Résultats de la recherche
-
Community Structure of copepods in epipelagic layers in the Ross Sea and neighboring waters
Abstract: During the 9th research cruise of the R/V Kaiyo-maru, copepod samples were collected ... groups by cluster analysis based on species abundance and composition. Group 1 located in the north of ... the Southern Boundary of the Antarctic Circumpolar Current was characterized by high abundance (157.5 ... -2279.5; mean 610.5 inds. 1000 m-3) and dominance of Rhincalanus gigas (mean 88.4%). Group 2 located off ...
Meeting Document : WG-EMM-08/36 : Auteur(s): Y. Watanabe, S. Sawamoto, T. Ishimaru and M. Naganobu (Japan)
-
UPDATE ON ITEMS OF INTEREST TO WG-IMAF
Economic Zone that are relevant to the work of WG-IMAF. These developments include refinement of the ... requirement of fishing practices to reduce seabird bycatch by surface longline vessels and the introduction of ... regulations to reduce seabird bycatch by bottom longline vessels. The bycatch of seabirds by fisheries within ... (Convention seabirds) is detailed. This paper includes a tabulation of observed captures by species and ...
Meeting Document : WG-FSA-08/47 : Auteur(s): N. Walker (New Zealand)
-
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 : Auteur(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 : Auteur(s): K. Sawada and M. Furusawa (Japan), N.J. Williamson (USA)
-
Status of krill target strength
Abstract: Empirical estimates for the target strength of krill are extracted from the literature ... . These are confined to measurements on aggregations of live euphausiids, which should avoid a frequent ... cause of bias in single-animal measurements, namely thresholding. Theoretical estimates for the target ... strength are derived from the deformed-cylinder scattering model assuming specific sets of physical and ...
Meeting Document : WG-KRILL-92/11 : Auteur(s): K.G. Foote (Norway), D. Chu and T.K. Stanton (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 : Auteur(s): Delegation of Germany
-
A Comparison Between Age Determinations of the Antarctic Fish Notothenia gibberifrons Lönnberg Using Scales and Otoliths
Abstract: Scales and otoliths were collected from 304 specimens of the Antarctic fish Notothenia ... gibberifrons. When interpreted separately, only 25% of scale and otolith readings agreed. When a scale and ... otolith from a single simultaneously, 75% of readings agreed. of otolith readings changed between specimen ... were interpreted 60% of scale readings and 30% separate and simultaneous interpretations. Estimates of ...
Meeting Document : WG-FSA-89/13 : Auteur(s): R. Coggan (United Kingdom), K. Skora (Poland), A. Murray and M. White (United Kingdom)
-
Analysis of observer coverage for Japanese krill fishing vessels
Abstract: Sources of variability of krill mean length and fish bycatch number was investigated to ... explore proper allocation of scientific observers on Japanese krill fishing vessels using the data from ... 1995 to 2008. Based on the multistage sampling theory, we derived the equation of variance in four ... coefficients of variation (CV) caused by the shifts in coverage at different sampling stages. Vessel coverage ...
Meeting Document : WG-SAM-10/17 : Auteur(s): T. Okuda, M. Kiyota and H. Okamura (Japan)
-
Two decades of variability in krill predators at Bird Island, South Georgia and their potential as ecosystem indicators
Abstract: The breeding performance of seabirds and seals at Bird Island, South Georgia, in the ... Southern Ocean, has been recorded annually for over two decades as part of a large marine ecosystem ... monitoring programme. We examined the mechanistic relationships between, and patterns of inter-annual ... included foraging performance, offspring survival, offspring mass, the contribution of Antarctic krill ...
Meeting Document : WG-EMM-12/16 : Auteur(s): S.L. Hill, C.M. Waluda, H.J. Peat and S. Fielding (United Kingdom)
-
Potential climate change effects on the habitat of Antarctic krill
summer foraging sites of many of these predators are concentrated between 0° and 90°W. Parts of this ... sector have experienced recent localised sea surface warming of up to 0.2°C per decade, and ... projections suggest that further widespread warming of 0.27° to 1.08°C will occur by the late 21st century. We ... assess the influence of projected warming on Antarctic krill habitat quality. The results divide the ...
Meeting Document : WG-EMM-13/20 : Auteur(s): S.L. Hill, T. Phillips and A. Atkinson (United Kingdom)