Résultats de la recherche

1. Estimation of natural mortality using catch-at-age and aged mark-recapture data: a multi-cohort simulation study comparing estimation for a model based on the Baranov equations versus a new mortality equation.

   obtained by integrating an ordinary differential equation (ODE) for within-year population dynamics. The ... process error in predicted catch-at-age numbers. Simulations assumed 1 000 releases per year over 12 years ... new mortality equation. Abstract / Description:  An estimation strategy for natural mortality, M ... population. Estimation for the BODE model requires an extra component to the log-likelihood which defines the ... ) model) uses an ODE with constant within-year catch per unit time for each age class, and as a result ... of the population size for each age class and year of fishing. Allowing an adequate time for mixing ... time. The initial age structure at the first year of fishing and for subsequent years is obtained by ... obtained by integrating an ordinary differential equation (ODE) for within-year population dynamics. The ...

   Science Journal Paper : CCAMLR Science, Volume 18 (CCAMLR Science, Volume 18) : 1–27 : Auteur(s): Candy, S.G.

2. 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

   obtained using proportions-at-length and fishery- and year-specific age–length keys (ALKs) for years 1998 ... trawl ground at HIMI were used to estimate M. Catch and releases by age class for this fishery were ... in R, based on alternative ordinary differential equations (ODE) for within-year population dynamics ... directly from the estimates of population numbers-at-age. The properties of these two models for estimation ... age frequencies within each fishing year. For an M of 0.155, the expected number of recaptures fitted ... fishery- and year-specific age–length keys (ALKs) for years 1998 to 2008. A large proportion of the ... - tured fish assigned to age classes used for model- ling. The numbers of recaptures by year of release ... fish in the catch and ,iy aN the predicted number of fish in the population of age class a in year ...

   Science Journal Paper : CCAMLR Science, Volume 18 (CCAMLR Science, Volume 18) : 29–45 : Auteur(s): Candy, S.G., D.C. Welsford, T. Lamb, J.J. Verdouw and J.J. Hutchins

3. 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 ... Zealand for subsequent confirmation of their identity by researchers from the National Institute of Water ... methodology has yet to be validated for this species. Von Bertalanffy growth parameters were calculated from ... exhibited a degree of sexual dimorphism. The age at which 50% of fish are sexually mature was estimated to ... 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 ... . holotrachys Species identifi cation and age estimation for M. whitsoni 44 Marriott et al. 0 10 20 30 ... % 80% 90% 100% 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 ... maturing. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 12 13 14 15 16 17 18 19 20 21 22 23 24 25 ...

   Science Journal Paper : CCAMLR Science, Volume 10 (CCAMLR Science, Volume 10) : 37–51 : Auteur(s): Marriott, P., P.L. Horn and P. McMillan

4. Estimation of effective sample size for catch-at-age and catch-at-length data using simulated data from the Dirichlet-multinomial distribution

   Paper Title:  Estimation of effective sample size for catch-at-age and catch-at-length data using ... year is important for such assessments, and this issue is studied using simulation. Between-haul ... gave accurate estimators of an ESS that is appropriate for haul-level heterogeneity with increasing ... method. To account for process error in the calculation of the ESS, the lack of fit of the age-structured ... sampling of the population age structure. For each of the 20 years in a replicate, catch-at- age ... fishery and let the number of fish sampled from age class a for year y, aggre- gated across all hauls (j ... by proportions by age class or length bin to give numbers by class/bin and year, an offset of log ... centred year value obtained from the integer values of year, y, so that for a 20-year simulation period ...

   Science Journal Paper : CCAMLR Science, Volume 15 (CCAMLR Science, Volume 15) : 115–138 : Auteur(s): Candy, S.G

5. A von Bertalanffy growth model for toothfish at Heard Island fitted to length-at-age data and compared to observed growth from mark–recapture studies

   Paper Title:  A von Bertalanffy growth model for toothfish at Heard Island fitted to length-at-age ... (IWLS), predicted substantially lower mean length-at-age for older ages compared to the VB curve fitted ... to give more realistic predictions of mean length-at-age for young fish. File:  03candy-etal.pdf ... -estimated parameters. A young-age adjustment (less than 5 years old) to the VB model is also given in order ... ed distribution with zero skew, and (ii) an exponential distribution for age- at-fi rst-capture that ... – 20 year range. This translated to larger predictions for the MLPLB-fi tted curve for ages below 5 ... mean length-at-age for ages above 15 years. When length bin relative sampling frequencies were also ... (2007): 43–66 43 A VON BERTALANFFY GROWTH MODEL FOR TOOTHFISH AT HEARD ISLAND FITTED TO LENGTH-AT-AGE ...

