Recent Submissions

  • Estimación del poder de pesca relativo y la eficiencia relativa entre la red comercial y la rastra en la pesquería de vieira patagónica.

    Campodónico, S.; Escolar, M.; Aubone, A. (2017)
    To accurately assess fish and invertebrate populations, the catch values obtained in research surveys are converted to absolute values considering the swept area and fishing gear efficiency. In the 1998-2007 period, Zygochlamys patagonica at Argentine Sea assessment surveys were carried out on board of the Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) research vessels using the dredge as fishing gear. Between 2008 and 2012 they were performed on board of commercial vessels of the scallop fleet with the net proper to each vessel. In order to normalize the temporal series of basic data, in this work the relative fishing power and the relative efficiency between both fishing gears were estimated. Considering the 0.5 dredge efficiency value currently applied, an estimate of 0.3468 net efficiency was obtained. Said result is valid for the vessel, fishing gear, dredge, management unit and time of the year in which the experience took place. The need of estimating the true efficiency of the dredge used in Patagonian scallop biomass assessment through an experimental ad hoc study is hereby emphasized.
  • Caracterización molecular de rayas simpátricas de los géneros Dipturus y Zearaja en el Mar Argentino por DNA barcode.

    Izzo, S.A.; Andreoli, G.; Figueroa, D.E.; Costagliola, M. (2017)
    Skates of the genera Dipturus and Zearaja present a particular challenge for fishery management and conservation, since they have been subject to intense exploitation in the last years. In the Argentine Sea, these genera are represented by D. leptocauda, D. trachyderma, D. argentinensis and Z. chilensis. These last three are sympatric species since they overlap in depth and geographic distribution. Their behavioral habits and the morphological similarity make these species, especially in juvenile stages, difficult to identify. The use of the mitochondrial gene Cytochrome C Oxidase I (COI) as a DNA Barcode (genetic barcode), is a useful molecular tool to identify morphologically similar species. In this work, we used the DNA Barcode to identify specimens of Z. chilensis that presented a different thorny pattern in their dorsal side and tail instead of the common pattern found in that species. Also, we compared the DNA Barcode with other sympatric skates' species to obtain a molecular characterization of the Dipturus and Zearaja. The DNA Barcode was obtained from 23 individuals collected along the Argentine continental shelf. The specimens were classified as D. argentinesis, Z. chilensis and Z. chilensis with a distinct different spinal pattern (specimens ZSP). The specimens were identified at species level by comparing their barcodes with reference sequences of specimens from the Pacific and Atlantic ocean in Barcode of Life Data System (BOLD), and also by the intra and interspecific Kimura two-parameter (K2P) distance. From this work, we conclude that the DNA Barcode is a useful and efficient molecular marker to identify skates' species, and is a useful tool as a reference parameter for the differentiation of the species.
  • Análisis dinámico-teórico de la relación entre la longitud del cable de arrastre y la profundidad de pesca para una rastra destinada a la captura de vieira y desarrollo del software de aplicación.

    Roth, R.R.; García, J.C.; Villalba, J. (2017)
    In this work the length of the trawl cable as a function of fishing depth for Patagonian scallop (Zygochlamys patagonica) catch at Argentine Sea, with dredge is determined in a theoretic way. A calculation sheet was designed to establish the cable length as a function of different parameters and develop an application software to estimate, in a quick way, the length/depth relationship. The software can be run in different devices of the Android or Windows operative systems and be integrated to the "CAPtura" database system used in Patagonian scallop assessment cruises. The calculation sheet allowed to determine that, if the dredge is operated at a trawl speed of 4 knots and 100 m fishing depth, the length/depth ratio should be close to four (4) to guarantee that the gear is in permanent contact with the seabed, especially at the beginning of the operation, when the absence of retained catch reduces the equipment weight. In order to obtain more accurate calculations to allow for a reduction of the security coefficient used to establish length, the tension generated in the cables should be measured in an actual work situation. Due to the lack of data about the coefficients of friction with the different types of seabed, those established for soil tillage were adopted, which meant a source of errors in calculations. In order to improve the estimates obtained, it is necessary to perform studies to determine them. The calculations made lead to conclude that the cable length is directly related, among other factors, to the trawl speed, the depth at which the work is performed and the weight of the fishing gear.
  • Clave para la identificación de los estadíos de desarrollo (inmaduros IV-V y adultos VI) de copépodos (Crustacea, Copepoda) del sector nerítico bonaerense y norpatagónico.

