Résultats de la recherche

1. A post-processing method to remove interference noise from acoustic data collected from Antarctic krill fishing vessels

   data has been recognised as an important way to estimate the distribution and relative abundance of ... the utility of fishing-vessel-based acoustic data for a range of objectives. File:  Wang et al.pdf ... degraded by interference noise due to the lack of synchronisation of the acoustic instruments found on some ... of the vessels. A simple method to remove significant interference noise was introduced based on ... 30 Wang et al. Figure 7: Frequency distribution of mean Sv (a) and variation of MVBS (b) for 20 ... of an attenuated signal may be compensated for by using the strength of the seabed return signal ... by fishing vessels. For example, the Chinese krill fishing vessel Fu Rong Hai was found to have two ... et al., 2014). For krill with length ranging from 30 to 60 mm, the target identification window is ...

   Science Journal Paper : CCAMLR Science, Volume 23 (CCAMLR Science, Volume 23) : 17–30 : Auteur(s): Wang, X., J. Zhang and X. Zhao

2. Acoustic estimates of krill biomass in the Elephant Island area: 1981–1993

   years 1981 to 1993 (with the exception of 1982 and 1986). Estimates for 1981 to 1991 are based on ... / Description:  Acoustic estimates of krill biomass in the vicinity of Elephant Island are presented for the ... previous reports adjusted for the recently proposed definition of krill target strength (Greene et al ... density over the 13-year period were 1 703 x  103 tonnes and 53.2 g/ 2. File:  01hewitt-demer.pdf ... surveys (30 mm and 41 mm). Klindt's biomass estimate for the 1985 survey may be adjusted by a factor ... from the two largest of the four surveys described by Hewitt and Demer (1993). Biomass estimates for ... vicinity of Elephant Island are presented for the years 1981 to 1993 (with the exception of 1982 and 1986 ... ). Estimates for 1981 to 1991 are based on previous reports adjusted for the recently proposed definition of ...

   Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 1–5 : Auteur(s): Hewitt, R.P. and D.A. Demer

3. Status of the FIBEX acoustic data from the West Atlantic

   Herwig. While there is an error factor due to the combination of data collected at 50 kHz (Walther Herwig ... are consistent with the other surveys. The authors can find no explanation for this difference. File ... apply an empirical correction based on the differences found in the field for the MVBS value found at ... as tonnes n mile-' with an integration interval of 9 760 m; however, for the re-analysis carried ... substantial overlap in the two survey areas and an almost complete overlap in their timing, i.e. February ... of the vessels, Itzurni, Dr Eduardo L. Holmberg, Odissey and Walther Herwig. While there is an error ...

   Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 35–48 : Auteur(s): Trathan, P.N. and I. Everson

4. By-catch, growth and feeding of Antarctic juvenile fish taken in krill (Euphausia superba Dana) fisheries in the South Georgia area, in 1992

   an investigation of juvenile Antarctic fish caught during krill fishing by the FV Grigory Kovtun in ... the area around South Georgia from May to July 1992. Two species were predominant in the by-catches ... for all trawls and for shelf trawls, respectively. For N. larseni the corresponding averages were 557 ... . were the most frequent. Only 4 and 5) could provide an explanation for the two species, E. superba ... ). Juveniles were then analysed for taxonomic identification, stomach content, standard length (with an ... t l 070 ind./tonne krill respectively. Although the arithmetic means were similar for the two ... normally distributed, estimations based on the delta distribution theory were used. For a more detailed ...

   Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 129–142 : Auteur(s): Pakhomov, E.A. and S.A. Pankratov

5. Attribtuion of acoustic echoes to squid in the south Atlantic

   order to characterise an acoustic signature that may be used to identify this species of squid ... is an advantage for making a positive identification of echoes. An initial review of the echocharts ... area at a depth of 25 m for 12 hours and caught an estimated 2 300 M. hyadesi (Table 2). No other ... reproduced as Figure 2. Most of the haul (the first seven hours) was through an area notable for the ... 02:lO 25 12:lO 2 0 01:30 100 02:25 130 01:45 80 00:30 20 01:55 150 01:30 60 ...

