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Some comments on the procedure for testing estimators of krill abundance which utilise survey data
a este respecto. 1. IN1RODUCTION A "straightforward" approach to abundance estimation from surveys ... from each transect is then treated as an independent estimate of the density in the area, and the mean ... still indicate statistically significant lack of fit in both cases, means that model misspecification ... parameter values are meaningful, given other data available from the survey. Attention is confined to model ... provide an encouraging improvement in fits to the distribution of inter-swarm distances observed on the ... Paper Title: Some comments on the procedure for testing estimators of krill abundance which ... computer generation of krill distribution patterns, which are compatible with existing information on the ... utilise survey data Abstract / Description: Since krill distributional data do show evidence of spatial ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/8 (Selected Scientific Papers, SC-CAMLR-SSP/8) : 191–205 : Author(s): Butterworth, D.S., D.L. Borchers and D.G.M. Miller
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Performance and geometry of the FP-120 trawl used during UK fish stock assessment surveys around South Georgia, Subarea 48.3
are automatically activated in sea water, and transmit their information to the vessel by means ... to be outliers and were omitted from the calculation of mean values of trawl geometry for each tow. Spurious ... (d) was performed: where W is the mean vessel speed through the water (knots). h = 29.36 + 0.01d ... opening (and, thus, swept area) of a bottom trawl are discussed. In situ measurements of the FP-120 trawl ... compared to values obtained from a previous equation. The resulting difference in biomass estimates is of ... Paper Title: Performance and geometry of the FP-120 trawl used during UK fish stock assessment ... presented. Regression equations for the estimation of horizontal opening from other, more easily measured ...
Science Journal Paper : CCAMLR Science, Volume 2 (CCAMLR Science, Volume 2) : 51–69 : Author(s): Pilling, G. and G. Parkes
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A simple approach for calculating the potential yield of krill from biomass survey results
captura. Se considera que los efectos estacionales tienen menos importancia. 1. IN1RODUCTION One ... of each year (Ny,o) is given by: (A.2) where R is the mean recruitment, and N(O; 0'2) is a normal ... distribution with zero mean and variance 0'2. Mass-at-age is obtained from the growth curve form used ... Paper Title: A simple approach for calculating the potential yield of krill from biomass survey ... results Abstract / Description: Estimates are calculated for the parameter λ in the yield equation Y = λ ... MB 0 for a krill fishery in which both the fishery and krill growth are seasonal. The criterion used ... for the calculations is that the probability that the krill spawning biomass drops below 20% of its ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/8 (Selected Scientific Papers, SC-CAMLR-SSP/8) : 207–217 : Author(s): Butterworth, D.S., A.E. Punt and M. Basson
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Management and uncertainty: the example of South Georgia
and revise conservation measures on the basis of the best scientific evidence available ••• ", while ... and proposed conservation measures." Though not very explicit on what is included the comparison ... the more conservative policy to exceed those from a policy of allowing non-directed fishing ... to consider ways in which CCAMLR can improve its ability to take decisions in the face of uncertainty ... uncertainty. The question is addressed specifically in terms of the fishery of Notothenia rossii around South ... Paper Title: Management and uncertainty: the example of South Georgia Abstract / Description ... : Decisions on fishery management are often made with some degree of uncertainty in scientific advice. Such ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 341-353 : Author(s): Gulland, J.A.
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Physical oceanographic setting of the Siedlecki January 1987, South Shetland Island data set
the extent of its variability, at a variety of scales (Gordon, 1988). The mean climatic condition exists ... from the open ocean, its only means of "communication" being vertical exchange processes (Gordon ... data set Abstract / Description: In the vicinity of the northern tip of the Antarctic Peninsula, the ... Paper Title: Physical oceanographic setting of the Siedlecki January 1987, South Shetland Island ... water from the Pacific Ocean. A series of fronts form which are collectively referred to as the Weddell ... continental margin water, advected into the region along the extreme western edge of the Weddell Gyre. It is ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/5 – Part II (Selected Scientific Papers, SC-CAMLR-SSP/5 – Part II) : 161-184 : Author(s): Gordon, A.L.
