INIDEP Informe Técnico

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Browsing INIDEP Informe Técnico by Subject "Buenos Aires"

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    Análisis de la utilización de la captura por unidad de esfuerzo de pescadilla de red (Cynoscion guatucupa) como índice de abundancia anual. Período 1992-2004
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2009) Perrotta, Ricardo G.; Ruarte, Claudio
    The stripped weakfish (Cynoscion guatucupa) caught in Brazil, Uruguay and Argentina (SW Atlantic) has a wide latitudinal distribution (22° S-43° S). In Argentina there are two main fishing areas, the Argentine-Uruguayan Common Fishing Zone and 'El Rincón', southern zone of the Buenos Aires littoral. The importance of the species makes it necessary to define an annual abundance index that would allow to diagnose the state of the stock. The model adjusted to calculate the index is the General Linear Model. The factors used were Year, Quarter, Length, Stratum (4 categories) and sub-areas (5 categories), all statistically significant. The problem generated by the presence in the model of first order interactions that include the Year factor is discussed. The importance of said interactions is assessed pursuant to the percentage of variance explained considering the model with and without such interactions. It is concluded that the catch per unit of effort series reflects space-temporal changes in the fleet activity not proportional to the biomass.
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    Análisis de las capturas de atunes realizadas por dos buques pesqueros de Mar del Plata, Argentina, entre enero y abril de 2010
    (INIDEP, 2011) Garciarena, A. David
    Data obtained by observers on board of two fishing vessels during six trips carried out between January-April 2010 to catch tuna were analyzed. Thirty-four fishing days were completed and of the 59 trawls performed 37 turned out positive (with tuna catches). The fishing gear consisted of a purse seine net. Exploitation took place within the Argentine-Uruguayan Common Fishing Zone, between 36° S-39° S. The main landings occurred in March and consisted of slender tuna, Allothunnus fallai (57%), followed by albacore, Thunnus alalunga (28.5%), in January and bonito, Sarda sarda (14%), in April. Sea surface temperature ranged 16 °C-19 °C. A total of 25 length frequency samples allowed to measure individuals of the species above mentioned and those of skipjack tuna (Katsuwonus pelamis). During fishing operations the death of some magellanic penguins (Spheniscus magellanicus) and soft-plumaged petrels (Pterodroma mollis) as well as catch of anchovy (Engraulis anchoita) were registered
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    La caballa (Scomber japonicus) y las condiciones del ambiente en el área "El Rincón" (39°40'-41°30' S) del Mar Argentino. Septiembre, 2000
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2003) Perrotta, Ricardo G.; Viñas, M.D.; Madirolas, Adrián O.; Reta, Raúl; Akselman, Rut; Castro Machado, Federico J.; Garciarena, A. David; Macchi, Gustavo J.; Moriondo Danovaro, Paula I.; Llanos, V.; Urteaga, J.R.
    Between September 1st and 6th a research cruise was carried out in the Buenos Aires shelf area of "El Rincon" 39°40'-41°30'S, Argentine Sea SW Atlantic. The total area studied was 2,527.8 nautical mile2. Knowledge of the commercial fleet location at the time of the survey allowed to intensify sampling in a 'miniarea' of 52,8 nautical mile2. The acoustic assessment of chub mackerel (Scomber japonicus) biomass was 49,511.9 t, 94 of which corresponded to this last area. Fish samples coming from fishing trawls included only adult individuals of 240-460 mm total length (TL) and ages ranging 2-11 years. The limit age was estimated at 13 years and natural and total mortality rates at 0.23 and 0.54, respectively. Oceanographic conditions were those typical of the winter season, characterized by the vertical homogeneity of the water column in temperature and salinity. The isotherms and isohalines distributed parallel to the 50 m isobath with values progressively decreasing from the coast towards the slope. Salinity values allowed to detect two hydrographic regimes: that of the San Matias Gulf 33.8-34.4 located to the West and covering more than half of the study area and the one of the Shelf Waters 33.5-33.79 occurring towards the East. A positive gradient in chlorophyll a concentration was observed in N-S sense and from the coast towards the shelf break. The highest densities of phytoplankton, with dominance of diatoms, were observed in the southern sector. Low concentrations of Alexandrium tamarense and Prorocentrum minimum, two potentially noxious dinoflagellates, were detected. The highest zooplankton biomass associated to the highest salinity values and salinity gradients, represented mostly by Calanoides cf. carinatus, was also detected in the southern sector. The western sector, influenced by the San Matias Gulf regime and characterized by high densities of both, phytoplankton and zooplankton, may constitute a potentially favourable feeding ground for chub mackerel.
