Search results
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Status of krill target strength
on aggregations of live euphausiids and should not be affected by a frequent cause of bias in single-animal ... there is an empirical basis. The theoretical estimates show a non-monotonic dependence of target strength on both animal ... size and transmit frequency, notwithstanding admitted shortcomings. Some recent single-animal ... of bias in single-animal measurements, namely thresholding. Theoretical estimates for the target strength ... at 30 and 20 kHz. Measurements at 30 kHz were performed near Bouvet Island in December 1979 on krill ... of this ! 108 article, a reasonable fixed value of radius of curvature for the animals is used. In order ... boundary of the animal) change slowly along its lengthwise axis. However, one must be cautious when ... of target strength in the article involve aggregations of animals, it is useful to compare the results ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/9 (Selected Scientific Papers, SC-CAMLR-SSP/9) : 101–126 : Author(s): Foote, K.G., D. Chu and T.K. Stanton
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Comparison of two methods to assess fish losses due to depredation by killer whales and sperm whales on demersal longlines
aimed at providing two indirect methods of assessment of depredated biomass over an 11-year period (2003 ... Paper Title: Comparison of two methods to assess fish losses due to depredation by killer whales ... and 739 ± 87 tonnes of Patagonian toothfish respectively were estimated to be depredated by the two ... species. When the two species co-occurred around vessels, 1 679 ± 74 tonnes were depredated. The second ... Science, Vol. 22 (2015): 1–14 1 Comparison of two methods to assess fish losses due to depredation ... (southern Indian Ocean). This study aimed at providing two indirect methods of assessment of depredated ... biomass over an 11-year period (2003 to 2013), accounting for spatial variations of depredation levels ... estimated to be depredated by the two species. When the two species co-occurred around vessels, 1 679 ± 74 ...
Science Journal Paper : CCAMLR Science, Volume 22 (CCAMLR Science, Volume 22) : 1–14 : Author(s): Gasco, N., P. Tixier, G. Duhamel and C. Guinet
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Towards an initial operational management procedure for the krill fishery in Subareas 48.1, 48.2 and 48.3
of krill over a 20-year harvesting period from falling below 60% of its average unexploited level; subject ... that TAC reductions may prove necessary during the 20-year period considered. Simulation tests, including ... that TAC reductions may prove necessary during the 20-year period considered. Simulation tests, including ... for the simulation testing of procedures, and an operational definition of CCAMLR Article II to provide criteria ... to these objectives. Since the analysis is stochastic, the statistics change from one 20-year simulation to the next ... of krill over a 20-year harvesting period from falling below 60% of its average unexploited level; subject ... that T AC reductions may prove necessary during the 20-year period considered. Simulation tests, including ... faible, pour une periode d'exploitation de 20 ans, de tomber au dessous de 60% de son niveau moyen non ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 189–219 : Author(s): Butterworth, D.S.
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A first attempt at an assessment of the Patagonian toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands EEZ
is substituted. (ii) Higher 2000 + 2001 catches and CPUEs Total catches and CPUEs for these two years (Tables ... in Table 5, together with those for projections to 2010 and to 2020 under a future constant annual catch ... (large) allowance for whale predation over the last two years. Overall, however, the broad results ... to this conclusion. Figure 4 plots the nominal CPUE by month over this two-year period, and confi rms a systematic ... Paper Title: A first attempt at an assessment of the Patagonian toothfish (Dissostichus ... eleginoides) resource in the Prince Edward Islands EEZ Abstract / Description: The history of the fishery for ... maximum of about 400 tonnes. Implications for surveillance are discussed. File: 02brandao-etal.pdf ...
Science Journal Paper : CCAMLR Science, Volume 9 (CCAMLR Science, Volume 9) : 11–32 : Author(s): Brandão, A., D.S. Butterworth, B.P. Watkins and D.G.M. Miller
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Target strengths of Antarctic krill (Euphausia superba)
on roughly one out of two days, and hurricane force about once a fortnight. Depending on the wind direction ... attached to a gantry positioned over one of two identical 4 x 4 m square moon-pools on the raft ... and lowering by a winch attached to a gantry positioned over one of two identical 4 x 4 m square moon-pools ... case, Event number 20, the number increased by two specimens, believed entrapped by the cage during ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I (Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I) : 265–279 : Author(s): Everson, I., D.G. Bone, J.L. Watkins and K.G. Foote
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Archival and satellite-linked data recorders
behaviour. The records can be recovered in one of two ways: the data recorder must either be recovered ... ’'s diving behaviour. The records can be recovered in one of two ways: the data recorder must ... provides an overview of currently-available data recorders for use in research on marine animals ... . These recorders are deployed on freely swimming animals and gather data on aspects of an animal’'s diving ... animals and gather data on aspects of an animal's diving behaviour. The records can be recovered in one ... la conduite de plongee d'un animal. Les enregistrements peuvent etre recuperes de deux fa~ons ... into two sections : Archival Recorders, which are attached to the animal of interest and subsequently ... data recorders for use in research on marine animals. These recorders are deployed on freely swimming ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/4 (Selected Scientific Papers, SC-CAMLR-SSP/4) : 475-493 : Author(s): Hill, R.D.
