Search results
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The role of fish as predators of krill (Euphausia superba) and other pelagic resources in the Southern Ocean (submitted to the 2008 Joint CCAMLR-IWC Workshop)
by mesopelagic fish in the Atlantic sector of the Southern Ocean. It is clear from this review that fish ... to be considered when evaluating patterns that have emerged in Southern Ocean ecosystems in the course of the 20 ... taken by mesopelagic fish in the Atlantic sector of the Southern Ocean. It is clear from this review ... emerged in Southern Ocean ecosystems in the course of the 20th century. As a first step towards ... and the large baleen whales in the first 80 years of the 20th century (the so called ‘krill surplus hypothesis ... span of typically 10–20 years (Kock et al., 1985; La Mesa et al., 2000) with the exception of the two ... for the split-years (1 July to 30 June) 1975/76 and 1977/78 (Table 5). Biomass estimates of C. gunnari were ... is by no means a pristine environ- ment. Human exploitation of the Southern Ocean started some 225 years ago ...
Science Journal Paper : CCAMLR Science, Volume 19 (CCAMLR Science, Volume 19) : 115–169 : Author(s): Kock, K.-H., E. Barrera-Oro, M. Belchier, M.A. Collins, G. Duhamel, S. Hanchet, L. Pshenichnov, D. Welsford and R. Williams
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Estimation of natural mortality for the Patagonian toothfish at Heard and McDonald Islands using catch-at-age and aged mark-recapture data from the main trawl ground
proportions-at-length and fishery- and year-specific age–length keys (ALKs) for years 1998 to 2008. A large ... obtained using proportions-at-length and fishery- and year-specific age–length keys (ALKs) for years ... Islands using catch-at-age and aged mark-recapture data from the main trawl ground Abstract / Description ... whereby the relatively long time series of catch-at-age and mark-recapture data from the main trawl ground ... ity , S 'a Age (years) ¢ a S 0.05 0.10 0.15 0.20 0.25 0.30 -5 30 0 -5 25 0 -5 20 0 -5 15 ... (years) (a) Age (yrs) P ro po rti on s 0.0 0.1 0.2 0.3 0 5 10 15 20 25 1998 2000 0 5 10 15 20 ... and releases by age class for this fishery were obtained using proportions-at-length and fishery- and year ... -specific age–length keys (ALKs) for years 1998 to 2008. A large proportion of the recaptures of fish ...
Science Journal Paper : CCAMLR Science, Volume 18 (CCAMLR Science, Volume 18) : 29–45 : Author(s): Candy, S.G., D.C. Welsford, T. Lamb, J.J. Verdouw and J.J. Hutchins
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Supplementary data on exploited stocks in Division 58.5.1 (Kerguelen)
Island) have made possible a review of the status of the various harvested fish stocks. Since 1984 ... Island) have made possible a review of the status of the various harvested fish stocks. Since 1984 ... . An assessment of the biomass of individuals aged more than three years present over the Kerguelen Shelf ... corresponding to the arrival (at the age of 5 to 6 years) of these juveniles on the shelf. A catch limited ... to average length at sexual maturity (33.5 and 33.8 cm at the age of 9 years). The length frequency ... of the exploited population comprising mainly individuals aged between 7 and 11 years. The biomass of the shelf ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/6 (Selected Scientific Papers, SC-CAMLR-SSP/6) : 147–161 : Author(s): Duhamel, G.
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A preliminary assessment of age and growth of Antarctic silverfish (Pleuragramma antarcticum) in the Ross Sea, Antarctica
-growing with a moderate longevity; the maximum estimated age was 14.3 years. Von Bertalanffy parameters ... –11.0 and 15.1–15.5 cm. Mean lengths of 4.9 and 7.3 cm (at ages 1.3 and 2.3 years respectively ... estimated age was 14.3 years. Von Bertalanffy parameters derived for both sexes combined are: L∞ 22.1 ... of 4.9 and 7.3 cm (at ages 1.3 and 2.3 years respectively) are consistent with those presented ... sampled from the Ross Sea. 0 10 20 30 40 50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Age (years) Fr eq ... ue nc y Age (years) Fr eq ue nc y 50 40 30 20 10 ... ) plus unsexed fish up to 5.3 years (thin line). 0 5 10 15 20 25 0 3 6 9 12 15 Age (years) St ... an da rd le ng th (c m ) 0 5 10 15 20 25 0 3 6 9 12 15 Age (years)Age (years ...
Science Journal Paper : CCAMLR Science, Volume 18 (CCAMLR Science, Volume 18) : 75–86 : Author(s): Sutton, C.P. and P.L. Horn
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Precautionary spatial protection to facilitate the scientific study of habitats and communities under ice shelves in the context of recent, rapid, regional climate change
(Subarea 48.1) between 1978/79 and 1989/90. Most fishing occurred in the two seasons 1978/79 and 1979/80 ... highlights how: CCAMLR Science, Vol. 20 (2013): 139–151 139 PRECAUTIONARY SPATIAL PROTECTION ... forward and it may be years or decades between major calv- ing events. Other changes in the mass balance ... of the northern edge of the George VI ice shelf (67.840°W 71.692°S) which lost ~993 km2 over a number of years ... existing ice shelves in Subareas 88.3, 48.1 and 48.5 should be preserved and protected for scientific study ... collapse in the future. Designation of areas under ice shelves as areas for scientific study would fulfil ...
