INIDEP Informe Técnico
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Browsing INIDEP Informe Técnico by Subject "Abundance"
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- ItemDistribución y abundancia de huevos y larvas de langostino patagónico (Pleoticus muelleri) (Penaeoidea, Solenoceridae) en las temporadas estivales de 2008 y 2009(Mar del Plata : Instituto Nacional de Investigación y Desarrollo Pesquero INIDEP, 2011) Moriondo Danovaro, P.The study on distribution and abundance of eggs and early planktonic stages of red shrimp, Pleoticus muelleri (Bate, 1888), contributes to a better knowledge of the species dynamics. Results from processing and analyzing 72 plankton samples collected with Bongo net during two research cruises on board of FV “Arbumasa XVIII” and RV “Capitán Oca Balda”, carried out in the Patagonian littoral in March 2008 and January 2009, are presented. In both cruises, eggs and larval stages were found all over the study area. The highest punctual densities of eggs were recorded in the area known as “La Pared” (46° 45’ S-65° 55’ W and 46° 50’ S-65° 55’ W). Eggs indicate the presence of shrimp reproductive concentrations which, while migrating eastwards towards waters of national jurisdiction, generate production scenarios characterized by high rates of catch per unit of effort and better commercial sizes. In the 2009 cruise, high densities of shrimp eggs were also found near Rawson area.
- ItemEstimación de un índice de abundancia anual de gatuzo (Mustelus schmitti) a partir de datos de la flota comercial argentina. Período 1992-2008(INIDEP, 2011) Pérez, M.; Massa, A.M.; Cordo, H.D.Patagonian smoothhound (Mustelus schmitti) is one of the predominant cartilaginous fishes of the Argentine Sea (SW Atlantic Ocean). It is caught, mainly, in the coastal multispecific fishery with nearly other 30 bony and cartilaginous species. The group is known as ‘variado costero’. In this work the smoothhound abundance indices (CPUE) and standardized efforts for the 1992-2008 period in the area between 34~’S-42~’S were estimated. The General Lineal Model (GLM) and data derived from the argentine commercial fleet were used. Other aspects that could affect estimates and trends of the annual indices were also analyzed. Mean CPUE values estimated with the GLM, considered as annual standardized abundance indices, show an increasing trend as of 2000; the highest relative levels correspond to the last three years of the study period
- ItemEstimación de un índice de abundancia anual estandarizado para pescadilla de red (Cynoscion guatucupa), mediante la aplicación de un modelo lineal general; período 1992-2003(Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2007) Ruarte, Claudio; Perrotta, Ricardo G.The stripped weakfish (Cynoscion guatucupa) has a wide latitudinal distribution (22° S-43° S) and it is object of fishery in Brazil, Uruguay and Argentina (SW Atlantic). In this last country, it is mainly captured in the coastal region of Buenos Aires Province by means of a fleet, which has between 20 m and 30 m length. In Argentina, the average landings in the last 5 years were 9,900 t. It is the second commercial species among the coastal groups. There are two main fishery areas of this species: the Argentinean-Uruguayan Common Fishing Zone (AUCFZ) and the El Rincón area, in the South of bonaerense littoral. Due to the importance of this species, it is necessary to define an index of annual abundance to allow a suitable diagnosis of the fishery condition. The General Linear Model is a suitable model to calculate this index. The factors used in this work were: year, trimester, 4 length categories and 5 sub areas. All of them were significant and reflect spatial-temporal changes in the abundance of this species. The model explained 34% of the total variability in the AUCFZ and 46% in the El Rincón. In general, the trends of catch per unit effort (CPUE) were similar and increasing in both areas, registering a greater increase in the internal areas. On the other hand, the fleet displacements between the areas and the reduction of the total fishery area caused a rise in the annual CPUE and a fall of the captures. These captures were dominated by adults but with an important presence of juveniles in the coastal zone off Mar del Plata city.
- ItemÍndice de abundancia del grupo merluza de edad 2 en el área de cría patagónica. Período 1995-1998(Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2003) Castrucci, R.; Aubone, Aníbal; Pérez, M.; Renzi, M.A.An abundance index of hake Merluccius hubbsi individuals age 2 was estimated in the nursery area south of 41°S Argentine Sea, SW Atlantic. The analysis comprised the 1995-1998 period and was made with data derived from research surveys programmed to that end. A mean value estimator of CPUE catch in number of individuals per trawl hour based on delta distribution was used. The spatial distribution of CPUE of age groups 1 and 2 in the area surveyed, total length distribution per survey and the corresponding age composition are presented. The declining trend of abundance index of hake age 2 observed during the four year period amounted to 52.9.
- ItemNematodes parásitos como indicadores biológicos de Macruronus magellanicus(Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2006) Incorvaia, I.S.; Hernández, Daniel R.A wide distributional range species can constitute many populations or fishing stocks which can be whole or partly overlapped within their distribution area, reason why they must be clearly identified. Therefore, proper identification of stocks is necessary for fisheries management, as this is the unit to which the fishing effort should be applied. The parasitological method is one of the systems currently used to determine stock. Nematodes parasites of Macruronus magellanicus (longtail hake) collected during surveys enmarked between 45º S-55º S in the Southwest Atlantic were studied. Nematodes that could be used as biological indicators were selected. Mean abundance values of L3 Anisakis simplex and Hysterothylacium aduncum were estimated. Three different areas of abundance were recognized: coastal with high abundance, intermediate with mixed values and continental slope with low abundance.
- ItemPesca comercial de merluza al sur de 41°S y estimación de índices de abundancia derivados de la flota pesquera(Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2003) Irusta, G.; Pérez, M.; Renzi, M.A.; Castrucci, R.The activity of fishing fleets for hake Merluccius hubbsi south of 41°S Argentine Sea, SW Atlantic, is described. In order to establish the standard group of vessels, density indices derived from research cruises and ice-chilling fleets were related. Group four 1,400-1,800 HP related better to the abundance trend. Also, two series of indices associated to different fractions of the population were estimated: juveniles age 2) and adults age 3-5. Finally, a total catch per unit effort CPUE for the region south of 41°S, which showed a declining trend during the period considered 1991-1997, was calculated.