Fiscal Year
2013
Title
Field survey of rocky shore ecosystem in Shizugawa Bay
Project and Theme
Project 1. Study on ecological succession of fisheries ground
Representative Organization: Tohoku University
Theme2. Ecosystems and genetic researches to conserve and restore the coastal fisheries areas in Miyagi Prefecture| Representative person | Yukio Agatsuma |
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| Organization | Tohoku University |
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| Department | Graduate School of Agricultural Science |
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Research InformationPeriod and Interval2013/04/01 - 2014/03/31
monthly
Research Area
Shizugawa Bay
CategoryField survey
OverviewLarge perennial kelp Eisenia bicyclis provides foods for commercially important organisms such as sea urchin Strongylocentrotus nudus and abalone Haliotis hannai hannai. We study the effect of tsunami and subsidence on population dynamics of the kelp, sea urchin, and abalone. We also study the effect of oceanographic condition on growth and color of commercially important kelp Undaria pinnatifida cultivated in Shizugawa Bay.
Overview of the Observation
Research Point Table
| Point | | Name | Parmanent site |
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| Coordinates | 38.6589,141.4491 |
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| Name | A |
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| Coordinates | 38.6736,141.5111 |
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| Name | B |
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| Coordinates | 38.6758,141.4958 |
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| Name | C |
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| Coordinates | 38.6581,141.4511 |
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| Name | D |
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| Coordinates | 38.6453,141.495 |
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| Name | E |
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| Coordinates | 38.6369,141.5244 |
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Research Point Map & Track Chart Map & Point List
Results and Future PlanWe studied population dynamics of the large perennial kelp Eisenia bicyclis at a parmanent study site located in the innermost part of the Shizugawa Bay (Bentenzaki). Density of the kelp decreased between November 2013 and February 2014 at two deeper depth zones (5.9 and 7.5m-depth) but not at three shallower depth zones (1.5, 3.1, and 4.7m-depth). During this periods, density of the sea urchin Mesocentrotus nudus increased at three deeper depth zones. The kelps growing at the deeper depth zones might be destructively grazed by the sea urchins. We also studied the effect of nutrient enrichment on production of the kelp Undaria pinnatifida cultivated in the innermost part of the Bay. We found that nutrient enrichment by coated fertilizer enhanced growth of the kelp Undaria pinnatifida. Further study is needed to ensure production and quality of the cultivated kelp by using fertilizer.
Investigation Item and Data Acquisition
| Investigation Item | Data Acquisition |
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| Sea urchin | Density, size frequency in test diameter |
| Large perennial kelp Eisenia bicyclis | Densities of adults and juveniles |
| Cultivated kelp Undaria pinnatifida | Thallus length, wet weight, density, nitrogen concentration |
| Environmental condition | Light and nutrient conditions, temperature, sediment |
Reference
Related Observation Plan
Related Observation Data
Person in charge of Investigation
| Representative person | Yukio Agatsuma |
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| Organization | Tohoku University |
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| Department | Graduate School of Agricultural Science |
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| Representative person | Hikaru Endo |
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| Organization | Tohoku University |
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| Department | Graduate School of Agricultural Science |
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| Fiscal Year | 2013 |
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| Organization | Tohoku University |
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| Category | Field survey |
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| Research Area | South Sanriku |
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| Discipline | Ocean physics -> Water temperature
Ocean physics -> Ocean current / Tidal current (Current direction/Current speed)
Ocean physics -> Others
Ocean chemistry -> Nutrients
Ocean environment -> Nutrients
Ocean biology / Ocean ecology -> Biomass
Ocean biology / Ocean ecology -> Physiology
Ocean biology / Ocean ecology -> Ecology
Ocean biology / Ocean ecology -> Sea algae
Ocean biology / Ocean ecology -> Seaweed beds / Tidal flats distribution
Ocean biology / Ocean ecology -> Others
Topography / Geology / Geophysics -> Seabed morphology
Topography / Geology / Geophysics -> Bottom sediment
Topography / Geology / Geophysics -> Marine sediments
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