ABSTRACT : Effective plans for resolving the marine litter issue need to be implemented, and clarifying the marine litter budget in closed water areas is one way to solve the issue. The marine litter budget in the Seto Inland Sea was therefore estimated using the beach litter, questionnaire surveys regarding collected amounts of marine litter, and existing data. The marine litter budget in the Seto Inland Sea was explained using a single box, assuming complete mixing and uniform density. If the standing stock of drifting and beach litter combined is 3,400 tons, then the inflow of litter into this sea from rivers is 3,000 tons/year, generation of litter at sea is 1,200 tons/year, and inflow from the open ocean is 300 tons/year. The amount of marine litter that is collected on the beach and surface in this sea is 1,400 tons/year, outflow to the open ocean is 2,400 tons/year, and sedimentation to the sea bottom is 700 tons/year. Based on these findings, reduction in the standing stock of marine litter and effective collection process were discussed.

ABSTRACT： “Imitation stone” came to be used from 1930's in Japan. It was used mainly in those days in a zoo and an aquarium. In U.S.A., it was used in many theme parks. As a result, the technique of the imitation stone progressed. After 1990, imitation stone came to be used for the maintenance of the coast in Japan. However, there is the construction example feeling sense of incongruity for a coastal landscape. Therefore this study performed questioner survey to evaluate the photograph of the imitation stone. As a result of having compared the success example with the failure example, I discovered the right usage of the imitation stone for the coast.

ABSTRACT : This study is to investigate non-economical value of the “subsistence use” of Tokyo Bay. The occupation of the seaweed cultivation and fishing which represents the Edo culture has declined by reclamation and urban development of metropolitan area for economical purposes. It is very important to make clear the non-economical value of Tokyo Bay at the present moment when economic development has been achieved and new well-being is being groped. Non-economical value is thought to exist in the occupation of seaweed cultivation and fishing before the era of modern rapid economic growth. In this study non-economical value is investigated through analysis of the documents of lives and interview of the people engaged in fishery. The motives of the actions and statements not related with economical purposes were analyzed, and non-economical values were extracted. The non-economical values include spiritual value related with the purpose of life and strengthening the bond in local community.

ABSTRACT : Real-time tsunami prediction methods are developed in this study by an inverse method and an artificial neural network (ANN) method without using the seismic information but only using offshore observed water level variation. The inverse method first estimates tsunami sources and then predicts tsunami profiles with high accuracy for inshore points of interests. The predicted information is easily updated by using longer observation data. On the other hand, the ANN method predict only highest and lowest water level rises and falls; it has a merit that the computation time is several seconds after getting a tsunami profile at a fixed offshore location. The ANN parameters were determined for different tsunami profiles generated by different fault models considering non-uniformity of tsunami source. It was confirmed that ANN gives fast and reliable tsunami predictions once offshore tsunami elevation can be obtained. Both real-time tsunami prediction methods are able to complement the tsunami warning or tsunami advisory provided by the Japan Meteorological Agency for locations of interest taking into account of the detail coastal topography.

ABSTRACT : Bivalves generally form a multilayer structure on coastal artificial substrata. It is indispensable to predict changes in material cycle and food chain due to activities of bivalves such as mussels. If ingestion and respiration rates of an individual mussel are multiplied by total population number, their total fluxes are overestimated since the inner mussels do not contribute to the ambient material cycle. In the present study, a multilayer structure of mussels on cylindrical substrata was investigated at the mouth of Sumida River in Tokyo Bay. The ratio of active mussels to total amount of mussels was revealed in the field investigation. A population model for mussels on cylindrical substrata was developed and validated by the observations. The population model predicted that ingestion and respiration rates are smaller by 20 to 30% than those in the case when all the mussels are assumed to be active in the mussel bed.

ABSTRACT: Along with the growing recognition of the necessity of the integrated coastal management in Japan, the importance of groping for the way of the coastal management has been rising significantly. The objective of this study is to discuss the fishermen’s role in the coastal water zone environmental management in Shiba branch office of Yokohama FCA’s, where fishery is still one of the major activities even after the fishery right was abandoned. As a result, fisherman plays the role in facilitating communication and building common objectives among various users, and also, in pulling up the willingness for the people to continue to the management. Through these actions, fishermen acquire the legitimacy of coastal management. It is also been clarified in this paper that it is essential for the fishermen’s group to acquire the new legitimacy to respond to social demands, and also necessary to make every effort to maintain vitality of the group, to play the successful role in coastal management.

ABSTRACT : The subject of the case study in this paper is all international distribution activities at the Port of Nagoya in the Chubu Metropolitan area where Toukai, Tou-Nankai or Nankai Earthquakes is anticipated in the near future. The concept of the Business Continuity Management shall be developed through research on the current measures taken by the enterprises and organizations who are the port-users. Then the goals and problems regarding the recovery of port functions will be identified. Furthermore, we will attempt to propose technological means to solve the problems and achieve the goals. We believe this study will provide valuable guidelines for the port function recovery in the Chubu area at the time of earthquakes. It will also serve as effective guiding philosophy for many ports in Japan and around the world which face similar problems.

ABSTRACT: The Japanese coastal zones are affected by the warm current and the cold current. The various kinds of seaweed beds are distributed in Japan. In late years, the seaweed beds are decreasing nationwide. The seaweed beds are so-called "a cradle of the sea" bringing up the juvenile fish of many fishery resources. The functions of seaweed beds are the habitation area, the hiding area and the feeding area of the juvenile fishes. Furthermore, the seaweed beds have the function to absorb nutrient and carbon dioxide. Seaweeds become "the drifting algae", flow out into the offshore and change into inorganic matter. In this paper, firstly the process of the drifting algae have analyzed by numerical model. Secondly, several artificial seaweed reefs were compared the quantity of nitrogen absorption of the seaweed beds. Finally, the cost-effectiveness analysis of the seaweed bed creation in Bisan-Seto, Seto Inland Sea has carried out. Main results are as follows. The nitrogen absorption of seaweed beds is 0.18-0.57kg/year/m², and its economical benefit is about 4,000-14,000 yen/year/m². The drifting algae have the function to flow out nutrient into the offshore.