A basic study on acoustical measurement of underwater temperature

東京水産大学海洋生産学科東京水産大学海洋生産学科東京水産大学海洋生産学

Communication and positioning system using geostationary satellites

東京水産大学海洋生産学科東京水産大学海洋生産学科東京水産大学海洋生産学科東京商船大学情報通信工学研究

Distribution of phytoplankton chlorophyll continuously recorded in the JARE-25 cruise to Syowa Station, Antarctica (SIBEX I)

The attempt was made to record the geographical distribution of chlorophyll α on a finer scale over semi-global ranges. A prototype of continuous measuring-recording system was designed and built in icebreaker SHIRASE and rich data on chlorophyll distribution were collected on the JARE-25 cruise (1983/84) to Syowa Station in Antarctica. Diel variation of chlorophyll in the Antarctic Ocean was also documented. The results obtained confirm gross patterns of the geographical distribution and diel variation reported by many previous authors. Furthermore, several facts are newly found : e.g., relationships of chlorophyll to temperature are quite variable among different sea areas, diel variation is less intense in the coastal area where a 12-hour periodicity is influential, and occurrence of a certain hydrographic condition which enhances phytoplankton productivity in the area between the Agulhas Convergence and the Subtropical Convergence south of South Africa

Observation of the marine benthic organisms at Syowa Station in Antarctica using a remotely operated vehicle

The authors participated in the 25th Japanese Antarctic Research Expedition and conducted observation of benthos near Syowa Station in Antarctica using a remotely operated vehicle. In addition to a TV camera, the vehicle was equipped with two still cameras for "stereographic" photographs. As a result of analysis of those photographs, the authors were able to determine the distribution density of benthos. In shallow waters (10 and 16m), motile animals such as urchins (Sterechinus neumayeri) were plentiful, while as the water got deeper (40 and 80m), sessile animals such as tubeworms increased. At the deepest location observed in this study, 200m, Bryozoa were dominant; areas existed where Bryozoa covered the entire seabed

Development of an instrumant for observing fish behavior under the sea ice using ultrasonic pinger near Syaowa Station

This paper describes the development of hardware and software designed for observing fish behavior under the sea ice near Syowa Station, during the 34th Japanese Antarctic Research Expedition (JARE-34) 1992-1994. The system consists of one master station and eight secondary stations and ultrasonic pingers. Each secondary station is composed of an ultrasonic transducer, an ultrasonic transceiver and a radio transceiver. The master station's unit consists of eight channel radio receivers, a transmitter and a 32 bit personal computer. The master unit fixes the fish 3D positions by measuring the time difference between sound reception at the secondary units. At the same time the master unit's computer displays the fish position, while recording measured time differences into the hard disk. Using this system, we tracked Emerald Rock Cod (Trematomus bernacchii) nine times successfully