Detection of sea turtle behavior in a submerged bag net of the set net using acceleration data logger

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07524
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: Shiode Daisuke 東京海洋大学, 学術研究院, 助教 (40361810)
• Co-Investigator(Kenkyū-buntansha): 内田 圭一 東京海洋大学, 学術研究院, 准教授 (50313391) ; 胡 夫祥 東京海洋大学, 学術研究院, 教授 (80293091)
• Co-Investigator(Renkei-kenkyūsha): MIYAMOTO YOSHINORI 東京海洋大学, 学術研究院, 教授 (80251685) ; AKIYAMA SEIJI 東京海洋大学, 学術研究院, 准教授 (00251679) ; TOKAI TADASHI 東京海洋大学, 学術研究院, 教授 (30237044)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: ウミガメ / 定置網 / 混獲 / 突き上げ行動 / 加速度ロガー / はばたき周波数

Outline of Final Research Achievements

When sea turtles accidently enter into a fully-submerged bag net of the set net, they tend to push up the upper net in need of fresh air. In this study, we tried to detect pushing-up behaviors of sea turtles in a bag net with a tri-axial acceleration data logger. Behavior of turtles in the experimental bag net in a tank was recorded by an underwater video camera, and the number and duration of pushing-ups were confirmed. Detection of pushing-up was attempted by filtering the time series attitude angle and the ODBA (Overall Dynamic Body Acceleration) of the turtle which were converted from the static surge acceleration or the tri-axial dynamic acceleration. Moreover, the condition for detection was applied to the results of sea trials. The most accurate threshold was 10 degrees in attitude angle, but ODBA value was not effective for loggerhead turtles. The additional factor of swimming depth could improve precision of the detection in a field experiment.

Free Research Field

生産システム学