Search results
-
Using stationary acoustic platforms to assess precision and accuracy of acoustical krill surveys
issues of krill migrating too close to the surface to be acoustically detected, as well as potential ... issues of diel changes in acoustic scattering strengths. However, due to logistic constraints, acoustic ... effects of krill vertical distribution on survey results. The Institute of Marine Research, Norway has on ... the South Orkney Islands since 2014, and in this report some of these data have been analysed in order ...
Meeting Document : WG-EMM-2019/32 : Author(s): T. Klevjer, G. Skaret and B.A. Krafft
-
On commercial significance of krill aggregations
of acoustic investigation obtained in the Soviet trawler operation areas in Subareas 48.1-48.4 were ... numbering 22000 hauls for the period of 1986-1990 and those from Ukrainian trawlers for the period of 2001 ... and 2002 (2380 hauls). In the course of the recent twenty years, krill has been fished in the areas ... with biomass density of at least 100 g/m2. This threshold value of krill commercial biomass ...
Meeting Document : WG-EMM-03/31 : Author(s): S.M. Kasatkina (Russia)
-
Catchability of midwater trawls in relation to krill fishery
estimation of total krill lengths distribution, obtained on the basis of trawl samples from different catched ... total distribution of krill length, obtained using weighting of trawl samples (usually 200 ind.) against ... the catch, may considerably differ (statistically significantly) from that calculated on the basis of ... trawling. The example of trawl samples processing for the study area off Elephant Island is presented ...
Meeting Document : WG-EMM-98/20 : Author(s): S.M. Kasatkina (Russia)
-
ACCURACY OF BENTHIC INVERTEBRATE BY-CATCH IDENTIFICATION BY OBSERVERS OPERATING IN THE HEARD ISLAND AND MCDONALD ISLANDS PATAGONIAN TOOTHFISH LONGLINE FISHERY
Abstract: As a means of testing the accuracy of observer identifications and to provide ... Antarctic Division (AAD). Observers displayed a high level of accuracy (89%) in the identification of ... longline invertebrate by-catch. Common taxonomic errors included the misclassification of stylasterids ... training in the classification of cnidarians (stony corals, soft corals and stylasterids) and coral-like ...
Meeting Document : WG-FSA-09/23 : Author(s): T. Hibberd (Australia)
-
Interannual variation in the diet of the Antarctic prion Pachyptila desolata at South Georgia
Abstract: The diet of the Antarctic Prion Pachyptila desolata was examined using food samples ... was mainly crustaceans, with a small proportion of myctophid fish and trace amounts of cephalopods ... copepods, especially Rhincalanus gigas and Calanoides acutus, in two years of low krill abundance ... . Differences in the prey species taken and observations of foraging behaviour suggest that in years of low ...
Meeting Document : WG-EMM-97/12 : Author(s): Croxall, J.P., Edwards, T.M., Reid, K.
-
Conditions for the precise measurement of fish target strength in situ
Abstract: Conditions for precise measurement of in situ fish target strength (TS) are empirically ... studied and two indexes are introduced for this purpose. One is the number of fish in the effective ... reverberation volume which contributes echo formation at a certain instant and the other is the percentage of ... the multiple echoes which is derived from a residual of the single echo extraction. With the decrease ...
Meeting Document : WG-Krill-94/35 : Author(s): K. Sawada and M. Furusawa (Japan), N.J. Williamson (USA)
-
Estimation of krill (Euphausia superba) mortality and production rate in the Antarctic peninsula region
Peninsula from 26 December 1989 to 14 January 1990. Results were compared with data of an identical survey ... exceeded a factor of 35 times, while interannual variability between available surveys reached only a ... factor of 1.6 times. Krill mortality was calculated by linearized catch curve analysis and resulted a ... rate of Z=0.88 (1989/90) and Z=0.96 (1987/88). Production was estimated and resulted a P/B ratio of ...
Meeting Document : WG-KRILL-91/15 : Author(s): Delegation of Germany
-
On interim distribution of the trigger level in the fishery for Euphausia superba in statistical Subareas 48.1, 48.2, 48.3 and 48.4
Abstract: This text is revised version of earlier presented by Ukraine document WG-EMM-16/56 ... . Taking into account the current state of krill fishery in Area 48 and other important factors, Ukraine ... proposes to upgrade the Conservation Measure 51-07 in order to redistribute the trigger level of catch in ... 620 000 tonnes between Subareas in Area 48 in a new percentage limits. This revision of CM 51-07 ...
Meeting Document : CCAMLR-XXXV/30 : Author(s): Delegation of Ukraine
-
Preliminary tag-recapture based population assessment of Antarctic toothfish in Subarea 48.4
Abstract: The stock of Antarctic toothfish (D. mawsoni) in CCAMLR subarea 48.4 is estimated from ... tagging returns to be 982 tonnes in 2018. Applying the CCAMLR agreed precautionary assumption of average ... biomass across the time series and harvest rate of γ = 0.038, implies a 2018/19 yield of 37 tonnes ... the 48.4 Antarctic toothfish as a separate stock. Based on the biological characteristics of the ...
Meeting Document : WG-FSA-18/26 : Author(s): T. Earl and A. Riley
-
Modelling growth of Antarctic krill: a new approach to describing the growth trajectory
from population-level data consisting of modal lengths obtained from a time sequence of length ... frequency samples. We develop an alternative approach to predicting the trajectory of length over time using ... a step-growth function that combines models of instantaneous growth rate (IGR) at moult calibrated ... from direct measurements of individual pre- and post-moult krill sampled from the wild with a model of ...
Meeting Document : WG-EMM-05/27 : Author(s): S. Candy and S. Kawaguchi (Australia)