Результаты поиска

1. Comparison of two methods to assess fish losses due to depredation by killer whales and sperm whales on demersal longlines

   conservation issues. However, estimating the amount of resource depredated can be especially challenging when ... depredation occurs on fish in the marine environment. This is the case for killer whales (Orcinus orca) and ... sperm whales (Physeter macrocephalus) depredation on the demersal Patagonian toothfish (Dissostichus ... eleginoides) longline fishery operating within the Crozet Islands EEZ (southern Indian Ocean). This study ... leaves no information to compare catch rates in the absence of odontocetes. In order to support those ... effect of depredation but no data would have been available for comparison so the arbitrary choice was ... recent years of this study: fishing vessels no longer concentrate in the Crozet Islands in February as ... that results obtained are extremely consistent to those using the CPUE method with no significant ...

   Science Journal Paper : CCAMLR Science, Volume 22 (CCAMLR Science, Volume 22) : 1–14 : Автор(ы): Gasco, N., P. Tixier, G. Duhamel and C. Guinet

2. Reproductive performance of seabirds and seals at South Georgia and Signy Island, South Orkney Islands, 1976-1987: implications for Southern Ocean monitoring studies

   / Description:  Aspects of the reproductive performance over the last decade of black-browed, grey-headed and ... reviewed. Breeding success of the wandering albatross, which breeds in winter and eats fish and squid, has ... remained constant, while population size has declined gradually but significantly. The other species at ... species; circumstantial evidence relating this to reduced availability of krill is discussed. The ... and P. Rotheryl (United Kingdom) Abstract Aspects of the reproductive performance over the last ... , South Orkney Islands, are summarised and reviewed. Breeding success of the Wandering Albatross, which ... gradually but significantly. The other species at South Georgia, which breed in summer and feed ... reduced availability of krill is discussed. The fluctuations in reproductive performance of the krill ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/4 (Selected Scientific Papers, SC-CAMLR-SSP/4) : 445-447 : Автор(ы): Croxall, J.P., T.S. McCann, P.A. Prince and P. Rothery

3. Determination of Antarctic krill acoustic back-scattering cross-section

   / Description:  When determining the density krill of concentrations it is necessary to know the acoustic cross ... -section of back-scattering of krill. The target strength can be determined in situ by measuring the echo ... signal from one specimen resolved by the hydroacoustic instrument. By calculating the mean level of the ... directivity diagramme of the antenna and the mean level of the standardized echo signal, it is possible to ... When determining the density krill of concentrations it is necessary to know the acoustic cross ... -section of back-scattering of krill. The target strength can be determined in situ by measuring the echo ... signal from one specimen resolved by the hydroacoustic instrument. By calculating the mean level of the ... directivity diagramme of the antenna and the mean level of the standardized echo signal, it is possible to ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 141-152 : Автор(ы): Protaschuk, V.A. and T.A. Lukashova

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

   survey boxes (dimensions 80 km × 100 km) north of South Georgia. The reconstructions were generated from ... line-transect acoustic survey data gathered in the boxes during austral summers from 1996 to 2000 ... . Krill densities had previously been determined at approximately 0.5 km intervals along each of the ten ... 80 km transects in each box, providing about 1 600 density estimates per box. The MaxEnt technique ... km) north of South Georgia. The reconstructions were generated from line-transect acoustic survey ... data gathered in the boxes during austral summers from 1996 to 2000. Krill densities had previously ... been determined at approximately 0.5 km intervals along each of the ten 80 km transects in each box ... , providing about 1 600 density estimates per box. The MaxEnt technique uses an iterative Bayesian approach ...

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

5. Telemetry monitoring of ecological resources

   monitoring using the Argos/Tiros system and satellite transmission of data are also covered. File:  24 ... . Transmitters on the animals have no special requirements. This system offers possibility as a remote ... there is no easy way to distinguish the animals on the chart. To meet the need to monitor more animals ... and off if desired. Since the system has no moving parts it can operate over a wide temperature ... Argos data processing and to use the down-link data to determine location with an on-site data ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/4 (Selected Scientific Papers, SC-CAMLR-SSP/4) : 495-511 : Автор(ы): Kuechle, V.B.

