|
|
|
| Registros recuperados: 12 | |
|
| |
|
|
| Aubone, A.; Wöhler, O.C.. |
| With the purpose of easening its application, the theory of parameter estimation by the maximum likelihood method is presented. The theory is general and useful for linear and nonlinear models. The method is applied to the von Bertalanffy´s growth model for individual data and for mean values of length-at-age. Statistical tests to compare parameters from different population groups are presented. Problems caused by lack of verification of assumptions are discussed. An example of its application is given and results of nonlinear least squares estimations are compared to those obtained with Allen´s method. An example of application implemented on a calculus spreadsheet is attached. |
| Tipo: Journal Contribution |
Palavras-chave: Growth curves; Mathematical models; Mathematical models; Http://aims.fao.org/aos/agrovoc/c_24199. |
| Ano: 2000 |
URL: http://hdl.handle.net/1834/2541 |
| |
|
|
| Ercoli, R.; Garcia, J.C.; Aubone, A.; Salvini, L.; Bertelo, R.. |
| This work reports on the inter rod distance in a single sorting grid adapted for the escape of hake juveniles. A good performance of the device was reported due to the DEJUPA trials carried out in April 1997. In may 1998 a new survey with DEJUPA was carrie out with 30 mm, 33 mm, and 40 mm separation distance bars, in order to optimise the escape of the species at first length maturity (35 cm). Selectivity curves with maximum likelihood method were obtained for each inter rod distance being the length at 50. (L50) 29, 32 and 37 respectively. A weighd lineal regression (Feasible General Squares Model) between L50 and inter rod distance was fitted from each L50 estimated variance. An estimation of 37 mm inter rod distance for L50=35 cm total length was... |
| Tipo: Journal Contribution |
Palavras-chave: Gear selectivity; Bottom trawls; Juveniles; Juveniles; Http://aims.fao.org/aos/agrovoc/c_25393. |
| Ano: 2000 |
URL: http://hdl.handle.net/1834/2536 |
| |
|
|
| Dato, C.V.; Bambill, G.A.; Cañete, G.R.; Villarino, M.F.; Aubone, A.. |
| Based on the comparison between length composition of landings and that of research cruises, filtered by the selectivity of the mesh used by the commercial fleet, to rebuild length distribution of catches, an indirect quantitative method was developed and used to estimate, in weight and number, the individuals discarded by the commercial fleet south of 41° S. Discards ranged between 15,563 and 46,113 annual tons in the 1986-1993 period which represented 10-13% in weight and 28-32% in number of actual catches, composed of around 87% of individuals age group 1, 12% of age group 2 and the rest of individuals age groups 0 and 3. |
| Tipo: Journal Contribution |
Palavras-chave: Gadoid fisheries; Commercial fishing; Statistical analysis; Statistical analysis; Http://aims.fao.org/aos/agrovoc/c_7378. |
| Ano: 2006 |
URL: http://hdl.handle.net/1834/1587 |
| |
|
| |
|
|
| Pineda, S.E.; Aubone, A.; Brunetti, N.E.. |
| Beaks of Loliginid squids have very similar morphological features making identification of the species to be quite difficult. A new metodology to identify species from the relative growth of some parts of the beak is presented. Samples of Loligo gahi and Loligo sanpaulensiswere obtained from ten reserch cruises of RVS "Dr. Holmberg" and "Captain Oca Balda" and eight commercial landings at Mar del Plata Port during the period 1992-1993. The results obtained using the new metodology (Metric Discriminant Criterium)were compared with those resulting from the application of the Fisher's Lineal Discriminant Criterium. Both mantle length - rostral length and total weight - rostral length relationships, corresponding to each species were fitted. Either upper or... |
| Tipo: Journal Contribution |
Palavras-chave: Morphometry; Methodology; Growth curves; Methodology; Http://aims.fao.org/aos/agrovoc/c_12522. |
| Ano: 1996 |
URL: http://hdl.handle.net/1834/1961 |
| |
|
| |
|
| |
|
|
| Pérez, M.; Aubone, A.; Simonazzi, M.A.; Irusta, C.G.. |
| Precision of abundance index estimation Merluccius hubbsi is directly related with the variability that normally occurs during the fishing operation and consequently in the geometry of the net duringeach haul. Some of these factors can be controlled, therefore the standardization of the sampling methodology avoids differences in the behaviour and 'work' of the net minimizing variations in the catchability between hauls. The acoustic equipment (SCANMAR) in there search vessels, allows to monitore the fishing operation during the trawl and to develop strategies in order to reduce the variability and to improve the precision of the estimations. The applicability of the methodology and there for the validity of the estimates indifferent cruises must be studied... |
| Tipo: Journal Contribution |
Palavras-chave: Fishing operations; Abundance; Sampling; Fishery surveys; Eco surveys; Swept area. |
| Ano: 1998 |
URL: http://hdl.handle.net/1834/5786 |
| |
|
|
| Villarino, M.F.; Aubone, A.. |
| The total length distribution of pink cuskeel Genypterus blacodes catches is difficult to obtain. On the contrary, it is easy to have access to the head length distribution. So, the purpose of this study was to obtain a relationship between a certain head measurement and total length to estimate the length distribution of the catches. Individuals were obtained from bottom-trawl surveys between 39°-47°S and the San Jorge Gulf of the Argentine sea. Sets of measurements of total length (LT), maxillar length (Lmax), head length (Lc),orbital length (Lo), preorbital length (Lpo) and head length-total length ratio (r=Lc/LT) by sex were obtained. The total length was estimated with a regression model using the head length as independent variable. No significant... |
| Tipo: Journal Contribution |
Palavras-chave: Size distribution; Regression analysis; Fishery surveys; Regression analysis; Http://aims.fao.org/aos/agrovoc/c_16335. |
| Ano: 2000 |
URL: http://hdl.handle.net/1834/2532 |
| |
|
| |
| Registros recuperados: 12 | |
|
|
|
