Résultats de la recherche
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Laboratory target strength measurements of free swimming Antarctic krill (Euphausia superba)
single animal insonifications. For mean length classes in the range [29.6, 36.2] mm the median single ... -animal target strengths are in the range [-76.7,-71.8] dB. Monte Carlo computer simulations were used to ... evaluate the effects of varying the ratio of largest to smallest echo amplitudes for a given ensemble, thus ... bias was then determined for each ensemble of experimental data and used to determine corrections which ...
Meeting Document : WG-EMM-97/75 : Auteur(s): Pauly, T., Penrose, J.D.
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Further computations of the consequences of setting the annual krill catch limit to a fixed fraction of the estimate of krill biomass from a survey
), as a function of the fraction of the biomass estimate which is set as the catch for a 20-year period ... a summer harvest. However, the imposition of an upper bound of 1.5 yr-1 on the effective annual ... et al. (1992) put forward an extension of the harvesting model of Beddington and Cooke (1983) to ... over the ranges of uncertainty for a number of model parameters. Results are provided for the ... any year, an upper bound of 1.5 yr-l is placed on the effective annual fishing mortality for fully ... biomass estimate which is set as the catch for a 20-year period. Three possible fishing seasons are ... drawn at random from pre-specified distributions for each simulation of a 20-year period of harvesting ... ) requested that statistics be provided for a 10- as well as a 20-year period of harvesting. Calculations ...
Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 81–106 : Auteur(s): Butterworth, D.S., G.R. Gluckman, R.B. Thomson, S. Chalis, K. Hiramatsu and D.J. Agnew
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Trends of Antarctic fur seal population at SSSI No. 32, Livingston Island, South Shetlands, Antarctica
parameters to an environmental index (the Southern Ocean Oscillation Index- SOI). Two fur seal censuses were ... environmental phenomena if the population is under a monitoring programme, and may have an interesting effect on ... Abstract: We update in this paper the previously reported model for the Antarctic fur seal ... . From this, we estimated an overall increase of 17% in the total population, including in this figure a ...
Meeting Document : WG-EMM-99/16 : Auteur(s): R. Hucke-Gaete, D. Torres, A. Aguayo, J. Acevedo and V. Vallejos (Chile)
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Cetaceans as indicators of historical and current changes in the East Antarctica ecosystem
Antarctic minke whales could have decreased in recent years. Decrease in availability of krill for this ... the East Antarctica ecosystem in the context of two hypotheses, the ‘krill surplus’ hypothesis in the ... middle of the past century and the recovery of krill-eater large whales since the 1980’s. There was an ... have been translated into better nutritional conditions for some krill predators like the Antarctic ...
Meeting Document : WG-EMM-16/64 : Auteur(s): Y. Fujise and L.A. Pastene
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REPORT OF THE SECOND MEETING OF THE SEABIRD BYCATCH WORKING GROUP, HERMANUS, SOUTH AFRICA, 17-18 AUGUST 2008
a useful model for ACAP, noting that an observer program with high levels of coverage had been ... fell into two broad categories: those focused on the trawl warps, and those focused around trawl nets ... . For reducing seabird strikes on trawl warps, the use of bird-scaring lines has been proven to be the ... warp strikes, there continues to be the need for more work on effective measures for reducing seabird ...
Meeting Document : WG-FSA-08/61 : Auteur(s): ACAP Seabird Bycatch Working Group
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Krill (Euphausia superba Dana) resources and distribution in the Wilkes Land area in the seasons 1986 to 1989
mainly focused on the search for exploitable krill aggregations. Two research vessels were simultaneously ... account an area to the north of the edge of the continental slope. Each subarea was described in terms of ... was considered as the most valuable for the krill fishery. Krill aggregations were most frequently and ... for Fisheries 3 The annual period used is the split-year 1 July to 30 June. Split-year is denoted by ... for exploitable krill aggregations. Two research vessels were simultaneously involved in the survey ... 1986 50 12.2 1000 50.0 20 to 21 April 3 1986 300 3.5 158 47.5 24 to 30 April 4 1987 127 14.0 1510 ... : Assessments ofkrill resources for subarea ill (64°40' to 66°20'S, 143° to 1500 E). Sequential Period of Area ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 149–162 : Auteur(s): Dolzhenkov, V.N. and V.P.Timonin
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MITIGATION OF SEABIRD CAPTURES DURING HAULING IN CCAMLR LONGLINE FISHERIES
Abstract: In recent years there has been an increased focus on reducing ‘residual’ seabird ... suggests that there are two key aspects of effective BED, firstly that they provide a deterrent to birds ... incorporates the two key functional characteristics required to reduce seabird captures during the haul ... three types and recommendations are made on a Type III BED that was developed in Division 58.5.2 and ...
Meeting Document : WG-IMAF-09/14 : Auteur(s): E. Reid, B. Sullivan (BirdLife International), K. Reid (Secretariat) and J. Clark (United Kingdom)
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Entanglement of Antarctic fur seals (Arctocephalus gazella) in man-made debris at Signy Island, South Orkney Islands, 2004/05
Island, South Orkney Islands are reported for the 2004/05 summer season. There were two sightings of ... one case the entangling material had become attached to a rock and the animal was tethered to the ... ground. The incidence of entanglement at Signy Island, albeit very low, highlights the need for CCAMLR ...
Meeting Document : SC-CAMLR-XXIV/BG/18 : Auteur(s): Delegation of the United Kingdom
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Adélie penguins as indicators of the state of the sea-ice in Adélie Land
weakened young chicks. While we haven’t seen yet the consequences of this “zero year” on the demography of ... Island, Terre Adélie, failed to fledge their chicks. This catastrophic breeding failure resulted from two ... factors. First, the season saw an extreme sea-ice extent that forced Adélie parents to cover great ... desertion by the partner and the risk of dying of prolonged fast for the chick(s). Second, the season was ...
Meeting Document : WG-EMM-17/01 Rev. 1 : Auteur(s): Y. Ropert-Coudert, A. Kato and C. Barbraud
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Adélie penguin foraging behaviour and breeding success in seasons of contrasting krill availability (Mawson Coast, Antarctica)
period. Data on meal mass and foraging trip duration were combined to provide an index of provisioning ... Abstract: Parameters measured under the CCAMLR Ecosystem Monitoring Program (CEMP) for Adélie ... present during the two-week survey period in 2001 than in 2003. Penguin parameters that showed significant ... differences between the two seasons included A5: foraging trip duration, A6: breeding success and A8: meal ...
Meeting Document : WG-EMM-03/44 : Auteur(s): J. Clarke, M. Tierney, S. Candy, S. Nicol, L. Irvine and K. Kerry (Australia)