Acoustic estimation of krill biomass in R.V. KAIYO MARU SIBEX I survey area (Indian Sector of the Southern Ocean)
スポンサーリンク
概要
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During the austral summer of 1983-84,the acoustic survey to estimate the biomass of krill (Euphausia superba) was carried out twice in the area between 65°and 75°E and south of 61°S in the Indian Sector of the Southern Ocean by the R. V. KAIYO MARU participating in SIBEX I. The southern limits of the study areas were 64°S for the first survey and 69°S for the second. The mean volume back-scattering strength was measured by horizontal interval of 1nnautical mile and 7 vertical channels in the depth range between the top depth (10-25m) and 200m, using the 200kHz echo sounder with a digital integrator. The scattering strength was converted into the weight density using the constant mean target strength per kg. The estimated mean weight density per unit surface area in the nighttime was significantly lower than the density in the daytime. The tendency for krill to rise near the surface at night might give a lower bias to the nighttime estimate. The analysis using only the daytime data (3346 intervals throughout the whole survey) resulted in the mean surface density of 15.9g/m^2 in the area (3.45×(10)^5(km)^2). The total biomass estimated from the survey was 5.49 milliont. Discussion was made on possible errors or biases of the estimate, derived from adequacy of the absorption attenuation coefficient adopted in the survey, statistical sampling error, occurrence of krill beyond the depth range of the acoustic detection, and target strength error.
- 国立極地研究所の論文
著者
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Komaki Yuzo
Far Seas Fisheries Research Laboratory
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Komaki Yuzo
Far Sea Fisheries Research Laboratory
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Shirakihara Kunio
Shimonoseki University Of Fisheries
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Nakayama Kakusuke
Hokko Maru, Hokkaido Regional Fisheries Research Laboratory
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Nakayama Kakusuke
Hokko Maru Hokkaido Regional Fisheries Research Laboratory
関連論文
- Occurrence of armoured dinophytes along the longitude of 75゜E in the Antarctic Ocean (extended abstract)
- Changes in the condition of the surface water and distribution of Euphausia superba DANA between 65゜E and 75゜E in the Antarctic Ocean during the pack ice melting season (extended abstract)
- Biomass and population structure of Antarctic krill (Euphausia superba DANA) collected during SIBEX II cruise of R.V. KAIYO MARU
- Distribution of particulate organic materials in the Pacific and Indian Sectors of the Antarctic Ocean in the austral summer
- Morphology and distribution of heterotrophic protists along 75゜E in the Southern Ocean
- Target strength of krill in situ at the frequency of 200kHz
- Acoustic estimation of krill biomass in R.V. KAIYO MARU SIBEX I survey area (Indian Sector of the Southern Ocean)
- Temperature and geostrophic flow distributions along 90゜W, the Drake Passage and 30゜W in the Southern Ocean in December 1984-January 1985 (abstract)
- Meridional temperature gradient in the eastern Drake Passage in December 1984 (abstract)
- Ecological characteristics of Euphausia superba DANA in the Southern Ocean (abstract)
- Distribution and abundance of pelagic fishes in the epipelagic layers of the Indian Sector of the Southern Ocean in summer, 1983-84