STUDY ON THE NATURE RESTORATION OF JINZU RIVER FOR IMPROVEMENT OF THE HABITAT OF Oncorhynchus masou masou

Abstract

In Jinzu River, Oncorhynchus masou masou has decreased for about 50 years. The existence of large pool is very important, but, for O. masou masou spending most of the duration of survival in a river, O. masou masou habits information is not known enough. A movement course of O. masou masou was clarified by using the radio telemetry system. O. masou masou spent summer in large pool of the main stream and it went up at a branch (Kumano River) and laid eggs, but some barrages disturbed going up. Therefore, for the resources recovery of O. masou masou, restoration of large pool in main stream and the improvement of some barrages in a branch are important.