Résultats de la recherche
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Acoustic data analysis and models of krill spatial distribution
/ Description: Acoustic data obtained on 4-5 January 1987 aboard the R/V Professor Siedlecki were used in three ... (spatial autocorrelation of krill biomass) and the frequency distribution of krill biomass estimate. The ... wavenumber spectrum resembles a white noise at scales of 2-20 km, although at scales smaller than 1 km the ... spectrum appears to lose its power significantly. The semivariance of biomass does not vary significantly ... obtained on 4-5 January 1987 aboard the RN ProfesSor Siedlecki were used in three descriptors of krill ... autocorrelation of krill biomass) and the frequency distribution of krill biomass estimate. The wavenumber ... spectrum resembles a white noise at scales of 2-20 km, although at scales smaller than 1 .km the spectrum ... appears to lose its power significantly. The semivariance of biomass does not vary significantly over ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I (Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I) : 311–329 : Auteur(s): Morin, A., A. Okubo and K. Kawasaki
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Growth and natural mortality of Patagonian rockcod (Patagonotothen guntheri shagensis) from Shag Rocks shelf
shagensis) from Shag Rocks shelf Abstract / Description: The parameters of Bertalanffy’s growth equation ... -weight data of research and fishery survey cruises in the Shag Rocks area from 1978 to 1986. The natural ... mortality rate was assessed by six different methods and was within a range of 0.63 to 1.06. The mean value ... of natural mortality M=0.8 was used in calculations and the optimal age and length for harvesting ... ROCKCOD (PATAGONOTOTHEN GUNTHERI SHAGENS/S) FROM SHAG ROCKS SHELF V.1. Shlibanov Abstract The ... calculated by using age and length-weight data of research and fishery survey cruises in the Shag Rocks ... area from 1978 to 1986. The natural mortality rate was assessed by six different methods and was ... within a range of 0.63 to 1.06. The mean value of natural mortality M=0.8 was used in calculations and ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/6 (Selected Scientific Papers, SC-CAMLR-SSP/6) : 111–121 : Auteur(s): Shlibanov, V.I.
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Potential interactions between wandering albatrosses and longline fisheries for Patagonian toothfish at South Georgia
Patagonian toothfish at South Georgia Abstract / Description: We examine the extent of overlap between South ... May and October (main chick-rearing period). However during the chick-brooding period, from March ... through mid-May, adult birds of both sexes spend most of their time at sea over the South Georgia ... continental shelf in areas very similar to where the longline fishery operates and are therefore at serious ... transit to or from their breeding site at Bird Island. Therefore, during the post-brood chick-rearing ... and from the breeding site) was associated with the Patagonian Shelf, particularly slope areas over ... Cross, Madingley Road Cambridge CB3 OET United Kingdom Abstract We examine the extent of overlap ... ) and between late May and October (main chick-rearing period). However during the chick-brooding ...
Science Journal Paper : CCAMLR Science, Volume 3 (CCAMLR Science, Volume 3) : 101–110 : Auteur(s): Croxall, J.P. and P.A. Prince
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Estimating confidence intervals for fish stock abundance estimates from trawl surveys
estimates of abundance obtained from trawl surveys conducted by means of the swept area method, using ... likelihood ratios from Aitchison's delta distribution. Simulation tests of the method show that unbiased ... estimates of density and biomass can be obtained and that the estimated confidence intervals have close to ... the nominal coverage probability. Performance deteriorates in cases where few of the hauls contain ... by means of the swept area method, using likelihood ratios from Aitchison's delta distribution ... . Simulation tests of the method show that unbiased estimates of density and biomass can be obtained and that ... the estimated confidence intervals have close to the nominal coverage probability. Performance ... deteriorates in cases where few of the hauls contain fish and the coefficient of variation (CV) is high. The ...
Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 203–207 : Auteur(s): de la Mare, W.K
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Selectivity of commercial and research trawls in relation to krill
/ Description: This paper describes the results of fishing a single krill aggregation with a commercial trawl ... RT 72/308 and an Isaacs-Kidd midwater research trawl (IKMT). The commercial trawl catches contained ... more large krill (35-58 mm) than catches of the research trawl (30-54 mm). The maximum difference in ... krill length composition was observed between catches made by the research trawl, while in commercial ... m along the belly line. The trawl bag has no rope or large-mesh sections. Therefore, the effective ... This paper describes the results of fishing a single krill aggregation with a commercial trawl RT 72 ... /308 and an Isaacs-Kidd midwater research trawl (IKMT). The commercial trawl catches contained more ... large krill (35-58 mm) than catches of the research trawl (30-54 mm). The maximum difference in mean ...
