Recently, the creation of the marine algae community in the structure is requested as an environmental symbiosis function. The structure that adds this function has been constructed also in Hokkaido. The transition of the marine algae community on the structure after it had constructed was monitored for a long term in the revetment in the Samani fishing port and the Urakawa port.
In the Samani fishing port, Laminaria angustata was dominant species as well as the region of the rocky shore in the surrounding in about three years after it had constructed. Moreover, the amount of the seaweed became the similar in a surrounding rocky shore region. In the Urakawa port revetment, the amount of the seaweed on a front mound became the similar in a surrounding rocky shore in about one and a half years after it had constructed. It was observed that the marine algae community on a front mound is the same as it in the rocky shore region.