Resultados de la búsqueda
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Preliminary results of a bottom trawl survey around Elephant Island in October and December 1987
Chaenocephalus aceratus, Notothenia gibberifrons and N. neglecta at least since February 1985. In N. rossii the ... proportion of larger (= older) fish in the catches increased. Composition of the catches of C. gunnari ... other shelf areas of the Peninsula region. File: 09-Kock.pdf ... of catches. Analysis of length frequency distributions indicate little or no changes in the stock ... and N. neg/ecta at least since February 1985. In N. rossii the proportion of larger (= older) fish in ... the catches increased. Composition of the catches of C. gunnari differed significantly from that in ... previous seasons which argues for an exchange with C. gunnari from other shelf areas of the Peninsula ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/5 – Part II (Selected Scientific Papers, SC-CAMLR-SSP/5 – Part II) : 185-200 : Autor(es): Kock, K.-H.
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Discrimination of Macrourus whitsoni and M. caml (Gadiformes, Macrouridae) using otolith morphometrics
otolith morphometrics Abstract / Description: That the predominant by-catch of grenadier by the toothfish ... fishery in the Ross Sea region is comprised of two species, rather than being solely Macrourus whitsoni ... , was recognised in 2010 with the identification of a new species, M. caml. Grenadier are the main by ... -catch in the toothfish fishery and modelling suggests that they may be subject to predation release as ... inadequate information on the spatial distributions of the two species of grenadiers, no information on ... changes to the by-catch rates of the two spe- cies and no capacity to investigate changes to the age ... given in Table 3. While there was no significant difference between the discrimination function for ... folds. The coefficients are fitted to all data (n = 527). Model using no biological data ...
Science Journal Paper : CCAMLR Science, Volume 22 (CCAMLR Science, Volume 22) : 15–28 : Autor(es): Pinkerton, M.H., C. Ó Maolagáin, J. Forman and P. Marriott
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Reproductive performance of seabirds and seals at South Georgia and Signy Island, South Orkney Islands, 1976-1987: implications for Southern Ocean monitoring studies
/ Description: Aspects of the reproductive performance over the last decade of black-browed, grey-headed and ... reviewed. Breeding success of the wandering albatross, which breeds in winter and eats fish and squid, has ... remained constant, while population size has declined gradually but significantly. The other species at ... species; circumstantial evidence relating this to reduced availability of krill is discussed. The ... and P. Rotheryl (United Kingdom) Abstract Aspects of the reproductive performance over the last ... , South Orkney Islands, are summarised and reviewed. Breeding success of the Wandering Albatross, which ... gradually but significantly. The other species at South Georgia, which breed in summer and feed ... reduced availability of krill is discussed. The fluctuations in reproductive performance of the krill ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/4 (Selected Scientific Papers, SC-CAMLR-SSP/4) : 445-447 : Autor(es): Croxall, J.P., T.S. McCann, P.A. Prince and P. Rothery
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Comparison of two methods to assess fish losses due to depredation by killer whales and sperm whales on demersal longlines
conservation issues. However, estimating the amount of resource depredated can be especially challenging when ... depredation occurs on fish in the marine environment. This is the case for killer whales (Orcinus orca) and ... sperm whales (Physeter macrocephalus) depredation on the demersal Patagonian toothfish (Dissostichus ... eleginoides) longline fishery operating within the Crozet Islands EEZ (southern Indian Ocean). This study ... leaves no information to compare catch rates in the absence of odontocetes. In order to support those ... effect of depredation but no data would have been available for comparison so the arbitrary choice was ... recent years of this study: fishing vessels no longer concentrate in the Crozet Islands in February as ... that results obtained are extremely consistent to those using the CPUE method with no significant ...
Science Journal Paper : CCAMLR Science, Volume 22 (CCAMLR Science, Volume 22) : 1–14 : Autor(es): Gasco, N., P. Tixier, G. Duhamel and C. Guinet
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On reproduction of Electrona carlsbergi (Tåning)
presents results from histological examinations of gonads of Electrona carlsbergi from the Atlantic sector ... of the Southern Ocean. From materials available it has been ascertained that E. carlsbergi spawns in ... the notal waters. Maturation of females begins when body length reaches 76 to 78 mm. Vitellogenesis is ... . Maturation of ovaries is continuous, and spawning is serial. The spawning season is long and coincides with ... diameter from 10 to 30 J.Ill1. The membrane has no structure. The cytoplasm is heterogeneous; the ... fish cannot spawn in the Antarctic zone at all or that no spawning might have occurred in the period ... gonads of Electrona carlsbergi from the Atlantic sector of the Southern Ocean. From materials available ... it has been ascertained that E. carlsbergi spawns in the notal waters. Maturation of females begins ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 397–409 : Autor(es): Mazhirina, G.P.
