Résultats de la recherche

1. Estimation of krill (Euphausia superba) mortality and production rate in the Antarctic Peninsula region

   ratio of 0.88 to 0.94 for different years. The exchange rate of water masses and krill biomass within ... Antarctic Peninsula region Abstract / Description:  A net sampling survey for krill was carried out by RV ... data of an identical survey with RV Polarstern in 1987/88. Seasonal variation between summer and winter ... one summer season was roughly estimated as two times from which follows a maximum total effective ... three year life span of krill. Their age group 1 (20 to 43 mm) included the two age groups 1+ and 2 ... methodological approaches. For a long time krill was thought to live only for two or three years and spawn only ... varied between Z = 0.88 and 0.96 for data from two different years. Natural mortality and the growth ... Antarctic Peninsula survey area for different years. 30 • PN87/88 29 oME89/90 28 z27 .E 26 25 ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/8 (Selected Scientific Papers, SC-CAMLR-SSP/8) : 159–176 : Auteur(s): Siegel, V.

2. Preliminary model of krill fishery behaviour in Subarea 48.1

   Elephant Islands in alternate years would result in an average yearly catch similar to that at present ... during alternate years. File:  06agnew-marin.pdf ... in Table 1 varied considerably, an approximate mean CV of 0.4 was used for all squares for these ... two major fisheries in the area. Catches by a single Chilean vessel for February, the only month in ... Livingston and Elephant Islands in alternate years would result in an average yearly catch similar to that ... Elephant Islands, the two major fishing areas, in alternate years. Closures were modelled by ...

   Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 71–79 : Auteur(s): Agnew, D.J. and V.H. Marín

3. A review of the effectiveness of streamer lines as a seabird by-catch mitigation technique in longline fisheries and CCAMLR streamer line requirements

   object be deployed windward of the hookline; and recommending that fishers deploy a minimum of two ... large degree on the precedent set by CCAMLR in 1991, the streamer line has become the primary, and most ... light of a review of existing literature and available data on the effectiveness of single and paired ... streamer lines on a voluntary basis according to performance and material standards. Based on the ... line: UW IW-50 Two streamer lines: IW-50+Cannon 10 20 30 40 50 ... November 2002 (Table 1). Streamer lines had an aerial extent of 30 to 70 m depending on sea state ... streamer line is important for two reasons: it maximises the effi ciency of the streamer line as a ... above the water using the boom-and-bridle system, achieving an aerial extent of up to 60 m. For all ...

   Science Journal Paper : CCAMLR Science, Volume 11 (CCAMLR Science, Volume 11) : 189–201 : Auteur(s): Melvin, E.F., B. Sullivan, G. Robertson and B. Wienecke

4. Length- and age-at-spawning of Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea

   maturation stage by approximately May each year. The age at 50% spawning for females on the Ross Sea slope ... stage for at least one year. Individual oocytes are then recruited into the vitellogenic phase over at ... spawn at a younger age with an A 50% of 12.8 years (95% CI 11.9–14.0) or 120.4 cm (95% CI 114.8–126.7 ... -at-spawning for female and male Antarctic toothfish (Dissostichus mawsoni) from fish sampled in the ... L50% for the hindcast ogive. 0 10 20 30 40 0. 0 0. 2 0. 4 0. 6 0. 8 1. 0 Age (y) P ro po rti ... assessment for D. mawsoni assumed an A50% of 9 years, corresponding to an L50% of 100 cm (95% range of ±15 ... Age (years) 0 10 20 30 ... 400 10 20 30 40 0. 0 0. 2 0. 4 0. 6 0. 8 1. 0 Age (y) P ro po rti on s pa w ni ng Female ...

   Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 53–73 : Auteur(s): Parker, S.J. and P.J. Grimes

5. Statistical problems in krill stock hydroacoustic assessments

   :  Two primary issues are at question for hydroacoustic assessments of krill. The first is the methods ... -strength measurements. In the case of statistical methods, there are no clear guidelines for deciding what ... needs for improvements in sampling design and tests for systematic trends in survey data collected from ... to be not the absolute amount of biomass present in an area, but rather how it is distributed. The ... HYDROACOUSTIC ASSESSMENTS M.C. Macaulay Abstract Two primary issues are at question for hydroacoustic ... patch dominated year) it can quickly obtain sufficient food for its needs. If, however, it must spend a ... its own requirements to have sufficient for its offspring too. Figure 1 shows an example of this with ... biomass present in an area, but rather how it is distributed. The issue of patchy years vs more even ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I (Selected Scientific Papers, SC-CAMLR-SSP/5 – Part I) : 301–309 : Auteur(s): Macaulay, M.C.

