Experimental research on the life space of the deep-sea large-sized swift-moving benthic organisms
| Project/Area Number |
14540575
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
生態
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
OHTA Suguru The University of Tokyo, Ocean Research Institute, Professor, 海洋研究所, 教授 (10013591)
|
|---|
| Project Period (FY) |
2002 – 2004
|
| Project Status |
Completed (Fiscal Year 2004)
|
| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥2,300,000 (Direct Cost: ¥2,300,000)
|
|---|
| Keywords | Benthos / Up-swimming / Community structure / Bait-trap / Deep-sea camera / Current meter / Bottom water movement / Gravity current / 深海 / 大陸斜面 / 底魚 / 中層への泳ぎ上り / 生活圏 / 底生性魚類 / 海底係留系 / 深海トロール / 鰾 / 奇網 |
|---|
| Research Abstract |
Bottom-moored beat-trap-camera-current meter systems were deployed on the deep-sea floor to attract benthic swift-moving organisms by remote chemical stimuli and possibly by auditory sense. Experiments of this year were focused on the vertical migration of deep-sea demersal fishes and decapods using vertical series of baited-traps on a single mooring system during KT-04-07 and KT-04-10 cruises.
Bottom-moored system consisted of a bottom base (bait-trap, camera, current meter and acoustic releaser mounted on a frame with buoys and ballast weights), and a series of bait traps situated 50m, 100m, 200m and 400m above bottom. Bottom mooring duration was 24 hours. The camera recorded and the bottom bait-trap collected ordinary benthic faunal composition and biomass as can be expected. Two deep-sea cods, Physiculus maximoviczi were collected 200m off bottom, and gave the actual data of 200m/24hrs vertical migration. However, the components of the vertical migrants were only a fraction of the members inhabiting the deep-sea floor. The results of the Sagami Trough evidenced another pronounced events. Dense clouds of gravity currents attacked the station, and the bottom 100m layer was severely blurred by the sediment clouds and collected no catch and gave no photographic records. Some elements collected 200m off the bottom can be interpreted as the avoidance of the gravity currents. Many reports of the rarely occurring swimming up of deep-sea macrourids are apt to lead to the overestimation of the swimming up movement of the many demersal fishes. These notion contradicts to the low density of midwater prey organisms.
Parallel experiments of intensive trawling revealed, 1)subtle difference of the faunal composition in the daytime trawl and nighttime trawl on the upper bathyal zone, and 2)the change in bathymetrical zonation and food habit along with the growth. These results were published on the domestic and international journals.
|
Report
(4 results)
Research Products
(5 results)