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    Las condiciones oceanográficas en el área marplatense (37° 00' S-38° 24' S) y su relación con la distribución de la caballa (Scomber japonicus). Octubre-noviembre de 1999
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2009) Reta, Raúl; Perrotta, Ricardo G.; Garciarena, A. David
    Results obtained during a research cruise carried out along the coastal area of Mar del Plata (Buenos Aires, Argentina) in November 1999 are presented. The objective of the research cruise was to estimate chub mackerel (Scomber japonicus) abundance with acoustic methods and establish its relation to the hydrographic conditions. The information gathered was complemented with data of catches obtained by a commercial vessel that operated simultaneously in the study area. Environmental data from other research cruises and satellite information were also taken into account to obtain contemporary sea surface temperature and wind speed and direction data. The main species of catches of the research cruise and commercial vessel were horse mackerel (Trachurus lathami) and anchovy (Engraulis anchoita). No chub mackerel was detected during the acoustic assessment; however, the species was caught by the commercial vessel in the southern part of the study area and near the thermohaline front. Chub mackerel yields were very low if compared to those regularly recorded in the area and time the purse-seine fleet operates and that are typical of an advanced fishing season (January). The advection of estuarine waters from the de la Plata river, conditioned by the winds field, generated the displacement of low salinity waters over the coastal area that surpassed the regular southern limits. The positive anomalies of sea surface temperature in the region, that reached values close to 3 °C, could have caused the partial exclusion of chub mackerel in the coastal region of Mar del Plata.
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    Crecimiento de la merluza (Merluccius hubbsi) del Atlántico sudoccidental entre 1993-2003 al norte y sur de 41º S
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2009) Renzi, Marta A.; Santos, Betina A.; Abachian, Viviana E.
    The reading of otoliths sagittae collected during the INIDEP (National Institute for Fisheries Research and Development, Argentina) assessment cruises carried out in the 1993-2003 period allowed to estimate length and weight growth parameters and the condition factor of hake (Merluccius hubbsi) and to prospect the two management units of the species north and south of 41ºS (Argentine Sea, SW Atlantic). A great variability in total length and weight in each age group was observed; nevertheless, stable mean length and weight values per age group were observed in the period analyzed. Besides, the values estimated to determine possible growth variations in each and between both management units north and south of 41ºS were compared. The comparison of growth curves of males and females in each area showed highly significant differences. When each sex between stocks was compared, some years those differences were observed for growth as a whole and only for some parameters in others.
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    Desove en cautiverio y calidad de los huevos y larvas del besugo, Pagrus pagrus (L.)
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2006) Aristizábal, Eddie O.
    Spontaneous spawning of red porgy was achieved in captivity by using photoperiod and temperature control systems along the year. During a four-month reproduction period females released in average about 0.2 times their own body weight in oocytes with an energy content of 5.71 J mg-1 wet weight. A total of 28.8 x 106 eggs and approximately 200 g of viable eggs (wet weight) per female kg were obtained. The eggs and larvae quality in terms of hatching and larval survival rates experienced a significant variation during the spawning season ranging between 0%-92% and 0.3%-33.2% respectively. Comments in reference to the probable causes of these variations and the need of carrying on with this line of research are presented.
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    Distribución de desovantes y estimación de variables reproductivas del efectivo norteño de merluza (Merluccius hubbsi) (35º'S-41º'S) durante mayo de 2009
    (INIDEP, 2011) Rodrigues, Karina A.; Macchi, Gustavo J.
    Spawning and reproductive variables of the northern hake stock were analyzed using macroscopic and histologic gonad information derived from samples collected in May 2009. The study includes estimates of batch fecundity, spawning frequency, oocyte dry weight and size at first maturity. During May 2009 the reproductive activity of the northern hake stock took place mainly near the 50 m isobath, north of 37° S. Spawning occurred within a temperature range of 9 °C-15 °C that coincided with a bottom thermal front. Size at first maturity, much lower than that reported at the beginning of the 1980s, showed differences between males (27.16 cm TL) and females (32.84 cm TL). The reproductive frequency was estimated at one spawning every 13 days and mean batch fecundity (764,545 oocytes) resulted higher than in April 2003. Likewise, oocyte dry weight exceeded that of April 2003, which might be associated to the size composition of each reproductive group
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    Distribución y estructura de tallas de la palometa (parona signata, carangidae) y el pampanito (stromateus brasiliensis, stromateidae) en relación con las condiciones oceanográficas en la Zona Común de Pesca (34° s-38° s) y estimación de la longitud de primera madurez sexual. Julio de 2001
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), 2006) Perrotta, Ricardo G.; Guerrero, Raúl A.; Carozza, Claudia R.; Quiroga, Pedro; Macchi, Gustavo J.
