Abstract
Growth and yield of Laminaria japonica culture in the coastal areas of Minamata City, Yatsushiro Sea, was experimentally studied for 3 years, from the 2004 to the 2006 seasons. The purpose of this study was to estimate the withdrawal of eutrophicating substances, such as N and P, and to increase juvenile fisheries resources through cultivation of such seaweed. Thin ropes on which the young sporophytes (seedling) were attached were cultured from early December, when water temperature dropped to 20°C, until middle of May, when water temperature increased to about 20°C. Final yield of seaweed for the 2006 season was 11.8 tons, 7.5 tons for Laminaria japonica, and 4.3 tons for Undaria pinnatifida, which has been cultured at the same time with Laminaria. These yields amounted to the withdrawal of 74.5 kg of N, and 10.3 kg of P, from the water. Further works and development for the future was described.
