Abstract
The investigation of interrelation between attaching organisms and corrosion rate on the mild steel test plate was conducted. The test plates were exposed for 215 days at 1 to 20m depth in Suruga Bay, Sizuoka, Japan. The corrosion rates were revealed to decrease with increasing of attaching organisms and to increase with reducing of them. The green mussles Perna viridis were simultaneously obverved in scattered among on the shell surface of barnacles which already settled and covered over the steel test plates at 1 to 5m depth. The time of attaching of these green mussels in Suruga Bay was estimated to be before the end of November based on the comparative observations on the wet weight and shell size of individuals collected at Tokyo Bay in the same year.
