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Registros recuperados: 21 | |
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Cotter, John; Mesnil, Benoit; Witthames, Peter; Parker-humphreys, Matt. |
This paper reviews a selection of nine indicators for assessing the biological state of a fish population monitored only by using trawl surveys in which catchability is assumed constant from time to time and place to place. The intention is to inform or remind of the range of possibilities and of associated practical and statistical issues. The indicators, grouped according to relationships with abundance, length, age, weight, and reproduction, are documented in a standard format covering estimation, interpretability, sensitivity, considerations for reference points where possible, and an example of their application. Lastly, selected indicators together with year-class curves fitted to abundance indices-at-age are applied to the North Sea cod to... |
Tipo: Text |
Palavras-chave: Ecosystem approach to fisheries management; Year class curves; Weight index; Maturity stage; Age composition; Length based indicators; Biological indicators. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6901.pdf |
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Rosecchi, E. |
The four Sparidae studied are coastal species that regularly enter the Mediterranean coastal salt lagoons. Changes in diet with regard to size class of fish, and occasionally season, are detailed. For each species, diets in the sea and in the lagoons are compared using several methods and show differences. Individuals from lagoons do not eat, or in very low numbers, mollusks, echinoderms and decapods. However, as their feeding is very rich and diverse, sparid fishes can probably find in the lagoons, whatever their age, the prey necessary to their growth. Trophic factors cannot explain age structure in lagoons and the absence of some age classes. |
Tipo: Text |
Palavras-chave: Pisces; Sparidae; Trophic levels; Age composition; Predation. |
Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/publication-1774.pdf |
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Junquera, Susana. |
Using the fishing records from the most relevant ports of the Cantabrian and Galician coasts, th history of the anchovy (Engraulis encrasicholus ) fishery in this area is reconstituted. The crisis observed and the variations in the fishing areas throughout the time are analyzed. An estimation of the age classes composition in the catches founded on commercial classification data can be made. The hypothesis of existence of a core population in the Southern part of the Bay of Biscay is presented and that only under certain advantageous condition the expansion of this species throughout all the Cantabrian Sea was possible. |
Tipo: Text |
Palavras-chave: Pisces; Age composition; Population dynamics; Catch/effort; Fishery statistics. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/publication-1795.pdf |
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Hansen, J.E.; Garciarena, A.D.. |
As part of the research programs performed yearly at the Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP, Mar del Plata, Argentina) some important basic data about the commercial fisheries usually included in internal reports are registered. This formal paper is a review and summary of size and age composition estimates of commercial catches (discards included) of Northern Argentine anchovy (34ºS-41ºS) obtained between 1990-2011. The basic data resulting from the examination of 521 samples from fishing vessels included 62,466 fish length measurements and 26,667 valid age readings from which the corresponding 22 annual age-length keys were built. The annual estimates of the individual total length-total weight relation parameters and of... |
Tipo: Journal Contribution |
Palavras-chave: Pelagic fisheries; Stock assessment; Commercial fishing; Catch composition; Age composition; Size distribution; Clupeoid fisheries. |
Ano: 2013 |
URL: http://hdl.handle.net/1834/5502 |
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Massa, A.M.. |
The gatuzo, Mustelus schmitti, lives in the Southamerican Atlantic coastal waters from up to 23°S (Brazil)down to 47°S (Argentine), and is the greatest species of the Bonaerense and North Patagonian shores. This species is the most exploited elasmobranch of this region, within the last six years catch has exceeded 10,000 t per year and it is vulnerable to overexploitation due to reproductive aspects, with a low rate of changes, as well as distribution patterns. In order to relate size distribution and nursery areas, and environmental temperature and salinity variability, were obtained within six INIDEP 'Coastal Project' research cruises from 34° to 42°S from boundaries to 50 mts isobaths, during the spring seasons between 1994 to 1997. Cluster analysis... |
Tipo: Theses and Dissertations |
Palavras-chave: Size distribution; Age composition; Sex ratio; Growth curves; Environmental effects; Brackishwater environment; Age composition; Sex ratio; Brackishwater environment; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_1050. |
Ano: 1998 |
URL: http://hdl.handle.net/1834/3584 |
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Barretto, A.C.. |
The age-class distribution of the Brazilian flathead Percophis brasiliensis in relation to environmental variables in spring and winter, and the growth of both sexes, were studied in the SW Atlantic Coastal System (SACS)(34°S-31° S). Growth was studied from 1449 individuals (n=853, spring (1998 + 2000), n=596, winter (2004)) to which size (TL), sex, and age were determined. Age was determined considering that an opaque plus a hyaline band (present in the transverse section of the sagitta otolith) represented 1 year of life. The age-class distribution in spring and winter was established through hierarchical clustering and non-metric multi-dimensional scaling (nMDS analysis). This analysis grouped sampling stations (n=109, spring 1998; n=160, winter 2004)... |
Tipo: Theses and Dissertations |
