Abstract
The effect of substrata directions on the biomass of attaching organisms at Nishiura-Kishoh, Numazu, Suruga Bay was investigated. Cathodically protected mild steel plate was used as a substratum and installed in the six different directions of upper and bottom as horizontal orientation, of east, west, south and north as vertical orientation at 3 meters depth. A decrease in the cathodic current density resulted in the high amount of barnacles covering the substratum specifically Styela plicata together with other attaching organisms. Moreover, significant differences in the species composition and development between the upper and bottom directions of the horizontally oriented substrata were obserbved. However, the biomass of barnacles and mussels attaching on the four directions of vertically-oriented substrata were slightly varied.