    Samples were obtained using bottom trawl nets during a coastal research cruise carried out on board of the RFV “Dr. E. L. Holmberg” between 3rd. and 16th. July 2001. The spatial distribution of surface and bottom temperature and salinity fields was analyzed at the oceanographic stations sampled in each trawl position. The analysis allowed to characterize the oceanographic conditions of the area during the sampling period and to compare them to the historic seasonal mean. 669 leatherjack specimens of 9-55 cm total length (TL) caught at depths ranging 5-29 m and 1,372 butterfish individuals of 6-40 cm total length (TL) caught at depths ranging 4-29 m were sampled. Length at first sexual maturity for both sexes was also estimated. Results were: leatherjack: L50 (cm) = 30.06 and butterfish: L50 (cm) = 23.12. It is worth mentioning that the presence of adult leatherjack near Mar del Plata (Buenos Aires prov., Argentina) suggests that the resource may become one of the target species for the coastal fleet.
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    Estimación 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, Ana 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
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    Estimaciones de la biomasa de merluza (Merluccius hubbsi) en los sectores argentino y uruguayo de la Zona Común de pesca argentino-uruguaya (34º 00º S-39º 30º S) Y en el área que se extiende hasta 41º S (ZEE Argentina) en 1994, 1996-2001 y 2003
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2009) Bezzi, S.I.; Ibáñez, P.M.
    Hake (Merluccius hubbsi) biomass in the Argentine and Uruguayan sectors of the Argentine-Uruguayan Common Fishing Zone (AUCFZ) and in the area that extends from the limit of the shared zone to 41° S was estimated (SW Atlantic Ocean). The contribution to the strata total biomass in each sector was analyzed and complemented with observations on the structure of the population. The basic data to estimate biomass derived from the evaluation surveys of the Hake Project carried out in winter or spring 1994, 1996-2001 and 2003. In 1999 biomass north of 41° S decreased to 30. (112,280 t) of the estimates made for 1994. In 2000 it increased to 165,000 t and in 2003 it was estimated at 156,407 t. A remarkable decrease of the AUCFZ percentage of contribution to the total biomass north of 41° S was registered. The result was an increase of the contribution corresponding to the intermediate zone that in 2003 contributed 54. of the total biomass. The modal class was equal to or smaller than 25 cm in the Uruguayan sector, between 13-37 cm in the Argentine sector and smaller than 35 cm in the intermediate zone where it reached 22 cm in 2000 and 27 cm in 2001. The rest of the years it varied between 38-41 cm. In the intermediate zone the average length and the modal class were larger than in the AUCFZ sectors.
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    Estudios químicos y bacteriológicos del río Baradero (Argentina): calidad sanitaria del agua y aptitud de los peces para consumo humano
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2003) Costagliola, Marcela; Seigneur, G.N.; Jurquiza, Verónica
    As a result of an agreement signed by the Municipal Government of Baradero Buenos Aires Province, Argentina and the INIDEP, the sanitary quality of the Baradero River waters was studied and fish safety assessed. Results of five field surveys carried out between 1993 and 1997 are studied. Organochlorine and organophosphorate pesticide residues, as well as traces of heavy metals were analyzed in 49 fish specimens and aerobic heterotrophic bacteria (AHB), total coliform bacteria (TC) and fecal coliform bacteria (FC) were counted out in 7 sampling stations placed on the coast and the riverbed. Alpha Hexachlorohexane, gamma Hexachlorohexane, beta Hexachlorohexane, Aldrin, Heptachlor epoxide, pp'DDE and Dieldrin were detected in fish tissues. The values of AHB found in different stations were not statistically different. The FC density on the coast was significantly greater than that found in the riverbed. Enterobacter cloacae, Morganella morganii, Proteus mirabilis, Escherichia coli, Aeromonas hydrophila and Non-O1 Vibrio cholerae were identified. It is concluded that the current levels of heavy metals and pesticide residues in fish are not dangerous for the average consumer nevertheless, further research is needed to assess the risk for groups with higher consumption rates, such as sport and subsistence fishers. On the other hand, there is microbiological pollution in the river owed to both, industrial wastewater and sewage discharges. The recorded bacterial stocks, pathogenic or potentially pathogenic, are susceptible to cause illnesses.
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    Evolución reciente de la captura por unidad de esfuerzo (1993-2004) y de las tallas medias (1993-2005) del pez palo (Percophis brasiliensis) en el litoral marítimo entre 34º S y 42º S
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2009) Rico, María Rita; Perrotta, Ricardo G.