Science Journal Paper : CCAMLR Science, Volume 20 (CCAMLR Science, Volume 20) : 139–151 : Author(s): Trathan, P.N., S.M. Grant, V. Siegel and K.-H. Kock
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Low genetic diversity and temporal stability in the Antarctic toothfish (Dissostichus mawsoni) from near-continental seas of Antarctica
locations, or between samples collected in consecutive years, were observed. These results, based ... in the allelic frequencies for several loci compared to previously published data highlight the need for further ... between geographic locations, or between samples collected in consecutive years, were observed ... . Discrepancies in the allelic frequencies for several loci compared to previously published data highlight ... ) and is restricted to the Convention Area man- aged by CCAMLR. The fishery for D. mawsoni started in the late 1990s ... (age 0+ and 1+), with total length between 41 and 117 mm, are found during spring and summer ... ed li ne ag e le uk ae m ia -li ke p ro te in (M LL ) M LL :9 5 A /G M LL _F ... to the bottom, become benthic and spend a few years on the continen- tal shelf at depths of 50–300 m (Roshchin ...
Science Journal Paper : CCAMLR Science, Volume 21 (CCAMLR Science, Volume 21) : 1–9 : Author(s): Mugue, N.S., A.F. Petrov, D.A. Zelenina, I.I. Gordeev and A.A. Sergeev
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Is current management of the Antarctic krill fishery in the Atlantic sector of the Southern Ocean precautionary?
estimated subarea biomass in up to 20% of years due to high variability in krill biomass indices. The actual ... in up to 20% of years due to high variability in krill biomass indices. The actual exploitation rate ... in 1991, is 0.62 million tonnes year –1, equivalent to ~1% of the regional biomass estimated in 2000. Each ... subarea has also had its own catch limit, between 0.093 and 0.279 million tonnes year –1, since 2009 ... of individuals aged more than about 1 year) in the upper 500 m of the water column. Krill are also found ... and the associated subarea catch limits are generally precautionary with aver- age exploitation rates ... exceed 9.3% of conservatively estimated subarea biomass in up to 20% of years due to high variability ... . the total weight of reproductively mature individuals) after 20 years of fishing should not be below 75 ...
Science Journal Paper : CCAMLR Science, Volume 23 (CCAMLR Science, Volume 23) : 31–51 : Author(s): Hill, S.L., A. Atkinson, C. Darby, S. Fielding, B.A. Krafft, O.R. Godø, G. Skaret, P.N. Trathan and J.L. Watkins
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Estimates of fish stock biomass around South Georgia in January/February 1985
in stock size to 10 – 20% of that estimated before the onset of heavy fishing. In C. gunnari the fishery ... is dependant on the abundance of the recruiting year class. Conservation measures adopted by CCAMLR in 1984 ... – 20% of that estimated before the onset of heavy fishing. In C. gunnari the fishery is dependant ... on the abundance of the recruiting year class. Conservation measures adopted by CCAMLR in 1984 are discussed ... (> 35 cm) were still common, recent catches were seen domi na ted by 3 years old. fish (age class II ... - - 6 - niles (age class O and 1) the entire population had been sampled adequate- ly. In comparison ... that catches consisted mostly of age classes I (mean length"' 17 cm) and II (mean le_ngth ,.., 25 cm ... ) and a minor proportion of age classes III-V. Only single spec:imens larger than 40 cm was ca ught (fig ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/2 (Selected Scientific Papers, SC-CAMLR-SSP/2) : 1-32 : Author(s): Kock, K.-H.
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An iterative model to construct an age/length key to assess the age composition of a new fishery for Dissostichus eleginoides in Chilean waters
Paper Title: An iterative model to construct an age/length key to assess the age composition ... estimation of age composition of catch requires that age/length data and random length frequency have been ... sampled from the same population. If such sampling is not possible the estimates of the age distribution ... could be biased. By using an iteration algorithm it is possible to overcome this limitation. The age ... 2: PHCYHOK 1: PHCYHOK 2: 20 List of Tables Age composition of D. eleginoides catches obtained ... estimation of age composition of catch requires that age/length data and random length frequency have been ... sampled from the same population. If such sampling is not possible the estimates of the age distribution ... could be biased. By using an iteration algorithm it is possible to overcome this limitation. The age ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/9 (Selected Scientific Papers, SC-CAMLR-SSP/9) : 11–20 : Author(s): Robotham, V. H. and Z. Young U.
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Species identification and age estimation for the ridge-scaled macrourid (Macrourus whitsoni) from the Ross Sea
Paper Title: Species identification and age estimation for the ridge-scaled macrourid (Macrourus ... and Atmospheric Research (NIWA). Two species were found, Macrourus whitsoni and M. holotrachys. A previously aged ... and the geographic source of the aged sample. Counts of translucent zones were made from baked and cross-sectioned ... in the Ross Sea (CCAMLR Subarea 88.1). The zones are assumed to form annually as this ageing methodology has ... was attributed to each age estimate, as follows: 1. certain count 2. uncertainty of ±1 year 3. uncertainty ... are apparent for all three parameters (Table 3). However, the lack of fi sh aged younger than 9 years has ... , the mean age at maturity was estimated to be 12 years for males and 14 years for females. DISCUSSION ... 55 60 Age (years) To ta l l en gt h (c m ) Males Males Females Females Figure 2: Raw age ...
Science Journal Paper : CCAMLR Science, Volume 10 (CCAMLR Science, Volume 10) : 37–51 : Author(s): Marriott, P., P.L. Horn and P. McMillan