Development of Marinesnow Analyzing System by using Digital Camera

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 11558065
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: Environmental dynamic analysis
• Research Institution: The University of Tokyo
• Principal Investigator: KOIKE Isao Ocean Research Institute, The University of Tokyo, Professor, 海洋研究所, 教授 (30107453)
• Co-Investigator(Kenkyū-buntansha): NAKAMURA Tetsuya Nichiyu-Giken LTD., Ocean Engineering Section, Researcher, 海洋事業推進室, 研究員
• Project Period (FY): 1999 – 2000
• Keywords: marine snow / large sinking particles / digital camera / white LED light source / deep sea / food webs / cycling of bioelements

Research Abstract

Marine snow is defined as visible marine aggregates (size range more than 0.5mm in diameter) and has been recognized as an important role in the transfer of organic carbon in the upper ocean into deep sea basin through aggregating numerous small organic debris into large size enough for sinking. At the same time, marine snow supplies organic materials to deep-sea organisms as a basis of the food webs. There have been many attempts to apply video-camera or steal-camera for the study of marine snow in various institutions. Those attempts, however, have been hampered by tedious treatment of obtained huge data of pictures. In this study, by taking the advantage of recent advancement of digital camera and other technologies, we developed compact marine snow camera system, which can use down to 6000m depth. The system is composed of light source, digital camera, and data processing portion and all together are assembled into compact flame together with a buttery case. For the light source, we tried to apply white LED light source at the first time deep sea instruments, since buttery consumption of the LED light source is far less than conventional strobe-light. By compiling more than 1000 of single light sources into a flat panel, enough amount of light intensity for photograph of marine snow was obtained. The light panel was arranged to be 90 degree for the camera to get parallel light source. The instrument can accommodate some 250 pictures at the one trip, which is enough to picture 1-5m interval depths at the major thermocline depth (200-800m layers). This system uses the wire-winch on board of research vessel, and collected the data in the memory within the system. After recovery the system on board, the picture data is transferred into data processing system within 30 minutes. In future, real time transfer of data from the system through an armored cable during deploy of the system is possible.