Résultats de la recherche
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Comparison of estimators of effective sample size for catch-at-age and catch-at-length data using simulated data from the Dirichlet-multinomial Distribution
Abstract: The incorporation of “effective sample size” (ESS) in integrated assessments is an ... approximate but simple way of modelling the distribution of catch-at-age or catch-at-length frequencies using ... frequencies. The ESS applied within the definition of the negative log-likelihood contribution to the ... -length frequency data relative to the other types of data used in integrated assessments of toothfish ...
Meeting Document : WG-SAM-07/7 : Auteur(s): S.G. Candy (Australia)
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On biogeographic patterns of benthic invertebrate mega fauna on shelf areas of the Southern Ocean Atlantic sector
Abstract: The ideal approach to bioregionalisation of Antarctic and Southern Ocean shelf ... communities incorporates a range of data on physical, environmental and biological properties, as well as the ... interaction of these properties. Here, benthic invertebrate megafaunal communities of shelf habitats within ... the Atlantic sector of the Southern Ocean were analysed quantitatively from scientific survey trawl ...
Meeting Document : WS-BSO-07/10 : Auteur(s): S.J. Lockhart and C.D. Jones (USA)
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Reasons of differences between distribution and density of mackerel icefish (Champsocephalus gunnari) aggregations in the South Georgia area during summer and autumn periods in different years from the bottom trawl survey data
the largest aggregations of food organisms are concentrated at the beginning of the spring period ... . Icefish concentrations were detected at the periphery of a cyclonic meander or in the centre of the ... anticyclonic circulation formed by the Weddell waters. Confinement of the fish to the boundary of water masses ... between the shelf waters and ACC was also traced. Favourable conditions for formation of dense ...
Meeting Document : WG-FSA-05/77 : Auteur(s): Zh.A. Frolkina (Russia)
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On possibility of using acoustic method to improve quality of Champsocephalus gunnari biomass estimates in Subarea 48.3
Abstract: An attempt has been made to study icefish as an object of acoustic survey basing on the ... acoustic and biological data obtained by Russian RN ATLANTIDA in the area of South Georgia Island (January ... -February 2000). Estimation of possible target strength values was made by a comparison to TS of other fish ... and physical body properties. There has been proved a comparability of Ch.gunnari length frequencies ...
Meeting Document : WG-FSA-00/31 : Auteur(s): S. Kasatkina (Russia)
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On the state of Champsocephalus gunnari stock in Subarea 48.3 and methods of its assessment
2000 showed clearly a necessity to revise the methods of icefish (which is near-bottom and pelagic fish ... species) biomass assessment based on the results of bottom trawl surveys. A question on unreliability of ... stock assessment was repeatedly raised on the meetings of Working Group on Fish Stock Assessment (WGFSA ... ) both during the period of the icefish fishery in 1980s and after its ceasing in 1990s. In all cases, a ...
Meeting Document : WG-FSA-00/45 : Auteur(s): K. Shust, V. Senioukov, P. Gasiukov and A. Kozlov (Russia)
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Analyses of acoustic line-transect data from the waters around South Georgia: estimation of krill (Euphausia superba Dana) biomass
Abstract: A large-scale acoustic survey of zooplankton stocks of the waters around South Georgia ... various definitions of strata. The total biomass in the area of 155 786 km2 was estimated to be 1.8225 x ... 106 t (Coefficient of Variation = 9.5%). This gives an estimate of mean density throughout the region ... of 11.7 t km-2. Although the estimate of the mean is not sensitive to the definition of strata, the ...
Meeting Document : WG-KRILL-91/30 : Auteur(s): E. Murphy, I. Everson and A. Murray (United Kingdom)
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The Role of Fish as Predators of Krill (Euphausia superba) and Other Pelagic Resources in the Southern Ocean
number of food studies were conducted. Currently, the best estimates of krill consumption by fish are 23 ... – 29. 106 tonnes of krill and other pelagic prey taken annually by demersal fish and 7 – 44. 106 tonnes ... confidence limits. Major shortcomings of the consumption estimated for mesopelagic fish are the validity of ... hydro-acoustic biomass estimates conducted in the late 1980’s and the lack of quantitative food ...
Meeting Document : CCAMLR-IWC-WS-08/09 : Auteur(s): Collins, M.A., Williams, R., Agnew, D.J., Kock, K.-H., Belchier, M., Shust, K.V., Welsford, D., Hanchet, S., Pshenichnov, L., Barrera-Oro, E.
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A RE-APPRAISAL OF THE TOTAL BIOMASS AND ANNUAL PRODUCTION OF ANTARCTIC KRILL
Abstract: Despite much research on Euphausia superba, estimates of their total biomass and ... revisions in acoustics have made it possible to refine previous estimates. Net-based databases of density ... and length frequency (KRILLBASE) yield a summer distributional range of ~19 x106 km2 and a mean total ... abundance of 8x1014 postlarvae with biomass of 379 million tonnes (Mt). These values are based on a ...
Meeting Document : WG-EMM-08/17 : Auteur(s): A. Atkinson (United Kingdom), V. Siegel (Germany), E.A. Pakhomov (South Africa), M.J. Jessopp (United Kingdom) and V. Loeb (USA)
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Results of acoustic assessment of krill biomass in Subarea 48.2 during summer 1996
Abstract: In the period from 24 February to 7 March 1996 in the cruise of RV "Atlantida" ... ; acoustic assessment of krill biomass and distribution was carried out in study area restricted with 59° 10 ... ' S- 60°30' S and 42 °00' W- 50°00 'w within Subarea 48.2. The study area of 19.200 ... sq.mi1es was located in the zone of two circulation systems of climatic scale interaction: Antarctic ...
Meeting Document : WG-EMM-96/36 : Auteur(s): Sunkovich, V.I., Kasatkina, S.M., Abramov, V.M., Polischuk, M.I., Sushin, V.A., Shnar, V.N.
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Demographic studies of Antarctic krill Euphausia superba Dana in the Cooperation and Cosmonaut Seas (Indian sector of the Southern Ocean)
Abstract: The reproductive state and size composition of Euphausia superba collected in the ... Indian sector of the Southern Ocean from 1985 to 1990 were analyzed to estimate its growth, life span and ... mortality rates. The duration of the life cycle of E.superba exceeded 5 years in the Cosmonaut Sea and 6 ... -0.133 mm.d-1, during the first year of life, to 0.019-0.022 mm.d-1 during the fifth year. Von ...
Meeting Document : WG-Krill-94/16 : Auteur(s): E.A. Pakhomov (Ukraine)