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The use of predator-derived krill length-frequency distributions to calculate krill target strength
mean krill length frequency because this might introduce additional errors into the estimate of krill ... et al. (1988). After measuring krill in a sample to the nearest millimetre, the mean TS ... calculated from acoustic data. Changes in the lengthfrequency distribution of krill over a period of a few ... Paper Title: The use of predator-derived krill length-frequency distributions to calculate krill ... krill sampled from the diet of predators to provide a length-frequency distribution of krill at times ... to gain important estimates of krill biomass at times of the season hitherto unavailable from ...
Science Journal Paper : CCAMLR Science, Volume 8 (CCAMLR Science, Volume 8) : 155–163 : Author(s): Reid, K. and A.S. Brierley
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Results of the CCAMLR Antarctic fish otoliths/scales/bones exchange system
aHaJIff3a, BbInOJIHeHHOro 60JIee H MeHee on bITHbIMff ffCCJIe.llOBa TeJI5.lMR Resumen Un sistema de ... ' as being annual by means of counting daily increments. Length frequency distributions have been used ... exchange. The 'best' age is not necessarily the true age nor is it the majority 'reading' nor the mean ... . antarcticum. Agreement between otoliths and scales of individual N. gibberifrons was in the order of 50 ... Paper Title: Results of the CCAMLR Antarctic fish otoliths/scales/bones exchange system Abstract ... / Description: An exchange system was established among Members of CCAMLR to compare age determinations for the ... same species among different laboratories. Four species were included in the exchange: Notothenia ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/6 (Selected Scientific Papers, SC-CAMLR-SSP/6) : 197–226 : Author(s): Kock, K.-H.
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Estimating the impact of depredation by killer whales and sperm whales on longline fishing for toothfish (Dissostichus eleginoides) around South Georgia
the proportion of sets where they are present is between 3 and 5%. Over the seven years of study, mean pod size ... Georgia Figure 7: Mean (+95% CI) of killer whale and sperm whale pod size observed around fishing ... Paper Title: Estimating the impact of depredation by killer whales and sperm whales on longline ... data collected on longliners between 2003 and 2009 were analysed to look at the levels of depredation ... 3.8% and sperm whales on 17.7% of lines. Killer whales appear in pod sizes normally of 4 to 10 animals ... , and often appear to actively seek out fishing vessels and ‘strip’ the line of a large number of ...
Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 163–178 : Author(s): Moir Clark, J. and D.J. Agnew
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Movement, growth and available abundance to the fishery of Dissostichus eleginoides Smitt, 1898 at Heard Island, derived from tagging experiments
it can be seen as a conservative estimate. Sensitivity to the application of this rate was considered ... . In addition, the greater catches from ground B as compared to other areas mean that the reduction ... Patagonian toothfish (Dissostichus eleginoides) in different sectors of the Southern Ocean are considered to ... these data. The bulk of the data show that fish disperse only a very short distance, up to 15 n miles in ... most cases, from their point of release. This may be explained in part because of the concentration of ... resident during their phase in the depth range of the fishing grounds, but they move on once they approach ...
Science Journal Paper : CCAMLR Science, Volume 9 (CCAMLR Science, Volume 9) : 33–48 : Author(s): Williams, R., G.N. Tuck, A.J. Constable and T. Lamb
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Factors that may influence the accuracy of abundance estimates from CCAMLR tag-recapture programs for Dissostichus spp. and best practice for addressing bias
Factors that may InFluence the accuracy oF abundance estImates From ccamlr tag-recapture programs ... representative sampling has been mandated in Conservation Measure (CM) 41-01, Annex C, since 2010/11, so ... –66. CCAMLR. 2012. Schedule of Conservation Meas- ures in Force 2012/13. CCAMLR, Hobart, Aus- tralia ... Paper Title: Factors that may influence the accuracy of abundance estimates from CCAMLR tag ... Lincoln-Petersen equation, the simplest form of an abundance estimator using tag-recapture data, was used ... programs. The methods that have been used in CCAMLR tag-recapture programs to mitigate such biases, or to ... -recapture data. Due to the complexity of toothfish movements throughout their life cycle, as well as the ...
Science Journal Paper : CCAMLR Science, Volume 20 (CCAMLR Science, Volume 20) : 63–72 : Author(s): Welsford, D.C. and P.E. Ziegler