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Estimation of natural mortality using catch-at-age and aged mark-recapture data: a multi-cohort simulation study comparing estimation for a model based on the Baranov equations versus a new mortality equation.
, M, using multiple cohorts and multiple years of catch-at-age and aged mark-recapture data was tested using ... applied. Two alternative estimation models were developed both using a Poisson likelihood for annual ... obtained by integrating an ordinary differential equation (ODE) for within-year population dynamics ... ; constant catch ODE (CCODE) model uses a new total mortality ODE with constant within-year catch per unit ... but the latter q fraction of the year, then this two-period equation can be defined ... , this gave year classes or cohorts (c) of 1 to 46 corresponding to calendar years of 1975 to 2020 for which ... –7.30 CCODE 0.10 LN 0.0993 0.1485 –27.64, 20.58 –0.73 14.87 15.76 BODE 0.13 LNf 0.1266 0.0709 –12.06 ... multiple cohorts and multiple years of catch-at-age and aged mark-recapture data was tested using ...
Science Journal Paper : CCAMLR Science, Volume 18 (CCAMLR Science, Volume 18) : 1–27 : Author(s): Candy, S.G.
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Estimating optimal observer coverage in the Antarctic krill fishery
have been placed on approximately 50% of vessels fishing in any one season, and have been present ... on board for about 30% of that season. They have achieved a rate of krill sampling equivalent to 18 ... , 20% of total season hauls sampled for krill and an equivalent or higher sampling proportion ... suggest that such strategies should be pursued for at least four years before the Scientific Committee ... to test, with this dataset, whether one year of full observer coverage would have been equivalently ... in the Antarctic krill fishery • a target coverage rate of >50% of vessels each year; • a target of >20 ... in g (% ) A ca m ar 20 02 30 7 A cr ux 20 02 35 4 C hi yo ... 46 3 22 4 13 7 61 56 30 41 12 Fe ol en t 20 05 43 1 43 6 32 6 75 ...
Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 139–154 : Author(s): Agnew, D.J., P. Grove, T. Peatman, R. Burn and C.T.T. Edwards
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On the power to detect changes using the standard methods for monitoring parameters of predatory species
changes of 10%, 20% and 30% of the mean value (males, 12.4 days; females, 10.0 days) for the 5 years ... in the individual proportions of pairs raising zero, one or two chicks might be detectable using sample sizes much ... the power to distinguish between the mean values of parameters obtained in two or more years. We may also ... on two years or five years of monitoring (though for detecting a trend, the number of years will be very ... Paper Title: On the power to detect changes using the standard methods for monitoring parameters ... of predatory species Abstract / Description: The CCAMLR guidelines (CCAMLR, 1989) for analyzing the ... considered here are insufficient for conducting power analyses (penguin arrival weight A1.1, trend in penguin ... population size A3.1, penguin demography A4.1, penguin fledging weight A7.1). Alternative forms for analyses ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/6 (Selected Scientific Papers, SC-CAMLR-SSP/6) : 377–397 : Author(s): Boveng, P. and J.L. Bengtson
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Antarctic krill and ecosystem management – from Seattle to Siena
documenting developments during CCAMLR’s first 20 years of existence. File: 12miller.pdf ... ), with the three papers documenting developments during CCAMLR’s first 20 years of existence. ... to be consistent with the objectives of the CAMLR Convention, particularly its Article II. Emphasis is given ... to be consistent with the objectives of the CAMLR Convention, particularly its Article II. Emphasis is given ... ), with the three papers documenting developments during CCAMLR’s fi rst 20 years of existence. Résumé Il s’agit ... a 20-year period (where Y = yield and B0 = unexploited biomass). Because the model is run many times ... a 20-year period of harvesting, should be equal to 10%’. This approach required an estimate of pre ... with the objectives of the CAMLR Convention, particularly its Article II. Emphasis is given to the initiation ...
Science Journal Paper : CCAMLR Science, Volume 9 (CCAMLR Science, Volume 9) : 175–212 : Author(s): Miller, D.G.M