Résultats de la recherche

1. Maximum entropy reconstructions of krill distribution and estimates of krill density from acoustic surveys at South Georgia, 1996–2000

   uses an iterative Bayesian approach to infer the most probable krill density for each of the 32 000 0.5 ... Entropy (MaxEnt) reconstructions of krill distribution and estimates of mean krill density within two ... krill densities for each survey, for which the confidence limits are often narrower than those ... survey area, and provides an estimate of the standard deviation about the mean for each cell. The ... ( 19 97 ), JR 28 ( 19 98 ), JR 38 ( 19 99 ) an d A T L D ( 20 00 ). A xe s ar e ... not possible to satisfy all the conditions for a MaxEnt solution. Cruise Year Box Jolly and Hampton ... (MaxEnt) have been used successfully for many years in numerous branches of physical science to ...

   Science Journal Paper : CCAMLR Science, Volume 10 (CCAMLR Science, Volume 10) : 91–100 : Auteur(s): Wafy, M.H., A.S. Brierley, S.F. Gull and J.L. Watkins

2. Detection and quantitative estimation of krill concentrations by hydroacoustic instruments

   instruments was established on board the research vessel Odissey during the international expedition under the ... transmitter frequency. Thus, echo sounders operating at comparatively low frequencies (20-30 kHz) are much ... increase in frequency from 35 kHz to 250 kHz results in an almost two fold increase of 0. At frequencies ... towed antennae is their ease of calibration in the sea - an especially important feature for echo ... desirable that the range of detection for an individual krill should be extended to the limit possible ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 123-139 : Auteur(s): Yudanov, K.I.

3. Age determination of Champsocephalus gunnari Lönnberg, 1905 (Channichthyidae) taken in the South Georgia area in 1990

   USSR conducted two research cruises using the vessels RV Hill Cove and RV Akademik Knipovich to study ... -26 and 30-34 cm. Only vertebra samples (n =140) were used in age determination. Age groups from 1+ to ... 9+ were present in catches. Two peaks in size composition correspond with fish of the 1987 and 1985 ... /86 year classes. The first small peak corresponds with the strong 1988 year class. File:  17 ... . Yearly growth marks in vertebrae preparations for the age groups observed usually appear as two dark ... ., 20 (2): 39-47. KOCHKIN, P.N. 1986. A rapid method for estimating mean length of Champsocephalus ... assessments and, consequently, setting an optimum catch quota depends on the accuracy of age determination ... conducted two research cruises on the vessels RV Hill Cove and RV Akademik Knipovich to study the status of ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 285–293 : Auteur(s): Kochkin, P.N.

4. Foraging behaviour and reproductive success in chinstrap penguins: the effects of transmitter attachment

   method with which to monitor foraging trip duration in penguins by the CCAMLR (Commission for the ... , South Shetland Islands. In total, one member of each pair at 20 nests and both members of each pair at ... of this study demonstrate that, for the size of transmitter used (1.4 cm 2 front section area); there ... on: (i) the effects of radio transmitter attachment on nest attendance, foraging trip duration, nest ... 666 nests on Seal Island, South Shetland Islands. In total, one member of each pair at 20 nests and ... 20 000 pairs of chins trap penguins nest on Seal Island, South Shetland Islands, Antarctica (600 ... instrumented failed before the first nest check on 30 December (the instrumented birds could not be located ... visually, although one was regularly detected on the radio-telemetry data logger). A test for whether the ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/8 (Selected Scientific Papers, SC-CAMLR-SSP/8) : 291–303 : Auteur(s): Croll, D.A., J.L. Bengtson, P.L. Boveng, M.E. Goebel and J.K. Jansen

5. Size at sexual maturity of Patagonian toothfish (Dissostichus eleginoides)

   (Dissostichus eleginoides) caught in the commercial fishery within Subarea 48.3. The results for 1996 indicate ... that L m50 occurs at 78.5 cm total length for male and 98.2 cm for female fish. In 1997 the results for ... male fish were essentially the same. For female fish there is evidence that in 1997 a significant ... allowing for this bias indicates that L m50 for female fish in 1997 was no different to that for 1996. The ... errors) for 'spawners' based on an upper asymptote of l-propn. An estimate of population L,,,, (with ... leading to an enlarged ovary of about 20% of the fish total mass. Spawning occurs in the period July to ... fit logistic models with an additional parameter for non-response (usually called 'immunity' in the ... language of bioassay - see Finney, 1978, Chapter 20) to cater for the situation where a proportion (propn ...

