Yoshihiro Suenaga

Techniques for Improvement of Marine Environment Including the Biological Production Using the Industry By-Product

These The state of the aquatic environment in the Seto Inland Sea Japan has become a critical problem. Therefore the development of technology for improving and maintaining the aquatic environment and creating new habitats for marine organisms has become urgent. The present research and study as undertaken in order to develop a new CaCO3 porous material with high bio-affinity for use as a marine habitat. Material tests ere conducted to develop an effective porous material suitable for carbonation. Iron and steel slag (air cooled blast furnace slag) and concrete by-products of reconstruction were used as aggregate in forming the porous material and the void ratios and compressive strengths of the porous material ere studied. The porous material as carbonated, using special carbonation equipment, and the carbonation was observed by a scanning electron microscope. It was possible to confirm an increase in C (carbon) and a decrease in Ca (calcium) in the porous surface. An artificial reef of the CaCO3 porous material will be installed in the Seto Inland Sea and the effect of bait organism curing and organism aggregation will be verified by field observations.

Research on the Discoloration of Nori (Porphyra) and Characteristics of Water Quality Using the Numerical Model

In and around the Seto Inland Sea Japan, there are many aquaculture facilities for Nori (Porphyra). Recently, the production of Nori (Porphyra) severely decreased at Kagawa prefectural coast, eastern Bisan Seto. We have conducted the field research and calculated the trajectories of nutrient particles under the condition in which western wind velocity changes using the numerical model. From the results of field research and numerical simulation, we suggested that Nori bad harvest was caused due to a little rain in the autumn season. It was also suggested that at Nori bad harvest area, the nutrient supply by river discharge was so important for aquaculture of Nori.