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Length-based assessments revisited – why stock status and fishing mortality of long-lived species such as toothfish cannot be inferred from length-frequency data alone
development. The failure of the tag-recapture program to provide robust assessments in many areas and doubts ... other informative estimators for stock abundance and productivity, the review and the simulations ... enter the fishery and the remaining population continues to increase in size (and age). If there is no ... ) with 0% as a target level or 30–40% where no upper size limit exists. The proportional length-based ... come as no surprise, but simply high- light the limitations of using length-frequency data for the ... CCAMLR aims to ensure that the development of a new and exploratory fishery does not occur faster than ...
Science Journal Paper : CCAMLR Science, Volume 18 (CCAMLR Science, Volume 18) : 57–73 : Autor(es): Ziegler, P.E., D.C. Welsford and A.J. Constable
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Maximum entropy reconstructions of krill distribution and estimates of krill density from acoustic surveys at South Georgia, 1996–2000
survey boxes (dimensions 80 km × 100 km) north of South Georgia. The reconstructions were generated from ... line-transect acoustic survey data gathered in the boxes during austral summers from 1996 to 2000 ... . Krill densities had previously been determined at approximately 0.5 km intervals along each of the ten ... 80 km transects in each box, providing about 1 600 density estimates per box. The MaxEnt technique ... km) north of South Georgia. The reconstructions were generated from line-transect acoustic survey ... data gathered in the boxes during austral summers from 1996 to 2000. Krill densities had previously ... been determined at approximately 0.5 km intervals along each of the ten 80 km transects in each box ... , providing about 1 600 density estimates per box. The MaxEnt technique uses an iterative Bayesian approach ...
Science Journal Paper : CCAMLR Science, Volume 10 (CCAMLR Science, Volume 10) : 91–100 : Autor(es): Wafy, M.H., A.S. Brierley, S.F. Gull and J.L. Watkins
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Determination of Antarctic krill acoustic back-scattering cross-section
/ Description: When determining the density krill of concentrations it is necessary to know the acoustic cross ... -section of back-scattering of krill. The target strength can be determined in situ by measuring the echo ... signal from one specimen resolved by the hydroacoustic instrument. By calculating the mean level of the ... directivity diagramme of the antenna and the mean level of the standardized echo signal, it is possible to ... When determining the density krill of concentrations it is necessary to know the acoustic cross ... -section of back-scattering of krill. The target strength can be determined in situ by measuring the echo ... signal from one specimen resolved by the hydroacoustic instrument. By calculating the mean level of the ... directivity diagramme of the antenna and the mean level of the standardized echo signal, it is possible to ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 141-152 : Autor(es): Protaschuk, V.A. and T.A. Lukashova
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Sexing of adult Adélie penguins by discriminant analysis of morphometric measurements
determine the sex of Adélie penguins. A sample of 46 adult birds was taken for measurement from the breeding ... population at Stranger Point (King George/25 de Mayo Is., South Shetland Islands). The sex of each bird had ... been determined earlier by means of observing the birds' breeding behaviour (first incubation ... shift). It was found that the combination of flipper breadth, bill depth and length of the middle toe ... determine the sex of Adelie penguins. A sample of 46 adult birds was taken for measurement from the ... breeding population at Stranger Point (King George/25 de Mayo Is., South Shetland Islands). The sex of ... each bird had been detennined earlier by means of observing the birds' breeding behaviour (first ... incubation shift). It was found that the combination of flipper breadth, bill depth and length of the middle ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 543–549 : Autor(es): Scolaro, J.A., Z.B. Stanganelli, H. Gallelli and D.F. Vergani
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[node:field-journal-volume]:37-51
. 10 (2003): 37–51 37 SPECIES IDENTIFICATION AND AGE ESTIMATION FOR THE RIDGE-SCALED MACROURID ... (MACROURUS WHITSONI) FROM THE ROSS SEA P. Marriott National Institute of Water and Atmospheric Research ... , Wellington New Zealand Abstract Samples of macrourid rattail by-catch from the toothfi sh fi shery in the ... confi rmation of their identity by researchers from the National Institute of Water and Atmospheric ...
Science Journal Paper : 37–51