Recently more careful environmental consideration is needed on the occasion of port and airport construction. Construction of port structures gives new physical environmental conditions onto ecosystem around port. However, relationship between marine ecosystem and marine conditions has never been investigated sufficiently. The authors collected the data on marine organisms and executed several field investigation.
　The factors relating to the ecological environment of marine organisms (sessile animals, mobile animals and seaweed) on port structures are sunlight, water quality, current, wall properties of the port structures and waves, etc. The authors considered that both waves and structure type to be the most predominant, and analyzed the relationship between these two physical factors and the quantity and quality of marine organisms which prevailed.