    Brazilian flathead (Percophis brasiliensis), of wide latitudinal distribution (23° S-47° S), is caught in Argentina in two coastal areas north and south of the Province of Buenos Aires delimited by the 39° S latitude. The species shows the highest abundance and catch yield percentages ( 5. ) of all coastal fish groups. The importance of the species makes it necessary to analyze mean lengths and define an annual abundance index that would allow to diagnose the state of the stock. To calculate the index the General Linear Model was adjusted. The factors used were Year, Quarter and 4 sub-areas, all statistically significant. The problem generated by the presence in the model of first order interactions that include the Year factor is discussed. It is concluded that the catch per unit of effort series did not represent changes in the resource abundance. Results suggest that caution should be taken when using the values normally considered to diagnose the state of the stock and implement management measures. Based on catch and effort values, the most important sub-areas were the mouth of the Río de la Plata river (1) and the Mar del Plata adjacent areas (3). A decreasing trend of the mean length throughout the study period was also observed.
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    Inventario íctico del litoral costero bonaerense y uruguayo
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2009) Ruarte, Claudio; Rico, María Rita; Lucifora, L.
    The bibliography and the registries of fish caught in the Buenos Aires (Argentina) and Uruguay coastal littoral area during 33 research cruises were analyzed to elaborate the first ichthyic inventory of the region. A total of 147 species belonging to 71 families was registered. The figure represents 48% of the specimens reported for the Argentine-Uruguayan Common Fishing Zone and 37% of the marine species mentioned for the SW Atlantic. The list of coastal marine fishes of Uruguay and north of Argentina is the first attempt to provide basic information to evaluate possible temporal changes of the ichthyic composition in the area. The lists or inventories constitute an essential tool for fisheries management, the generation of statistic data and gathering of information useful for resource assessment.
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    Pesca comercial y captura por unidad de esfuerzo de la merluza (Merluccius hubbsi) entre 34º S-41º S durante el período 1986-2005 y evidencias sobre cambios en la distribución y composición por tallas del recurso
    (Mar del Plata: Instituto Nacional de Investigación y Desarrollo Pesquero, 2009) Irusta, C. Gabriela; Castrucci, Roberto O.; Simonazzi, Mario A.
    The activity of the hake (Merluccius hubbsi) commercial offshore ice chilling fleet and its relation to concentration, distribution and population areas of the stock distributed between 34ºS - 41ºS is described. The catch per unit of effort (CPUE) for the 1986-2005 period was estimated applying the General Linear Model. Data derived from the offshore fishing logs provided by the Argentine Secretary of Agriculture, Farming, Fishing and Food Administration and the information obtained in research cruises carried out in 1994, 1996-2001, 2003-2005 to evaluate the resource population abundance. During the main fishing time in the sector (quarter 2) and up until 1991 the fleet scattered within the Argentine-Uruguayan Common Fishing Zone (SW Atlantic). Later on the activity concentrated south of 39ºS where catches and the nominal effort reached their maximum value to decrease northerly as a result of the depletion of stock concentration and the development of the hake fishery in the Patagonian area. The zone south of 39º S is a sector of low concentrations where adult individuals prevail and a transfer zone of the fleet towards Patagonian fishing grounds (41ºS - 48ºS). The annual CPUE estimated with the General Linear Model decreased by 49% in the study period. As of 2000 the fishery became variable as regards catches, fishing effort and operation areas and more dependent on important recruitments as a consequence of the marked decrease of adults population abundance.
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    Precisión en las evaluaciones por área barrida de algunos peces demersales costeros entre los 34º S Y 42º S, Atlántico Sudoccidental
    (Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Mar del Plata, 2010) Hansen, J.E.; Hozbor, Natalia M.; Lagos, A. Nerina; Martos, Patricia
    To estimate the biomass of six species, the stratified design used at present for demersal coastal fish stocks is compared against other design alternatives. Density data (t mn-2 between 34ºS and 42ºS, from the coast line to 50m depth, corresponding to whitemouth croaker (Micropogonias furnieri), patagonian smoothhound (Mustelus schmitti), stripped) weakfish (Cynoscion guatucupa), angular angel shark (Squatina guggenheim), brazilian flathead (Percophis brasiliensis) and skate (Sympterygia bonapartii) collected in surveys carried out in spring and winter in the Argentine Sea (SW Atlantic), were analyzed. The spatial distribution of the species was strongly contagious and influenced by bottom salinity. Different marine zones that showed special salinity features for a long time were defined to test bounded strata accordingly. The simple random design caused, in general, greater uncertainty than any of the stratified designs when using the 17 fixed strata surveyed during the last cruises or when two ‘new designs’ that included 7 strata, different for spring and winter, were adopted. Although no stratified scheme showed superiority to assess all and every species, their comparative advantages are discussed. Assessments made with the design used at present seem to be less efficient in winter thus suggesting that, in the future, surveys should be carried out in spring. No great differences among designs were found when the efficiency gain-sample size relation was studied and that resulted very low above 150 trawls if compared to the cost of using the research vessel.