Abstract
The ecological-designed revetment in Ohama area in the Port of Akita, Japan (Ohama revetment) was implemented along the Sea of Japan with unique structural features. The revetment was designed for attempting to develop a macro algae bed as a spawning ground of sandfish. In this study, a set of field observation of environmental factors and an assemblage of marine organisms was conducted after completion of the revetment for a year. Low salinity in the water surface and decreasing relative light intensities with depth were observed around the revetment. Diatoms, chameleon goby (Tridentiger trigonocephalus), bivalve (Mytilus galloprovincialis), and sea cucumber (Stichopus japonica) were dominant species around the revetment. These results indicate that the water structure around the revetment had strong stratification, and the revetment functioned as a habitat for various marine organisms. Sandfish were sampled around the revetment; however, they did not spawn on the revetment. Macro algae are essencial substrates for sandfish spawning, but few macro algae have developed on the revetment because of strong stratification. An artificial spawning materials could provide altanative solu-tion for the case. This report described an initial situation; however, continuous monitoring is needed to determine the dynamics of the assemblage of marine organisms and to estimate its potential as a spawning site.