    Ramírez, F.C.; Derisio, C. (2017)
    In this work compilation is made of the descriptions provided by different authors about the ontogenetic changes that occur along the vital cycle of a group of planktonic copepods from Argentine Sea. The list includes 17 species common to the Buenos Aires and northpatagonian neritic sector, namely: calanoids Calanus simillimus, C. australis, Calanoides carinatus, Neocalanus tonsus, Eucalanus monachus, Paracalanus parvus, Ctenocalanus vanus, Clausocalanus brevipes, Drepanopus forcipatus, Centropages brachiatus, Acartia tonsa, Labidocera fluviatilis and Temora stylifera; ciclopoids Oithona nana and O. helgolandica and harpacticoids Euterpina acutifrons and Microsetella norvegica. The ontogenetic descriptions correspond to copepodids development stages IV and V and adults (VI) with specification of the differences between sexes. Stages previous to IV were not included since they do not have the fifth pair of legs, element of an essential diagnostic value. The information, based on morphological and meristic details of the abdomen and fifth pair of legs, is presented through an algorithm with drawings and photomicrographies trying to avoid, as far as possible, the need for a previous dissection.
  • Age and growth of Whitemouth croaker (Micropogonias furnieri) larvae and juveniles.

    Braverman, M.; Brown, D.R.; Acha, E.M. (2017)
    With the aim of studying the age and daily growth of whitemouth croaker (Micropogonias furnieri) larvae and juveniles, the microstructure of sagittae otoliths of 122 individuals 3-25 mm standard or notochord length (SL or NL) size range and 7-92 days old was analyzed. Specimens derived from the turbidity front of the Río de la Plata area (Argentina) the main spawning zone of the species. Counting and measuring of the increments width along the otolith major radius were performed. The length-at-age data were fitted to the linear model (R2 = 0.875) and that of Laird-Gompertz (R2 = 0.881) with L0 = 2.44 and 2.76 mm, respectively, that represents the average length at hatch. With the Laird-Gompertz model an inflection point at 31 days and 10.23 mm SL was obtained. The instantaneous growth rates as a function of length showed a bell shape with an increment of 0.19-0.28 mm day-1 (27 mm SL asymptotic length). The growth rate derived from the linear model was 0.25 mm day-1. A linear relationship between the otolith major radius and length was found. The analysis of increments width as a function of age showed a trend similar to the one described in the Laird-Gompertz model.
  • Análisis de poblaciones virtuales modificado a partir de una aproximación a la ecuación de captura permitiendo una implementación numérica sencilla.

    Hernández, D.R.; Mendiolar, M. (2017)
    A modification to the Virtual Population Analysis as a result of an approximation to the catch equation that allows to avoid solving nonlinear equations in each cohort reconstruction process is presented. The relative errors obtained when estimating the fishing instantaneous mortality rate per age (maximum and mean in absolute value) remained lower than 1.4 percent within the M and F range values (natural instantaneous mortality rate and fishing instantaneous mortality rate) considered (0 menor o igual que M menor o igual que 1.2 y 0 menor o igual que F menor o igual que 2). The new method can be adapted to a particular situation (M and F range values) by simply solving an optimization problem (minimization of the maximum relative error absolute value) easily achieved using a calculation sheet or considering the approximation corresponding to any of the domains hereby analyzed.
  • Comparación del uso de red de arrastre comercial versus rastra en el monitoreo de la fauna acompañante en la pesquería de la vieira patagónica (Zyglochlamys patagonica) en la Argentina.

