Survey of environment and benthos in fisheries ground

Fiscal Year

2013

Title

Survey of environment and benthos in fisheries ground

Project and Theme

Project 1. Study on ecological succession of fisheries ground
Representative Organization: Tohoku University
Theme1. Environmental monitoring in coastal sea areas of Miyagi Prefecture
Representative personYoshinari Endo
OrganizationTohoku University
DepartmentGraduate School of Agricultural Science

Research Information

Period and Interval
2013/04/01 - 2014/03/31
monthly
Research Area
Onagawa Bay
Category
Field survey
Overview
The aim of this observation is to understand impacts on environments (water and sedimetnt quality, plankton and benthos) by the tsunami . Specifically as follows. 1. Distribution and origin of deposited materials in Onagawa Bay. 2. Dinstibution of harmful chemicals in fisheries grounds at Onagawa Bay. 3. Ecological succession of benthic community in fisheries grounds at Onagawa Bay. 4. Monitoring of growth and survival of Japanese scallop as indicator of environments in fisheries grounds

Overview of the Observation

Research Point Table
Point
Name1
Coordinates38.44123,141.4586
Name2
Coordinates38.4346,141.46818
Name3
Coordinates38.4295,141.4788
Name4
Coordinates38.42365,141.49153
Name5
Coordinates38.42363,141.50493
Name6
Coordinates38.4237,141.52158
Name7
Coordinates38.42398,141.53778
Name11
Coordinates38.40182,141.4749
Name12
Coordinates38.41193,141.48242
Name16
Coordinates38.43588,141.4777
Name17
Coordinates38.43543,141.48842
Research Point Map & Track Chart Map & Point List
0061_R01.pdf
Results and Future Plan
The concentration of heavy metal and COD in the sediment were higher than that before the tsunami in Onagawa Bay. Moreover, macrobenthos community changed after the tsunami, namely, species had tolerance for pollution predominated. It seems that these phenomenon were caused by the mud (thickness of a mud layer was 6-15cm) deposited on the sea floor by the tsunami. Judging from vertical distribution of Cesium-137 concentrations in the mud layer, there is a possibility that the sediment turns mud into sand depending on the mud erosion in a short term. Moreover, the benthos had ability for high dispersion tended to predominant after the tsunami, however, the dominant species before the tsunami gradually increased. In this way, the tendency that the bottom environment on the sea floor in Onagawa Bay is gradually returning to the environment before the tsunami is recognized. Therefore, it will be necessary to investigate the environment and the benthos on the sea floor continuously in future.

Investigation Item and Data Acquisition

Investigation ItemData Acquisition
Water qualityTemperature, Salinity, DO, Nutrient, Toxic substance (COD, Oil, Cadmium, Mercury, Lead, PCB, Hydrogen sulfide, 1,1,1-trichloroethane, Dioxin
Sediment qualityGrain size composition, COD, Toxic substance (TS, Cadmium, Chromium, Mercury, Organic phosphorus, PCB, Copper, Lead, Arsenic, Nickel, Ignition loss)
MacrobenthosDistribution and species composition
Japanese scallopGrowth and survival

Reference

Related Observation Plan
FY2013 Survey of environment and benthos in fisheries ground
Related Observation Data
Water quality monitoring in Onagawa Bay
Phytoplankton Nagatsuraura 130926
Phytoplankton Ogatsubay 130925
Phytoplankton Oppabay 131004_1030
Phytoplankton Samenoura 130930
Phytoplankton Nagatsuraura 140222
Phytoplankton Ogatsubay 140226
Phytoplankton Oppabay 140225_0304
Phytoplankton Samenoura 140227
Zooplankton Nagatsuraura 130926
Zooplankton Ogatsubay 130925
Zooplankton Oppabay 131004_1030
Zooplankton Samenoura 130930
Zooplankton Nagatsuraura 140222
Zooplankton Ogatsubay 140226
Zooplankton Oppabay 140225_0304
Zooplankton Samenoura 140227
Nutrients-Chl.a Nagatsuraura 130926
Nutrients-Chl.a Ogatsubay 130925
Nutrients-Chl.a Oppabay 131004_1030
Nutrients-Chl.a Samenoura 130930
Nutrients-Chl.a Nagatsuraura 140222
Nutrients-Chl.a Ogatsubay 140226
Nutrients-Chl.a Oppabay 140225_0304
Nutrients-Chl.a Samenoura 140227
FY2013_Rinko-Profiler at 3 ocean areas in Miyagi Prefecture
Distribution survey of wild population of Halocynthia roretzi_Distribution of ascidians at Sandoujisaki in Samenoura Bay
Distribution survey of wild population of Halocynthia roretzi_one year juvenile of H. roretzi on bottom block in Samenoura Bay
Distribution survey of wild population of Halocynthia roretzi_one year juvenile of H. roretzi on bottom block in Samenoura Bay (short)
Distribution survey of wild population of Halocynthia roretzi_Sakikamasaki in Samenoura Bay
Distribution survey of wild population of Halocynthia roretzi_Yoriisomarushimasaki in Samenoura Bay
Related Site
http://www.agri.tohoku.ac.jp/teams/english/index.html

Person in charge of Investigation

Representative personKenji Kaneko
OrganizationTohoku University
DepartmentGraduate School of Agricultural Science

Keywords

Fiscal Year2013
OrganizationTohoku University
CategoryField survey
Research AreaSouth Sanriku
DisciplineOcean physics -> Water temperature
Ocean physics -> Salinity
Ocean physics -> Transparency / Turbidity
Ocean chemistry -> Dissolved oxygen
Ocean chemistry -> Nutrients
Ocean environment -> Chemical oxygen demand (COD)
Ocean environment -> Nutrients
Ocean environment -> Plant pigments
Ocean environment -> Heavy metals
Ocean environment -> Oil
Ocean environment -> Transparency
Ocean biology / Ocean ecology -> Arthropods
Ocean biology / Ocean ecology -> Mollusks