The object of experiment 1 was to check the difference of growth on a spore of seaweed (Ecklonia cava) in the culture tank with or without iron fertilizer. Before executing this experiment we had to get the algae and then dry it in the shade. After extracting seedlings we had put it in the culture tank (Photo 3).

　

　

The experimental date was from October 25 to November 11, 2001 and the place was at building No.5, Department of Oceanic Architecture and Engineering at Nihon University in Japan. We set two tanks; one with iron fertilizer and the other without iron fertilizer. The size of the tanks was 800 x 400 x 500 mm and the volume of seawater was 100 liters. The culture tanks are shown in Photo 4. The iron fertilizer used in this experiment included salt (right side in Photo 2).

　

Figure 1 shows a diagram of the culture tank. Slide glasses were set at the center of the tanks for checking spores by use of a microscope. The weight of iron fertilizer used in this experiment was 40 g, which had been referred to by Hotta and Suzuki (2000), so that the concentration of iron is 0.07(g/L). The other experimental conditions were referred by Sudo, 1948 (Table 1).

　

　

　

　

　

Photo 5 is the result after three days using a microscope. The average number of spores in this case, used with iron fertilizer, was thirty-two, and the number of spores used without iron fertilizer was eighteen. The germination of spores used with the iron fertilizer was much better than the germination of spores without using the iron fertilizer.

　

　

Photo 6 is the result after five days. The average number of spores used with iron fertilizer was twenty-nine, and the number of spores used without the iron fertilizer was sixteen. In the case of including iron fertilizer, distinguishable male and female were found out, but we could not see these in the other case.