1998 Fiscal Year Final Research Report Summary
Functional Relationships between Biological Production Process of Bivalve and Water-Current in Estuary
| Project/Area Number |
08660219
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
General fisheries
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
ITO Kinuko Agricultural Science, Tohoku University Assistant Professor, 農学部, 助手 (90191931)
|
|---|
| Project Period (FY) |
1996 – 1998
|
| Keywords | Tidal Flat / Bivalve / Biological Production Process / Water current / Ecosystem / Functional Relationships / Species-Interaction |
|---|
| Research Abstract |
The present study was designed to make clear Functional Relationships between Biological Production Process of Bivalve and Water-Current in Estuary. In order to evaluate the importance of tidal flat on conservation of environments and nursery ground of fish, the most important thing is to solve the complex mechanism of biological production system connecting with physcochemical condition of environment. In this study, we are focusing benthic animal, bivalves which are important species in brackish water ecosystem. The conclusion of this study is as follows.
(1) Transport mechanism on the nutrients which were essential for growth of benthic diatom were cleared, And it was indicated that the continuity among different micro-subsystems are maintained through the transport on nutritional substances by the water current and animal activity.
(2) Some patterns of distributions of bivalve specialized with ecological characteristics were detected. Dominant species of bivalve is Nuttalliaolivacea
… More
on tidal flat in the Naton flyer.
(3) The highest density of Nuttalliaolivacea was indicated at the tidal flat in center of River, where higher velocity of water was decided. The main factors were sediment condition and food availability by controlled with patterns of water current.
(4) Marking- recapture method on growth experiment in the field in order to make clear the biological production mechanism was established. Annual growth of ; increase in shell length was 12-l4mm/year, increase in body weight was 2.8-3.lg/year.
(5) The regression of growth on feeding rate of N.olivacea under the rearing experiments could be determined, And the relationship between the growth and amount of food could be determined in the fields.
(6) Interesting interaction between N.olivacea (bivalve)and K.bicoloratus.(fish) is going to be solved as feeding pressure. High pressure( 1 .5times per day a individual) was observed in April to May in Natori River.
(7) Recovery levels of tentacle of siphon of N.olivacea after cutting on laboratory experiments were determined .And theestimation of feeding pressure on N.olivacea by Kareius bicoloratus in the fields by the procedure according to level of recovery of siphon. Less
|
