Cordo, H.D.. |
| Catch per unit of effort (CPUE)analysis of the Argentine surimi fleet is a routine work to estimate abundance indices of southern blue whiting Micromesistius australis. Several analysis of this fishery suggest that, as of the years when intensive fishing by foreign and national fleets started, the resource has suffered a marked decline. When calculating the CPUE it is common practice to take into acount only trips and fishing operations with high catches of the target species fishing operations directed to other species are not considered to avoid underestimations. Therefore, in order to include a percentage of catch of the analyzed species higher than a subjective value, available data are filtered. However, because only operations with high yield are... |
| Tipo: Journal Contribution |
Palavras-chave: Catch/effort; Yield; Commercial fishing; Overfishing; Stock assessment; Stock assessment; Overfishing. |
| Ano: 2002 |
URL: http://hdl.handle.net/1834/1584 |
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| Pawlowski, Lionel; Lorance, Pascal. |
| In the Northeast Atlantic fishery for roundnose grenadier Coryphaenoides rupestris, discards account for about 30% of the catch in weight. Data on discards are scarce; however, length distributions and discard rates appear to be relatively stable from year to year. In contrast, landings data available since 1990 show that the average pre-anal fin length has decreased from 20.7 cm in 1990 to 15.2 cm in 2008, resulting in a 58% reduction of the mean individual weight (850 g in 2008) and an increasing occurrence of overlapping class sizes between landings and discards in recent years. For stock assessment, the method of separable virtual population analysis (SVPA) was used. However, because of the lack of discard data for many of the years covered by the... |
| Tipo: Text |
Palavras-chave: Stock assessment; Fishing effort; Discards; Time series; Macrouridae; Coryphaenoides rupestris; Atlantic Ocean. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11175/7527.pdf |
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| Pons, Maite; Branch, Trevor A.; Melnychuk, Michael C.; Jensen, Olaf P.; Brodziak, Jon; Fromentin, Jean-marc; Harley, Shelton J.; Haynie, Alan C.; Kell, Laurie T.; Maunder, Mark N.; Parma, Ana M.; Restrepo, Victor R.; Sharma, Rishi; Ahrens, Robert; Hilborn, Ray. |
| Commercial tunas and billfishes (swordfish, marlins and sailfish) provide considerable catches and income in both developed and developing countries. These stocks vary in status from lightly exploited to rebuilding to severely depleted. Previous studies suggested that this variability could result from differences in life-history characteristics and economic incentives, but differences in exploitation histories and management measures also have a strong effect on current stock status. Although the status (biomass and fishing mortality rate) of major tuna and billfish stocks is well documented, the effect of these diverse factors on current stock status and the effect of management measures in rebuilding stocks have not been analysed at the global level.... |
| Tipo: Text |
Palavras-chave: Fisheries management; Marine conservation; Stock assessment; Stock status; Tuna fisheries. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00333/44383/44107.pdf |
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| Abban, E.K.; Asante, A.K.; Falk, T.M.. |
| Ghana is one of the countries bordering theAtlantic Ocean on the coast of Africa. The country is located between latitudes 5" N and11" N and longitudes 1" E and 3" W Thecoastline of Ghana, approximately 550 kmlong, is dotted with about 50 lagoons andestuaries that, together with rocky capes and avariety of sandy bays, constitute its coastalwetlands (Armah 1993). These lagoons,estuaries and associated floodplains providehabitats for a variety of wildlife including birdsand fishes (Ntiamoa-Baidu 1991). With an estimated 40 000 ha surface area, the lagoonsare important fish and fisheries resources forassociated communities. The fish speciescomposition of these lagoons varies slightly,but a constant and predominant species is theblack-chinned tilapia,... |
| Tipo: Proceedings Paper |
Palavras-chave: Fish species; Stock assessment. |
| Ano: 2000 |
URL: http://hdl.handle.net/1834/698 |
