Résultats de la recherche
-
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 ... normal distributions are used to show that there is a difference between the real mean parameter for a ... . Combining all data for both sexes is considered as a procedure for avoiding the necessity of sex ... knowledge about the sex ratio between years makes combining the data a very doubtful procedure and use of a ...
Meeting Document : WG-CEMP-92/11 : Auteur(s): D.J. Agnew (Secretariat)
-
Monitoring a marine ecosystem using responses of upper trophic level predators
population size, breeding performance, offspring growth rate, foraging behaviour and diet. A method was ... developed for reducing these multivariate time-series to a single vector, called a combined standardised ... index (CSI). 2. Sensitivity analyses showed that missing values had a large effect upon the accuracy of ... significantly low values. There was a significant non-linear functional response (similar to the Holling Type II ...
Meeting Document : WG-EMM-01/25 : Auteur(s): I.L. Boyd and A.W.A. Murray (United Kingdom)
-
A RE-APPRAISAL OF THE TOTAL BIOMASS AND ANNUAL PRODUCTION OF ANTARCTIC KRILL
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 ... throughput for a species of this size. The similarity between the three production estimates reflects a broad ... agreement between the three growth models used, plus the fact that, for a given population size, production ...
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)
-
A simulation study of krill fishing by an individual Japanese trawler (SC-CAMLR-VI/BG/37)
Abstract: A model is set up for the operation (which includes both searching and fishing) of a ... Japanese krill trawler over a half-month period. It is based on an underlying krill distribution model ... the operation is compared with (and partially tuned to) statistics for a sample of data from the ... commercial fishery. A major inconsistency is found: haul times are a factor of 4-5 times greater in reality ...
Meeting Document : WS-KCPUE-89/04 : Auteur(s): D.S. Butterworth (South Africa)
-
A simulation study of krill fishing by an individual JAPANESE trawler
Abstract: A model is set up for the operation (which includes both searching and fishing) of a ... Japanese krill trawler over a half-month period. It is based on an underlying krill distribution model ... the operation is compared with (and partially tuned to) statistics for a sample of data from the ... commercial fishery. A major inconsistency is found: haul times are a factor of 4-5 times greater in reality ...
Meeting Document : SC-CAMLR-VII/BG/37 : Auteur(s): D.S. Butterworth (Invited Expert)
-
Influence of the quality and quantity of data from a multi-year tagging program on bias and precision of biomass estimates from an integrated stock assessment – update
estimates from an integrated tag-based assessment are influenced by various aspects of a multi-year tagging ... emerged within this overall trend. The results show that in the early stages of the tagging program, a ... high tag size-overlap is imperative to maximise the likelihood of a robust assessment. Tagging fish ... with a low tag size-overlap, even with large numbers, is likely to result in overestimates of biomass ...
Meeting Document : WG-FSA-12/18 : Auteur(s): P.E. Ziegler (Australia)
-
The krill maturity cycle: a conceptual description of the seasonal cycle in Antarctic krill
Abstract: A long term study on the maturity cycle of Antarctic krill was conducted in a research ... aquarium. Antarctic krill were either kept individually or in a batch for 8 months under different ... . Based on these results, and information available from previous studies, we suggest a conceptual model ... describing seasonal cycle of krill physiology which provides a framework for future studies and highlight the ...
Meeting Document : WG-EMM-06/23 : Auteur(s): S. Kawaguchi, T. Yoshida, L. Finley, P. Cramp and S. Nicol (Australia)
-
The case for a Ross Sea marine reserve
Abstract: The Ross Sea continental shelf and slope have a number of characteristics that make it ... an ideal candidate for a marine reserve, as evidenced by its inclusion in the list of 11 priority ... .¹ With exceptional biodiversity and evolutionary significance, as well as its potential as a climate ... a no-take MPA encompassing the shelf and slope. Scientific information presented to CCAMLR and the ...
Meeting Document : CCAMLR-XXX/BG/23 : Auteur(s): Submitted by ASOC
-
Use of a population model to assess the impact of longline fishing on wandering albatross populations
Abstract: An age-structured model of a wandering albatross Diomedea exulans population is ... Possession Island Crozets, during 1968 to 1986. The simulation results portray a population decreasing at a ... albatross mortality is presumed to have increased as a result of deaths caused by longline fishing vessels ... eleginoides in Antarctica. Assuming longline fishing operations affect juveniles more than adults, there is a ...
Meeting Document : WG-IMALF-94/08 : Auteur(s): Coleen L. Moloney, John Cooper, Peter G. Ryan and W. Roy Siegfried (South Africa)
-
Influence of data quality and quantity from a multiyear tagging program on an integrated fish stock assessment
Abstract: Using a modeling framework for toothfish (Dissostichus spp.) population dynamics ... an integrated tag-based assessment are influenced by various aspects of a multiyear tagging program ... better-quality tagging data. The results showed that even when tag releases were distributed over a ... relatively large number of size classes, low recapture numbers collected in short tagging programs with a 100 ...
Meeting Document : WG-FSA-13/P03 : Auteur(s): P. Ziegler