Krill (Euphausia superba) distribution in relation to water movement and phytoplankton distribution off the northern South Shetland Islands
surveyed to investigate mechanisms for the formation of krill concentrations and to estimate acoustic ... biomass of krill in the 1990/91 austral summer. Main krill concentrations occurred in the shelf waters ... north of the islands, as usual. Tracks of drifting buoys (with curtain drogues at 30 m depth where krill ... for krill.) High concentrations of chlorophyll a were also measured in the shelf waters, showing a spatial ...
Meeting Document : WG-KRILL-91/22 : Author(s): Delegation of Japan
Abstract: The influences of biological and physical factors in the environment upon krill ... austral summer. Krill showed a distinct offshore-inshore heterogeneities in abundance and maturity stage ... zone (37.3 g/m2), and the highest along the shelf break (135.1 g/m2) in the inshore zone; krill were ... factors were considered to be responsible for this characteristic distribution of krill. Diatoms were ...
Meeting Document : WG-KRILL-93/38 : Author(s): T. Ichii, H. Ishii and M. Naganobu (Japan)
Differences in distribution and population structure of krill (Euphausia superba) between penguin and fur seal foraging areas near Seal Island
Abstract: Shipboard tracking study for krill-eating predators (penguins and female fur seals ... . Penguin foraging areas were formed in inshore region, where krill frequently occurred but higher density ... areas of krill (≥250g/m2) were rather limited. In contrast, fur sea! foraging areas were formed ... in offshore region, where krill occurred only occasionally but they tended to form extensive aggregations (ca ...
Meeting Document : WG-KRILL-92/27 : Author(s): T. Ichii, H. Ishii (Japan), J.L. Bengtson, P. Boveng, J.K. Jansen (USA) and M. Naganobu (Japan)
Possible effects of different levels of fishing on krill on predators - some initial modelling attempts
of the parameters of predator survival rates as functions of krill abundance, by considering a krill dynamics model ... for certain krill predator species. A "one-way" interaction model is developed, in which krill ... indicate that variability in the annual recruitment of krill results in predator populations being less ... resilient to krill harvesting than deterministic evaluations would suggest. However, the analyses also raise ...
Meeting Document : WG-KRILL-93/43 : Author(s): D.S. Butterworth and R.B. Thomson (South Africa)
the situation where predator survival rates depend on other factors in addition to krill biomass ... . This is achieved by making the survival rates depend instead on krill "availability", where ... there is a random component in the relationship between krill biomass and availability. An examination ... resilience of the albatross population to the effects of a krill fishery. An approach for estimating ...
Meeting Document : WG-Krill-94/24 : Author(s): D.S. Butterworth and R.B. Thomson (South Africa)
Abstract: Estimation of krill target strength was made by ensonification of encaged live krill ... and using trawling-acoustic method. Ensonification of encaged live krill. For aggregations with mean lengths ... in the range (45,50) mm the mean single-krill target strengths are in the range (-68,-69) dB at 136 kHz ... . For aggregations with mean lengths in the range (43,47)mm the mean single-krill target strengths are in the range ...
Meeting Document : WG-KRILL-91/29 : Author(s): S.M. Kasatkina (USSR)
Abstract: Temporal and spatial variability of krill distribution characteristics was investigated ... in an 8 x 6 mile micropolygon, where eight consecutive hydroacoustic surveys were carried out. Krill aggregations ... number varied within the board range from 1 918 to 7 000 and further to 1 554 units. Krill biomass ... in the polygon varied spasmodically within the range from 1 091 to 6 085 tonnes. Krill distribution variability ...
Meeting Document : WG-KRILL-93/35 : Author(s): S.M. Kasatkina, E.N. Tymokhin, P.P. Fedulov and K.E. Shulgovskiy (Russia)
Report of biological observations carried out on board the krill fishing vessel More Sodruzhestva in April to August 1991
Abstract: An observation program was carried out by a biologist-observer on board the krill ... observation of krill fishing operations, collection and processing of catch samples for analysing ... physiological status and size composition of krill and also for determining the level of by-catch of juvenile ... channichthyids. In general, krill density in Subarea 48.2 was twice as high as that in Subarea 48.3. Catch-per ...
Meeting Document : WG-KRILL-92/06 : Author(s): V.I. Latogursky (Russia)
Note on maturity of krill in relation to interannual fluctuations of food environment in the seas around the South Shetland Islands
Abstract: Relationship between food environment and maturity of krill around the South Shetland ... in fraction larger than 2um was high, feeding activity of krill was also high in the natural environment ... . 5 years data from commercial krill trawlers indicates that percentages of occurrence of gravid female ... was high when the feeding activity of the krill was high through out the season. Therefore, interannual ...
Meeting Document : WG-KRILL-93/27 : Author(s): M. Naganobu and S. Kawaguchi (Japan)
Abstract: This paper uses actual krill length frequency data in an attempt to address the problem ... of determining adequate sample size to obtain representative krill length frequency distributions from commercial ... decomposition) which may influence length frequency data quality are also considered. The attention of WG-Krill ... is drawn to the following: * All measurements of length from commercial krill catches should as far ...
Meeting Document : WG-KRILL-90/27 : Author(s): D.G.M. Miller (South Africa)