Search results
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Consideration of major issues in ecosystem monitoring and management
by cohort analysis or some other age-based analysis after the event. These methods are well described ... / Description: This paper outlines the requirements of an ecosystem approach to the management of Southern ... Ocean resources and highlights the need for information on harvested and dependent species, their ... interactions and the manner in which their populations vary naturally. Large-scale interactions are catered for ... in the Krill Yield Model (KYM). Smaller-scale interactions centre around three main categories: the ...
Science Journal Paper : CCAMLR Science, Volume 9 (CCAMLR Science, Volume 9) : 213–232 : Author(s): Everson, I
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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 : Author(s): Protaschuk, V.A. and T.A. Lukashova
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Using ecosystem monitoring data to detect impacts
to begin at t = 1 and low values of at indicate unfavourable conditions. Hill et al. 200 All ... reference points and reference periods, there is an upward trend in 1.s pn after 1991, and it rapidly ... Paper Title: Using ecosystem monitoring data to detect impacts Abstract / Description: The ... purpose of ecosystem monitoring programs is to indicate the state of ecosystems and whether they have been ... using monitoring data with no control sites. These methods assess either (i) the expected probability of ... an observed value in an unimpacted system, or (ii) the frequency of values below a fixed reference ...
Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 197–212 : Author(s): Hill, S.L., J. Forcada, P.N. Trathan and C.M. Waluda
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Preliminary model of krill fishery behaviour in Subarea 48.1
: A simple model of the behaviour of the krill fishery in FAO Statistical Subarea 48.1 (South Shetland ... Islands and Antarctic Peninsula) is described. Parameters of the model are calculated from Chilean fishery ... data over the period 1989 to 1992. The distribution of catches predicted by the model, which is ... restricted to the four months December to March, compares favourably with the historical distribution of ... simple model of the behaviour of the krill fishery in FAO Statistical Subarea 48.1 (South Shetland ... Islands and Antarctic Peninsula) is described. Parameters of the model are calculated from Chilean ... fishery data over the period 1989 to 1992. The distribution of catches predicted by the model, which is ... restricted to the four months December to March, compares favourably with the historical distribution of ...
Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 71–79 : Author(s): Agnew, D.J. and V.H. Marín
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Estimating krill recruitment and its variability
likelihood method is developed for the decomposition of krill density-at-length data into the proportion of ... surveys in the South Atlantic and the Indian Ocean sectors of the Southern Ocean give a mean recruitment ... rate for 1+ krill (the ratio of the number of krill aged one year to the number of krill aged one year ... and above) of 0.339 with a standard deviation (SD) of 0.100. The corresponding result for recruitment ... 7050 Tasmania, Australia Abstract A maximum likelihood method is developed for the decomposition ... of krill density-at-length data into the proportion of recruits in a population sampled by a net ... haul survey. Preliminary results from a series of five net haul surveys in the South Atlantic and the ... Indian Ocean sectors of the Southern Ocean give a mean recruitment rate for l+ krill (the ratio of the ...
Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 55–69 : Author(s): de la Mare, W.K
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Detection and quantitative estimation of krill concentrations by hydroacoustic instruments
instruments Abstract / Description: The limited capabilities of existing hydroacoustic instruments in ... in areas surveyed. The task of detecting surface concentrations of krill can be solved with the help ... of towed acoustic antennae. The practical possibility of detecting dispersed krill by hydroacoustic ... instruments was established on board the research vessel Odissey during the international expedition under the ... ESTIMATION OF KRILL CONCENTRATIONS BY HYDROACOUSTIC INSTRUMENTS K.I. Yudanov (U.S.S.R.) Abstract The ... concentrations of krill lead to considerable underestimates of krill biomass in areas surveyed. The task of ... detecting surface concentrations of krill can be solved with the help of towed acoustic antennae. The ... the research vessel Odissey during the international expedition under the FIBEX program. It was ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 123-139 : Author(s): Yudanov, K.I.
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Some principles for fisheries regulation from an ecosystem perspective
/ Description: The paper discusses some principles to be considered in the formulation of a framework for the ... regulation of fisheries from an ecosystem perspective, under the Convention for the Conservation of Antarctic ... regulation which have a more rigorous scientific interpretation than the broad principles of conservation set ... out in the Convention. An important property required for subsidiary objectives is that they are ... REGULATION FROM AN ECOSYSTEM PERSPECTIVE W.K. de la Mare (Australia) Abstract The paper discusses some ... principles to be considered in the formulation of a framework for the. regulation of fisheries from an ... ecosystem perspective, under the Convention for the Conservation of Antarctic Marine Living Resources. An ... rigorous scientific interpretation than the broad principles of conservation set out in the Convention ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 323-339 : Author(s): de la Mare, W.K.
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Alternative methods for determining subarea or local area catch limits for krill in Statistical Area 48
precautionary catch limit on krill (Euphausia superba) in Statistical Area 48. The measure also implies an ... ) the degree to which information on biological relationships is considered; (ii) the cost of data ... collection; (iii) the reliability of required information; (iv) the ease of enforcement; (v) the effects on ... current fishing patterns; and (vi) the potential for delay in implementing the alternative. An alternative ... (Euphausia superba) in Statistical Area 48. The measure also implies an application in future of ... or local area krill catch limits are evaluated relative to six criteria: (i) the degree to which ... information on biological relationships is considered; (ii) the cost of data collection; (iii) the ... reliability of required information; (iv) the ease of enforcement; (v) the effects on current fishing ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/9 (Selected Scientific Papers, SC-CAMLR-SSP/9) : 237–249 : Author(s): Watters, G. and R.P. Hewitt
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A risk-management framework for avoiding significant adverse impacts of bottom fishing gear on Vulnerable Marine Ecosystems
Ecosystems (VMEs) are avoided. Due to the high levels of uncertainty surrounding both the evidence of VME ... presence and the consequences of interaction with different types of gear, a risk-management framework is ... proposed, similar to that which has been used successfully to minimise the effects of longline fishing ... mortality on seabirds. Risk is broadly defined as the conditional probability of adverse impacts given ... MARINE ECOSYSTEMS K. Martin-Smith Australian Antarctic Division Department of the Environment, Water ... , Heritage and the Arts 203 Channel Highway, Kingston 7050 Tasmania, Australia Email – keith.martin-smith ... impacts of bottom fishing gear on Vulnerable Marine Ecosystems (VMEs) are avoided. Due to the high levels ... of uncertainty surrounding both the evidence of VME presence and the consequences of interaction ...
Science Journal Paper : CCAMLR Science, Volume 16 (CCAMLR Science, Volume 16) : 177–193 : Author(s): Martin-Smith, K
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Choosing distance between acoustic survey tacks
mathematical model was used to show that the distance between acoustic survey tacks can reasonably be selected ... on the basis of typical size of the surveyed region, allowable relative error in the biomass estimate ... , and the variation coefficient of the density values of the krill concentrations. It is recommended ... that the suggested criterion be applied in real hydroacoustic surveys. File: 08-Kalikhman-et-al.pdf ... mathematical model was used to show that the distance between acoustic survey tacks can reasonably be selected ... on the basis of typical size of the surveyed region, allowable relative error in the biomass ... estimate, and the variation coefficient of the density values of the krill concentrations. It is ... recommended that the suggested criterion be applied in real hyroacoustic surveys. CHOISIR LA DISTANCE ...
Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 153-164 : Author(s): Kalikhman, I.L., Z.I. Kizner, B.R. Zaripov and W.D. Tesler