    Schejter, L.; Escolar, M. (2017)
    In this study presentation is made of the information on specific richness and composition of the benthic community associated to Patagonian scallop fishery obtained analyzing the data derived from research and stock assessment cruises carried out in the 1995-2013 period in the zone named as Management Unit B (in front of Mar del Plata coast, Buenos Aires). The area was studied and assessed with dredges and commercial trawl nets. The results obtained suggest that the richness range per station would be higher in the years in which samplings of the benthic community derived from catches performed with dredge, gear that would allow a better estimate of species richness per site. A larger number per sample and a better representation of the less significant and smallest ones was detected.
  • Daño en invertebrados bentónicos en la captura incidental de la pesquería de vieira patagónica.

    Escolar, M.; Schwartz, M.; Marecos, A.; Herrera, S.; Díaz, R.; Schejter, L.; Campodónico, S.; Bremec, C.S. (2017)
    Patagonian scallop (Zygochlamys patagonica) fishery catch, at Argentine sea, is mechanically processed on board where non target species and scallops that do not reach the commercial size are separated with metal drums and discarded to sea. The aim of this study was to analyze the direct damage produced to the main bycatch invertebrate species, distinguishing between that caused by trawling and the one generated by the on board selection process. The subsamples were collected during the 2012 assessment cruises carried out on board of commercial vessels equipped with different selection process systems. Sea urchin Sterechinus agassizii, organism with a very fragile body structure, was the most affected species. It was observed that many benthic invertebrates are retained by the on board selection process thus passing to the final stage, reason for which they do not survive. An additional discard point in one of the vessels allows most species to return to sea with a damage similar than when they arrived to deck. The level of damage varied among species and, even within the same species, according to size. The level of damage, specific to each species, is related to the individuals morphology.
  • Actividad reproductiva del salmón de mar (Pseudopercis semifasciata) en aguas costeras de la Provincia de Buenos Aires en el período 2012-2014.

    López, S.; Militelli, M.I. (2017)
    The reproductive activity of Argentine sandperch (Pseudopercis semifasciata) in the Buenos Aires Province coastal waters close to the Quequén/Necochea port, Buenos Aires, Argentine sea, was analyzed. The material derived from landing samplings performed by the Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) in the 2012-2014 period. The study of gonadal maturity stages allowed to determine that the species reproductive time in the area extends from August through February, with a marked increase of the gonadosomatic index and the presence of females in spawning activity or with postovulatory follicles, indicators of recent spawnings. Batch fecundity, that showed a positive relationship with the length and weight of ovary-free females, had a mean value of 93,483 hydrated oocytes. Relative fecundity varied between 18 and 51 oocytes per gram of ovary-free female and showed a negative linear relationship with length and weight. The dry weight and diameter of hydrated oocytes and the oily drop did not relate to the maternal characteristics in a significant way. The largest landings, that took place in March, September and October, showed that the last two months coincided with the time of the highest reproductive activity of the species.
  • Índices ponderados de abundancia relativa, obtenidos a partir de modelos lineales generalizados, considerando la presencia de valores nulos de captura.

    Hernández, D.R.; Pérez, M.A.; Cortés, F. (2017)
    General Linear Models (GLM) and generalized linear models (GLMs), that allow to integrate in a simple way the different factors that influence catch per unit of effort (CPUE) variation, are used to estimate annual abundance indices. The effect associated to the Year factor is considered and, based on the results obtained, the index is built. Nevertheless, when significant interactions that include said factor occur, the result is indices proportional to the mean annual abundance of each year with proportion coefficients that depend on the year, which does not allow to compare the series terms. In this paper the weighted abundance indices obtained with the GLM and GLMs are established and how to define the population mean annual density as a function of the parameters of the models used is considered. An application example with null CPUE values in patagonian smoothhound is shown and debate on the correct selection of the fleet to provide the data used to estimate annual weighted abundance indices presented.
  • Características limnológicas, ictiofauna y abundancia de Odontesthes bonariensis de 35 lagunas de la región pampeana (Argentina).

