Sterile Ulva, which is a macroalga, has the potential to grow stably; therefore, this seaweed is expected to be an efficient resource of functional food containing various nutrients such as sulfur amino acids, proteins, carbohydrates, and minerals. Ulva latuca was selected from the "Marine Park" in Tokyo Bay, and its growth rate (g-dry/[m2.d]) was measured using model reactors located on the land or on the surface of the sea at Yokohama. The growth rate of U. lactuca was recorded to be approx 20 g-dry/(m2.d), which is estimated to be 10 times greater than that in a natural field in the Marine Park. In addition, this growth rate was higher than that of conventional crops such as corn and rice on a farm or paddy. These data led us to newly design and propose a floating type of labor-efficient U. lactuca production system. d-Cysteinolic acid, which is included in U. lactuca as a major sulfur amino acid, inhibited the Fenton reaction, resulting in suppression of hydroxyl radical production and singlet oxygen. Addition of the sulfur amino acid (1 microM) to HepG2 cells markedly decreased the intracellular triglyceride level. Hence, this proposed facility also has the potential for industrial production of a valuable resource for the primary prevention of lifestyle-related diseases using enriched or eutrophied seawater.

Masashi MIYASAKA Buoyancy-driven vertical piling breakwater-a new type of breakwater formed by upper and lower steel pipes rises above sea level by feeding the air into the upper pipe when high waves or tsunamis are imminent , whereas it normally rests inside the lower pile installed below seabed so that navigation is undisturbed . This paper outlines the results of a series of experiments by a large scale physical model and of the numerical analyses with regard to the rising / sinking behavior of the breakwater. The results clearly demonstrate that: 1) The time required for raising the upper pipe is just a few minutes, being rapid enough to prevent tsunamis from attacking harbors; and 2) The numerical model gives good approximation and is fairly applicable.