| Case Name |
The fishery damage by National Isahaya Bay Reclamation Work |
| Pictograph |
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| Date |
April 14, 1997 |
| Place |
Nagasaki Prefecture |
| Location |
The Isahaya Bay |
| Overview |
In spite of the opposition of many fishery party and local people, the water gate of the Isahaya Bay salt pan embankment was closed on April 14 in 1997.
National Isahaya Bay Reclamation Work was started following this, and over 90% of the construction has already ended.
The purpose of this project is " 1. Realising the agriculture with the high productivity by developping the large-scale, flat superior farmland which has the regulating reservoir and the water whose source is the regulating reservoir. 2. Strengthening the disaster prevention function against the storm tide, the flood, and the ill-drainage in the backswamp. "
But National Isahaya Bay Reclamation Work is said to have caused something unusual in the Ariake Sea, and it has also caused the large disturbance of the fisheries promotion that is the decrease in the laver harvest and so on .
The nation and Nagasaki Prefecture should carry out the proper reevaluation for this project, and make public.
The examination of stopping the project has also been required. |
| Incident |
The content of the construction is isolating the end of the Isahaya Bay by the salt pan embankment and creating the reclamation farmland about 700 hectares inside.
About the cause-and-effect relationships between National Isahaya Bay Reclamation Work and something unusual in the Ariake Sea, the investigation work has still been continued. |
| Sequence |
In April of 1997, The south part of the Isahaya Bay salt pan embankment was closed at a length of about 1.2km .
In March of 1999, the Isahaya Bay salt pan embankment was completed.
In December of 2000, the great bad crop of the laver started in the Ariake Sea.
In March of 2001, the Minister of Agriculture, Forest and Fishery manifested "interrupting the construction".
the Minister of Agriculture, Forest and Fishery decided to release the drainage gate.
In January of 2002, the Minister of Agriculture, Forest and Fishery resumed the construction in spite of the opposition of the fishermen.
In November of 2002, the "Come back, the Ariake Sea! Litigation" plaintiffs ( 416 members ) went to Saga district court over the first suit that is "Requiring to stop constructing the front embankment of the Isahaya Bay Reclamation Work".
On August 26 in 2004, Saga district court ordered "Don't continue the construction till the initial judgment". |
| Cause |
* The holes ,which were dug in order to pick sea sand, have been a hotbed of the anoxic water mass.
* The salt pan embankment has caused weakening the tidal current and raiseing the tidal level.
* "Foul water" discharged from regulating reservoir has contaminated the whole Ariake Sea.
* The Isahaya Tideland Mud Flat , which had retained the high clarification function, decreased because of the closing the salt pan embankment.
Because of the drainage from the regulating reservoir, the discharge volume of organic matters, phosphorus, nitrogen, and so on have increased.
* The holes, the embankment, and the foul water, have caused generation of the red tide.
* Since there had not been countermeasures against the high water at all at the Oura Harbor, the dangers in typhoon ( , storm tide, or flood tide ) increased after the completion of the salt pan embankment. |
| Response |
When the crop of the laver was bad, some fishermen have carried out the acid treatment which began at the middle at the 1970's.
But it is said that the acid treatment may cause the further vicious circle. |
| Countermeasures |
Against the background of the national criticism which was "Once public work starts, it never stops", in December of 1997 Prime Minister Ryutaro Hashimoto directed the 6 public work relation of 6 ministries and agencies concerning public works to introduce the reevaluation system of public works.
That was why, the Ministry of Agriculture, Forest and Fishery has introduced its own reevaluation system starting in fiscal 1998.
But this reevaluation system has many imperfections, which are pointed out. |
| Knowledge Comment |
* When the Government plans and undertakes projects, it should consider the latest socioeconomic situations, environmental problems, and so on.
And the Government should carry out the strict evaluation ,which is based on fair and proper information, in the transparent process.
* According to the change of the socioeconomics situation, the administration should carry out the reevaluation anytime.
* If they take makeshift action on situations without examining the basic measure, it may cause the vicious circle by. |
| Background |
The Isahaya Bay Reclamation has the long history .
The durable reclamation had been carried out by the technology which skillfully utilized the natural environment called "the sight frontage reclamation" since about 600 years ago.
Today's plan of the large-scale and compound reclamation was started by "the Nagasaki Large Reclamation Plan" in 1952.
The project done at present was named after "the Isahaya Bay Disaster Prevention Total Reclamation Project" planned in 1983.
The drastic extension in the construction period ( the completion schedule : fiscal 2006 ) and the increase in the cost ( 249 billion yen ) have been expected. |
| Scenario |
| Primary Scenario
|
Organizational Problems, Poor Management, Poor Concept, Poor Strategy or Concept, Misjudgment, Narrow Outlook, Insufficient Analysis or Research, Insufficient Prior Research, Planning and Design, Poor Planning, Non-Regular Action, Change, Secondary Damage, Damage to Environment, Damage to Society, Change in Perception
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| Sources |
http://www2s.biglobe.ne.jp/~isahaya/
|
| Number of Deaths |
0 |
| Number of Injuries |
0 |
| Physical Damage |
the decrease in the fishries |
| Consequences |
The administration disregarded the opposition of the local inhabitant, and brought about the national criticism and distrust which is "Once public work runs, it never stops". |
| Field |
Civil Engineering
|
| Author |
KUNISHIMA, Masahiko (The University of Tokyo)
MIURA, Tomohide (The University of Tokyo)
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