Résultats de la recherche
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Reconciling theoretical versus empirical target strengths of krill; effects of phase variability on the distorted wave Born approximation
, the authors noted that the differences were not entirely due to noise. In this study, the accuracy of ... elements of a discretized bent cylinder (krill model) causes a dramatic flattening in the side-lobe regions ... 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 ...
Meeting Document : WG-EMM-02/50 : Auteur(s): D.A. Demer and S.G. Conti (USA)
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Population demography of Antarctic fur seals: the costs of reproduction and implications for life-histories
Abstract: 1. This study examined the costs of reproduction in terms of future survival and ... result of pregnancy which accounted for 40–50% of adult female mortality. This effect was greatest in the ... animals having been pregnant in the previous year. 6. Reproduction incurs costs to females, in terms of ... . 2. Population age structures were used, in conjuction with the measured age-specific survival rates ...
Meeting Document : WG-EMM-95/26 : Auteur(s): Reid, K., Croxall, J.P., Lunn, N.J., Boyd, I.L.
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Modelling Movement of Antarctic Krill (MMAK): the importance of retention, dispersal and behaviour for krill distribution – a project update
that influence the distribution of Antarctic krill in CCAMLR Area 48, focussing in particular on the ... investigate the impact of physical and behavioural processes on the distribution of krill in this area, at ... being investigated, which will include examination of the role of tides in determining on-shelf ... Antarctic Wildlife Research Fund, to improve current understanding of the regional and local-scale processes ...
Meeting Document : WG-EMM-18/06 : Auteur(s): S.E. Thorpe, E.F. Young, E.J. Murphy, O.R. Godø and A.H.H. Renner
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Effects of different harvesting strategies on the stock of Antarctic icefish Champsocephalus gunnari around South Georgia
harvesting alternative. In the absence of regular recruit surveys constant fishing at F0.1 is most likely to ... Abstract: The effects of a number of harvesting strategies on the Antarctic icefish ... years after a good recruitment,- pulse fishing at an interval of 3 years with no fishing in between;- a ... shift in partial recruitment values due to changes in net selectivity. For the projections recruitment ...
Meeting Document : SC-CAMLR-VIII/BG/47 : Auteur(s): Delegation of Federal Republic of Germany
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A re-analysis of the Kerguelen Shelf and Skiff Bank stocks of Champsocephalus gunnari
-frequency data for the years 1981 to 1990. Cohort analysis yielded a Stock Biomass of 22 711 tonnes in 1988 ... possible declining trend in the abundance of this stock. Author(s): G. Duhamel (France) and D.J. Agnew ... Abstract: Catches of Champsocephalus gunnari from the Kerguelen Shelf and Skiff Bank stocks were ... re-calculated from those used by the Working Group on Fish Stock Assessment in 1989 using length ...
Meeting Document : WG-FSA-90/17 : Auteur(s): G. Duhamel (France) and D.J. Agnew (Secretariat)
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Some aspects of size composition dynamics of Antarctic toothfish (Dissostichus mawsoni) from the Ross Sea (Statistical Subarea 88.1)
mawsoni) from catches in different statistical areas of the Ross Sea was given. Biological data for two ... both periods of the fishery, in the southern statistical areas (SSRU H, I, K, L), the portion of small ... -sized immature fish had increased though the average size of fish in catches had not changed ... Abstract: The analysis of the data on size composition of Antarctic toothfish (Dissostichus ...
Meeting Document : WG-FSA-12/17 : Auteur(s): A.K. Zaytsev (Ukraine)
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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
assessing the long-term yield for toothfish fisheries in CCAMLR uses estimates of density of juvenile ... fishery. At the 2003 meeting of WG-FSA a number of inconsistencies were identified in the estimation of ... the recruitment series for Subarea 48.3. In light of this, the Scientific Committee agreed that there ... analyses; which age groups should be included in the estimation of recruitment, and the need for a clear ...
Meeting Document : WG-FSA-04/92 : Auteur(s): C.R. Davies, E.M. van Wijk and A.J. Constable (Australia)
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Acoustic visualization of the three-dimensional prey field of foraging chinstrap penguins
Abstract: Predator-prey interactions play an important role in determining the dynamics of ... the surface distribution of penguins and krill distributed in the 30- 40 m depth layer; no spatial ... ecosystems. Recently, concerns have arisen due to the commercial harvesting of Euphausia superba, the ... Antarctic krill, a keystone prey species in the Southern Ocean food web. It has been difficult to evaluate ...
Meeting Document : WG-Joint-94/12 : Auteur(s): J.E. Zamon, C.H. Greene, E. Meir, D.A. Demer, R.P. Hewitt and S. Sexton (USA)
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Population variability of biological parameters of penguins along the Antarctic Peninsula
contribute to the general knowledge of penguin biological variation, to generate a data baseline in the ... parameters and factors affecting penguins biology along the Antarctic Peninsula is presented in order to ... context of environmental changes such as climate change and human activity and to support the proposal of ... the Western Antarctic Peninsula protected marine area. The results show higher levels of immunological ...
Meeting Document : WG-EMM-2019/72 : Auteur(s): A. Barbosa
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Observation of fishing operation and distributional behaviour of krill on a krill trawler off Wilkes Land during the 1985/86 season
judge the towing direction. Size of fished swarms ranged from 100 m to 10 km with different distribution ... operation was described in detail. Fish finder was most useful in detecting swarms while sonar was used to ... in different fishing areas. While catch per towing time reflects within-swarm density catch per day ... was thought to be a good index to measure abundance of concentration. Comparison of such index across ...
Meeting Document : SC-CAMLR-VI/BG/35 : Auteur(s): T. Ichii (Japan)