6. On reproduction of Electrona carlsbergi (Tåning)

   presents results from histological examinations of gonads of Electrona carlsbergi from the Atlantic sector ... of the Southern Ocean. From materials available it has been ascertained that E. carlsbergi spawns in ... the notal waters. Maturation of females begins when body length reaches 76 to 78 mm. Vitellogenesis is ... . Maturation of ovaries is continuous, and spawning is serial. The spawning season is long and coincides with ... diameter from 10 to 30 J.Ill1. The membrane has no structure. The cytoplasm is heterogeneous; the ... fish cannot spawn in the Antarctic zone at all or that no spawning might have occurred in the period ... gonads of Electrona carlsbergi from the Atlantic sector of the Southern Ocean. From materials available ... it has been ascertained that E. carlsbergi spawns in the notal waters. Maturation of females begins ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 397–409 : Автор(ы): Mazhirina, G.P.

7. Sexing of adult Adélie penguins by discriminant analysis of morphometric measurements

   determine the sex of Adélie penguins. A sample of 46 adult birds was taken for measurement from the breeding ... population at Stranger Point (King George/25 de Mayo Is., South Shetland Islands). The sex of each bird had ... been determined earlier by means of observing the birds' breeding behaviour (first incubation ... shift). It was found that the combination of flipper breadth, bill depth and length of the middle toe ... determine the sex of Adelie penguins. A sample of 46 adult birds was taken for measurement from the ... breeding population at Stranger Point (King George/25 de Mayo Is., South Shetland Islands). The sex of ... each bird had been detennined earlier by means of observing the birds' breeding behaviour (first ... incubation shift). It was found that the combination of flipper breadth, bill depth and length of the middle ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 543–549 : Автор(ы): Scolaro, J.A., Z.B. Stanganelli, H. Gallelli and D.F. Vergani

8. Modelling krill recruitment

   observed values of the mean proportion of recruits and its variance to model recruitment in a krill ... population in terms of numbers of recruits. The method includes the calculation of natural mortality and ... other parameters consistent with the observed proportional recruitment parameters. A procedure is given ... for generating families of recruitment functions which are consistent with the statistical uncertainty ... , Australia Abstract A method is developed for using observed values of the mean proportion of recruits ... and its variance to model recruitment in a krill population in terms of numbers of recruits. The ... method includes the calculation of natural mortality and other parameters consistent with the observed ... which are consistent with the statistical uncertainty in the observed recruitment parameters. Resume ...

   Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 49–54 : Автор(ы): W.K. de la Mare

9. Areas of seabed within selected depth ranges in CCAMLR Subarea 48.3, South Georgia

   and deeper than 500 m have been estimated from nautical charts. The results are presented by CCAMLR ... Georgia and the whole of Subarea 48.3. An asterisk (*) indicates that there are no reported soundings for ... estimated from nautical charts. The results are presented by CCAMLR fine-scale reporting areas. Resume ... KapTaM 6bIJla onpe,lleJleHa nJlOlIla,llb yqaCTKOB MopCKoro ,llHa no r Jly6HHHbIM ropH30HTaM OT 50 ,llO ... 250 MeTpoB, OT 250 ,llO 500 MeTpoB H rJly6)1{e.Pe3YJlbTaTbI npe,llcTaBJleHbI no MeJlKOMaCIIITa6HbIM ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 459–466 : Автор(ы): Everson, I. and S. Campbell

10. Length-based assessments revisited – why stock status and fishing mortality of long-lived species such as toothfish cannot be inferred from length-frequency data alone

    development. The failure of the tag-recapture program to provide robust assessments in many areas and doubts ... other informative estimators for stock abundance and productivity, the review and the simulations ... enter the fishery and the remaining population continues to increase in size (and age). If there is no ... ) with 0% as a target level or 30–40% where no upper size limit exists. The proportional length-based ... come as no surprise, but simply high- light the limitations of using length-frequency data for the ... CCAMLR aims to ensure that the development of a new and exploratory fishery does not occur faster than ...

    Science Journal Paper : CCAMLR Science, Volume 18 (CCAMLR Science, Volume 18) : 57–73 : Автор(ы): Ziegler, P.E., D.C. Welsford and A.J. Constable

Страницы