    Mancini, M.; Grosman, F.; Sanzano, P.; Del Ponti, O.; Salinas, V. (2016)
    In this work the distribution and abundance of egg cases of skates Bathyraja brachyurops and B. macloviana on the Buenos Aires continental shelf and the Mar del Plata submarine canyon are analyzed and stages of embryonic development described. Although distribution, similar for both species, was registered south of 37° S at 84-215 m depth, some cases of B. macloviana were found down to 1,395 m. The highest abundance of B. brachyurops was recorded between 97-145 m and 251 m and that of B. macloviana at 94-105 m. Results indicate similar oviposition areas that coincide with the Argentine break front and the Patagonian scallop banks. Cases with embryos in different stages of development were collected. The anatomical structures, similar for both species in the first stages, showed differences in spinulation and pigmentation in the final ones. In both species early stages of development were found between July and September. The different stages observed in B. brachyurops embryos in July suggest oviposition at different times of the year. Those of B. macloviana found in the same stage in different seasons and in different stages in the same season suggest a similar oviposition pattern.
  • Desarrollo embrionario de Pagrus pagrus bajo distintas condiciones de salinidad y temperaturas de incubación.

    Berrueta, M.M.; Suárez, J.; Aristizábal, E.O. (2016)
    Pagrus pagrus is a demersal species widely distributed in the Mediterranean and the eastern and western shores of the Atlantic Ocean. In Argentina it distributes naturally along the coast of the Buenos Aires Province between 10 and 50 m depth. The estimate of egg quality during the early stages of embryonic development is a useful predictive criterion to evaluate the potential of the species to produce juveniles. The aim of this study was to describe in detail the stages of embryonic development and larval hatching time under different conditions of salinity and temperature. The fertilized eggs obtained from natural spawning were incubated at 15, 30 and 40 salinity levels combined with 14 and 18 °C temperature. In the different experiments the embryonic stages were photomicrographed and structures described. Egg development was completed in all experiments made. At 18 °C the fully formed embryo hatched at 40 h postfertilization; at 14 °C hatching occurred 73 h after. The effect of salinity on embryonic development was reflected in an irregular growth of blastomeres during the cleavage stages at 15 and 40 salinity with a subsequent abnormal development of the caudal region in larvae incubated at said levels. Knowing the embryonic stages, sequence of segmentation, time of organ formation and duration of embryonic development until hatching is a basic requirement to evaluate the quality of egg batches devoted to mass larvae production.
  • Distribución y abundancia de cápsulas de huevo y aspectos del desarrollo embrionario de las rayas Bathyraja brachyurops y Bathyraja macloviana en la plataforma bonaerense.

    Vazquez, D.M.; Gabbanelli, V.; Díaz de Astarloa, J.M. (2016)
    In this work the distribution and abundance of egg cases of skates Bathyraja brachyurops and B. macloviana on the Buenos Aires continental shelf and the Mar del Plata submarine canyon are analyzed and stages of embryonic development described. Although distribution, similar for both species, was registered south of 37° S at 84-215 m depth, some cases of B. macloviana were found down to 1,395 m. The highest abundance of B. brachyurops was recorded between 97-145 m and 251 m and that of B. macloviana at 94-105 m. Results indicate similar oviposition areas that coincide with the Argentine break front and the Patagonian scallop banks. Cases with embryos in different stages of development were collected. The anatomical structures, similar for both species in the first stages, showed differences in spinulation and pigmentation in the final ones. In both species early stages of development were found between July and September. The different stages observed in B. brachyurops embryos in July suggest oviposition at different times of the year. Those of B. macloviana found in the same stage in different seasons and in different stages in the same season suggest a similar oviposition pattern.
  • Análisis de los desembarques declarados de condrictios a partir de la implementación de la veda en el área del tratado del Río de la Plata y su Frente Marítimo (2006-2014).

    Bernasconi, J.F.; Monsalvo, M.; Prosdocimi, L.; Martínez-Puljak, G.; Navarro, G. (2016)
    In 2007 the Comisión Técnica Mixta del Frente Marítimo established a closed area to bottom trawl in fishing rectangle 3656 to protect chondrichthyan reproductive aggregations and juveniles. The aim of this work was to analyze the evolution of said measure, the skate and shark landings declared during the 2006-2014 period in said rectangle and the distribution of the fleet before and after implementation. In the period evaluated, the duration of the closed area it was extended from 59 to 151 days and a reduction of tonnes of skates and sharks declared in the Argentine Uruguayan Common Fishing Zone of rectangle 3656 and an increase in the participation of said species in landings of the area of provincial jurisdiction was observed. The same trend was proved in the fishing activity if compare the season 2006-2007 (without closed area) and the season 2012-2013 (with closed area). During the closed season a northeast displacement of activities, a high catch level and fishing operations in the adjacent rectangles were observed.
  • Morfometría y topología del cerebro del pez tetra cola roja, Aphyocharax anisitsi (Characiformes: Characidae).