   Science Journal Paper : CCAMLR Science, Volume 14 (CCAMLR Science, Volume 14) : 43–66 : Auteur(s): Candy, S.G., A.J. Constable, T. Lamb and R. Williams

6. A comparison between otoliths and scales for use in estimating the age of Dissostichus eleginoides from South Georgia

   Paper Title:  A comparison between otoliths and scales for use in estimating the age of ... result in large errors in age data for long-lived species, usually due to compression of scale circuli ... otoliths and scales give the same age estimates, and compared the precision of age estimation for both ... Dissostichus eleginoides from South Georgia Abstract / Description:  Age composition is fundamental to ... . Sustainable exploitation rates should have been 20-30% of that based on age determinations from scales, in ... use of otoliths and scales in estimating tootlifish age 0 10 20 30 40 50 10 20 30 40 50 Reader l ... suckers grew quickly at ages 4-7 years, few surviving beyond an age of 9 years. Annual mortality was ... using scales than otoliths. There was evidence that for fish older t l~an 16 years (estimated using ...

   Science Journal Paper : CCAMLR Science, Volume 8 (CCAMLR Science, Volume 8) : 75–92 : Auteur(s): Ashford, J.R., S. Wischniowski, C. Jones, S. Bobko and I. Everson

7. Methods of age determination for mackerel icefish (Champsocephalus gunnari Lönnberg 1905) from the South Georgia Island shelf

   age assessments of fish longer than 30 cm having an enlarged otolith centre. An age/length key for the ... Paper Title:  Methods of age determination for mackerel icefish (Champsocephalus gunnari Lönnberg ... taken in the period July to September. The latter was done using specimens from strictly defined age ... third quarter of the year was also calculated. File:  04-Frolkina.pdf ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/6 (Selected Scientific Papers, SC-CAMLR-SSP/6) : 37–49 : Auteur(s): Frolkina, Zh.A.

8. Assessment and tag program adaption methods for exploratory fisheries in the CAMLR Convention Area: an example application for Division 58.4.3a

   Convention Area: an example application for Division 58.4.3a Abstract / Description:  A methodology for the ... tagging levels that will produce an expected abundance estimate in the following year of a given precision ... Paper Title:  Assessment and tag program adaption methods for exploratory fisheries in the CAMLR ... initial stock assessment and adaption of catch limits and tagging rates is presented for new and ... proxy for the abundance estimate one might expect in the assessment. The aim is to pro- vide an ... given year or years. No dispersion terms were estimated for the recapture event for obvious reasons ... 0.13 with a 10% CV, and for age-at-maturity a value of 13 years with again a CV of 10%. The resultant ... Assessment And tAg progrAm AdAption methods for explorAtory fisheries in the CAmlr Convention AreA: An ...

   Science Journal Paper : CCAMLR Science, Volume 16 (CCAMLR Science, Volume 16) : 101–113 : Auteur(s): Hillary, R.M

9. An integrated stock assessment for the Patagonian toothfish (Dissostichus eleginoides) for the Heard and McDonald Islands using CASAL

   Paper Title:  An integrated stock assessment for the Patagonian toothfish (Dissostichus ... eleginoides) for the Heard and McDonald Islands using CASAL Abstract / Description:  An integrated stock ... assessment for the Patagonian toothfish (Dissostichus eleginoides) for the Heard and McDonald Islands (CCAMLR ... Division 58.5.2), using CASAL and data consisting of multi-year random stratified trawl survey (RSTS ... variation (CV) for length given age, (ii) use of non-informative pri- ors for year-class strength ... -year seasons) for the main trawl ground, and (v) the use of an improved estas edades disminuye. El ... was modelled as an age-structured population with 35 separate age classes, from age 1 to 35 years ... von Bertalanffy growth model that incorporates an early age (<5 years old) adjustment as described ...

   Science Journal Paper : CCAMLR Science, Volume 15 (CCAMLR Science, Volume 15) : 1–34 : Auteur(s): Candy, S.G and A.J. Constable

10. Review of length-weight relationships for Antarctic krill

    Paper Title:  Review of length-weight relationships for Antarctic krill Abstract / Description ... :  Length-weight relationships for krill, Euphausia superba (as well as relationships for other Antarctic ... euphausiid species), are listed for ash-free dry weight, dry weight, and wet weight. The accuracy of length ... discussed. Recommendations for possible uses of reviewed length-weight relationships are presented. File ... have been established over the years for Antarctic krill Euphausia superba, but this information is ... 927mg 913mg 931 mg 912mg 860mg 796mg Data for February were collected in different years and ... for wet wei~ht (in mg) and total length (AT in mm). Month Several years Several years ... WG-KRILL-92/1S REVIEW OF LENGTH-WEIGHT RELATIONSHIPS ...

    Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/9 (Selected Scientific Papers, SC-CAMLR-SSP/9) : 145–155 : Auteur(s): Siegel, V.

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