Abstract
Reduction of seaweed beds called Isoyake has become a serious problem in coastal prefectures in Japan. Isoyake Recovery Guideline was published in 2007. This report was reviewed about various effects and problems for grazing control techniques of herbivorous fishes which have been conducted in many places after publishing this guideline. And then, it was discussed about the present status of each element techniques and the problems which it should solve in the future. As a result, as grazing control techniques of herbivorous fish, we found that active "removal" for lowering the density of herbivorous fish is more important than "defense" or "dispersion". As the specific case about active removal, it was shown about gill net catch tests of Kyphosus bigibbus we have carried out in 2014 in Iki, Nagasaki prefecture.