   Science Journal Paper : CCAMLR Science, Volume 5 (CCAMLR Science, Volume 5) : 259–271 : Auteur(s): Goss, C., P. Rodhouse, J.L. Watkins and A.S. Brierley

6. A quantified Bayesian Maximum Entropy estimate of Antarctic krill abundance across the Scotia Sea and in small-scale management units from the CCAMLR-2000 Survey

   area. Density values for the unsurveyed off-transect portions of the survey area were inferred, and ... thus values for total biomass across the survey area, and within individual small-scale management ... estimated due to the sparseness of data in these regions. The MaxEnt formalism allows an objective choice of ... the parameters of the estimation method, and hence an objective choice of the most probable ... et al. 100 and Sibisi, 1990; Gull and Skilling, 1991; Skilling, 1991; see Sivia, 1996 for an ... which expresses a preference for smoothness (since an equal distribution of krill across all cells has ... particular application of the MaxEnt method. In astrophysics, for example, the data from an instru- ment may ... simply an approximation to a Gaussian point spread func- tion. It is necessary to choose a width for ...

   Science Journal Paper : CCAMLR Science, Volume 13 (CCAMLR Science, Volume 13) : 97–116 : Auteur(s): Heywood, B.G., A.S. Brierley and S.F. Gull

7. Status of the Polish FIBEX acoustic data from the West Atlantic

   variation which has previously been reported for the area and shown to be important. File:  10trathan ... C is (BTOMASS, 1991). an equipment constant (20 dB). MVBS values with time and positional data ... calibration at the time of FIBEX (BIOMASS, 1986). Calibration was undertaken on two separate occasions; the ... m isobath is shown for reference. than -87.5 dB (including those values on transect heads). The 1 ... that based on the old TS estimates. The new overall density estimate for both strata is approximately ...

   Science Journal Paper : CCAMLR Science, Volume 6 (CCAMLR Science, Volume 6) : 125–132 : Auteur(s): Trathan, P.N., J. Kalinowski and I. Everson

8. A review of the trophic role of mesopelagic fish of the family Myctophidae in the Southern Ocean ecosystem

   on the dietary requirements of myctophids are vital for assessing the role of these fishes in the ... for myctophids. Mean yearly production of zooplankton in this area is 1.2 billion tonnes (Voronina ... throughout the entire year, and by high plankton productivity to depths of 500 m or greater (Voronina, 1971 ... intake for this species in the Scotia Sea and the PFZ is close to the value for the overall rate of ...

   Science Journal Paper : CCAMLR Science, Volume 2 (CCAMLR Science, Volume 2) : 71–77 : Auteur(s): Kozlov, A.N

9. Catch per unit effort and proportional recruitment indices from Japanese krill fishery data in Subarea 48.1

   general decrease in krill density in the study area were considered as possible reasons for this. On the ... period. The use of different fishing strategies in response to a demand for higher product quality and a ... 48.1 (Antarctic Peninsula region) from 1980 to 1996 were calculated based on logbook data from Japanese ... et al. (1997) for two year classes: the 1991/92 year class, which showed apparently higher values ... than those obtained by Siegel, and the 1987/88 year class, for which proportional recruitment was ... results, discrepancies in proportional recruitment from two year classes were observed between our study ... Livingston Island area. Two reasons for this decreasing trend are suggested. One of the possible reasons is ...

   Science Journal Paper : CCAMLR Science, Volume 4 (CCAMLR Science, Volume 4) : 47–63 : Auteur(s): Kawaguchi, S., T. Ichii and M. Naganobu

10. Biology and harvesting of Dissostichus eleginoides around the Kerguelen Islands (Division 58.5.1)

    from year to year and highly dependent on the harvestable resources of Champsocephalus gunnari. Vital ... biological information on population dynamics, as well as demographic structures and trends observed in an ... (Division 58.5.1) Abstract / Description:  Dissostichus eleginoides is becoming an increasingly important ... abundance index, is provided. Prospects for exploitation are discussed with respect to the development of ... well as demographic structures and trends observed in an abundance index, is provided. Prospects for ... ) recorded for the Kerguelen Islands fishery (Division 58.5.1) since the establishment of an EEZ. The ... establishment of an EEZ. Total and directed fishing effort (Western area) for Dissostichus eleginoides (in ... indicated with an arrow. Li~t of Figures Length frequency distribution of Dissostichus eleginoides for ...

    Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/8 (Selected Scientific Papers, SC-CAMLR-SSP/8) : 85–106 : Auteur(s): Duhamel, G.

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