Результаты поиска

1. Distribution of fish larvae at South Georgia: horizontal, vertical, and temporal distribution and early life history relevant to monitoring year-class strength and recruitment

   / Description:  Four studies on the early life history stages of Antarctic fish at South Georgia are reported ... . In winter and summer fish larvae and early juveniles were present over the continental shelf and ... abundant near the coast, but rare in oceanic waters. During winter in the 265 m deep fiord of Cumberland ... East Bay the early stages of many species were found throughout the water column. In summer only four ... September to 5 october, 1983, approximately one month after the zone survey. Results Eggs of either ... light period after dawn they were at 0-70 m depth, and later before sunset at 2-70 m, but not in the ... only 12-32 mm standard length. Nototheniops larseni larvae after sunset were most abundant in the ... after dark, then down to 2-70 m depth during daylight, although at all parts of the diurnal cycle some ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/4 (Selected Scientific Papers, SC-CAMLR-SSP/4) : 105-141 : Автор(ы): North, A.W.

2. Data on krill (Euphausia superba Dana) consumption by coastal fishes in Division 58.4.2 (Kosmonavtov and Sodruzhestva Seas)

   58.4.2 (Kosmonavtov and Sodruzhestva Seas) Abstract / Description:  Current estimates of the level of ... krill consumption (Euphausia superba) are based on data obtained from the Atlantic sector which have ... then been extrapolated over all of Antarctica. According to these calculations the entire amount of ... krill consumption have thus far only been carried out for the Scotia and Lazarev Seas (Kock, 1985 ... requirements for fish were 1.5 x 103 tonnes at the beginning of the season and 0.36 x 103 tonnes at the end ... , V.A. Bibik and V.V. Gerasimchuk* Abstract * Current estimates of the level of krill consumption ... (Euphausia superba) are based on data obtained from the Atlantic sector which have then been extrapolated ... over all of Antarctica. According to these calculations the entire amount of kriU consumed is between ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/8 (Selected Scientific Papers, SC-CAMLR-SSP/8) : 305–319 : Автор(ы): Pakhomov, Y.A., V.A. Bibik and V.V. Gerasimchuk

3. Length-based assessment for mackerel icefish (Champsocephalus gunnari) at South Georgia

   Georgia Abstract / Description:  The current CCAMLR assessment method for mackerel icefish ... (Champsocephalus gunnari) in Subarea 48.3 employs the CCAMLR mixture analysis program (CMIX) and generalised yield ... the given harvest control rule to set a two-year total allowable catch (TAC). One issue is the ... accurate identification of age cohorts from the survey data. In this paper a length-based approach is ... that the exploited biomass is equal to 75% of the unexploited biomass (after two years). From this ... the population and the model advances the dynamics (now including this exploitation rate) to the end ... of the first ‘year’. 5. Steps 3 and 4 are then repeated to give the population abundance at the end ... algorithm is used to esti- mate the fixed harvest rate that ensures that the biomass at the end of the two ...

   Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 129–137 : Автор(ы): Hillary, R.M., C.T.T. Edwards, R.E. Mitchell and D.J. Agnew

4. Target strengths of Antarctic krill (Euphausia superba)

   Paper Title:  Target strengths of Antarctic krill (Euphausia superba) Abstract / Description:  The ... and 120 kHz in a sheltered bay at South Georgia. The results indicate that the Target Strength values ... towelling. The cages were constructed by sewing, with monofilament nylon, pre-cut octagonal end panels of ... monofilament nylon, pre-cut octagonal end panels of the mesh to the long edges of a pre-cut rectangular panel ... stored on a BAS data logger at the end of each interval. 4.3 Calibration On-axis calibration with ... half-filled with surface sea water. After reaching the predetermined number, more or less, the tub wa ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I (Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I) : 265–279 : Автор(ы): Everson, I., D.G. Bone, J.L. Watkins and K.G. Foote

5. Integrating Count Effort by Seasonally Correcting Animal Population Estimates (ICESCAPE): a method for estimating abundance and its uncertainty from count data using Adélie penguins as a case study

   reported measures of uncertainty associated with originally published counts are propagated through to the ... , the method is applied to several examples of published studies of Adélie penguin abundance at breeding ... breeding pairs, although the software has been developed to accommodate adjustment and aggregation of other ... Adélie penguins, the method and implementation is sufficiently general to be easily adapted for other ... the breeding population as the number of breeding pairs or nests present one week after the peak in ... after the peak in egg laying (Southwell et al., 2010), consistent with the CCAMLR Ecosystem Monitoring ... adults present as breeding pairs at the beginning of incubation; had adult counts been undertaken ear ... , Heritage and the Arts 203 Channel Highway Kingston, Tasmania 7050 Australia Email – john.mckinlay ...

   Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 213–227 : Автор(ы): McKinlay, J., C. Southwell and R. Trebilco

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

   between 29 November and 17 December 1986 by the R.V. Professor Siedlecki using a Polish B-454 otter trawl ... relatively strong 1983/84 year class that would be expected to reach length of 50% maturity by the end of ... 1987/88 or the beginning of 1988/89. Although estimates of biomass of C. aceratus have been ... December 1986 by the R.V. Professor Siedlecki using a Polish B-454 otter trawl. Biomass was estimated ... National Marine Fisheries Service Woods Hole, Mass. U.S.A. The decline of groundfish stocks since the ...

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

7. Spawning locations of mackerel icefish at South Georgia

   :  Historical information on the distribution of spawning and larval mackerel icefish (Champsocephalus gunnari ... inshore spawning at South Georgia during April within and close to the bays on the north side of the ... island. Some spawning almost certainly occurs over much of the island shelf, although is this appears to ... . There are also indications of a possible second spawning season in January, although the evidence is ... separated by latitude 54"s at the western end of South Georgia and longitude 37"W. In addition, Shag Rocks ... the western end of South Georgia. No data were available from Shag Rocks for May and June. The ... fourth close to Drygalski Fjord at the eastern end of the island (Figure 4). Larval C. gtlntzavi were ... number of larvae was caught at the nearshore end, and the statistical distribution of larval density (A ...

   Science Journal Paper : CCAMLR Science, Volume 8 (CCAMLR Science, Volume 8) : 107–118 : Автор(ы): Everson, I., A.W. North, A. Paul, R. Cooper, N.C. McWilliam and K.-H. Kock

8. Acoustic estimates of krill density at South Georgia, 1981 to 1998

   11 austral summers between 1981 and 1998 are presented. Krill density at the island fluctuated widely ... from year to year over that time, ranging from ≈ 2 to  ≈ 150 g m-2 (fresh mass). The 1982, 1991 and ... % confidence limits <15 g m-2). For five of the summers between 1990 and 1998 it was possible to calculate ... density was higher to the east. File:  04brierley-etal.pdf ... , and values reported for cruises after this time are thus what we consider to be the best estimates ... effective start and end positions for the analyses reported here were often constrained only by ... western end of South Georgia than the east (Everson, 1984; Boyd, 1993; Trathan et al., 1998), and the ... differing levels of predation at each end, or may indicate the existence of different populations at, or ...

   Science Journal Paper : CCAMLR Science, Volume 6 (CCAMLR Science, Volume 6) : 47–57 : Автор(ы): Brierley, A.S., J.L. Watkins, C. Goss, M.T. Wilkinson and I. Everson

9. Calibration of an acoustic echo-integration system in a deep tank, with system gain comparisons over standard sphere material, water temperature and time

   outlines the theory and procedures for calibrating an echo integration acoustic system with a standard ... sphere. It presents the results of an extensive calibration of a Simrad EK500 scientific echosounder with ... length (0.1, 0.3 and 1.0 ms), target depth (0.8 to 7.5 m), and time (149 days). The total range in TS ... gain, including the effects of temperature, standard sphere and time, is 2.9 dB. Gain values calibrated ... EK500 processes the signal digitally immediately following the receiver front end. Therefore, changes ... ocean water pumped from the end of Scripp's pier. A pump and refrigeration unit allowed the water ... . Therefore, if no data were collected exactly on axis, the nearest data to the axis were used after being ... encountered during the survey. The calibration should be repeated at least twice, before and after the survey ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/9 (Selected Scientific Papers, SC-CAMLR-SSP/9) : 127–144 : Автор(ы): Demer, D.A. and R.P. Hewitt

10. Target strengths of krill at 136 and 20 kHz

    . Ensonification of encaged live krill. For aggregations with mean lengths from 45 to 50 mm the mean single-krill ... the mean single-krill target strengths range from-71 to-77 dB at 20 kHz. Trawl hydroacoustic method ... . For aggregations with mean lengths from 47 to 50 mm the mean target strengths ranged from-71 to-75 dB ... . At the same frequency for aggregations with mean lengths in the range 41 to 47 mm the mean single ... . Krill specimens were removed from the catch and placed in a container of sea-water. After sorting ... were then measured at the end of each test. Hydroacoustic calibration was carried out using a ... . TS values for the empty cage and the cage containing krill were recorded 40 minutes after submersion ... only assessed in cases when krill removed from the cage after the test in another container were ...

    Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/8 (Selected Scientific Papers, SC-CAMLR-SSP/8) : 141–157 : Автор(ы): Kasatkina, S.M.

Страницы