Palavras-chave: Age groups; Age composition; Environmental factors; Geographical distribution; Population structure; Growth; Environmental effects; Coastal waters; Age composition; Environmental factors; Geographical distribution; Population structure; Growth; Age groups; Coastal waters; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_2594; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_6115; Http://aims.fao.org/aos/agrovoc/c_3394; Http://aims.fao.org/aos/agrovoc/c_28628; Http://aims.fao.org/aos/agrovoc/c_25205. |
Ano: 2007 |
URL: http://hdl.handle.net/1834/3017 |
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Hansen, J.E.. |
This paper deals with the commercial landings of bonaerensis anchovy at the Port of Mar del Plata (Buenos Aires province,Argentina), during the years 1986 to 1990. The mean catch was 15,501t per year. A total of 59 fish samples were taken for total length distributions (N=20164), and 24 sub-samples (N=2370) were analyzed to record individual data (length, weight, sex, sexual stage, age fromotoliths reading). The numer of fish per kg ranged between 28 and 53(mean=34.6). The mean size was 156.63 mm, and the most abundant fish in the landings were those being 3 and 2 years old, as it was also recorded during the period 1980-1985. Ordinary length-weight relationships by season were fitted, and the results were as follows:1) Autumn-Winter: W=8.5* 10-7* L3.392;... |
Tipo: Journal Contribution |
Palavras-chave: Length-weight relationships; Size distribution; Sexual maturity; Clupeoid fisheries; Biological sampling; Age composition; Commercial land use; Cohort analysis. |
Ano: 1997 |
URL: http://hdl.handle.net/1834/5794 |
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Cousseau, M.B.; Gru, D.L.. |
Samples of Sardina fueguina (Sprattus fuegensis)were taken during research cruises carried out in 1974 and 1978. Length and age frequency distributions were analyzed, and von Bertalanffy growth parameters were calculated for the coastal waters of two geographical regions: Province of Santa Cruz and northern part of Malvinas Islands. Lenght and weight growth curves have been calculated for each region and each year. Marked differences have been found between gowth parameters of both regions, and the calculated values showed a good fit with the observed ones. According to these results, it is possible to assume that the sardines of both regions constitute two different populations. However, more information on the total distribution of the species will have... |
Tipo: Journal Contribution |
Palavras-chave: Age composition; Growth curves; Stock identification; Sardine fisheries; Age composition; Http://aims.fao.org/aos/agrovoc/c_29093. |
Ano: 1982 |
URL: http://hdl.handle.net/1834/2052 |
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Renzi, M.A.; Santos, B.A.; Simonazzi, M.. |
Hake Merluccius hubbsi population structure in 1993, 1994, 1996, 1997 and 1998 and age and sex distribution during 1997 are analyzed. Data were obtained in research surveys. At the end of winter 1997 concentrations of juveniles were found in the San Jorge Gulf Argentine Sea, SW Atlantic, with maximum yields of 10,000 individuals per trawl hour for age 1 and 2,500 individuals per trawl hour for age 2. The highest concentrations of adults were found in the Gulf and South of 47°S, between the 100 and 200 m isobath, maximum yields of up to 1,700 individuals per trawl hour for age 3 and up to 90 individuals per trawl hour for age 7 and older. In spite of the decrease in population abundance, the basic age structure juveniles, young adults and old adults was... |
Tipo: Journal Contribution |
Palavras-chave: Sex ratio; Age composition; Mortality; Fishery surveys; Gadoid fisheries; Age composition; Sex ratio; Mortality; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_4945. |
Ano: 2003 |
URL: http://hdl.handle.net/1834/2471 |
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Lillo, S.; Céspedes, R.; Díaz, E.; Ojeda, V.. |
El presente estudio tiene como objetivo evaluar el stock de merluza de tres aletas (Micromesistius australis) a través del método hidroacústico, entre las latitudes 47º y 51º Sur. Como parte del proyecto, se realizó entre el 2 y el 15 de agosto del 2003 a bordo del B/C “Abate Molina” un crucero de prospección dirigido a evaluar mediante un método de evaluación directa (evaluación acústica) su biomasa, abundancia y distribución, estimar la importancia relativa de la fauna acompañante, condiciones reproductivas y tróficas del stock. Durante el estudio se realizaron 13 lances de pesca y 49 transectas acústicas. Los resultados muestran que la merluza de tres aletas se distribuyó asociada al borde de la plataforma y talud continental, con una biomasa estimada... |
Tipo: Report |
Palavras-chave: Stock assessment; Biomass; Population structure; Age composition; Geographical distribution; Acoustic equipment; Stock assessment; Biomass; Population structure; Age composition; Geographical distribution; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_6115; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_5083. |
Ano: 2004 |
URL: http://hdl.handle.net/1834/1698 |
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Hansen, J.E.; Buratti, C.C.; Garciarena, A.D.. |
Advise on Biologically Allowable Catch (BAC) for Southern Argentine anchovy (Engraulis anchoita, 41° S-48° S) during 2012. To assess the evolution since 1990 and the current status of Argentine anchovy Southern stock, an Age Structured Population Model (ASPM) was used. Modeling of catches according to a four-month period pulses allowed to predict annual yields so as to get them close to the nominal catches officially recorded. Some independent indexes of stock abundance (eight acoustic estimates of total biomass and five estimates of spawning stock biomass obtained with the Daily Egg Production Method) and the proportion of individuals per age group assessed during the same cruises were used to calibrate the fitting. No stock-recruitment function but a... |
Tipo: Journal Contribution |
Palavras-chave: Stock assessment; Yield; Statistical models; Age composition; Clupeoid fisheries. |
Ano: 2013 |
URL: http://hdl.handle.net/1834/5508 |
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Registros recuperados: 21 | |
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