Science Journal Paper : CCAMLR Science, Volume 4 (CCAMLR Science, Volume 4) : 161–169 : Auteur(s): Kasatkina, S.M
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Differentiation of independent populations of Antarctic krill
circulation. On the basis of the review, it is suggested that there is probably one composite population of E ... . superba in the Southern Ocean subdivided into several independent sub-populations. The number of these sub ... -populations is expected to correspond with the number of quasi-stationary cyclonic water circulations. At ... development due to homogeneity of physical environmental parameters. To the best of our knowledge, no ... no papers dealing with the subject of variability of krill inhabiting different areas of the ... and morphophysiological variability of krill and Antarctic water circulation. On the basis of the ... review, it is suggested that there is probably one composite population of E. superba in the Southern ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 275-281 : Auteur(s): USSR
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Estimating krill recruitment and its variability
likelihood method is developed for the decomposition of krill density-at-length data into the proportion of ... surveys in the South Atlantic and the Indian Ocean sectors of the Southern Ocean give a mean recruitment ... rate for 1+ krill (the ratio of the number of krill aged one year to the number of krill aged one year ... and above) of 0.339 with a standard deviation (SD) of 0.100. The corresponding result for recruitment ... . The problem with krill is that there is no reliable method of direct age determination. One indirect ... frequency data have no unusual statistical properties. The usual method assumes that length frequency data ... 7050 Tasmania, Australia Abstract A maximum likelihood method is developed for the decomposition ... of krill density-at-length data into the proportion of recruits in a population sampled by a net ...
Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 55–69 : Auteur(s): de la Mare, W.K
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Status of krill target strength
Paper Title: Status of krill target strength Abstract / Description: Empirical estimates for the ... measurements, namely thresholding. Theoretical estimates for the target strength are derived from the deformed ... is an empirical basis. The theoretical estimates show a non-monotonic dependence of target strength ... high signal-to-noise-ratio conditions, are consistent with the general pattern. Several specific ... date, there is no theory that adequately describes the scattering of sound by zooplankton. The animals ... ) involved detennination of krill density by trawling. No comments are made by the author on this sampling ... , so no assessment can be made here as to the accuracy of this density detennination. In two studies ... are very few data concerning the distribution of orientation and no specific information on shape ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/9 (Selected Scientific Papers, SC-CAMLR-SSP/9) : 101–126 : Auteur(s): Foote, K.G., D. Chu and T.K. Stanton
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Discrimination of Macrourus whitsoni and M. caml (Gadiformes, Macrouridae) using otolith morphometrics
otolith morphometrics Abstract / Description: That the predominant by-catch of grenadier by the toothfish ... fishery in the Ross Sea region is comprised of two species, rather than being solely Macrourus whitsoni ... , was recognised in 2010 with the identification of a new species, M. caml. Grenadier are the main by ... -catch in the toothfish fishery and modelling suggests that they may be subject to predation release as ... inadequate information on the spatial distributions of the two species of grenadiers, no information on ... changes to the by-catch rates of the two spe- cies and no capacity to investigate changes to the age ... given in Table 3. While there was no significant difference between the discrimination function for ... folds. The coefficients are fitted to all data (n = 527). Model using no biological data ...
Science Journal Paper : CCAMLR Science, Volume 22 (CCAMLR Science, Volume 22) : 15–28 : Auteur(s): Pinkerton, M.H., C. Ó Maolagáin, J. Forman and P. Marriott
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Preliminary results of a bottom trawl survey around Elephant Island in October and December 1987
Chaenocephalus aceratus, Notothenia gibberifrons and N. neglecta at least since February 1985. In N. rossii the ... proportion of larger (= older) fish in the catches increased. Composition of the catches of C. gunnari ... other shelf areas of the Peninsula region. File: 09-Kock.pdf ... of catches. Analysis of length frequency distributions indicate little or no changes in the stock ... and N. neg/ecta at least since February 1985. In N. rossii the proportion of larger (= older) fish in ... the catches increased. Composition of the catches of C. gunnari differed significantly from that in ... previous seasons which argues for an exchange with C. gunnari from other shelf areas of the Peninsula ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/5 – Part II (Selected Scientific Papers, SC-CAMLR-SSP/5 – Part II) : 185-200 : Auteur(s): Kock, K.-H.