    Rincón, L.; Cavallino, L.; Alonso, F.; Lo Nostro, F.; Pandolfi, M. (2016)
    Tonic immobility (TI) is an innate and reversible response to stress observed in a large number of taxa that includes elasmobranches. Although in aquariums it constitutes a safe tool in animal handling procedures, little is known about its physiological effect. Blood lactate concentration is used as an indicator of the stress derived from elasmobranches catch and handling. The aim of this study was to evaluate the response to stress produced in Myliobatis goodie using TI as a handling tool. Thirteen specimens were subject to constant and interrupted TI during which blood samples were taken at 0, 10, 30, 60, 90 and 120 min interval. It was observed that in TIconst lactate concentration (mmol l-1) remains more stable through time (t0 = 1.23; t10 = 2.33; t30 = 3.23; t60 = 3.55; t90 = 4.48; t120 = 5.3). TIint showed that each procedure generates an increase in levels (t0 = 1.17; t10 = 2.19; t30 = 3.96; t60 = 5.04; t90 = 8.10; t120 = 8.42). Results indicate that TIconst prevents significant increments in blood lactate levels; thus, it can be considered a useful tool to be used in procedures that require to secure and retain organisms for long periods of time.
  • Evaluación de la inmovilidad tónica como técnica para minimizar el estrés de manejo en cautiverio de chuchos (Myliobatis goodei) mediante la medición de lactato en sangre.

    Jañez, J.; Abraham, C.; Palmerio, A.; Argemi, F. (2016)
    Tonic immobility (TI) is an innate and reversible response to stress observed in a large number of taxa that includes elasmobranches. Although in aquariums it constitutes a safe tool in animal handling procedures, little is known about its physiological effect. Blood lactate concentration is used as an indicator of the stress derived from elasmobranches catch and handling. The aim of this study was to evaluate the response to stress produced in Myliobatis goodie using TI as a handling tool. Thirteen specimens were subject to constant and interrupted TI during which blood samples were taken at 0, 10, 30, 60, 90 and 120 min interval. It was observed that in TIconst lactate concentration (mmol l-1) remains more stable through time (t0 = 1.23; t10 = 2.33; t30 = 3.23; t60 = 3.55; t90 = 4.48; t120 = 5.3). TIint showed that each procedure generates an increase in levels (t0 = 1.17; t10 = 2.19; t30 = 3.96; t60 = 5.04; t90 = 8.10; t120 = 8.42). Results indicate that TIconst prevents significant increments in blood lactate levels; thus, it can be considered a useful tool to be used in procedures that require to secure and retain organisms for long periods of time.
  • Biology and fishery of long tail hake (Macruronus magellanicus) in the Southwest Atlantic Ocean.