6. Seabird mortality in the Patagonian toothfish longline fishery around Crozet and Kerguelen Islands, 2001–2003

   and relating to fishing techniques) have an effect on the observed numbers of seabirds caught ... petrels and grey petrels is explained by the time of year, geographical area and type of longliner (manual ... breeding season, except for giant petrels. The highest mortality of white-chinned petrels, grey petrels ... baited longlines. Based on the results of this analysis, several recommendations are made with the aim of ... for the two years, and is linked to the repro- ductive cycle of the species most frequently caught ... populations, based on the mean by-catch rate for the year 2001/02 (highest rates) compared to the size of ... Collection of data The fi shing year extends from 1 September to 31 August. There are two types of ... ) varies considerably for a particular year according to the geographical area, and for a particular ...

   Science Journal Paper : CCAMLR Science, Volume 12 (CCAMLR Science, Volume 12) : 53–80 : Auteur(s): Delord, K., N. Gasco, H. Weimerskirch, C. Barbraud and T. Micol

7. Significant conservation benefits obtained from the use of a new fishing gear in the Chilean Patagonian toothfish fishery

   artisanal trotline fishery for Patagonian toothfish (Dissostichus eleginoides) in Chile is described. The ... modified artisanal system, which includes a net sleeve that is placed on secondary vertical lines, has ... sperm and killer whales on fish catch rate was assessed during September–December 2006. The results were ... ~70–74 cm Ø~30 cm Ø~10–15 cm ~100–120 cm Hooks Snoods ~20 cm ~15 cm ~25 cm Weight 4–8 kg ... net sleeves at an estimated cost of US$25–30 each. However these net sleeves are durable and can be ... step in the search for an effective deterrent to the dep- redation of fish by marine mammals. The ... ). The results for 2006 were absolute; no birds were killed from an effort of almost 4 million hooks ...

   Science Journal Paper : CCAMLR Science, Volume 15 (CCAMLR Science, Volume 15) : 79–91 : Auteur(s): Moreno, C.A., R. Castro, L.J. Mújica and P. Reyes

8. [node:field-journal-volume]:37-51

   . holotrachys Species identifi cation and age estimation for M. whitsoni 44 Marriott et al. 0 10 20 30 ... In 1999, CCAMLR observers collected macrou- rid otoliths, for subsequent ageing, on two com- mercial ... 40 50 60 70 80 90 100 0 5 10 15 20 25 30 35 40 45 50 55 60 Age (years) To ta l l en gt h ... to collect macrourid specimens for identifi cation. The requirements were ‘Two fi sh at random are ...

   Science Journal Paper : 37–51

9. Performance and geometry of the FP-120 trawl used during UK fish stock assessment surveys around South Georgia, Subarea 48.3

   surveys around South Georgia, Subarea 48.3 Abstract / Description:  Methods for calculating the horizontal ... presented. Regression equations for the estimation of horizontal opening from other, more easily measured ... variables, such as tow speed and trawl depth, are proposed. Biomass estimates for the major fish species ... used during the 1993/94 UK fish stock assessment survey around South Georgia on the MV Cordella are ... , biomass, finfish, CCAMLR INTRODUCTION Surveys using bottom trawls have been used for over 20 years to ... be used to estimate the horizontal opening based on an assumed linear relationship between the two ... of Trawl Geometry For a distance travelled over the ground g and an estimated horizontal opening h ... (17, 20 and 21) were logged every 30 seconds and the fourth (22) every 20 seconds. The hydrophone ...

   Science Journal Paper : CCAMLR Science, Volume 2 (CCAMLR Science, Volume 2) : 51–69 : Auteur(s): Pilling, G. and G. Parkes

10. Mitigation of seabird captures during hauling in CCAMLR longline fisheries

    / Description:  In recent years there has been an increased focus on reducing seabird captures that occur during ... suggest that there are two key aspects of effective BEDs, firstly that they provide a deterrent to ... these two key functional characteristics into the specification of a BED to be deployed by longline ... swimming or ‘jumping’ into the area around the hauling bay. Based on this analysis, CCAMLR incorporated ... MRAG Ltd 18 Queen Street, London W1J 5PN United Kingdom Abstract In recent years there has been an ... the hauling bay. Based on this analysis, CCAMLR incorporated these two key functional characteristics ... CAMLR Convention Area and to make recommendations for moving toward prescriptive advice on a standard ... this information, albeit often on an ad hoc basis, the observers play a key role in the iterative ...

    Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 155–162 : Auteur(s): Reid, E., B. Sullivan and J. Clark

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