ABSTRACT : Beach nourishment using gravel is one of the effective measures against beach erosion because of the high stability of gravel compared with fine sand. In many cases, the macadam gravel is used for nourishment material so that the sharp-pointed shape of gravel is of concerned. In this study, the change in the shape of gravels due to wave abrasion was investigated. Gravel samples were collected from the Jinkoji and Akashi coasts in Ibaraki Prefecture, where beach nourishment using coarse materials have been carried out since 2005. Samples were taken from the different cross-shore locations while changing the elevation of the beach. Grain size and roundness were measured. It was found that roundness of gravels with an initial value of 0.2 rapidly converges to 0.4-0.5 within approximately two months, implying that the macadam gravels can be safely used as the nourishment materials. In addition, due to the abrasion test of sampled gravels, the content of gravel was as high as 53% of all the volume after the rotation of 2000 times, implying that the nourishment gravels can be kept at least by a half while exhibiting the nourishment effect.

ABSTRACT : Environmental impact assessment (EIS) has become the common requirement for construction projects in recent years. However, the implementation of EIS for the construction project of seacoast protection facilities is limited. In addition, the prediction method of environmental impact for such project is still a subject of investigation. For these reasons, the purposes of this study are set to clarify the association between marine organisms and their habitats through statistical analysis based on field observation data and to predict environmental influence based on the identified association through the analysis. In addition, the result of the statistical analysis was used to evaluate important environmental indicators of physical components of the habitats for the environmental monitoring. This study provides the example of predicting environmental impact by seacoast protection facilities with the actual field data. Also, the result implied the effectiveness of the investigative process established in this study for predicting environmental effect in the similar projects.

ABSTRACT：Through an analysis of the Kasai Seaside Discovery Program which was conducted by the TUMST researcher group and the interpreters (the environmental education practitioners), the potential and the challenges in a collaboration of university and interpreters are discussed. Exchanging knowledge and methods between the groups will help in realizing a high-quality marine environmental education program, while there are remaining challenges to be solved, including cost-effectiveness of programs, setting program coordinators at university, and the need to have an effective education system that combines university education and lifelong education.

ABSTRACT: We investigated distributions of oxygen and carbon dioxide in the bottom waters of the eastern part of Osaka Bay in high temperature seasons of 2009 and 2010. Indoor experiments were also conducted to examine the effect of hypoxia and high CO₂ concentration on the survival of southern rough shrimp. CO₂ concentrations of the bottom water increased with decreasing dissolved oxygen and concentrations of dissolved oxygen clearly showed an inverse correlation with those of CO₂. Indoor experiments revealed that the 24-hour median lethal concentration of dissolved oxygen was 1.1mg/l (17% in saturation) at 25℃ for adult southern rough shrimp. No marked difference was observed on the mortality of southern rough shrimp between a combination of high CO₂ (1300ppm) with low dissolved oxygen and a combination of normal CO₂ (450ppm) with low dissolved oxygen.