    Giussi, A.R.; Zavatteri, A.; Di Marco, E.J.; Gorini, F.L.; Bernardele, J.C.; Marí, N. (2016)
    Long tail hake is one of the most important finfish resources in the Southwest Atlantic Ocean (SAO). This demersal-pelagic fish is widely distributed from 35° S to 56° S between 50 and 800 m depth. In the Patagonian region the species is found on the shelf, associated with three different water masses: Coastal, Shelf and Malvinas Waters, while north of 45° S it is related to the shelf break, following the Malvinas waters. A separate small stock, evident because of its different growth patterns, occurs inside San Matías Gulf. There is no strong difference in growth patterns between sexes, however females are larger than males, principally after the first maturity that occurs at 3 years old. Maximum age observed was 16 years old, but fish older than 12 years are scarce in the population. The dietary composition changes during the life cycle, juveniles are mainly microphagous and adults incorporate larger preys of several invertebrates and vertebrates taxa. Principal food items are zooplankton species; the most abundant are hyperiid amphipods and euphausiids. Fish and cephalopods are secondary prey. Few fish species predate on long tail hake: Southern hake (Merluccius australis), spiny dogfish (Squalus acanthias), and Argentine hake (M. hubbsi). Cannibalism is not reported in long tail hake. Spawning areas have not been detected yet but some signals in somatic conditions allow inferring that this process may occur during spring. A systematic series of summer demersal standard swept area trawl surveys has been conducted since 1992 to assess the population, suggesting that maximum long tail hake biomass was more than 2 million tonnes in the mid 1990's. Those results were employed as an index of abundance in the annual stock assessment to establish the Total Allowable Catch, but neither environmental variables nor economic effects have been considered yet. Fishing activities began during the mid 1970's when yields were not significant, but beginning in the 1980's several fleets targeted long tail hake, increasing catches up to 168,000 t. Products are exported to Europe, Asia and South America.
  • Biology and fishery of the Southern hake (Merluccius australis) in the Southwest Atlantic Ocean.

    Giussi, A.R.; Gorini, F.L.; Di Marco, E.J.; Zavatteri, A.; Marí, N. (2016)
    Southern hake (Merluccius australis) is distributed mainly south of 50° S around South America, occurring in cold temperate waters of subantarctic origin. In the Southwest Atlantic Ocean (SAO) only adults are abundant. This species is icththyophagous and malacophagous, feeding mainly on long tail hake (Macruronus magellanicus) and several cephalopods (Illex argentinus, Onykia ingens, Doryteuthis gahi). Age and growth studies show significant sexual differences; females grow to a larger size than males. In recent years, the highest biomasses, estimated from trawl surveys using the swept area method, are about 10,000 t. Fish 4 to 8 years old usually dominate commercial landings. Only a few factory trawler vessels have southern hake as a target species. They operate over the main fishing grounds located near Tierra del Fuego and at the eastern mouth of the Beagle Channel. Average annual landings are about 5,000 t.
  • Biology and fishery of the Argentine hake (Merluccius hubbsi).

    Irusta, G.; Macchi, G.J.; Louge, E.; Rodrigues, K.A.; D'Atri, L.L.; Villarino, M.F.; Santos, B.A.; Simonazzi, M.A. (2016)
    Argentine hake (Merluccius hubbsi) is a demersal, eurythermic and euryhaline species associated to subantarctic waters of the continental shelf and slope. The species, considered the main fishery resource of Argentina that in 2011 reached the maximum catch and export levels, distributes from Southern Brazil to 55° S in a 50-400 m depth range. The three stocks identified, located between 34° S-41° S, south of said latitude and in the San Matías Gulf, show differences as regards reproduction and nursery areas and time, meristic and morphometric characters, abundance level and growth parameters. At the Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) annual assessments of the exploitation status of the stocks north and south of 41° S are carried out and management recommendations made. In this chapter, the biology, fishery characteristics, population abundance and structure and management recommendations for the two main Argentine hake stocks are described.
  • Mar del plástico: una revisión del plástico en el mar.

    Elías, R. (2015)
    80 percent of plastic pollution at sea derives from land sources; the remaining 20 percent is of marine origin. Plastic pollution causes plugging of energy production cooling systems and entanglement of propellers, affects aquaculture development and deteriorates aesthetic values. The damage caused at all levels of marine life includes plankton, benthic invertebrates and large mammals. Plastic intake releases toxic substances and reduces efficiency of physiologic processes, with the consequent risk of direct or indirect death. The increase of plastic debris in the oceans is directly related to consumption and people's unawareness. The seas of Brazil, Uruguay, Argentina and Chile, South American countries far away from large production and consumption centers, show an incipient plastic pollution. A key source of pollution is the inadequate management of waste such as dumps in the open, lack of selection and recycling of plastic materials, of rain water treatment and irresponsible tourism. Recycling is an essential tool to reduce oil use, carbon dioxide emissions and toxic residues.

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