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| Palha de Sousa, L.; Abdala, S.; Brito, A.. |
| O camarão de superfície do Banco de Sofala representa uma importante fonte de divisas para Moçambique. O estado de conhecimento sobre a pescaria encontra-se distribuído por fontes bibliográficas diversas incluindo principalmente relatórios internos. Este trabalho tem como principal objectivo compilar todos os dados e informação sobre a pescaria e o stock de camarão de superfície no Banco de Sofala desde o início da sua exploração comercial até ao presente momento. Nele se inclui uma breve descrição da pescaria, a evolução do esforço de pesca, capturas e os respectivos rendimentos da pescaria. É feita referência à história das diferentes medidas de gestão adoptadas sobre o licenciamento, a malhagem mínima, vedas e Total Admissível de Captura (TAC). É... |
| Tipo: Journal Contribution |
Palavras-chave: Shrimp fisheries; Fishing effort; Stock assessment. |
| Ano: 2011 |
URL: http://hdl.handle.net/1834/5139 |
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| Ruarte, C.O; Rico, M.R.. |
| Stripped weakfish is one of the ensemble of species known as “variado costero” most frequently landed. Considering that fact, determination of abundance indices is particularly relevant to apply assessment models and make recommendations to allow for a proper fishery management. The aim of this study was to obtain those indices of the species derived from research cruises carried out in the Argentine-Uruguayan Common Fishing Zone AUCFZ area (34°S-39°S) in the 1993-2006 period. In order to improve the traditional estimate accuracy modeling was used. To formulate the general linear models year, stratum, length, bottom salinity, depth factors and population data such as mean size and juveniles percentage were used. The percentages of variance explained in the... |
| Tipo: Journal Contribution |
Palavras-chave: Abundance; Mathematical models; Stock assessment; Coastal fisheries; Cynoscion guatucupa; Marine environment. |
| Ano: 2014 |
URL: http://hdl.handle.net/1834/5821 |
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| Sánchez, R.P.; de Ciechomski, J.D.. |
| A bongo sampler fifted with nets of two different mesh sizes, 330 and 505 u. was used to collected 137 ichthyoplankton samples in the coastal areas off Buenos Aires Province in October, 1981. The efficiency of the two meshes for catching anchovy eggs and larvae and total ichthyoplankton was examined. The statistical analysis of the samples shows that there are no significant differences between the numbers of anchovy and total eggs collected by the different meshes. As regards anchovy and total larvae the finer mesh showed as significantly higher catching efficiency. The results of this partial estimate do not suggest that a major revision of the total assessment of the complete stock is necessary. |
| Tipo: Journal Contribution |
Palavras-chave: Stock assessment; Fish eggs; Stock assessment; Http://aims.fao.org/aos/agrovoc/c_24251. |
| Ano: 1984 |
URL: http://hdl.handle.net/1834/2044 |
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| Lillo, S.; Barbieri, M.A.; Espejo, M.; Castillo, J.; Miranda, H.; Córdova, J.; Saavedra, A.; Rojas, M.; Cancino, C.; Flores, F.; Reyes, H.. |
| En el presente informe se entregan los resultados finales del proyecto FIP 2003-34, cuyo objetivo general fue estimar mediante métodos in situ, la fuerza de blanco de las especies merluza del sur y merluza de cola (Merluccius australis y Macruronus magellanicus). En primer lugar durante el desarrollo del proyecto, se debió proponer un enfoque metodológico dirigido a efectuar las mediciones de fuerza de blanco considerando las características del recurso y los medios tecnológicos disponibles. En segundo término, se procedió a definir un sistema acústico a emplear para lo cual se analizaron diferentes alternativas, seleccionándose un sistema compuesto de un transductor de profundidad que era desplegado en las profundidades de distribución de los recursos... |
| Tipo: Report |
Palavras-chave: Stock assessment; Acoustic equipment; Echo surveys; Target strength; Stock assessment; Http://aims.fao.org/aos/agrovoc/c_24251. |
| Ano: 2005 |
URL: http://hdl.handle.net/1834/1812 |
