| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2012: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2011: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
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| Research Abstract |
To elucidate common or different mechanisms of synchronous stock decline of megabenthos with different reproductive season in Tokyo Bay, factors affecting mortality during the early life stages of mantis shrimp (Oratosquilla oratoria; summer spawner) and marbled sole (Pseudopleuronectes yokohamae; winter spawner) were investigated.
Field surveys revealed that mortality between larval and juvenile stages might have affected abundance of mantis shrimp. Analysis of spatio-temporal changes in juvenile mantis shrimp and environmental factors showed that hypoxia could cause failure of settlement and contraction of spatial distribution of juveniel, thereby resulted in decrease of young-of-the-year abundance. On the other hand, field surveys revealed that water temperature was a critical factor affecting young-of-the-year abundance of marbled sole; increase in water temperature during reproductive season might have affected mortality of marbled sole between spawning and early larval stages.
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