Search results
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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 ... krill swarms at random within larger aggregation features termed concentrations; these concentrations ...
Meeting Document : WG-KRILL-91/21 : Author(s): D.S. Butterworth, D.L. Borchers and D.G.M. Miller (South Africa)
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Reconciling theoretical versus empirical target strengths of krill; effects of phase variability on the distorted wave Born approximation
scattering from elements of a discretized bent cylinder. It was empirically validated at 120 kHz near ... Abstract: A model was recently proposed to predict the target strengths (TS) of Antarctic krill ... ]. Based on the distorted wave Born approximation (DWBA), the model depends upon the coherent summation of ... broadside incidence (?? 90°), but large discrepancies were observed at other angles away from the main lobe ...
Meeting Document : WG-EMM-02/50 : Author(s): D.A. Demer and S.G. Conti (USA)
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Analysis of trawl data from the South Georgia krill fishery
Abstract: Data from individual trawls carried out by vessels operating in the krill fishery at ... South Georgia are examined and a range of descriptive measurements reflecting the operation of the ... fishery are produced. The measurements indicate that the krill fishery at South Georgia is geographically ... focussed, operating in a limited area along the shelf edge on the northern coast of the island. Each day a ...
Meeting Document : WG-EMM-97/41 : Author(s): Parkes, G., Trathan, P.N., Everson, I., Murphy, E.J.
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A review and preliminary analysis of CEMP data
Abstract: A review of the data in the CEMP database revealed minor inconsistencies that have now ... . Other problems were detected, such as the use of old forms and Standard Methods, and the increasing ... amount of automated data being collected and submitted. Members should ensure that they use the most ... current Standard Methods and CEMP forms found on the website (www.ccamlr.org). A review of the standard ...
Meeting Document : WG-EMM-02/7 : Author(s): Secretariat
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On the intensity of sampling krill trawl catches
(e.g. length-with-age). At present, and in the interests of both statistical rigour and the efficiency ... most purposes a minimum sample size of at least 100 animals/trawl is necessary to obtain statistically ... of determining adequate sample size to obtain representative krill length frequency distributions ... from commercial catches. In addition, the possible effect of two other factors (within-trawl ...
Meeting Document : WG-KRILL-90/27 : Author(s): D.G.M. Miller (South Africa)
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Progress report on the Weddell Sea Research Program Stage II
, 2014. A total of 34 longlines were set: the Option I – 10+20 and the Option II – 4 at the depths ... Abstract: Results of longline survey on Antarctic toothfish in the Weddell Sea (Stage II) are ... presented in the paper. Options I and II of the survey were carried out from February 10 to February 22 ... ranging from 605 to 2031 m. A total number of hooks- 116 100, fishing area – 13565 km 2. Catch value of ...
Meeting Document : WG-FSA-14/03 Rev. 2 : Author(s): A.F. Petrov, I.I. Gordeev, S.V. Pianova and E. F. Uryupova (Russia)
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Theoretical considerations for estimating the density of cohorts and mean recruitment of Patagonian toothfish (Dissostichus eleginoides) based on research trawl survey data
fishery. At the 2003 meeting of WG-FSA a number of inconsistencies were identified in the estimation of ... , recognizing the importance of obtaining a consistent and reliable recruitment series for review at the 2004 ... assessing the long-term yield for toothfish fisheries in CCAMLR uses estimates of density of juvenile ... toothfish derived from research trawl surveys as an estimate of absolute abundance of recruitment to the ...
Meeting Document : WG-FSA-04/92 : Author(s): C.R. Davies, E.M. van Wijk and A.J. Constable (Australia)
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Distribution and diet of juvenile Patagonian toothfish on the South Georgia and Shag Rocks shelves (Southern Ocean)
Abstract: The distribution and diet of juvenile (<750 mm) Patagonian toothfish are described ... from 4 annual trawl surveys (2003-06) around the island of South Georgia in the Atlantic sector of the ... Southern Ocean. Recruitment of toothfish varies inter-annually, and a single large cohort dominated during ... the four years surveyed. Most juveniles were caught on the Shag Rocks shelf to the NW of South Georgia ...
Meeting Document : WG-FSA-07/P4 : Author(s): M.A. Collins, K.A. Ross, M. Belchier, K. Reid. (Mar. Biol., 152: 135–147 (2007)).
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Trends in bird and seal populations as indicators of a system shift in the Southern Ocean
components is poorly understood because of the difficulty of obtaining long-term data sets on marine ... organisms. The Southern Ocean plays a critical role on global climate and there is growing evidence of ... in mid 1980s, being particularly important in the in the sub-Antarctic sector. At the same time with ... a time lag of 2–9 years with temperatures, the population size of most seabirds and seals monitored ...
Meeting Document : WG-EMM-03/53 : Author(s): H. Weimerskirch, P. Inchausti, C. Guinet and C. Barbraud (France)
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Relative selectivity of four sampling methods using traps and trawls for male snow crabs (Chionoecetes opilio)
deployed during the day. and (4) bottom trawl deployed at night. Catches were characterized in terms of ... , were larger than those caught in the trawl; the size of crabs caught in the trawl at night was larger ... Abstract: Catch rate and catch composition of male snow crabs were compared for four sampling ... crab body sizes, shell conditions, and claw allometry. We concluded that: 1) mean and modal size of ...
Meeting Document : WS-CRAB-93/11 : Author(s): J.M. Hoenig and E.G. Dawe (USA)