Resultados de la búsqueda
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Progress on the application of an age-structured production model fitted to commercial catch-rate and catch-at-length data to assess the toothfish (Dissostichus eleginoides) resource in the Prince Edward Island vicinity
allow the estimation of a selectivity-at-age function that decreases at larger ages. This is, in ... particular, to accommodate the view of the August 2003 meeting of the Subgroup on assessment methods that 0.2 ... yr-1 is likely the largest value of natural mortality M that is plausible for toothfish. Catch, catch ... . In the meantime, based upon a cautious interpretation of projections over the wide range of current ...
Meeting Document : WG-FSA-03/97 : Autor(es): A. Brandão and D.S. Butterworth (South Africa)
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The three-frequency method for classifying the species and assessing the size of two euphausiids (Euphausia superba and Euphausia crystallorophias)
rule methodologies. This paper explores applications of the multi-frequency method using data from ... , the sampled areas, the instrumental and the sampling strategies varied. First, on the basis of the ... echo-integrations, made simultaneously either at two or at three frequency, and of the results of net ... acoustic estimates of euphausiid lengths, derived from the fluid sphere model, are compared with lengths ...
Meeting Document : WG-EMM-02/37 : Autor(es): M. Azzali, G. Lanciani and I. Leonori (Italy)
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Fecundity and size at sexual maturity of the bigeye grenadier (Macrourus holotrachys) at South Georgia (CCAMLR Subarea 48.3)
at different stages of development suggesting that M. holtrachys may have an extended spawning season ... . Analyses of size at sexual maturity indicate that Lmat 50 occurs at 29cm (pre-anal length) whilst Lint 50 ... final ovarian development is a prolonged process in M. holotrachys which probably lasts for a period of ... greater than a year. Sex ratios of specimens caught in the longline fishery are highly skewed with females ...
Meeting Document : WG-FSA-02/26 : Autor(es): T. Mulvey, S.A. Morley, M. Belchier and J. Dickson (United Kingdom)
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Identification of Amblyraja species in the longline fishery in Subarea 48.3 – CCAMLR
A.georgiana. Male A. sp.anon attain 50% maturity at a total length of 97cm, 13 cm greater than the length at ... 50% maturity for A.georgiana. Comparisons of colour and patternation were found to be consistent ... proportionally longer claspers to total length (2.77% difference between averages) than male A.sp.anon. 94% of ... captures of A.sp.anon were found at depths >1000m, where 85% of A.georgiana were caught in depths ...
Meeting Document : WG-FSA-02/54 : Autor(es): M. Endicott (United Kingdom), L.J.V. Compagno (South Africa) and D.J. Agnew (United Kingdom)
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CIRCULATION IN THE ROSS SEA SECTOR OF THE SOUTHERN OCEAN: REPRESENTATION IN NUMERICAL MODELS
Abstract: The circulation in the Ross Sea sector of the Southern Ocean is examined in three ... numberical models of intermediate to high resolution. Despite the model differences (including physics ... , forcing) the circulation representation is relatively consistent, both in terms of the mean and some ... aspects of monthly variability. This could point to strong bathymetric constraints on the circulation. In ...
Meeting Document : WG-EMM-09/41 : Autor(es): G.J. Rickard (New Zealand), M. Roberts (United Kingdom), M.J.M. Williams, A. Dunn, M.H. Smith and M. Pinkerton (New Zealand)
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BIOMASS ESTIMATES AND SIZE DISTRIBUTIONS OF DEMERSAL FINFISH ON THE ROSS SEA SHELF AND SLOPE FROM THE NEW ZEALAND IPY-CAML SURVEY, FEBRUARY-MARCH 2008
Abstract: during February and March 2008 as part of the International Polar Year. The main aim of ... the survey was to carry out a Census of Antarctic Marine Life in this regionfocussing on sampling the ... each stratum. The trawl survey of the shelf area focused mainly on icefishes, notothens, Antarctic ... silverfish, and glacial squid whilst the survey of the slope area was designed to target the macrourid M ...
Meeting Document : WG-FSA-08/31 : Autor(es): S.M. Hanchet, M.L. Stevenson (New Zealand), C. Jones (USA), P.M. Marriott, P.J. McMillan, R.L. O’Driscoll, D. Stevens, A.L. Stewart and B.A. Wood (New Zealand)
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On the taxonomy of the Lepidonotothen squamifrons group (Pisces, Perciformes, Notothenioidei)
Abstract: The Lepidonotothen squamifrons group has been described to be comprised of 3 species: L ... overlapping. Enzyme electrophoresis of enzyme polymorph isms has been applied to specimens morphologically ... ; represent only populations of one species. Evidence is presented that the third species of the group, L ... comprised of only one species, Lepidonotothen squamifrons (Günther, 1880). We found no statistically ...
Meeting Document : WG-FSA-93/25 : Autor(es): R. Schneppenheim and K.-H. Kock (Germany), G. Duhamel (France) and G. Janssen (Germany)
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Variations in food composition and feeding intensity of mackerel icefish (Champsocephalus gunnari) at South Georgia
Abstract: The diet composition and feeding intensity of mackerel icefish (Champsocephalus gunnari ... ) around Shag Rocks and the mainland of South Georgia was investigated in January/February 1985, January ... of krill and Themisto in the diet items varied considerably between the three seasons, whereas the ... proportion of mysids in the diet remained fairly constant. krill is obviously the prefered diet. In years of ...
Meeting Document : WG-FSA-92/26 : Autor(es): K.-H. Kock (Germany), I. Everson (United Kingdom), S. Wilhelms (Germany), S. Campbell (United Kingdom), J. Szlakowski (Poland), G. Parkes (United Kingdom), Z. Cielniaszek (Poland) and C. Goss (United Kingdom)
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Can we use discriminant function analysis to sex penguins prior to calculating an index of a morphometric parameter?
sex of individuals, it is only able to correctly sex a certain proportion of birds. Two overlapping ... functions are able to correctly determine the sex of birds with greater than 80% success the difference ... . Combining all data for both sexes is considered as a procedure for avoiding the necessity of sex ... determination, but uncertainty in sex ratios can lead to considerable Type I and Type II errors. Lack of ...
Meeting Document : WG-CEMP-92/11 : Autor(es): D.J. Agnew (Secretariat)
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Some comments on the procedure for testing estimators of krill abundance which utilise survey data
Abstract: Since krill distributional data do show evidence of spatial correlation, estimators of ... performance in practice. Such studies require a simple method for computer generation of krill distribution ... " models of krill distribution are considered. These achieve overall spatial correlation by placing ... encouraging improvement in fits to the distribution of inter-swarm distances observed on the 1981FIBEX survey ...
Meeting Document : WG-KRILL-91/21 : Autor(es): D.S. Butterworth, D.L. Borchers and D.G.M. Miller (South Africa)