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| Restrepo, Victor R; Ortiz De Urbina, J; Fromentin, Jean-marc; Arrizabalaga, Haritz. |
| Knowledge of gear-specific selectivity patterns can be useful in age-structured analyses. In recent assessments of eastern Atlantic bluefin tuna, Thunnus thynnus, the SCRS has derived selectivity estimates from the results of virtual population analyses. This document proposes an alternative approach, based on equilibrium catch curves, that is simple to apply and that relies on a smaller set of assumptions. The study uses the catch-at-age data from the last assessment conducted in 2002, and estimates recent and historical selectivity patterns for the total stock as well as some of the major gears (trap, baitboat, purse seine and longline). The resulting estimates seem reasonable for the various gears, given prior knowledge. The document also presents... |
| Tipo: Text |
Palavras-chave: Gear selectivity; Stock assessment; Bluefin tuna. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00192/30326/28800.pdf |
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| Fromentin, Jean-marc; Bonhommeau, Sylvain. |
| This study aims at examining the selectivity patterns among gears and years of the fleets targeting bluefin tuna in the Northeast Atlantic and Mediterranean Sea between 1970 and 2009, using catch curve analyses. The main outputs may be summarized as follow: (i) the general pattern of selectivity has highly varied through time, moving from ages 1-3 to ages 10+ from the 1970s to the 2000s; (ii) this important temporal drift primarily resulted from changes in PS selectivity patterns; (iii) these drastic variations in selectivity among gears and years can affect simple indicators which do not incorporate such information; (iv) the catch-at-age (CAA) matrix seems to be impaired by several inconsistencies that affect primarily the partial CAA of the purse... |
| Tipo: Text |
Palavras-chave: Gear selectivity; Stock assessment; Bluefin tuna. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00192/30279/28747.pdf |
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| Fromentin, Jean-marc; Arrizabalaga, Haritz; Restrepo, Victor R; Ortiz De Urbina, J. |
| The 2004 data exploratory meeting concluded that it was no longer defensible to assess the East Atlantic and Mediterranean population using methods that assume that the catch-atsize/age is known exactly, until extensive improvements in fisheries statistics are made. For these reasons, we here investigated the potential benefits of the year-class curve analysis. The robustness and consistency of our results tend to advocate that this method is, in the present situation, a good alternative to ADAPT (among others). As a whole, the estimates of Z from the year-class curve analyses applied on the Spanish trap and Japanese long line fishery data appear indeed to be in good or excellent agreement with ADAPT outputs for the same period and same age-classes. This... |
| Tipo: Text |
Palavras-chave: Fishing and natural mortalities; Year-class curves; Stock assessment. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00192/30325/28799.pdf |
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| Ksouri, J.; Elferjani, H.; Mensi, F.. |
| L’identification d’un principe actif servant en thérapie osseuse a propulsé l’algue brune Padina pavonica au rang des algues à intérêt économique très prisées à l’échelle mondiale et en Tunisie. L’évaluation des potentialités de cette espèce au niveau d’un site atelier, Cap Zebib (Nord-Est de la Tunisie), a été initiée pour éclairer les décideurs sur l’état du stock, afin que l’autorisation pour la collecte d’un certain tonnage de cette algue soit accordée en connaissance de cause. A Cap Zebib, l’espèce en question étant localisée dans la zone comprise entre 0 et 10 m, la biomasse naturelle disponible est évaluée à 112,5 tonnes de matière fraîche, soit 25 tonnes de matière sèche (22,2%). Le rendement global est de 0,850 t/ha. Mais, comme la majeure partie... |
| Tipo: Journal Contribution |
Palavras-chave: Biomass; Commercial species; Seaweed products; Seaweeds; Stock assessment. |
| Ano: 2008 |
URL: http://hdl.handle.net/1834/4251 |
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| Registros recuperados: 173 | |
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