Evaluation of carbonated solids as seaweed bed substratum

The average number and length of Sargassum plants that have settled on the three types of substrata, carbonated steel-making slag block, granite stone , and cement concrete block, deployed from April 1998 to January 1999 at Ko une, the Seto Inland Sea of Japan, were compared. Results showed that maximum length of Sargassum plants that have settled on the three types of substrata did not vary significantly, so the strength o f adhesion of the plants was the same for all substratum types. On the othe r hand, the average number of plants that have settled on the test pieces o f carbonated steel-making slag block was higher than that on the cement con crete block although not significantly different from that on the granite s tone. This suggests that carbonated steel-making slag blocks have good pote ntial as seaweed bed substrata.