   Science Journal Paper : CCAMLR Science, Volume 6 (CCAMLR Science, Volume 6) : 37–46 : Auteur(s): Everson, I. and A.W. Murray

6. A balanced model of the food web of the Ross Sea, Antarctica

   information on trophic links across all the major biota of the Ross Sea and tests for data consistency. The ... recent year (1990–2000). The focus of the model is on the role of Antarctic toothfish in the food web ... efficiency) and all groups together was 1.7%, and for diet fractions was 0.6%. Large but not implausible ... effects of the fishery for Antarctic toothfish (Dissostichus mawsoni). The model consolidates quantitative ... given predator based on an estimate of the quality of the available diet information for that predator ... . The model is an important step towards understand- ing the potential effects of the fishery for ... al., 2007). The aim of the present study is to model an average or typical year, rep- resentative of ... assumption that all parts of the ecosystem will be in balance in an average year. These balance equa- tions ...

   Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 1–31 : Auteur(s): Pinkerton, M.H., J.M. Bradford-Grieve and S.M. Hanchet

7. Phytoplankton distribution in the mixed layer: implication to krill abundance

   Antarctic Ocean, we estimate the depth of the mixed layer and its turbulence intensity from an Ekman layer ... . However, the effect on the dynamics is vital, affecting the distribution of particles in the upper ocean ... follow ( 2 ) (Gregg, 1987). Figure 2 shows the dissipation profile for UlO = 1, 5, 10 and 20 m sec-1 ... A is a constant of an order one. For the sake of simplicity we have used A= 1 . Therefore by ... (solid line) and the dissipation spectrum (dotted line) for N=0.001 rad S-1 and U10=1, 5, 10 and 20 m ... sec-1 at 61°S. Since N can be an order of magnitude larger than 0.001 Figure 4 is prepared for N=0.01 ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I (Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I) : 331–356 : Auteur(s): Yamazaki, H. and T.R. Osborn

8. Age, growth and mortality of Patagonian toothfish (Dissostichus eleginoides) caught off Kerguelen

   estimated to be –0.6 years and residual variance 2.9. Age distributions of toothfish caught by two vessels ... otoliths from reference collections were used to measure precision; relative bias for the age data was ... depth or season. Age–length keys were constructed for use in assessing toothfish catches made by ... sexes were found, estimating von Bertalanffy parameters for males to be L ∞ = 95.9, K = 0.12, t 0 = –4.6 ... estimated for reader R2. 0 10 20 30 40 50 T ot al le ng th ( cm ) 0 20 40 60 80 100 120 140 ... ge ( ye ar s) 0 10 20 30 40 50 Reference age (years) 0 10 20 30 40 50 E st im at ed a ... Estimated age (years) 0 10 20 30 40 50 T ot al le ng th ( cm ) 0 20 40 60 80 100 120 140 (a ... for all reference otoliths. To do this, an ANOVA randomised complete blocks design was used ...

   Science Journal Paper : CCAMLR Science, Volume 12 (CCAMLR Science, Volume 12) : 29–41 : Auteur(s): Ashford, J., G. Duhamel, C. Jones and S. Bobko

9. Results of fish stock assessment survey, South Georgia region, November - December 1986

   rossii and Patagonotothen brevicauda guntheri were an order of magnitude lower than observe by Kock in ... than 1984/85, although not by an order of magnitude. Abundances of Notothenia gibberifrons and ... /85 year classes. Coefficients of variation ranged from 67.9% (Notothenia squamifrons) to 12.6% (C ... described based on results of a stratified random bottom trawl survey. A total of 124 tows were undertaken ... lengths ranged between 13-76 cm, with an overall mean length of 34.2 cm (Figure 20). In contrast to ... ' 1"0/ ,9, o 10 20 30 40 LENGTH, CM 50 Figure 3. Length frequency distribution, li. rossii ... :::> 0 w ~ 20 u... 10 o ( ~, o 10 20 30 40 50 LENGTH, CM Figure 5. Length frequency distribution ... Z w :::> 0 w Cl::: ~ 50 o 'I' (,\ (I'Y'\(II'¥I' '\{'\ o 10 20 30 40 50 LENGTH, CM Figure ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/4 (Selected Scientific Papers, SC-CAMLR-SSP/4) : 143-183 : Auteur(s): Gabriel, W.L.

10. Size and density of krill layers fished by a Japanese trawler in the waters north of Livingston Island in January 1988

    tow were: one (30 instances); two (one instance); three (two instances); and six (one instance). All ... 10 20 30 40 50 60 70 80 NET V 0 L U MED ENS IT Y ( g. m-3 ) Figure 3: Frequency distributions of ... -operative survey between RV Kaiyo Maru and a Japanese trawler was conducted from 17 to 20 January 1988 on ... the fishing ground north of Livingston Island (Figure 1). A total of 30 experiments on TS measurement ...

    Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/6 (Selected Scientific Papers, SC-CAMLR-SSP/6) : 339–345 : Auteur(s): Endo, Y. and Y. Shimadzu

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