Browsing by Author "Cañete, G.R."

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    Áreas potenciales de descarte de merluza para la actividad de la flota comercial argentina
    (Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Mar del Plata, 2006) Dato, C.V.; Villarino, M.F.; Cañete, G.R.
    To improve the quality of the resource assessment it is necessary to estimate discards and quantify them applying an adequate methodology. The purpose of this work is to detect areas where the activity of the commercial fleet coincides with zones of high concentration of juveniles because they are potential discard areas. To establish possible seasonal and/or interannual variations, length distribution data derived from hake research surveys carried out on board of INIDEP vessels during the 1986-1993 period were analyzed. Samples were grouped per statistical rectangle on the basis of catch weighted average and mean, variance, skewness and kurtosis were calculated. The resulting parameters were subjected to a cluster analysis using the Euclidean distance and Ward index. Besides, juveniles percentage (individuals below 35 cm total lenght) and sex proportion per statistical rectangle and season were calculated. To analyze the dynamics of the commercial fleet, catch and effort data for the same period were used. Results indicate that the areas of highest concentrations of juveniles are located north of 37° S and southwards between 43° S and 47° S, from the coast to 62° W, both at 50-150 m depth. The strong presence of the argentine commercial fleet in the southern area, intensified as of 1990, led to consider it a potential discard area. North of 37° S the fleet had scarce presence during the period analyzed. Neither area showed seasonal and/or interannual variations, so they were considered representative of the 1986-1993 period to estimate discards quantitatively.
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    El descarte en la flota comercial argentina dirigida a la pesquería de merluza. Período 1990-1997
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2003) Dato, C.V.; Villarino, M.F.; Cañete, G.R.
    Discards of the commercial fleet in the Argentine Sea (SW Atlantic) directed to hake Merluccius hubbsi were estimated in weight and number of individuals. The dynamics of the ice-chilling and freezer fleets per area and quarter and processes of discarding were analyzed. The estimation method was based on the comparison of landings and surveys length composition, the latter filtered by the selectivity of the mesh used by the commercial fleet to rebuild the length distribution of catches. It is concluded that discards had an annual variation of 42,000 t-148,000 t in the 1990-1997 period, which represented between 30 and 50 in weight and 11-24 in number of actual catches. The analysis of age groups affected by discards showed that over 90 corresponded to individuals age 1 and the rest to specimens age groups 0-2.
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    Dinámica de la flota comercial argentina dirigida a la pesquería de merluza (Merluccius hubbsi) en el Mar Argentino. Periodo 1990-1997
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2003) Dato, C.V.; Villarino, M.F.; Cañete, G.R.
    Since 1990, the Argentine commercial fleet directed to hake (Merluccius hubbsi) has obtained more than 70 of catches South of 41°S while to the North of this latitude the activity concentrated between 39°S and 41°S Argentine Sea, SW Atlantic. Bearing in mind the different characteristics of ice-chilling and freezer fleets, their activities were analyzed separately. Considering the relative percentages of catches declared in fishery statistics, the dynamics of each fleet is described per quarter and year. Special reference is made to 1997 when a closed area to protect juveniles was introduced between 44°S-47°S and 62°W-65°W. The freezer fleet activity, concentrated South of 41°S, especially South of 43°S, was stable throughout the period. It grouped around the closed area of Escondida Island during the summer 1st and 4th quarters) to disperse in deeper waters in winter 2nd and 3rd quarters. In the 2nd quarter it formed two nuclei, one to the North -and the most important- to the South of 41°S. The dynamics of the ice-chilling fleet per season was similar to that of the freezer fleetnevertheless, contrary to the latter, activities concentrated between 39°S and 42°S and, of the two nuclei formed in the 2nd quarter, the most important was the one North of 41°S. In 1995 a marked change was observed when concentration of the fleet ranged between 39°S and 42°S and the South nucleus practically disappeared.
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    Estimación cuantitativa del descarte en la pesquería de merluza realizado por la flota comercial argentina
    (Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Mar del Plata, 2006) Dato, C.V.; Bambill, G.A.; Cañete, G.R.; Villarino, M.F.; Aubone, Aníbal
    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.
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    Report of the INIDEP working group on assessment of hake (Merluccius hubbsi) north of 48° S (Southwest Atlantic Ocean)
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 1994) Bezzi, S.I.; Cañete, G.R.; Pérez, M.; Renzi, M.A.; Lassen, H.
    The assessment covers hake between 34° and 48°S (Argentina and Uruguay), excluding Golfo San Matías. Total international landings and Argentine catch-at-age and effort data available for the 1983-1991 period allowed an analytical assessment. Tunning of the VPA was made using Laurec-Shepherd analysis and Extended Survivor analysis. The results of these analysis are congruent with the information about the state of the stock. VPA biomass estimates are aound 2.1 and 2.7 mill. Tonnes, which are similar to those calculated through surveys. The Spawning Stock Biomass estimated for 1991 is considered to be within limits where the stock shows stable recruitment. At the present effort level, yield and Spawning Stock Biomass appear to remain stable. Management measures are also discussed.