A number of artificial reefs has been constructed in many coastal areas of Japan to enhance coastal fisheries. They can improve the productivity but also protect and recover fish habitats, as well as preserve and nurture fishery resources. New methods are required to assess the impact of artificial reefs on the local marine environment and to assess their commercial productivity. The acoustic method is the most practical way to determine the distribution and behavior patterns of various fish, which inhabit the three dimensional space. This information is essential to assess the relationship between the artificial reefs and fish behavior and distribution, and furthermore, the seaweed forest. As the area and depth of fishing developed grounds expand, a method for the evaluation of these grounds despite the time and location is a key requirement. To settle this problem, we explored the combined use of acoustic information from sonar and GIS-based 3D visualized software. This study provides a greater understanding of fish schools and seaweed distributions within the marine environment. It is considered that this method provides valuable fundamental information for building effective coastal fishing grounds and reefs.
