2006 Fiscal Year Final Research Report Summary
Spatial and temporal variation of planktonic larvae and juvenile of bivalve Meretrix lamarckiion on the exposed sandy beach
| Project/Area Number |
17560454
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
水工水理学
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
YAGI Hiroshi Tokyo Institute of Technology, Graduate School of Information Science and Engineering, Associate Professor, 大学院情報理工学研究科, 助教授 (80201820)
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| Co-Investigator(Kenkyū-buntansha) |
HIGANO Junya National Research Institute of Aquaculture, Fisheries Research Agency, Aquaculture Systems Division, Team leader, 生産システム部, チーム長 (80372019)
TAKEWAKA Satoshi University of Tsukuba, Graduate School of Systems and Information Engineering, Associate Professor, 大学院・システム情報工学研究科, 助教授 (80202167)
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| Project Period (FY) |
2005 – 2006
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| Keywords | exposed sandy beach / Meretrix lamarckiion / beach process / dispersion of planctonic larvae / ALC fluorescent maker / headland defense works / nearshore currents / wind-driven currents |
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| Research Abstract |
In order to understand the fundamental characteristics of movement and recruitment of planktonic larvae and juvenile of bivalve Meretrix lamarckiion on the exposed sandy beach, intensive field surveys and numerical modeling were performed in this study. In the field survey, spatial distribution of juvenile of Meretrix lamarckiion and beach profile changes were measured on the Ooarai coast in Ibaragi prefecture which is the most productive area of Meretrix lamarckiion in Japan. The field measurement results showed that the high density population of early stage juveniles distributed around the shoreline in autumn (recruitment), they moved to offshore region in winter and came back to the shoreline region in spring. This fact suggests that the juvenile of Meretrix lamarckiion seasonally change their habitat between the shoreline zone and offshore region. The fundamental characteristics of juvenile movement of short time scale in the shoreline zone were examined with the ALC fluorescent m
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arker experiment. On the other hand, in order to understand the behavior of planktonic larvae of Meretrix lamarckiion, the numerical model to simulate the dispersion process of planktonic larvae in the open coastal sea has been developed. This model consists of the hydrodynamic model which can simulate the processes from the shelf sea scale to surf zone scale, and planktonic larvae model which is based on the laboratory experiment by Higano et al, (1993). Numerical experiment results showed that the importance of surf zone vertical circulation. The planktonic larvae were trapped in the surf zone and prevented to outflow from the surf zone to offshore region due to the surf zone vertical circulation. Furthermore, the numerical experiments to examine the influence of the headland defense works showed that the offshore current induced due to the headland could outflow the planktonic larvae from the nearshore region. This fact suggests that the headland defense works have a large impact on the dispersion and recruitment process of planktonic larvae of Meretrix lamarckiion. Less
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Research Products
(2 results)
